Laser atherectomy uses light to break down hyperplastic tissue in an atherosclerotic plaque or restenosis of a stented lesion. In a new paper published in JACC Cardiovascular Interventions, investigators conducting the EXCITE ISR trial report that excimer laser atherectomy (ELA), used in addition to percutaneous transluminal angioplasty (PTA), is superior to PTA alone for treating patients with femoropopliteal in-stent restenosis.

Patients with peripheral artery disease (PAD) often have stents placed in the femoral or popliteal arteries, and while advances in stent technologies and materials have improved outcomes in these individuals, in-stent restenosis requiring a secondary intervention still occurs in many patients. “Within a year of stenting, restenosis occurs in 40–60% of cases, accounting for 115,000 patients suffering from femoropopilteal in-stent restenosis this year alone,” explains Eric Dippel of the Genesis Heart Institute, Davenport, IA, USA who led the study. “The EXCITE ISR trial is the first large prospective randomized study to show the superiority of laser atherectomy plus PTA versus PTA alone for the treatment of in-stent restenosis in femoropopliteal peripheral arterial disease,” adds Dippel.

The investigators originally aimed to include up to 318 patients with chronic PAD and an in-stent restenosis ≥50% in diameter within a previously implanted femoropopilteal stent. However, enrollment was stopped early when 250 individuals had been recruited because interim analyses indicated efficacy of ELA with PTA over PTA alone. Patients were randomly assigned (2:1) to receive either ELA with PTA (n = 169) or PTA alone (n = 81). The average length of the lesion in each patient group was 19.6 ± 12 cm and 19.3 ± 12 cm for the ELA with PTA and PTA alone respectively; >70% of lesions were >10 cm long.

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The primary efficacy end point was freedom from target lesion revascularization at 6 months follow-up. Secondary efficacy end points included procedural success, target lesion revascularization at 12 months follow-up, and lesion patency. The primary safety end point was any major adverse event (including all-cause death, unplanned limb amputation, or target lesion revascularization) over 30-day follow-up.

At 6 months, data were available for 117 and 56 patients in the ELA with PTA and PTA alone treatment groups, respectively. The primary efficacy outcome occurred in 73.5% of patients undergoing ELA with PTA and 51.8% in those undergoing only PTA (P <0.005). ELA with PTA was also superior to PTA throughout the remaining follow-up period to 12 months for both patency (defined as <50% diameter stenosis; P <0.005) and freedom from target lesion revascularization (P <0.003). Overall, ELA with PTA was associated with a 52% reduction in target lesion revascularization (HR 0.48, 95% CI 0.31–0.74). In the multivariate analysis, the risk of target lesion revascularization after ELA with PTA reduced compared with PTA alone with increasing length of lesion (HR 0.96, 95% CI 0.43–2.14 versus HR 0.31, 95% CI 0.17–0.58 for a lesion length of 5 cm and 35 cm, respectively). ELA with PTA was also superior to PTA alone for the primary safety outcome (94.2% versus 79.5%; P <0.001), which was again maintained at 1 year follow-up.

“EXCITE ISR clearly demonstrates that peripheral atherectomy products, in conjunction with PTA, are clinically superior to PTA alone in both safety and efficacy in treating femoropopliteal in-stent restenosis,” concludes Dippel, who adds, “this trial ... provides physicians [with] clinical outcomes-based evidence to treat this complicated patient population.”

Professor Thomas Zeller from Universitäts Herzzentrum in Bad Krozingen, Germany, who was not involved in the study, comments, “the general expectation is that laser debulking might further improve the performance of drug-eluting balloon [angioplasty] in in-stent restenosis treatment and might also supplement implantation of an endoprosthesis, which is another option to treat superficial femoral artery in-stent restenosis.” Zeller adds, “laser debulking as a stand alone procedure is somehow superior to plain balloon angioplasty but not the final solution for the treatment of superficial femoral artery in-stent restenosis.”