Cover Story

The Evolving Role of Atherectomy

Experts debate emerging evidence and rising use of vessel preparation for coronary and peripheral procedures.

The use of atherectomy to treat PAD and CAD is rising because of encouraging short-term results and a favorable reimbursement climate. But the question remains whether, particularly in conjunction with other technologies, atherectomy provides durable long-term results. A number of trials underway may ultimately decide that question.

“While we have been getting gratifying acute results, we still have to prove that by doing atherectomy, you are improving the long-term prognosis of the patient,” Samin K. Sharma, MD, FACC, FSCAI, director of clinical and interventional cardiology, president of the Mount Sinai Heart Network, director of international clinical affiliations and Anandi Lal Sharma professor of medicine (cardiology) at Icahn School of Mount Sinai, told Cardiology Today’s Intervention. “And that needs to be shown by various trials.”

Samin K. Sharma

Approximately 5% of interventions in the coronary arteries employ atherectomy, but the figure should be closer to 10% to match the proportion of patients with severely calcified lesions, Sharma said. In peripheral artery interventions, atherectomy is used more than 30% of the time, experts said (see Table for list of approved devices).

“The use of atherectomy in the U.S. is clearly on the rise and has increased significantly over the past couple of years,” Nicolas W. Shammas, MD, MS, EJD, FACC, FSCAI, founder and research director of the Midwest Cardiovascular Research Foundation, adjunct clinical associate professor of medicine at the University of Iowa, interventional cardiologist at Cardiovascular Medicine in Davenport, Iowa, and editor of the Textbook of Atherectomy, said in an interview. “In PAD, this is supported by data from the XLPAD registry, which showed that [in 2017] at participating centers, atherectomy exceeded the use of stenting. ... In office-based labs, atherectomy has skyrocketed.”

Atherectomy in PAD

The increasing popularity of atherectomy as a treatment for PAD appears to be driven by several factors, including the variety of peripheral artery lesion types that appear to benefit from it and the initial encouraging results for atherectomy as a treatment in conjunction with drug-coated balloons, experts said.

Source: © Lisa Clark

“There are three major categories where atherectomy seems to work well: total occlusions, long lesions and moderately or severely calcified lesions,” Shammas said. “These are the lesions that dissect the most and the ones where you have the most difficulty in getting a drug delivered to the target inside the vessel wall. So, by prepping the vessel, you both reduce the need for stenting and improve the drug penetration and concentration in the vessel.”

Because it enables other technologies to do their jobs effectively, atherectomy has become a key part of a strategy to prevent reinterventions and restenosis, George L. Adams, MD, MHS, MBA, FACC, FSCAI, director of cardiovascular and peripheral vascular research at Rex Hospital in Raleigh, North Carolina, and associate professor of cardiology at University of North Carolina School of Medicine, told Cardiology Today’s Intervention.

George L. Adams

“If you prep the vessel adequately with atherectomy, it causes microfissures,” he said. “When you use adjunctive balloon angioplasty after atherectomy, the microfissures help prevent spiral dissections and elastic recoil — either of those sets you up for having to place a stent. Also, these microfissures may allow biologics to get to the adventitia to prevent smooth muscle cell proliferation or restenosis.”

In the LIBERTY 360° study of a variety of endovascular interventions in patients with claudication or critical limb ischemia, initial outcomes with atherectomy appear encouraging, but it is too early to draw firm conclusions, William A. Gray, MD, system chief of the division of cardiovascular disease at Main Line Health and president of the Lankenau Heart Institute in Wynnewood, Pennsylvania, said in an interview.

William A. Gray

“At 18 months, the use of orbital atherectomy (Diamondback 360 Peripheral, Cardiovascular Systems Inc.) was not associated with hugely different outcomes in terms of freedom from major adverse events; probably the most dramatic outcome differences are in the Rutherford 6 classification,” he said. “There, freedom from major adverse events is about 10% better, and amputation-free survival seems to be better with orbital atherectomy compared with all-comers. But these are small numbers, and I wouldn’t want to make a strong outcomes statement until we did something more randomized and prospective.”

