TBD Meeting (4635-18)

CHICAGO – The Global Registry for Endovascular Aortic Treatment is a unique resource that, although still early in its planned 10-year follow-up period, has already yielded important insights into one of the hottest topics in endovascular repair of abdominal aortic aneurysms: that is, the impact of the proximal aortic neck, Clayton J. Brinster, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

The Global Registry for Endovascular Aortic Treatment (GREAT) is a prospective, observational, real-world registry that enrolled more than 5,000 consecutive patients undergoing endovascular aortic repair (EVAR) in the United States, Europe, Australia, New Zealand, and Brazil before enrollment closed in October 2016.

GREAT is the largest stent graft registry in the world. One of its special features is that it has essentially no exclusion criteria. This enables researchers to compare outcomes in patients undergoing on-label EVAR using devices deployed within the official instructions for use (IFU) to results in real-world practice, which not infrequently entails treatment for nonstandard indications using devices outside the narrowly defined IFU generated via pivotal clinical trials, explained Dr. Brinster, a vascular surgeon at the Ochsner Clinic Foundation in New Orleans.

The biggest limitation of GREAT is that it’s sponsored by Gore and restricted to recipients of GORE thoracic and abdominal stent grafts. However, the registry has an oversight and safety monitoring board that is independent of the company, Dr. Brinster continued.

He highlighted three recently published studies that have utilized early GREAT data to examine the impact on EVAR outcomes of various features of the proximal aortic neck.

An international team of investigators analyzed the incidence and impact of noncylindrical neck anatomy, defined as a 2-mm or greater change in diameter over the first 15 mm of proximal aortic neck length. Of 3,077 GREAT participants treated with the Gore Excluder endograft, 1,312, or 43%, had an hourglass, tapered, or conical neck shape that qualified as noncylindrical. Noncylindrical necks were more common in women. Fifteen percent of patients with a noncylindrical neck received the device outside the Excluder IFU, as did 11% with a cylindrical neck.

After an average follow-up of about 20 months, the noncylindrical neck group had a 3.1% rate of device-related intervention, significantly better than the 4.9% rate in patients with a cylindrical neck. In a multivariate regression analysis, female gender and maximum abdominal aortic aneurysm diameter were significant risk factors for device-related or endoleak-specific reintervention; noncylindrical neck morphology was not. Indeed, women were 2.2-fold more likely to require device-related reintervention than men (J Vasc Surg. 2018; 68[6]:1714-24).
 

Large proximal aortic neck

Of 3,166 consecutive patients in GREAT, 37.6% had a large aortic neck diameter, defined as 25 mm or wider. The rate of 5-year freedom from type Ia endoleak was 96.8% in the large-neck group, significantly less than the 98.6% rate in patients with a normal aortic neck diameter. Of note, rates didn’t diverge until after 2 years of follow-up, emphasizing the need for careful long-term surveillance despite initial technical success.

The 5-year rate of freedom from the primary composite endpoint of type Ia endoleak, reintervention, aortic rupture, or isolated aortic-related mortality was also significantly worse in the large-neck group: 81.3% versus 87%. Moreover, the 5-year survival rate was only 64.6% in the large–aortic neck group, compared with 76.5% in the comparator arm, even though aortic-related mortality didn’t differ between the two groups. “The findings raise the question of whether young patients, with predicted life expectancies exceeding 10 years, should receive standard endovascular intervention if they have large aortic neck diameters at baseline (Eur J Vasc Endovasc Surg. 2018;56[2]:189-99).

Severe neck angulation

Australian investigators wondered if the IFU for the Gore C3 Excluder was overly restrictive in defining abdominal aortic aneurysms with necks greater than 60 degrees as off-label for the device. In the first 1,394 patients enrolled in GREAT, the researchers identified 127 (9.2%) who exhibited more than 60 and less than 140 degrees of neck angulation and didn’t require endoanchors for proximal fixation. Their mean neck angle was 78 degrees, with a mean neck length of 29 mm. Mean graft oversizing was 23.5%, which was also outside the Excluder IFU.

During a median follow-up of 236 days there were 7 type Ia endoleaks, for an incidence of 5.6%. The degree of neck angulation, neck length, and the amount of oversizing were not associated with endoleak (Ann Vasc Surg. 2018;49:152-57). However, Dr. Brinster wants to see longer follow-up data before he is prepared to accept that a mean 23.5% graft oversizing is a benign intervention.

“One must remember that, with that percentage of oversizing in an already abnormal neck, aortic neck dilation could be a significant problem longer term,” the vascular surgeon said.

Dr. Brinster reported having no conflicts regarding his presentation.

bjancin@mdedge.com

CHICAGO – The Global Registry for Endovascular Aortic Treatment is a unique resource that, although still early in its planned 10-year follow-up period, has already yielded important insights into one of the hottest topics in endovascular repair of abdominal aortic aneurysms: that is, the impact of the proximal aortic neck, Clayton J. Brinster, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

The Global Registry for Endovascular Aortic Treatment (GREAT) is a prospective, observational, real-world registry that enrolled more than 5,000 consecutive patients undergoing endovascular aortic repair (EVAR) in the United States, Europe, Australia, New Zealand, and Brazil before enrollment closed in October 2016.

GREAT is the largest stent graft registry in the world. One of its special features is that it has essentially no exclusion criteria. This enables researchers to compare outcomes in patients undergoing on-label EVAR using devices deployed within the official instructions for use (IFU) to results in real-world practice, which not infrequently entails treatment for nonstandard indications using devices outside the narrowly defined IFU generated via pivotal clinical trials, explained Dr. Brinster, a vascular surgeon at the Ochsner Clinic Foundation in New Orleans.

The biggest limitation of GREAT is that it’s sponsored by Gore and restricted to recipients of GORE thoracic and abdominal stent grafts. However, the registry has an oversight and safety monitoring board that is independent of the company, Dr. Brinster continued.

He highlighted three recently published studies that have utilized early GREAT data to examine the impact on EVAR outcomes of various features of the proximal aortic neck.

An international team of investigators analyzed the incidence and impact of noncylindrical neck anatomy, defined as a 2-mm or greater change in diameter over the first 15 mm of proximal aortic neck length. Of 3,077 GREAT participants treated with the Gore Excluder endograft, 1,312, or 43%, had an hourglass, tapered, or conical neck shape that qualified as noncylindrical. Noncylindrical necks were more common in women. Fifteen percent of patients with a noncylindrical neck received the device outside the Excluder IFU, as did 11% with a cylindrical neck.

After an average follow-up of about 20 months, the noncylindrical neck group had a 3.1% rate of device-related intervention, significantly better than the 4.9% rate in patients with a cylindrical neck. In a multivariate regression analysis, female gender and maximum abdominal aortic aneurysm diameter were significant risk factors for device-related or endoleak-specific reintervention; noncylindrical neck morphology was not. Indeed, women were 2.2-fold more likely to require device-related reintervention than men (J Vasc Surg. 2018; 68[6]:1714-24).
 

Large proximal aortic neck

Of 3,166 consecutive patients in GREAT, 37.6% had a large aortic neck diameter, defined as 25 mm or wider. The rate of 5-year freedom from type Ia endoleak was 96.8% in the large-neck group, significantly less than the 98.6% rate in patients with a normal aortic neck diameter. Of note, rates didn’t diverge until after 2 years of follow-up, emphasizing the need for careful long-term surveillance despite initial technical success.

The 5-year rate of freedom from the primary composite endpoint of type Ia endoleak, reintervention, aortic rupture, or isolated aortic-related mortality was also significantly worse in the large-neck group: 81.3% versus 87%. Moreover, the 5-year survival rate was only 64.6% in the large–aortic neck group, compared with 76.5% in the comparator arm, even though aortic-related mortality didn’t differ between the two groups. “The findings raise the question of whether young patients, with predicted life expectancies exceeding 10 years, should receive standard endovascular intervention if they have large aortic neck diameters at baseline (Eur J Vasc Endovasc Surg. 2018;56[2]:189-99).

