A New Era of Atherectomy

Experts discuss the rising use of vessel-preparation devices during coronary and endovascular procedures.

Other tools for interventional cardiologists have come and gone, but atherectomy technology has persisted and — because of new products, new data and a favorable reimbursement climate — is growing in popularity.

In recent years, use of atherectomy devices, which cut, sand, shave or vaporize atherosclerotic plaque from diseased arteries, has increased from approximately 15% to more than 30% in peripheral interventional procedures, and from less than 2% to approximately 5% in coronary interventional procedures. As the evidence base mounts, those percentages are expected to continue to rise, experts told Cardiology Today’s Intervention.

Although the popularity of atherectomy is increasing in coronary and peripheral interventions, this is happening for different reasons.

During coronary interventions, in which atherectomy is almost exclusively performed in conjunction with stenting, its use enables stents to be deployed in patients with heavily calcified lesions who otherwise would be sent for CABG.

Cover illustration © Lisa Clark

“Atherectomy continues to stay because it facilitates stent delivery deployment and expansion,” 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 Zena and Michael A. Wiener Professor of Medicine (cardiology) at Icahn School of Medicine at Mount Sinai, said in an interview. “Atherectomy is in some ways a forgotten device ... but in the situation of a calcific lesion or calcific vessel, atherectomy is needed before good results from a stent can be obtained.”

During peripheral interventions, atherectomy use is growing because there is a trend away from implanting stents in the peripheral arteries due to concern about future complications, so many operators have turned to atherectomy, sometimes in conjunction with plain or drug-coated balloons, instead.

“The superficial femoral artery, where most peripheral interventions are performed, is not conducive to permanent vessel scaffolds,” Subhash Banerjee, MD, FACC, FSCAI, chief of the division of cardiology and co-director of the cardiac catheterization laboratory at VA North Texas Health Care System, and professor of medicine at University of Texas Southwestern Medical Center, Dallas, told Cardiology Today’s Intervention. “This has been realized by most operators and in most clinical studies.”

For coronary and peripheral interventions, their use is increasing because CMS has given atherectomy its own reimbursement code and no longer bundles it with stents, and because the newest atherectomy system (Diamondback 360 Coronary Orbital Atherectomy System, Cardiovascular Systems Inc.), introduced to the U.S. market in late 2012, is easier to prepare and use compared with older systems, experts said.

There are five main atherectomy technologies, some of which are approved for coronary and peripheral procedures, and some of which are approved for peripheral procedures only. What follows is a rundown of the evidence for their clinical use.

Directional Atherectomy

One of the first atherectomy technologies, directional atherectomy (TurboHawk and SilverHawk, Medtronic/Covidien/ev3) is approved only for treatment of lesions in the infrainguinal superficial femoral, popliteal and below-the-knee vessels. The device includes a rotating blade that shaves plaque and a nose cone that collects the plaque.

“The TurboHawk works nicely on very eccentric lesions because you can direct the cut toward that eccentricity, and it works well on calcified disease,” Nicolas W. Shammas, MD, MS, EJD, FACC, FSCAI, founder and research director of Midwest Cardiovascular Research Foundation in Davenport, Iowa, and adjunct clinical associate professor of medicine, University of Iowa, told Cardiology Today’s Intervention. “However, it requires frequent removal of the device to empty the nose cone, so that makes it a little cumbersome.”

Banerjee said adoption of directional atherectomy increased after the publication in 2014 of 1-year results of the prospective DEFINITIVE LE study. James F. McKinsey, MD, from New York-Presbyterian Hospital and University Hospital of Columbia and Cornell, and colleagues found that in 800 patients with claudication or critical limb ischemia who received directional atherectomy, the primary patency rate was 78% (95% CI, 74-80.6), which was similar in those with diabetes and without diabetes; freedom from major unplanned target limb amputation was 95% (95% CI, 90.7-97.4); and bailout stenting was required only 3.2% of the time.

“The very resounding message was that [directional] atherectomy could be performed alone,” Banerjee said. “Also, with devices that shave the plaque, operators were concerned about distal embolization, dissection and perforation, but those rates were 3.8%, 2.3% and 5.3%, respectively.”