Atherectomy in CAD

Atherectomy was used in more than 25% of coronary-artery interventional procedures before the advent of drug-eluting stents, but that fell to approximately 2% after DES became standard of care, and its use is now rising again for a number of reasons, according to Sharma, a member of the Cardiology Today’s Intervention Editorial Board.

“We are getting more complex patients referred because surgeons don’t want to take them,” he said. “This is one reason behind the increase in atherectomies, along with the introduction of new techniques — in the past, there was only rotational — and reimbursement.”

For the past 3 years, atherectomy has received its own ambulatory procedure code and can be billed as a separate procedure instead of as an adjunct to angioplasty and/or stenting, which has greatly decreased the cost to hospitals, Sharma said.

Although atherectomy “does increase the initial cost of the procedure, adequate lesion preparation may decrease the risk for future in-stent restenosis and stent thrombosis, therefore decreasing the overall cumulative costs of treating patients,” Michael S. Lee, MD, FACC, FSCAI, interventional cardiologist and associate professor of medicine at UCLA Medical Center, told Cardiology Today’s Intervention.

Michael S. Lee

In many patients with complex coronary disease, atherectomy may be needed to optimize the performance of a stent, Gray said.

“As we start to treat more complex patients with calcified disease, who are older, have had prior CABG, etc, an underexpanding stent forebodes worsening long-term outcomes in terms of restenosis,” he said. “Once a stent is underexpanded, it is difficult to get it expanded if you didn’t already prepare the vessel before stent implantation. The proximal heavily calcified lesions that don’t expand, especially in the left main artery, do benefit from atherectomy.”

Rsearch Continues

Atherectomy has been shown to improve procedural success and short-term outcomes, but knowledge gaps remain in many areas, including how durable the outcomes are, which types of atherectomy are best for which patients and whether imaging can maximize the effect of atherectomy, experts said.

One ongoing trial whose results will be anticipated is ECLIPSE, a comparison of orbital atherectomy (Diamondback 360 Coronary, Cardiovascular Systems Inc.) plus a DES with conventional balloon angioplasty plus a DES in approximately 1,800 patients with ACS or stable ischemic heart disease and severely calcified lesions. Among other outcomes, the researchers will be assessing whether there is a difference in cardiac death/target vessel-related MI/ischemia-driven target vessel revascularization.

“If the trial is positive, it will give a big push to this field,” Sharma said. “There have not been any trials that have increased the use of atherectomy as much as this one would.”

In the peripheral space, an anticipated study is REALITY, a prospective, single-arm assessment in up to 250 patients on the concomitant use of directional atherectomy (HawkOne and TurboHawk, Medtronic) and a DCB (IN.PACT Admiral, Medtronic) in terms of 1-year patency and 1-month freedom from adverse events.

“This may fill one of the knowledge gaps as to how we position atherectomy and drug-coated balloons in the future,” Gray said. “It is powered to see a difference.”

Additionally, in the JET-RANGER study, 255 patients will undergo random assignment to rotational atherectomy with aspiration (Jetstream, Boston Scientific) followed by a DCB or plain balloon angioplasty followed by a DCB.

“This is the first randomized trial in complex de novo femoropopliteal lesions powered to show superiority of the combination therapy of atherectomy plus DCB vs. DCB alone,” said Shammas, national chairman for the trial. “This is going to be an important study in terms of defining the value of atherectomy when added to drug-coated balloons in the setting of complex disease such as CTOs, long lesions and calcified disease.”

Remaining Questions

As the ongoing trials may provide further insights, they will not answer every question needed to understand the true value of atherectomy.

“We need to understand the value of embolic filter protection with atherectomy: how much do we need it and when we should use it,” Shammas said. “We know atherectomy tends to produce emboli more than stenting and angioplasty, and embolic filter protection seems to be on the rise; in some trials it’s used in 40% to 50% of patients despite not being mandated.”