Severe neck angulation

Australian investigators wondered if the IFU for the Gore C3 Excluder was overly restrictive in defining abdominal aortic aneurysms with necks greater than 60 degrees as off-label for the device. In the first 1,394 patients enrolled in GREAT, the researchers identified 127 (9.2%) who exhibited more than 60 and less than 140 degrees of neck angulation and didn’t require endoanchors for proximal fixation. Their mean neck angle was 78 degrees, with a mean neck length of 29 mm. Mean graft oversizing was 23.5%, which was also outside the Excluder IFU.

During a median follow-up of 236 days there were 7 type Ia endoleaks, for an incidence of 5.6%. The degree of neck angulation, neck length, and the amount of oversizing were not associated with endoleak (Ann Vasc Surg. 2018;49:152-57). However, Dr. Brinster wants to see longer follow-up data before he is prepared to accept that a mean 23.5% graft oversizing is a benign intervention.

“One must remember that, with that percentage of oversizing in an already abnormal neck, aortic neck dilation could be a significant problem longer term,” the vascular surgeon said.

Dr. Brinster reported having no conflicts regarding his presentation.

bjancin@mdedge.com

CHICAGO – The Global Registry for Endovascular Aortic Treatment is a unique resource that, although still early in its planned 10-year follow-up period, has already yielded important insights into one of the hottest topics in endovascular repair of abdominal aortic aneurysms: that is, the impact of the proximal aortic neck, Clayton J. Brinster, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

The Global Registry for Endovascular Aortic Treatment (GREAT) is a prospective, observational, real-world registry that enrolled more than 5,000 consecutive patients undergoing endovascular aortic repair (EVAR) in the United States, Europe, Australia, New Zealand, and Brazil before enrollment closed in October 2016.

GREAT is the largest stent graft registry in the world. One of its special features is that it has essentially no exclusion criteria. This enables researchers to compare outcomes in patients undergoing on-label EVAR using devices deployed within the official instructions for use (IFU) to results in real-world practice, which not infrequently entails treatment for nonstandard indications using devices outside the narrowly defined IFU generated via pivotal clinical trials, explained Dr. Brinster, a vascular surgeon at the Ochsner Clinic Foundation in New Orleans.

The biggest limitation of GREAT is that it’s sponsored by Gore and restricted to recipients of GORE thoracic and abdominal stent grafts. However, the registry has an oversight and safety monitoring board that is independent of the company, Dr. Brinster continued.

He highlighted three recently published studies that have utilized early GREAT data to examine the impact on EVAR outcomes of various features of the proximal aortic neck.

An international team of investigators analyzed the incidence and impact of noncylindrical neck anatomy, defined as a 2-mm or greater change in diameter over the first 15 mm of proximal aortic neck length. Of 3,077 GREAT participants treated with the Gore Excluder endograft, 1,312, or 43%, had an hourglass, tapered, or conical neck shape that qualified as noncylindrical. Noncylindrical necks were more common in women. Fifteen percent of patients with a noncylindrical neck received the device outside the Excluder IFU, as did 11% with a cylindrical neck.

After an average follow-up of about 20 months, the noncylindrical neck group had a 3.1% rate of device-related intervention, significantly better than the 4.9% rate in patients with a cylindrical neck. In a multivariate regression analysis, female gender and maximum abdominal aortic aneurysm diameter were significant risk factors for device-related or endoleak-specific reintervention; noncylindrical neck morphology was not. Indeed, women were 2.2-fold more likely to require device-related reintervention than men (J Vasc Surg. 2018; 68[6]:1714-24).
 

Large proximal aortic neck

Of 3,166 consecutive patients in GREAT, 37.6% had a large aortic neck diameter, defined as 25 mm or wider. The rate of 5-year freedom from type Ia endoleak was 96.8% in the large-neck group, significantly less than the 98.6% rate in patients with a normal aortic neck diameter. Of note, rates didn’t diverge until after 2 years of follow-up, emphasizing the need for careful long-term surveillance despite initial technical success.

The 5-year rate of freedom from the primary composite endpoint of type Ia endoleak, reintervention, aortic rupture, or isolated aortic-related mortality was also significantly worse in the large-neck group: 81.3% versus 87%. Moreover, the 5-year survival rate was only 64.6% in the large–aortic neck group, compared with 76.5% in the comparator arm, even though aortic-related mortality didn’t differ between the two groups. “The findings raise the question of whether young patients, with predicted life expectancies exceeding 10 years, should receive standard endovascular intervention if they have large aortic neck diameters at baseline (Eur J Vasc Endovasc Surg. 2018;56[2]:189-99).

Severe neck angulation

Australian investigators wondered if the IFU for the Gore C3 Excluder was overly restrictive in defining abdominal aortic aneurysms with necks greater than 60 degrees as off-label for the device. In the first 1,394 patients enrolled in GREAT, the researchers identified 127 (9.2%) who exhibited more than 60 and less than 140 degrees of neck angulation and didn’t require endoanchors for proximal fixation. Their mean neck angle was 78 degrees, with a mean neck length of 29 mm. Mean graft oversizing was 23.5%, which was also outside the Excluder IFU.

During a median follow-up of 236 days there were 7 type Ia endoleaks, for an incidence of 5.6%. The degree of neck angulation, neck length, and the amount of oversizing were not associated with endoleak (Ann Vasc Surg. 2018;49:152-57). However, Dr. Brinster wants to see longer follow-up data before he is prepared to accept that a mean 23.5% graft oversizing is a benign intervention.

“One must remember that, with that percentage of oversizing in an already abnormal neck, aortic neck dilation could be a significant problem longer term,” the vascular surgeon said.

Dr. Brinster reported having no conflicts regarding his presentation.

bjancin@mdedge.com

CHICAGO – Clinically significant aortic neck dilation occurs in one-quarter of patients after endovascular abdominal aortic aneurysm repair and is associated with sharply increased risk for type Ia endoleak, stent migration at the proximal seal zone, continued aneurysmal sack enlargement, and even aneurysm rupture, Jason T. Lee, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

Bruce Jancin/MDedge News

He cited what he considers to be the best-quality systematic review of the literature regarding proximal neck dilation after endovascular aneurysm repair (EVAR), which was conducted by investigators at Paracelsus Medical University in Nuremberg, Germany. The data, he said, speak to the importance of trying to minimize the chances of aortic neck dilation (AND).

The review, which included 26 published studies through 2015 and nearly 10,000 EVAR patients, concluded that AND occurred in 24.6% of these patients. The investigators defined AND as more than 3 mm of dilation, which with an average neck diameter of about 30 mm in all comers, would represent a 10% aortic neck-diameter expansion. The incidence of the composite adverse outcome of type I endoleak, stent migration, and reintervention during a maximum of 9 years of follow-up was 29-fold greater in the AND group than in AND-free patients (J Endovasc Ther. 2017;24[1]:59-67).

Continuing controversy exists regarding the extent to which post-EVAR AND is a manifestation of the underlying aneurysmal process as opposed to an adverse effect caused by the outward radial force applied by the stent. That being said, there are several factors related to AND that are potentially within the vascular interventionalist’s control. Topping the list is aggressive oversizing of self-expanding stent grafts in an effort to obtain an excellent seal, according to Dr. Lee, a professor of surgery at Stanford (Calif.) University.

“The data from multiple series definitely suggests that more than 20% oversizing is correlated with a higher incidence of AND. So maybe the answer is oversizing by more like 10%-15%,” the vascular surgeon said.