Rotational Atherectomy

Rotational atherectomy (Rotablator, Boston Scientific) features a nickel-plated brass burr coated with microscopic diamond crystals, which “spins extremely fast, between 140,000 and 190,000 rpm, over a guidewire, which allows creation of a channel and excises plaque by burrowing through it,” Banerjee told Cardiology Today’s Intervention. It is primarily used in coronary vessels, but is also indicated for lower-extremity vessels.

Experts said some of the strongest evidence for rotational atherectomy comes from the ERBAC study, which compared rotational atherectomy, excimer laser atherectomy and balloon angioplasty in 685 patients with symptomatic CAD requiring an intervention for a complex lesion. Nicolaus Reifart, MD, FESC, FACC, from Herzzentrum Frankfurt, Germany, and colleagues found that the procedural success rate was higher with rotational atherectomy (89%) than with excimer laser atherectomy (77%) or balloon angioplasty (80%; P = .0019), with no significant differences in major in-hospital complications. However, 6-month target lesion revascularization was higher for rotational atherectomy (42.4%) and excimer laser atherectomy (46%) than for balloon angioplasty (31.9%; P = .013).

“In the coronary field, we have shown that standalone atherectomy does not work, and has to combine with a stent procedure,” Sharma said. “It does improve procedural outcomes, but as far as restenosis is concerned, the data are conflicting.”

Also influencing practice was the ROTAXUS study, in which 240 patients with complex calcified coronary lesions were randomly assigned to stenting with or without rotational atherectomy, Philippe Généreux, MD, interventional cardiologist and director of the structural program at Hôpital du Sacré-Coeur, Montréal, and director of the angiographic core laboratory at the Cardiovascular Research Foundation/Columbia University Medical Center, New York, said in an interview.

While assignment to the atherectomy group was associated with greater procedural success (92.5% vs. 83.3%; P = .03) and less crossover (4.2% vs. 12.5%; P = .02), the primary endpoint of in-stent late lumen loss was slightly higher in the atherectomy group (0.44 mm vs. 0.31 mm; P = .04), while there were no differences in clinical adverse events such as stent thrombosis, need for revascularization or in-stent restenosis, Mohamed Abdel-Wahab, MD, from Segeberger Kliniken, Bad Segeberg, Germany, and colleagues reported.

“That being said, it may be better to take a small hit on the slight and clinically silent increase in late loss in order to successfully perform the procedure and deliver the stent,” Généreux said. “The big critique is that it was followed by the implantation of a first-generation paclitaxel-eluting stent (Taxus, Boston Scientific), and we know that we have way better drug-eluting stents now.”

Rotational Atherectomy, Thrombectomy

Another option is a single-use catheter indicated for both rotational atherectomy and thrombectomy (Jetstream, Boston Scientific), which enables the operator to perform cutting and aspiration simultaneously. It is approved for use in peripheral vessels only.

“It’s a skinny device advanced over a 0.014-in guidewire with a maximum rate of advancement about 1 mm/second,” Banerjee said. “It has a front cutting tip that makes passage through tight lesions possible. The aspiration is continuous as plaque is being depleted.”

Adoption of the technology began after publication in 2009 of the Pathway PVD trial, in which 172 patients (mean age, 72 years; 88 women; 210 lesions) with lower-limb ischemia, long lesions and severe stenosis were treated with an early version of the device. Thomas Zeller, MD, from the department of angiology at Heart-Centre Bad Krozingen, Germany, and colleagues reported a device success rate of 99%, 30-day major adverse event rate of 1%, 6-month TLR rate of 15%, 12-month TLR rate of 26% and 12-month restenosis rate of 38.2%, as well as significant improvements in Rutherford class and ankle-brachial index at 12 months.

Shammas noted that the Jetstream G3 Calcium study showed the device to be highly effective at removing calcium, as verified by IVUS analysis.

The aspiration feature may reduce the risk for distal embolization, but research is ongoing as to whether it is feasible to use a distal filter device during the procedure, as is commonly done with directional atherectomy, Banerjee said.

Excimer Laser Atherectomy

Excimer laser atherectomy, which uses a high-energy light beam to dissolve plaque without harming nearby healthy tissue, is approved for coronary and peripheral applications.

In the CELLO study published in 2009, use of the newest version of the technology (Turbo-Booster, Spectranetics) was studied in 65 de novo lesions in patients with peripheral artery disease.