Nicolas W. Shammas

Comparisons between the different types of atherectomy devices are also lacking, he said.

“We need to find out if there’s a difference between directional cutting vs. rotational cutting,” he said. “We need to find out whether the depth of injury created by certain atherectomy devices will impact short- and long-term outcomes.”

More work must be done on optimizing the patient population for atherectomy treatment, Lee said.

“We need to determine which subset of patients should be treated with atherectomy,” he said. “Currently, we use a relatively arbitrary determination of whether these technologies should be used. Conjunctive modalities such as IVUS and OCT are helpful to determine the degree of coronary artery calcification; in general, the arc of calcium greater than 270° is a threshold for use of atherectomy to modify the plaque.”

As personalization of care becomes more of an emphasis, more precise answers about who should receive atherectomy, and which kind, will be required, Adams said.

“We need a better understanding of which atherectomy devices work best in different plaque morphologies, different-sized lesions and different locations,” he said. “Also, with the advent of these biologic therapies, are there certain patient groups that derive more benefit, ie, women vs. men, diabetics vs. non-diabetics, hypertensives vs. nonhypertensives, high cholesterol vs. normal cholesterol. There is not one device that treats all, and we have to be selective and thoughtful in terms of using devices to the benefit of how each patient presents.” - by Erik Swain and Darlene Dobkowski

Disclosures: Adams reports he receives research grants from and consults for Boston Scientific, Cardiovascular Systems Inc., C.R. Bard, Medtronic and Philips. Gray reports he consults for Abbott Vascular, Boston Scientific, Cardiovascular Systems Inc., Cook Medical, Cordis, Medtronic, Shockwave Medical and W.L. Gore and Associates and holds stock in Biocardia, Coherex Medical, Contego Medical and Silk Road Medical. Lee reports no relevant financial disclosures. Shammas reports he receives research and educational grants from Boston Scientific, C.R. Bard and Intact Vascular and serves as national chairman for two atherectomy trials of Boston Scientific devices. Sharma reports he is a speaker for Boston Scientific and Cardiovascular Systems Inc.

The use of atherectomy to treat PAD and CAD is rising because of encouraging short-term results and a favorable reimbursement climate. But the question remains whether, particularly in conjunction with other technologies, atherectomy provides durable long-term results. A number of trials underway may ultimately decide that question.

“While we have been getting gratifying acute results, we still have to prove that by doing atherectomy, you are improving the long-term prognosis of the patient,” Samin K. Sharma, MD, FACC, FSCAI, director of clinical and interventional cardiology, president of the Mount Sinai Heart Network, director of international clinical affiliations and Anandi Lal Sharma professor of medicine (cardiology) at Icahn School of Mount Sinai, told Cardiology Today’s Intervention. “And that needs to be shown by various trials.”

Samin K. Sharma

Approximately 5% of interventions in the coronary arteries employ atherectomy, but the figure should be closer to 10% to match the proportion of patients with severely calcified lesions, Sharma said. In peripheral artery interventions, atherectomy is used more than 30% of the time, experts said (see Table for list of approved devices).

“The use of atherectomy in the U.S. is clearly on the rise and has increased significantly over the past couple of years,” Nicolas W. Shammas, MD, MS, EJD, FACC, FSCAI, founder and research director of the Midwest Cardiovascular Research Foundation, adjunct clinical associate professor of medicine at the University of Iowa, interventional cardiologist at Cardiovascular Medicine in Davenport, Iowa, and editor of the Textbook of Atherectomy, said in an interview. “In PAD, this is supported by data from the XLPAD registry, which showed that [in 2017] at participating centers, atherectomy exceeded the use of stenting. ... In office-based labs, atherectomy has skyrocketed.”

Atherectomy in PAD

The increasing popularity of atherectomy as a treatment for PAD appears to be driven by several factors, including the variety of peripheral artery lesion types that appear to benefit from it and the initial encouraging results for atherectomy as a treatment in conjunction with drug-coated balloons, experts said.