Another factor contributing to AND is the overwhelming popularity of self-expanding aortic stent grafts, now utilized in 95% of all EVARS done in the United States. Balloon-expandable stent grafts require much less oversizing – less than 5% – to maintain their diameter post deployment, but they are rarely used. Indeed, the only commercially available balloon-expandable device in the United States is the TriVascular Ovation stent system, which seals the stent graft to the wall of the aorta via polyethylene glycol rather than by radial force.

Intriguingly, Italian investigators have reported that, in a multicenter series of 161 patients who underwent EVAR with the Ovation endograft, no AND occurred at CT scanning done after a minimum of 24 months of follow-up (J Vasc Surg. 2016;63[1]:8-15).

Previous studies of the implications of AND after EVAR have been limited to comparisons of early-generation devices, so Dr. Lee and his coinvestigators conducted a retrospective review of a prospective Stanford database that included 86 patients who underwent elective, uncomplicated infrarenal endovascular abdominal aortic aneurysm repairs using a variety of contemporary stent grafts. Eighty-six percent of patients experienced AND during a median radiologic follow-up of 21.9 months, with a mean 1.3-mm increase at 30 days and 3.3 mm at most recent follow-up. The degree of AND correlated with the amount of oversizing. However, AND didn’t vary significantly by device type, which included the Cook Zenith, Gore Excluder, Medtronic Endurant, and Endologix Powerlink self-expanding stent grafts (Ann Vasc Surg. 2017;43:115-20).

Aortic anatomy also plays a role in AND. Shorter necks with severe angulation have been found to pose a higher risk. Open repair, which entails much less AND than does EVAR, may make more sense in that challenging anatomic situation, according to Dr. Lee.

He reported current research funding from Cook, Gore, and Medtronic.

bjancin@mdedge.com

CHICAGO – Clinically significant aortic neck dilation occurs in one-quarter of patients after endovascular abdominal aortic aneurysm repair and is associated with sharply increased risk for type Ia endoleak, stent migration at the proximal seal zone, continued aneurysmal sack enlargement, and even aneurysm rupture, Jason T. Lee, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

Bruce Jancin/MDedge News

He cited what he considers to be the best-quality systematic review of the literature regarding proximal neck dilation after endovascular aneurysm repair (EVAR), which was conducted by investigators at Paracelsus Medical University in Nuremberg, Germany. The data, he said, speak to the importance of trying to minimize the chances of aortic neck dilation (AND).

The review, which included 26 published studies through 2015 and nearly 10,000 EVAR patients, concluded that AND occurred in 24.6% of these patients. The investigators defined AND as more than 3 mm of dilation, which with an average neck diameter of about 30 mm in all comers, would represent a 10% aortic neck-diameter expansion. The incidence of the composite adverse outcome of type I endoleak, stent migration, and reintervention during a maximum of 9 years of follow-up was 29-fold greater in the AND group than in AND-free patients (J Endovasc Ther. 2017;24[1]:59-67).

Continuing controversy exists regarding the extent to which post-EVAR AND is a manifestation of the underlying aneurysmal process as opposed to an adverse effect caused by the outward radial force applied by the stent. That being said, there are several factors related to AND that are potentially within the vascular interventionalist’s control. Topping the list is aggressive oversizing of self-expanding stent grafts in an effort to obtain an excellent seal, according to Dr. Lee, a professor of surgery at Stanford (Calif.) University.

“The data from multiple series definitely suggests that more than 20% oversizing is correlated with a higher incidence of AND. So maybe the answer is oversizing by more like 10%-15%,” the vascular surgeon said.

Another factor contributing to AND is the overwhelming popularity of self-expanding aortic stent grafts, now utilized in 95% of all EVARS done in the United States. Balloon-expandable stent grafts require much less oversizing – less than 5% – to maintain their diameter post deployment, but they are rarely used. Indeed, the only commercially available balloon-expandable device in the United States is the TriVascular Ovation stent system, which seals the stent graft to the wall of the aorta via polyethylene glycol rather than by radial force.

Intriguingly, Italian investigators have reported that, in a multicenter series of 161 patients who underwent EVAR with the Ovation endograft, no AND occurred at CT scanning done after a minimum of 24 months of follow-up (J Vasc Surg. 2016;63[1]:8-15).

Previous studies of the implications of AND after EVAR have been limited to comparisons of early-generation devices, so Dr. Lee and his coinvestigators conducted a retrospective review of a prospective Stanford database that included 86 patients who underwent elective, uncomplicated infrarenal endovascular abdominal aortic aneurysm repairs using a variety of contemporary stent grafts. Eighty-six percent of patients experienced AND during a median radiologic follow-up of 21.9 months, with a mean 1.3-mm increase at 30 days and 3.3 mm at most recent follow-up. The degree of AND correlated with the amount of oversizing. However, AND didn’t vary significantly by device type, which included the Cook Zenith, Gore Excluder, Medtronic Endurant, and Endologix Powerlink self-expanding stent grafts (Ann Vasc Surg. 2017;43:115-20).

Aortic anatomy also plays a role in AND. Shorter necks with severe angulation have been found to pose a higher risk. Open repair, which entails much less AND than does EVAR, may make more sense in that challenging anatomic situation, according to Dr. Lee.

He reported current research funding from Cook, Gore, and Medtronic.

bjancin@mdedge.com

CHICAGO – Clinically significant aortic neck dilation occurs in one-quarter of patients after endovascular abdominal aortic aneurysm repair and is associated with sharply increased risk for type Ia endoleak, stent migration at the proximal seal zone, continued aneurysmal sack enlargement, and even aneurysm rupture, Jason T. Lee, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

Bruce Jancin/MDedge News

He cited what he considers to be the best-quality systematic review of the literature regarding proximal neck dilation after endovascular aneurysm repair (EVAR), which was conducted by investigators at Paracelsus Medical University in Nuremberg, Germany. The data, he said, speak to the importance of trying to minimize the chances of aortic neck dilation (AND).

The review, which included 26 published studies through 2015 and nearly 10,000 EVAR patients, concluded that AND occurred in 24.6% of these patients. The investigators defined AND as more than 3 mm of dilation, which with an average neck diameter of about 30 mm in all comers, would represent a 10% aortic neck-diameter expansion. The incidence of the composite adverse outcome of type I endoleak, stent migration, and reintervention during a maximum of 9 years of follow-up was 29-fold greater in the AND group than in AND-free patients (J Endovasc Ther. 2017;24[1]:59-67).

Continuing controversy exists regarding the extent to which post-EVAR AND is a manifestation of the underlying aneurysmal process as opposed to an adverse effect caused by the outward radial force applied by the stent. That being said, there are several factors related to AND that are potentially within the vascular interventionalist’s control. Topping the list is aggressive oversizing of self-expanding stent grafts in an effort to obtain an excellent seal, according to Dr. Lee, a professor of surgery at Stanford (Calif.) University.

“The data from multiple series definitely suggests that more than 20% oversizing is correlated with a higher incidence of AND. So maybe the answer is oversizing by more like 10%-15%,” the vascular surgeon said.

Another factor contributing to AND is the overwhelming popularity of self-expanding aortic stent grafts, now utilized in 95% of all EVARS done in the United States. Balloon-expandable stent grafts require much less oversizing – less than 5% – to maintain their diameter post deployment, but they are rarely used. Indeed, the only commercially available balloon-expandable device in the United States is the TriVascular Ovation stent system, which seals the stent graft to the wall of the aorta via polyethylene glycol rather than by radial force.

Intriguingly, Italian investigators have reported that, in a multicenter series of 161 patients who underwent EVAR with the Ovation endograft, no AND occurred at CT scanning done after a minimum of 24 months of follow-up (J Vasc Surg. 2016;63[1]:8-15).