Rajesh M. Dave, MD, from Harrisburg Hospital, Pennsylvania, and colleagues found that excimer laser atherectomy reduced percent diameter stenosis from 77% to 34.7% by itself and to 21% in conjunction with balloon angioplasty with or without stenting. Patency rates were 59% at 6 months and 54% at 12 months, freedom from TLR was 76.9% at 12 months and no major adverse events were reported.

Laser atherectomy has also been recently approved in the United States for the treatment of femoropopliteal in-stent restenosis, Shammas said.

Orbital Atherectomy

The newest atherectomy technology is orbital atherectomy, which has some similarities to rotational atherectomy, but instead of a burr has a diamond-coated crown rotating at a speed of 60,000 rpm to 200,000 rpm. It is approved for coronary and peripheral interventional procedures.

“The faster you spin, the larger the arc of rotation,” Banerjee said. “Because of that, you can treat different sizes of vessels with the same device.”

The ORBIT II study of 443 patients with severely calcified coronary lesions played a role in uptake of the device, experts told Cardiology Today’s Intervention. Jeffrey W. Chambers, MD, from Metropolitan Heart and Vascular Institute, Mercy Hospital, Minneapolis, and colleagues reported that mean lumen diameter increased from 0.5 mm before the procedure to 2.9 mm after; freedom from MACE at 30 days was 89.6%, beating the performance goal of 83%; residual stenosis of less than 50% after stenting without in-hospital MACE was 88.9%, beating the performance goal of 82%; and rates of MI, cardiac death and target vessel revascularization were less than 1% each.

“The data are very strong and encouraging, because they show a very low rate of ischemic adverse events, with lesions 1- and 2-year TLR and TVR rates similar to the ones showed in non-calcified lesions,” Généreux said. “But there were no comparators and there was no angiographic core lab analysis, which was the case with ROTAXUS. Without any prospective head-to-head comparison in a randomized trial, it’s impossible to be definitive on what represents the best option for lesion preparation of severely calcified lesions.”

In addition, in the CALCIUM 360 study, orbital atherectomy plus balloon angioplasty, compared with balloon angioplasty alone, was associated with a nonsignificantly higher rate of procedural success (93.1% vs. 82.4%; P = .27), a nonsignificantly lower rate of bailout stenting (6.9% vs. 14.3%; P = .44), nonsignificantly greater freedom from TVR at 1 year (93.3% vs. 80%; P = .14) and greater freedom from all-cause mortality at 1 year (100% vs. 68.4%; P = .01) in 50 patients with limb ischemia and calcified popliteal and infrapopliteal disease. However, this study was not powered for mortality. In addition, data from the CONFIRM registry of more than 3,000 patients demonstrated that orbital atherectomy is similarly safe and effective in patients with PAD with or without diabetes.

Price remains a concern, however, according to Généreux. “Some operators have been challenged by the price of the device. There is no doubt that Orbit II trial showed fantastic results with the use of orbital atherectomy before stent implantation, but with the lack of head-to-head data or imaging studies that demonstrate differential and favorable mechanisms of action, it might be difficult to justify the use of this device compared to other less expensive strategies. More cost analysis data are needed.”

Michael S. Lee, MD, FSCAI, associate professor of medicine at David Geffen School of Medicine at UCLA, said in an interview that the cost issue “has not affected [his] treatment paradigm.” However, he said, “operators who have outpatient surgical centers may opt to treat lesions with a less expensive atherectomy device, such as laser atherectomy.”

Market Penetration

Coronary atherectomy was used in only 1.8% of interventional coronary procedures in 2013, but that rose to 3.2% in 2014 and is expected to land somewhere between 4% and 5% in 2015, Sharma said. He noted that one factor is that atherectomy now has its own reimbursement code instead of being bundled in with stenting.

“Because of the data, because of the ease [of use of orbital atherectomy], because of the reimbursement, there is now a push,” he said. “Almost every month, I do training for atherectomy. A lot used to come until 2005 or 2006, because when the DES came along, people stopped believing in atherectomy. But now, in the last 2 years, about three physicians each month are coming to get training.”

There is still room for growth in coronary applications because about 8% to 10% of coronary lesions are heavily calcified, according to Sharma. “There is a chance for growth to maximum potential, 10%, when data come in showing better outcomes,” he said.