Source: © Lisa Clark

“There are three major categories where atherectomy seems to work well: total occlusions, long lesions and moderately or severely calcified lesions,” Shammas said. “These are the lesions that dissect the most and the ones where you have the most difficulty in getting a drug delivered to the target inside the vessel wall. So, by prepping the vessel, you both reduce the need for stenting and improve the drug penetration and concentration in the vessel.”

PAGE BREAK

Because it enables other technologies to do their jobs effectively, atherectomy has become a key part of a strategy to prevent reinterventions and restenosis, George L. Adams, MD, MHS, MBA, FACC, FSCAI, director of cardiovascular and peripheral vascular research at Rex Hospital in Raleigh, North Carolina, and associate professor of cardiology at University of North Carolina School of Medicine, told Cardiology Today’s Intervention.

George L. Adams

“If you prep the vessel adequately with atherectomy, it causes microfissures,” he said. “When you use adjunctive balloon angioplasty after atherectomy, the microfissures help prevent spiral dissections and elastic recoil — either of those sets you up for having to place a stent. Also, these microfissures may allow biologics to get to the adventitia to prevent smooth muscle cell proliferation or restenosis.”

In the LIBERTY 360° study of a variety of endovascular interventions in patients with claudication or critical limb ischemia, initial outcomes with atherectomy appear encouraging, but it is too early to draw firm conclusions, William A. Gray, MD, system chief of the division of cardiovascular disease at Main Line Health and president of the Lankenau Heart Institute in Wynnewood, Pennsylvania, said in an interview.

William A. Gray

“At 18 months, the use of orbital atherectomy (Diamondback 360 Peripheral, Cardiovascular Systems Inc.) was not associated with hugely different outcomes in terms of freedom from major adverse events; probably the most dramatic outcome differences are in the Rutherford 6 classification,” he said. “There, freedom from major adverse events is about 10% better, and amputation-free survival seems to be better with orbital atherectomy compared with all-comers. But these are small numbers, and I wouldn’t want to make a strong outcomes statement until we did something more randomized and prospective.”

Atherectomy in CAD

Atherectomy was used in more than 25% of coronary-artery interventional procedures before the advent of drug-eluting stents, but that fell to approximately 2% after DES became standard of care, and its use is now rising again for a number of reasons, according to Sharma, a member of the Cardiology Today’s Intervention Editorial Board.

“We are getting more complex patients referred because surgeons don’t want to take them,” he said. “This is one reason behind the increase in atherectomies, along with the introduction of new techniques — in the past, there was only rotational — and reimbursement.”

For the past 3 years, atherectomy has received its own ambulatory procedure code and can be billed as a separate procedure instead of as an adjunct to angioplasty and/or stenting, which has greatly decreased the cost to hospitals, Sharma said.

PAGE BREAK

Although atherectomy “does increase the initial cost of the procedure, adequate lesion preparation may decrease the risk for future in-stent restenosis and stent thrombosis, therefore decreasing the overall cumulative costs of treating patients,” Michael S. Lee, MD, FACC, FSCAI, interventional cardiologist and associate professor of medicine at UCLA Medical Center, told Cardiology Today’s Intervention.

Michael S. Lee

In many patients with complex coronary disease, atherectomy may be needed to optimize the performance of a stent, Gray said.

“As we start to treat more complex patients with calcified disease, who are older, have had prior CABG, etc, an underexpanding stent forebodes worsening long-term outcomes in terms of restenosis,” he said. “Once a stent is underexpanded, it is difficult to get it expanded if you didn’t already prepare the vessel before stent implantation. The proximal heavily calcified lesions that don’t expand, especially in the left main artery, do benefit from atherectomy.”

Rsearch Continues

Atherectomy has been shown to improve procedural success and short-term outcomes, but knowledge gaps remain in many areas, including how durable the outcomes are, which types of atherectomy are best for which patients and whether imaging can maximize the effect of atherectomy, experts said.