Previous studies of the implications of AND after EVAR have been limited to comparisons of early-generation devices, so Dr. Lee and his coinvestigators conducted a retrospective review of a prospective Stanford database that included 86 patients who underwent elective, uncomplicated infrarenal endovascular abdominal aortic aneurysm repairs using a variety of contemporary stent grafts. Eighty-six percent of patients experienced AND during a median radiologic follow-up of 21.9 months, with a mean 1.3-mm increase at 30 days and 3.3 mm at most recent follow-up. The degree of AND correlated with the amount of oversizing. However, AND didn’t vary significantly by device type, which included the Cook Zenith, Gore Excluder, Medtronic Endurant, and Endologix Powerlink self-expanding stent grafts (Ann Vasc Surg. 2017;43:115-20).

Aortic anatomy also plays a role in AND. Shorter necks with severe angulation have been found to pose a higher risk. Open repair, which entails much less AND than does EVAR, may make more sense in that challenging anatomic situation, according to Dr. Lee.

He reported current research funding from Cook, Gore, and Medtronic.

bjancin@mdedge.com

CHICAGO – A closer look at the landmark ATTRACT trial of pharmacomechanical catheter-directed thrombolysis for acute deep vein thrombosis (DVT) shows multiple benefits for the intervention versus standard anticoagulation alone in the subset of participants with iliofemoral DVT, Kush R. Desai, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

ATTRACT, a National Institutes of Health–sponsored, phase 3, multicenter, open-label, assessor-blinded study, was the first-ever randomized trial of pharmacomechanical catheter-directed thrombolysis (PCDT) for acute DVT.

The results caused a major stir because, despite a sound therapeutic rationale for the procedure, the incidence of chronic postthrombotic syndrome (PTS) at 24 months of follow-up was 47% in the PCDT plus anticoagulation group and 48% in controls on anticoagulation alone (N Engl J Med. 2017 Dec 7;377[23]:2240-52). Since then, that overall negative trial has been one of the hottest topics in DVT.

“This is the first thing your educated patients who come to the emergency department with DVT will ask about. It’s the first thing they’ll see when they go online and type in ‘thrombolysis DVT,’ ” noted Dr. Desai, an interventional radiologist at Northwestern University, Chicago.


But the trial has several major flaws, he cautioned. And contrary to popular opinion, ATTRACT is not the death knell for PCDT. Far from it.

“I don’t think the story stops with ATTRACT. This isn’t the end for PCDT in patients with iliofemoral DVT,” he asserted.

That’s in part because 301 of the 692 participants in ATTRACT had DVT of the femoropopliteal segment. That’s a population in which Dr. Desai and other interventionalists wouldn’t have anticipated seeing a benefit for PCDT, because their risk of PTS is so low.

“We know through historical data that patients with iliofemoral DVT are much more likely to develop PTS and to have recurrent DVT, so this is probably one of the major shortcomings of the trial,” he explained. “It’s through no fault of the trial investigators, because the study was planned years ago when we just didn’t know as much about PTS as we do now.

“The way I look at it is, I don’t practice in the way that ATTRACT was designed,” Dr. Desai said. “I don’t typically lyse or get referrals for lysis or thrombectomy in patients who have isolated femoropopliteal DVT. It has to involve at least the common femoral vein and frequently goes up to the iliac vein.”

The ATTRACT investigators’ recent subanalysis of the 391 participants with iliofemoral DVT showed that, although there was no difference between the two study arms in the occurrence of PTS through the first 24 months of follow-up, PCDT led to a 35% reduction in the incidence of moderate or severe PTS – by a margin of 18% versus 28% in controls.

Patients in the PCDT arm also experienced significantly greater improvement in venous disease-specific quality of life through 24 months, and a greater reduction in leg pain and swelling at 10 and 30 days (Circulation. 2018 Dec 4. doi: 10.1161/CIRCULATIONAHA.118.037425).

And moderate to severe PTS is a key outcome, Dr. Desai continued. Multiple studies have shown that patients with PTS have a worse quality of life than those with chronic lung disease, arthritis, or diabetes. Moreover, the 5%-10% of patients with symptomatic DVT who develop the most-severe form of PTS – characterized by severe pain, chronic ulcerations, stasis dermatitis, venous claudication, and intractable edema – have a quality of life comparable with patients with cancer or heart failure.

The 1.5% incidence of major bleeding within 10 days in the PCDT group was 200% higher than in controls, but none of it was life threatening.

“This is reassuring: Nobody had intracranial hemorrhage; nobody had a GUSTO 5 bleed,” Dr. Desai said.

Another limitation of the ATTRACT trial is that all but one of the devices utilized for PCDT were used off label. They weren’t designed for venous application. Several on-label rheolytic, rotational thrombectomy, or clot aspiration devices have been approved since enrollment in ATTRACT was closed. Future randomized trials will utilize on-label devices in patients with acute iliofemoral DVT to clarify the role of PCDT.

It’s noteworthy that nearly half of ATTRACT participants developed PTS within 24 months of their DVT despite being on optimal anticoagulation. It’s a finding that underscores the need for improved therapies. That was the impetus for development of first-generation catheter-directed thrombolysis utilizing a percutaneously inserted catheter to infuse a fibrinolytic drug directly to the thrombus to dissolve it rapidly.

But that form of catheter-directed thrombolysis has major disadvantages, Dr. Desai explained: It’s a multiday procedure requiring ICU-level care and prolonged exposure to powerful lytic agents.

“This is where things have changed with PCDT,” he said. “We can now, with on-label devices, accelerate the thrombolysis time, reduce lytic exposure, and I think also reduce the bleeding risk, although that hasn’t been shown in a trial yet. PCDT also reduces the necessity for ICU-level care and prolonged hospitalization.”

Dr. Desai no longer performs multiday lytic procedures. “In fact, with the introduction of the newer on-label devices, I haven’t done a multiday unilateral limb lytic procedure in a couple years. I think we’ve gotten to the point where we don’t need to do that anymore.”

Indeed, PCDT makes recanalization possible as a single-day, single-session procedure.

Dr. Desai views the recent ATTRACT subanalysis as hypothesis generating.

“Should PCDT be the first-line treatment in all proximal DVT patients? No it should not – and that’s not what I would have advocated even before ATTRACT came out,” he explained. “It’s sort of a salvage procedure for patients with iliofemoral DVT and moderate to severe symptoms. And there are a significant number of such patients.”

Current understanding of the pathophysiology of PTS is that a nondissolved thrombus at the valve leaflets becomes inflammatory, with resultant valvular dysfunction leading to venous reflux and venous hypertension. PCDT is consistent with the open-vein hypothesis, which posits that, by eliminating thrombus much faster than achievable via anticoagulation, valve integrity is maintained and PTS is prevented.

Dr. Desai reported receiving consulting fees from AngioDynamics, Boston Scientific, Cook Medical, and Spectranetics.

bjancin@mdedge.com

CHICAGO – A closer look at the landmark ATTRACT trial of pharmacomechanical catheter-directed thrombolysis for acute deep vein thrombosis (DVT) shows multiple benefits for the intervention versus standard anticoagulation alone in the subset of participants with iliofemoral DVT, Kush R. Desai, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

ATTRACT, a National Institutes of Health–sponsored, phase 3, multicenter, open-label, assessor-blinded study, was the first-ever randomized trial of pharmacomechanical catheter-directed thrombolysis (PCDT) for acute DVT.

The results caused a major stir because, despite a sound therapeutic rationale for the procedure, the incidence of chronic postthrombotic syndrome (PTS) at 24 months of follow-up was 47% in the PCDT plus anticoagulation group and 48% in controls on anticoagulation alone (N Engl J Med. 2017 Dec 7;377[23]:2240-52). Since then, that overall negative trial has been one of the hottest topics in DVT.

“This is the first thing your educated patients who come to the emergency department with DVT will ask about. It’s the first thing they’ll see when they go online and type in ‘thrombolysis DVT,’ ” noted Dr. Desai, an interventional radiologist at Northwestern University, Chicago.