Early data also suggest that atherectomy may be a valuable tool for vessel preparation before deployment of bioabsorbable coronary stents and scaffolds, which could be a driver of growth in the future, experts said.

Based on data from the XLPAD registry, atherectomy is now used in 36% to 40% of peripheral interventions, Banerjee said.

“There is a clear trend. The penetration of atherectomy was under 10% historically,” he said. “It got a good bump to 15% to 20% after DEFINITIVE LE. What we are seeing is further growth after introduction of drug-coated balloons because of the complementary nature of these technologies, operators have started using it, not based on large studies but on the presumption that this would work.”

More Data Needed

As encouraging as recent data have been and as popular as atherectomy is becoming, more data are needed — particularly from randomized controlled trials that directly compare atherectomy devices with each other and with other kinds of interventions — before the technology can reach its full potential in clinical practice.

“As the data continue to grow demonstrating the benefit of atherectomy, operators will see the safety and efficacy of this technology and adoption will increase over time,” Lee said. “Studies comparing atherectomy vs. conventional stenting should be performed to look at high-risk patients, including those with severe coronary calcification, especially in long, diffuse disease.”

Better data would also allow clearer guidelines and more uniform use of the technology, Shammas said.

“Because of the lack of good data out there, this is allowing wider room for operators to perform in a heterogeneous manner,” he said. “Data from well-designed and well-powered trials are needed to create a clear algorithm to formulate the best strategy for patients with lesions in PAD. With evidence-based guidelines, operators are more likely to follow them, regardless of reimbursement. As we develop more evidence-based algorithms in the future, the situation will become more data-driven and less dependent on cost and reimbursement.” — by Erik Swain

• References:
• Abdel-Wahab M, et al. JACC Cardiovasc Interv. 2012;doi:10.1016/j.jcin.2012.07.017.
• Généreux P, et al. Am J Cardiol. 2015;doi:10.1016/j.amjcard.2015.03.009
• Dave RM, et al. J Endovasc Ther. 2009;doi:10.1583/09-2781.1.
• Lee MS, et al. J Endovasc Ther. 2014;doi:10.1583/13-4449MR.1.
• McKinsey JF, et al. JACC Cardiovasc Interv. 2014;doi:10.1016/j.jcin.2014.05.006.
• Reifart M, et al. Circulation. 1997;doi:10.1161/01.CIR.96.1.91.
• Shammas NW, et al. J Endovasc Ther. 2012;doi:10.1583/JEVT-12-3815MR.1.
• Zeller T, et al. J Endovasc Ther. 2009;doi:10.1583/09-2826.1.

• For more information:
• Subhash Banerjee, MD, FACC, FSCAI, can be reached at 4500 S. Lancaster Road, Dallas, TX 72216; email: subhash.banerjee@utsouthwestern.edu.
• Philippe Généreux, MD, can be reached at Hôpital du Sacré-Coeur de Montréal, Université de Montréal, 5400 Boul. Gouin Ouest, Montréal, QC, H4J1C5 Canada; email: pgenereux@crf.org.
• Michael S. Lee, MD, FSCAI, can be reached at 100 Medical Plaza, Suite 630, Los Angeles, CA 90095; email: mslee@mednet.ucla.edu.
• Nicolas W. Shammas, MD, MS, EJD, FACC, FSCAI, can be reached at Midwest Cardiovascular Research Foundation, 1622 E. Lombard St., Davenport, IA 52803; email: shammas@mchsi.com.
• Samin K. Sharma, MD, FACC, FSCAI, can be reached at The Mount Sinai Hospital, One Gustave L. Levy Place, Box 1030, New York, NY 10029; email: samin.sharma@mountsinai.org.

Disclosures: Banerjee reports receiving research grants from Boston Scientific; consultant fees and speaker’s honoraria from Medtronic and Merck; and serving on the speaker’s board of Cardiovascular Systems Inc. Généreux reports receiving a research grant from Boston Scientific and receiving consultant/speaking fees and research grants from Cardiovascular Systems Inc. Lee reports consulting for Cardiovascular Systems Inc. Shammas reports receiving research and educational grants from Boston Scientific, Cardiovascular Systems Inc. and Medtronic. Sharma reports speaking and training for Boston Scientific and Cardiovascular Systems Inc.