One ongoing trial whose results will be anticipated is ECLIPSE, a comparison of orbital atherectomy (Diamondback 360 Coronary, Cardiovascular Systems Inc.) plus a DES with conventional balloon angioplasty plus a DES in approximately 1,800 patients with ACS or stable ischemic heart disease and severely calcified lesions. Among other outcomes, the researchers will be assessing whether there is a difference in cardiac death/target vessel-related MI/ischemia-driven target vessel revascularization.

“If the trial is positive, it will give a big push to this field,” Sharma said. “There have not been any trials that have increased the use of atherectomy as much as this one would.”

In the peripheral space, an anticipated study is REALITY, a prospective, single-arm assessment in up to 250 patients on the concomitant use of directional atherectomy (HawkOne and TurboHawk, Medtronic) and a DCB (IN.PACT Admiral, Medtronic) in terms of 1-year patency and 1-month freedom from adverse events.

PAGE BREAK

“This may fill one of the knowledge gaps as to how we position atherectomy and drug-coated balloons in the future,” Gray said. “It is powered to see a difference.”

Additionally, in the JET-RANGER study, 255 patients will undergo random assignment to rotational atherectomy with aspiration (Jetstream, Boston Scientific) followed by a DCB or plain balloon angioplasty followed by a DCB.

“This is the first randomized trial in complex de novo femoropopliteal lesions powered to show superiority of the combination therapy of atherectomy plus DCB vs. DCB alone,” said Shammas, national chairman for the trial. “This is going to be an important study in terms of defining the value of atherectomy when added to drug-coated balloons in the setting of complex disease such as CTOs, long lesions and calcified disease.”

Remaining Questions

As the ongoing trials may provide further insights, they will not answer every question needed to understand the true value of atherectomy.

“We need to understand the value of embolic filter protection with atherectomy: how much do we need it and when we should use it,” Shammas said. “We know atherectomy tends to produce emboli more than stenting and angioplasty, and embolic filter protection seems to be on the rise; in some trials it’s used in 40% to 50% of patients despite not being mandated.”

Nicolas W. Shammas

Comparisons between the different types of atherectomy devices are also lacking, he said.

“We need to find out if there’s a difference between directional cutting vs. rotational cutting,” he said. “We need to find out whether the depth of injury created by certain atherectomy devices will impact short- and long-term outcomes.”

More work must be done on optimizing the patient population for atherectomy treatment, Lee said.

“We need to determine which subset of patients should be treated with atherectomy,” he said. “Currently, we use a relatively arbitrary determination of whether these technologies should be used. Conjunctive modalities such as IVUS and OCT are helpful to determine the degree of coronary artery calcification; in general, the arc of calcium greater than 270° is a threshold for use of atherectomy to modify the plaque.”

As personalization of care becomes more of an emphasis, more precise answers about who should receive atherectomy, and which kind, will be required, Adams said.

“We need a better understanding of which atherectomy devices work best in different plaque morphologies, different-sized lesions and different locations,” he said. “Also, with the advent of these biologic therapies, are there certain patient groups that derive more benefit, ie, women vs. men, diabetics vs. non-diabetics, hypertensives vs. nonhypertensives, high cholesterol vs. normal cholesterol. There is not one device that treats all, and we have to be selective and thoughtful in terms of using devices to the benefit of how each patient presents.” - by Erik Swain and Darlene Dobkowski

Disclosures: Adams reports he receives research grants from and consults for Boston Scientific, Cardiovascular Systems Inc., C.R. Bard, Medtronic and Philips. Gray reports he consults for Abbott Vascular, Boston Scientific, Cardiovascular Systems Inc., Cook Medical, Cordis, Medtronic, Shockwave Medical and W.L. Gore and Associates and holds stock in Biocardia, Coherex Medical, Contego Medical and Silk Road Medical. Lee reports no relevant financial disclosures. Shammas reports he receives research and educational grants from Boston Scientific, C.R. Bard and Intact Vascular and serves as national chairman for two atherectomy trials of Boston Scientific devices. Sharma reports he is a speaker for Boston Scientific and Cardiovascular Systems Inc.