But the trial has several major flaws, he cautioned. And contrary to popular opinion, ATTRACT is not the death knell for PCDT. Far from it.

“I don’t think the story stops with ATTRACT. This isn’t the end for PCDT in patients with iliofemoral DVT,” he asserted.

That’s in part because 301 of the 692 participants in ATTRACT had DVT of the femoropopliteal segment. That’s a population in which Dr. Desai and other interventionalists wouldn’t have anticipated seeing a benefit for PCDT, because their risk of PTS is so low.

“We know through historical data that patients with iliofemoral DVT are much more likely to develop PTS and to have recurrent DVT, so this is probably one of the major shortcomings of the trial,” he explained. “It’s through no fault of the trial investigators, because the study was planned years ago when we just didn’t know as much about PTS as we do now.

“The way I look at it is, I don’t practice in the way that ATTRACT was designed,” Dr. Desai said. “I don’t typically lyse or get referrals for lysis or thrombectomy in patients who have isolated femoropopliteal DVT. It has to involve at least the common femoral vein and frequently goes up to the iliac vein.”

The ATTRACT investigators’ recent subanalysis of the 391 participants with iliofemoral DVT showed that, although there was no difference between the two study arms in the occurrence of PTS through the first 24 months of follow-up, PCDT led to a 35% reduction in the incidence of moderate or severe PTS – by a margin of 18% versus 28% in controls.

Patients in the PCDT arm also experienced significantly greater improvement in venous disease-specific quality of life through 24 months, and a greater reduction in leg pain and swelling at 10 and 30 days (Circulation. 2018 Dec 4. doi: 10.1161/CIRCULATIONAHA.118.037425).

And moderate to severe PTS is a key outcome, Dr. Desai continued. Multiple studies have shown that patients with PTS have a worse quality of life than those with chronic lung disease, arthritis, or diabetes. Moreover, the 5%-10% of patients with symptomatic DVT who develop the most-severe form of PTS – characterized by severe pain, chronic ulcerations, stasis dermatitis, venous claudication, and intractable edema – have a quality of life comparable with patients with cancer or heart failure.

The 1.5% incidence of major bleeding within 10 days in the PCDT group was 200% higher than in controls, but none of it was life threatening.

“This is reassuring: Nobody had intracranial hemorrhage; nobody had a GUSTO 5 bleed,” Dr. Desai said.

Another limitation of the ATTRACT trial is that all but one of the devices utilized for PCDT were used off label. They weren’t designed for venous application. Several on-label rheolytic, rotational thrombectomy, or clot aspiration devices have been approved since enrollment in ATTRACT was closed. Future randomized trials will utilize on-label devices in patients with acute iliofemoral DVT to clarify the role of PCDT.

It’s noteworthy that nearly half of ATTRACT participants developed PTS within 24 months of their DVT despite being on optimal anticoagulation. It’s a finding that underscores the need for improved therapies. That was the impetus for development of first-generation catheter-directed thrombolysis utilizing a percutaneously inserted catheter to infuse a fibrinolytic drug directly to the thrombus to dissolve it rapidly.

But that form of catheter-directed thrombolysis has major disadvantages, Dr. Desai explained: It’s a multiday procedure requiring ICU-level care and prolonged exposure to powerful lytic agents.

“This is where things have changed with PCDT,” he said. “We can now, with on-label devices, accelerate the thrombolysis time, reduce lytic exposure, and I think also reduce the bleeding risk, although that hasn’t been shown in a trial yet. PCDT also reduces the necessity for ICU-level care and prolonged hospitalization.”

Dr. Desai no longer performs multiday lytic procedures. “In fact, with the introduction of the newer on-label devices, I haven’t done a multiday unilateral limb lytic procedure in a couple years. I think we’ve gotten to the point where we don’t need to do that anymore.”

Indeed, PCDT makes recanalization possible as a single-day, single-session procedure.

Dr. Desai views the recent ATTRACT subanalysis as hypothesis generating.

“Should PCDT be the first-line treatment in all proximal DVT patients? No it should not – and that’s not what I would have advocated even before ATTRACT came out,” he explained. “It’s sort of a salvage procedure for patients with iliofemoral DVT and moderate to severe symptoms. And there are a significant number of such patients.”

Current understanding of the pathophysiology of PTS is that a nondissolved thrombus at the valve leaflets becomes inflammatory, with resultant valvular dysfunction leading to venous reflux and venous hypertension. PCDT is consistent with the open-vein hypothesis, which posits that, by eliminating thrombus much faster than achievable via anticoagulation, valve integrity is maintained and PTS is prevented.

Dr. Desai reported receiving consulting fees from AngioDynamics, Boston Scientific, Cook Medical, and Spectranetics.

bjancin@mdedge.com

CHICAGO – A closer look at the landmark ATTRACT trial of pharmacomechanical catheter-directed thrombolysis for acute deep vein thrombosis (DVT) shows multiple benefits for the intervention versus standard anticoagulation alone in the subset of participants with iliofemoral DVT, Kush R. Desai, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

ATTRACT, a National Institutes of Health–sponsored, phase 3, multicenter, open-label, assessor-blinded study, was the first-ever randomized trial of pharmacomechanical catheter-directed thrombolysis (PCDT) for acute DVT.

The results caused a major stir because, despite a sound therapeutic rationale for the procedure, the incidence of chronic postthrombotic syndrome (PTS) at 24 months of follow-up was 47% in the PCDT plus anticoagulation group and 48% in controls on anticoagulation alone (N Engl J Med. 2017 Dec 7;377[23]:2240-52). Since then, that overall negative trial has been one of the hottest topics in DVT.

“This is the first thing your educated patients who come to the emergency department with DVT will ask about. It’s the first thing they’ll see when they go online and type in ‘thrombolysis DVT,’ ” noted Dr. Desai, an interventional radiologist at Northwestern University, Chicago.


But the trial has several major flaws, he cautioned. And contrary to popular opinion, ATTRACT is not the death knell for PCDT. Far from it.

“I don’t think the story stops with ATTRACT. This isn’t the end for PCDT in patients with iliofemoral DVT,” he asserted.

That’s in part because 301 of the 692 participants in ATTRACT had DVT of the femoropopliteal segment. That’s a population in which Dr. Desai and other interventionalists wouldn’t have anticipated seeing a benefit for PCDT, because their risk of PTS is so low.

“We know through historical data that patients with iliofemoral DVT are much more likely to develop PTS and to have recurrent DVT, so this is probably one of the major shortcomings of the trial,” he explained. “It’s through no fault of the trial investigators, because the study was planned years ago when we just didn’t know as much about PTS as we do now.

“The way I look at it is, I don’t practice in the way that ATTRACT was designed,” Dr. Desai said. “I don’t typically lyse or get referrals for lysis or thrombectomy in patients who have isolated femoropopliteal DVT. It has to involve at least the common femoral vein and frequently goes up to the iliac vein.”

The ATTRACT investigators’ recent subanalysis of the 391 participants with iliofemoral DVT showed that, although there was no difference between the two study arms in the occurrence of PTS through the first 24 months of follow-up, PCDT led to a 35% reduction in the incidence of moderate or severe PTS – by a margin of 18% versus 28% in controls.

Patients in the PCDT arm also experienced significantly greater improvement in venous disease-specific quality of life through 24 months, and a greater reduction in leg pain and swelling at 10 and 30 days (Circulation. 2018 Dec 4. doi: 10.1161/CIRCULATIONAHA.118.037425).

And moderate to severe PTS is a key outcome, Dr. Desai continued. Multiple studies have shown that patients with PTS have a worse quality of life than those with chronic lung disease, arthritis, or diabetes. Moreover, the 5%-10% of patients with symptomatic DVT who develop the most-severe form of PTS – characterized by severe pain, chronic ulcerations, stasis dermatitis, venous claudication, and intractable edema – have a quality of life comparable with patients with cancer or heart failure.

The 1.5% incidence of major bleeding within 10 days in the PCDT group was 200% higher than in controls, but none of it was life threatening.

“This is reassuring: Nobody had intracranial hemorrhage; nobody had a GUSTO 5 bleed,” Dr. Desai said.

Another limitation of the ATTRACT trial is that all but one of the devices utilized for PCDT were used off label. They weren’t designed for venous application. Several on-label rheolytic, rotational thrombectomy, or clot aspiration devices have been approved since enrollment in ATTRACT was closed. Future randomized trials will utilize on-label devices in patients with acute iliofemoral DVT to clarify the role of PCDT.

It’s noteworthy that nearly half of ATTRACT participants developed PTS within 24 months of their DVT despite being on optimal anticoagulation. It’s a finding that underscores the need for improved therapies. That was the impetus for development of first-generation catheter-directed thrombolysis utilizing a percutaneously inserted catheter to infuse a fibrinolytic drug directly to the thrombus to dissolve it rapidly.

But that form of catheter-directed thrombolysis has major disadvantages, Dr. Desai explained: It’s a multiday procedure requiring ICU-level care and prolonged exposure to powerful lytic agents.

“This is where things have changed with PCDT,” he said. “We can now, with on-label devices, accelerate the thrombolysis time, reduce lytic exposure, and I think also reduce the bleeding risk, although that hasn’t been shown in a trial yet. PCDT also reduces the necessity for ICU-level care and prolonged hospitalization.”

Dr. Desai no longer performs multiday lytic procedures. “In fact, with the introduction of the newer on-label devices, I haven’t done a multiday unilateral limb lytic procedure in a couple years. I think we’ve gotten to the point where we don’t need to do that anymore.”

Indeed, PCDT makes recanalization possible as a single-day, single-session procedure.

Dr. Desai views the recent ATTRACT subanalysis as hypothesis generating.

“Should PCDT be the first-line treatment in all proximal DVT patients? No it should not – and that’s not what I would have advocated even before ATTRACT came out,” he explained. “It’s sort of a salvage procedure for patients with iliofemoral DVT and moderate to severe symptoms. And there are a significant number of such patients.”

Current understanding of the pathophysiology of PTS is that a nondissolved thrombus at the valve leaflets becomes inflammatory, with resultant valvular dysfunction leading to venous reflux and venous hypertension. PCDT is consistent with the open-vein hypothesis, which posits that, by eliminating thrombus much faster than achievable via anticoagulation, valve integrity is maintained and PTS is prevented.

Dr. Desai reported receiving consulting fees from AngioDynamics, Boston Scientific, Cook Medical, and Spectranetics.

bjancin@mdedge.com

CHICAGO – Home-based exercise for peripheral arterial disease–related walking limitations works at least as well as – and arguably better than – the supervised outpatient hospital clinic-based treadmill exercise programs of the type approved for coverage by the Centers for Medicare and Medicaid Services in 2017, Mary M. McDermott, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

“The prevailing thinking is that supervised treadmill exercise is more effective than home-based exercise for PAD. And for the outcome of treadmill walking that is true. But for the outcome of 6-minute walking distance, which I would argue is more relevant to walking in daily life, home-based exercise programs appear to be better. Supervised treadmill exercise interventions preferentially improve treadmill walking performance, and that doesn’t translate as well to walking in daily life. Home-based exercise, where patients walk in a corridor or on the ground, is more relevant to the type of walking that they want to do,” explained Dr. McDermott, professor of medicine at the university as well as a leader in the field of research on exercise as a treatment for PAD.

However, she added a caveat regarding home-based exercise for symptomatic PAD: For it to be effective it must incorporate proven behavioral change techniques, including goal setting, monitoring progress, accountability to a coach, and face-to-face visits at least once per month.

“It seems you can’t just tell PAD patients to go home and walk because most of them won’t do it,” observed Dr. McDermott, who is a general internist and geriatrician.

Home-based exercise programs aren’t reimbursed by the CMS. But studies by Dr. McDermott and other investigators indicate that the results are more durable than for supervised treadmill exercise. For example, in the Group Oriented Arterial Leg Study (GOALS) – a 6-month group-mediated cognitive behavioral intervention in which PAD patients built up to walking at home for up to 50 minutes per session 5 days per week – 6-minute walking distance (6MWD) remained significantly better than in controls at follow-up after completion of the intervention. In fact, 6MWD actually increased further between 6 and 12 months in the home exercise group (J Am Heart Assoc. 2014 May 21;3(3):e000711. doi: 10.1161/JAHA.113.000711). Dr. McDermott was the lead author for this study.

In contrast, another study by Dr. McDermott now in press for the same journal found that the improvement in 6MWD achieved in PAD patients over the course of a 6-month supervised treadmill exercise program was not maintained during the next 6 months after completion of the intervention. Indeed, 6MWD showed a steady decline from its apex at the intervention’s conclusion, such that at the 12-month mark it was no longer significantly different from that of the control group, according to Dr. McDermott.

The Society for Vascular Surgery recommends a supervised exercise program as first-line therapy for PAD patients with intermittent claudication, with a Class I Level of Evidence A designation. Home-based exercise also gets a Class I recommendation, albeit with Level of Evidence B.

Dr. McDermott believes a home exercise program makes the most sense for PAD patients after their CMS benefit for a supervised clinic-based program has run out, or for patients – and there are a great many – who either can’t or don’t want to participate in a supervised program. She and others who’ve led randomized controlled trials of supervised exercise programs have found that close to 70% of eligible PAD patients decline to participate because of the inconvenience of going to the hospital outpatient facility at least three times per week or for other reasons.

“Also, it’s important to recognize that attendance can be a challenge, even when supervised exercise is covered by insurance. In our randomized trials, where we provide transportation, we still see only 65%-70% adherence to attendance,” she noted.

She stressed that it’s crucial for physicians and surgeons to educate their PAD patients about what to expect from an exercise program, be it supervised or home based.

“It’s not like revascularization, where they’re going to feel better in their walking immediately. It really takes a commitment. Four to six weeks is usually required before patients begin to experience a benefit, and I think it’s really important for patients to know that so they don’t get discouraged in the first couple of weeks,” Dr. McDermott said.

Turning to the key evidence-based behavioral change techniques shared by successful home-exercise programs for PAD, she noted that the GOALS trial intervention utilized weekly group sessions in which simple cognitive behavioral self-regulatory techniques were used to help patients set and stick to home-based walking goals. A similarly positive randomized controlled trial by investigators at the University of Oklahoma utilized once-monthly group meetings at the medical center (J Am Heart Assoc. 2014 Sep 18;3(5):e001107. doi: 10.1161/JAHA.114.001107).

In contrast, in the recent HONOR randomized clinical trial, where Dr. McDermott and her coinvestigators tested whether a home-based exercise intervention in which the active treatment group utilized a Fitbit wearable activity monitor and telephone coaching over the course of 9 months, the results proved disappointing. The intervention was no more effective than was usual care at improving 6MWD (JAMA. 2018 Apr 24;319(16):1665-76).

“One of the things I learned from doing this trial is that for a home-based exercise intervention in PAD to be successful, it’s not easy and there really needs to be some ongoing contact with a coach or nurse or a staff member that the patient feels accountable to. A wearable device is not a durably effective motivator for PAD patients. I think the reason this trial didn’t work so well is that most of it was by telephone and it was easy for patients to avoid our calls if they weren’t walking. Patients were initially really enthusiastic about the Fitbit, but we found that over time they stopped wearing it,” she said.

Dr. McDermott heartily endorses the Society for Vascular Surgery’s Class I recommendation that all PAD patients with intermittent claudication should exercise regularly, including those who’ve undergone revascularization procedures. Numerous clinical trials have demonstrated additive clinical benefits for opening the peripheral artery and strengthening skeletal muscles.

Uptake of supervised exercise programs for symptomatic PAD since the CMS coverage decision is quite variable regionally. Integrating new programs into existing cardiac rehabilitation facilities is a natural fit because staff members are very familiar with structured treadmill exercises already on site, but some freestanding programs are run by vascular surgery groups or cardiologists.

“I think part of the reason it hasn’t been taken up faster is that the reimbursement is such that you’re not going to make money on it,” Dr. McDermott said.

Asked if all patients with PAD should undergo an exercise treadmill test before embarking on an exercise program, Dr. McDermott replied, “I’m part of a writing group for the American Heart Association on how to implement these new guidelines. We’re not formally recommending a stress test. Some cardiologists on the panel suggested that it should be individualized based on patient history and symptoms. If they’re having symptoms of chest pain or they have a significant cardiac history, go ahead with a stress test. I don’t think it’s going to be recommended as a routine practice, but it’s safest to get a stress test.”

She reported having no financial conflicts regarding her presentation.
 

Requirements for CMS coverage of supervised exercise for symptomatic PAD

*The exercise program must consist of 12 weeks of thrice-weekly sessions.

*It has to be prescribed by a physician following a face-to-face meeting with the patient during which the physician provides education on cardiovascular risk prevention.

*An additional 36 sessions of supervised exercise can be obtained with a written note of justification by the physician following completion of the initial 12 weeks.

*The sessions must take place in a physician’s office or an outpatient hospital setting.

*The exercise has to be supervised by a physician, physician assistant, or nurse specialist.

*The exercise must be delivered by qualified personnel trained in basic and advanced cardiac life support as well as exercise therapy for PAD.

bjancin@mdedge.com

CHICAGO – Home-based exercise for peripheral arterial disease–related walking limitations works at least as well as – and arguably better than – the supervised outpatient hospital clinic-based treadmill exercise programs of the type approved for coverage by the Centers for Medicare and Medicaid Services in 2017, Mary M. McDermott, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

“The prevailing thinking is that supervised treadmill exercise is more effective than home-based exercise for PAD. And for the outcome of treadmill walking that is true. But for the outcome of 6-minute walking distance, which I would argue is more relevant to walking in daily life, home-based exercise programs appear to be better. Supervised treadmill exercise interventions preferentially improve treadmill walking performance, and that doesn’t translate as well to walking in daily life. Home-based exercise, where patients walk in a corridor or on the ground, is more relevant to the type of walking that they want to do,” explained Dr. McDermott, professor of medicine at the university as well as a leader in the field of research on exercise as a treatment for PAD.

However, she added a caveat regarding home-based exercise for symptomatic PAD: For it to be effective it must incorporate proven behavioral change techniques, including goal setting, monitoring progress, accountability to a coach, and face-to-face visits at least once per month.

“It seems you can’t just tell PAD patients to go home and walk because most of them won’t do it,” observed Dr. McDermott, who is a general internist and geriatrician.

Home-based exercise programs aren’t reimbursed by the CMS. But studies by Dr. McDermott and other investigators indicate that the results are more durable than for supervised treadmill exercise. For example, in the Group Oriented Arterial Leg Study (GOALS) – a 6-month group-mediated cognitive behavioral intervention in which PAD patients built up to walking at home for up to 50 minutes per session 5 days per week – 6-minute walking distance (6MWD) remained significantly better than in controls at follow-up after completion of the intervention. In fact, 6MWD actually increased further between 6 and 12 months in the home exercise group (J Am Heart Assoc. 2014 May 21;3(3):e000711. doi: 10.1161/JAHA.113.000711). Dr. McDermott was the lead author for this study.

In contrast, another study by Dr. McDermott now in press for the same journal found that the improvement in 6MWD achieved in PAD patients over the course of a 6-month supervised treadmill exercise program was not maintained during the next 6 months after completion of the intervention. Indeed, 6MWD showed a steady decline from its apex at the intervention’s conclusion, such that at the 12-month mark it was no longer significantly different from that of the control group, according to Dr. McDermott.

The Society for Vascular Surgery recommends a supervised exercise program as first-line therapy for PAD patients with intermittent claudication, with a Class I Level of Evidence A designation. Home-based exercise also gets a Class I recommendation, albeit with Level of Evidence B.

Dr. McDermott believes a home exercise program makes the most sense for PAD patients after their CMS benefit for a supervised clinic-based program has run out, or for patients – and there are a great many – who either can’t or don’t want to participate in a supervised program. She and others who’ve led randomized controlled trials of supervised exercise programs have found that close to 70% of eligible PAD patients decline to participate because of the inconvenience of going to the hospital outpatient facility at least three times per week or for other reasons.

“Also, it’s important to recognize that attendance can be a challenge, even when supervised exercise is covered by insurance. In our randomized trials, where we provide transportation, we still see only 65%-70% adherence to attendance,” she noted.

She stressed that it’s crucial for physicians and surgeons to educate their PAD patients about what to expect from an exercise program, be it supervised or home based.

“It’s not like revascularization, where they’re going to feel better in their walking immediately. It really takes a commitment. Four to six weeks is usually required before patients begin to experience a benefit, and I think it’s really important for patients to know that so they don’t get discouraged in the first couple of weeks,” Dr. McDermott said.

Turning to the key evidence-based behavioral change techniques shared by successful home-exercise programs for PAD, she noted that the GOALS trial intervention utilized weekly group sessions in which simple cognitive behavioral self-regulatory techniques were used to help patients set and stick to home-based walking goals. A similarly positive randomized controlled trial by investigators at the University of Oklahoma utilized once-monthly group meetings at the medical center (J Am Heart Assoc. 2014 Sep 18;3(5):e001107. doi: 10.1161/JAHA.114.001107).

In contrast, in the recent HONOR randomized clinical trial, where Dr. McDermott and her coinvestigators tested whether a home-based exercise intervention in which the active treatment group utilized a Fitbit wearable activity monitor and telephone coaching over the course of 9 months, the results proved disappointing. The intervention was no more effective than was usual care at improving 6MWD (JAMA. 2018 Apr 24;319(16):1665-76).

“One of the things I learned from doing this trial is that for a home-based exercise intervention in PAD to be successful, it’s not easy and there really needs to be some ongoing contact with a coach or nurse or a staff member that the patient feels accountable to. A wearable device is not a durably effective motivator for PAD patients. I think the reason this trial didn’t work so well is that most of it was by telephone and it was easy for patients to avoid our calls if they weren’t walking. Patients were initially really enthusiastic about the Fitbit, but we found that over time they stopped wearing it,” she said.

Dr. McDermott heartily endorses the Society for Vascular Surgery’s Class I recommendation that all PAD patients with intermittent claudication should exercise regularly, including those who’ve undergone revascularization procedures. Numerous clinical trials have demonstrated additive clinical benefits for opening the peripheral artery and strengthening skeletal muscles.

Uptake of supervised exercise programs for symptomatic PAD since the CMS coverage decision is quite variable regionally. Integrating new programs into existing cardiac rehabilitation facilities is a natural fit because staff members are very familiar with structured treadmill exercises already on site, but some freestanding programs are run by vascular surgery groups or cardiologists.

“I think part of the reason it hasn’t been taken up faster is that the reimbursement is such that you’re not going to make money on it,” Dr. McDermott said.

Asked if all patients with PAD should undergo an exercise treadmill test before embarking on an exercise program, Dr. McDermott replied, “I’m part of a writing group for the American Heart Association on how to implement these new guidelines. We’re not formally recommending a stress test. Some cardiologists on the panel suggested that it should be individualized based on patient history and symptoms. If they’re having symptoms of chest pain or they have a significant cardiac history, go ahead with a stress test. I don’t think it’s going to be recommended as a routine practice, but it’s safest to get a stress test.”

She reported having no financial conflicts regarding her presentation.
 

Requirements for CMS coverage of supervised exercise for symptomatic PAD

*The exercise program must consist of 12 weeks of thrice-weekly sessions.

*It has to be prescribed by a physician following a face-to-face meeting with the patient during which the physician provides education on cardiovascular risk prevention.

*An additional 36 sessions of supervised exercise can be obtained with a written note of justification by the physician following completion of the initial 12 weeks.

*The sessions must take place in a physician’s office or an outpatient hospital setting.

*The exercise has to be supervised by a physician, physician assistant, or nurse specialist.

*The exercise must be delivered by qualified personnel trained in basic and advanced cardiac life support as well as exercise therapy for PAD.

bjancin@mdedge.com

CHICAGO – Home-based exercise for peripheral arterial disease–related walking limitations works at least as well as – and arguably better than – the supervised outpatient hospital clinic-based treadmill exercise programs of the type approved for coverage by the Centers for Medicare and Medicaid Services in 2017, Mary M. McDermott, MD, said at a symposium on vascular surgery sponsored by Northwestern University.

“The prevailing thinking is that supervised treadmill exercise is more effective than home-based exercise for PAD. And for the outcome of treadmill walking that is true. But for the outcome of 6-minute walking distance, which I would argue is more relevant to walking in daily life, home-based exercise programs appear to be better. Supervised treadmill exercise interventions preferentially improve treadmill walking performance, and that doesn’t translate as well to walking in daily life. Home-based exercise, where patients walk in a corridor or on the ground, is more relevant to the type of walking that they want to do,” explained Dr. McDermott, professor of medicine at the university as well as a leader in the field of research on exercise as a treatment for PAD.

However, she added a caveat regarding home-based exercise for symptomatic PAD: For it to be effective it must incorporate proven behavioral change techniques, including goal setting, monitoring progress, accountability to a coach, and face-to-face visits at least once per month.

“It seems you can’t just tell PAD patients to go home and walk because most of them won’t do it,” observed Dr. McDermott, who is a general internist and geriatrician.

Home-based exercise programs aren’t reimbursed by the CMS. But studies by Dr. McDermott and other investigators indicate that the results are more durable than for supervised treadmill exercise. For example, in the Group Oriented Arterial Leg Study (GOALS) – a 6-month group-mediated cognitive behavioral intervention in which PAD patients built up to walking at home for up to 50 minutes per session 5 days per week – 6-minute walking distance (6MWD) remained significantly better than in controls at follow-up after completion of the intervention. In fact, 6MWD actually increased further between 6 and 12 months in the home exercise group (J Am Heart Assoc. 2014 May 21;3(3):e000711. doi: 10.1161/JAHA.113.000711). Dr. McDermott was the lead author for this study.

In contrast, another study by Dr. McDermott now in press for the same journal found that the improvement in 6MWD achieved in PAD patients over the course of a 6-month supervised treadmill exercise program was not maintained during the next 6 months after completion of the intervention. Indeed, 6MWD showed a steady decline from its apex at the intervention’s conclusion, such that at the 12-month mark it was no longer significantly different from that of the control group, according to Dr. McDermott.

The Society for Vascular Surgery recommends a supervised exercise program as first-line therapy for PAD patients with intermittent claudication, with a Class I Level of Evidence A designation. Home-based exercise also gets a Class I recommendation, albeit with Level of Evidence B.

Dr. McDermott believes a home exercise program makes the most sense for PAD patients after their CMS benefit for a supervised clinic-based program has run out, or for patients – and there are a great many – who either can’t or don’t want to participate in a supervised program. She and others who’ve led randomized controlled trials of supervised exercise programs have found that close to 70% of eligible PAD patients decline to participate because of the inconvenience of going to the hospital outpatient facility at least three times per week or for other reasons.

“Also, it’s important to recognize that attendance can be a challenge, even when supervised exercise is covered by insurance. In our randomized trials, where we provide transportation, we still see only 65%-70% adherence to attendance,” she noted.

She stressed that it’s crucial for physicians and surgeons to educate their PAD patients about what to expect from an exercise program, be it supervised or home based.

“It’s not like revascularization, where they’re going to feel better in their walking immediately. It really takes a commitment. Four to six weeks is usually required before patients begin to experience a benefit, and I think it’s really important for patients to know that so they don’t get discouraged in the first couple of weeks,” Dr. McDermott said.

Turning to the key evidence-based behavioral change techniques shared by successful home-exercise programs for PAD, she noted that the GOALS trial intervention utilized weekly group sessions in which simple cognitive behavioral self-regulatory techniques were used to help patients set and stick to home-based walking goals. A similarly positive randomized controlled trial by investigators at the University of Oklahoma utilized once-monthly group meetings at the medical center (J Am Heart Assoc. 2014 Sep 18;3(5):e001107. doi: 10.1161/JAHA.114.001107).

In contrast, in the recent HONOR randomized clinical trial, where Dr. McDermott and her coinvestigators tested whether a home-based exercise intervention in which the active treatment group utilized a Fitbit wearable activity monitor and telephone coaching over the course of 9 months, the results proved disappointing. The intervention was no more effective than was usual care at improving 6MWD (JAMA. 2018 Apr 24;319(16):1665-76).

“One of the things I learned from doing this trial is that for a home-based exercise intervention in PAD to be successful, it’s not easy and there really needs to be some ongoing contact with a coach or nurse or a staff member that the patient feels accountable to. A wearable device is not a durably effective motivator for PAD patients. I think the reason this trial didn’t work so well is that most of it was by telephone and it was easy for patients to avoid our calls if they weren’t walking. Patients were initially really enthusiastic about the Fitbit, but we found that over time they stopped wearing it,” she said.

Dr. McDermott heartily endorses the Society for Vascular Surgery’s Class I recommendation that all PAD patients with intermittent claudication should exercise regularly, including those who’ve undergone revascularization procedures. Numerous clinical trials have demonstrated additive clinical benefits for opening the peripheral artery and strengthening skeletal muscles.

Uptake of supervised exercise programs for symptomatic PAD since the CMS coverage decision is quite variable regionally. Integrating new programs into existing cardiac rehabilitation facilities is a natural fit because staff members are very familiar with structured treadmill exercises already on site, but some freestanding programs are run by vascular surgery groups or cardiologists.

“I think part of the reason it hasn’t been taken up faster is that the reimbursement is such that you’re not going to make money on it,” Dr. McDermott said.

Asked if all patients with PAD should undergo an exercise treadmill test before embarking on an exercise program, Dr. McDermott replied, “I’m part of a writing group for the American Heart Association on how to implement these new guidelines. We’re not formally recommending a stress test. Some cardiologists on the panel suggested that it should be individualized based on patient history and symptoms. If they’re having symptoms of chest pain or they have a significant cardiac history, go ahead with a stress test. I don’t think it’s going to be recommended as a routine practice, but it’s safest to get a stress test.”

She reported having no financial conflicts regarding her presentation.
 

Requirements for CMS coverage of supervised exercise for symptomatic PAD

*The exercise program must consist of 12 weeks of thrice-weekly sessions.

*It has to be prescribed by a physician following a face-to-face meeting with the patient during which the physician provides education on cardiovascular risk prevention.

*An additional 36 sessions of supervised exercise can be obtained with a written note of justification by the physician following completion of the initial 12 weeks.

*The sessions must take place in a physician’s office or an outpatient hospital setting.

*The exercise has to be supervised by a physician, physician assistant, or nurse specialist.

*The exercise must be delivered by qualified personnel trained in basic and advanced cardiac life support as well as exercise therapy for PAD.

bjancin@mdedge.com