Discussion
These data from the XLPAD registry provide important insights into the contemporary use of stent and non-stent based revascularization procedures for the treatment of symptomatic infrainguinal PAD. Infrainguinal PAD in the SFA, longer lesion length, and presence of CTO are important predictors of stent use. Moreover, significantly more non-stent procedures are performed in the popliteal and BTK arterial locations, and have greater need for amputation and surgical revascularization compared with the stent group.
Operators use stents to primarily treat complex lesions with overall comparable outcomes to a non-stent strategy. Although non-stent treatments exhibit higher rates of surgical revascularization and amputation, this may be driven by a greater proportion of non-stent interventions performed in popliteal and BTK arterial locations, predominantly in patients with advanced Rutherford class. Patients with CLI are known to have greater severity of multilevel PAD and are more likely to experience adverse events, including amputation of the target limb, and higher all-cause mortality. In our study, we did not observe higher all-cause mortality in the non-stent group; however, the amputation rate was significantly higher. We also observed a higher amputation rate in this study compared with those previously reported. This could be attributed to: (1) pooling of above and below-the-ankle amputations; and (2) failure to capture planned vs unplanned amputations in the XLPAD registry. The high use of antiplatelet and lipid-lowering therapies in both study groups, along with inclusion of centers with well-developed PAD interventional programs in the XLPAD registry, may have contributed to the lower than expected mortality of patients in both groups.
Stent-based procedures were longer and required greater fluoroscopy times. These procedures tackled a larger number of CTOs and longer lesion lengths. Importantly, the need for repeat revascularization in the study was 30% at an average follow-up of 8.7 months. This high rate of repeat revascularization is consistent with results observed in a randomized trial of infrainguinal interventions in diabetics with >50% CTO and average lesion lengths >100 mm, and points to the need for applying alternative therapeutic strategies and technologies to improve outcomes in patients undergoing infrainguinal peripheral artery interventions.5 Although many trials have demonstrated superior patency of stents compared with balloon angioplasty for femoropopliteal PAD, they have been limited by relatively short lesion lengths, as well as under-representation of CTOs and patients presenting with CLI. Currently, there are no randomized trials comparing stent-based and atherectomy-based therapies for femoropopliteal and BTK-PAD.
Another important observation from this study is that it reported on the incidence of stent or target vessel thrombosis. This was observed exclusively in the stent group despite high use of antiplatelet therapy with aspirin and clopidogrel. However, the duration of dual-antiplatelet therapy was not captured as part of our study, and was left at the discretion of the operators. Future studies to test the impact of antiplatelet therapy duration on the durability of infrainguinal peripheral artery interventions are needed. The only randomized data in this area come from the results of the MIRROR (Management of Peripheral Arterial Interventions With Mono or Dual-Antiplatelet Therapy) study, which reported lower target lesion revascularization in only 20 patients treated with clopidogrel and aspirin compared with aspirin alone for a period of 6 months.
Study Limitations
This study is limited by missing follow-up information, selection bias due to non-randomized treatment assignments, predominantly male cohort, lack of data on minor or major amputations, the planned or unplanned nature of amputations, and duration of antiplatelet therapy. In addition, there is a lack of device-specific information, stent types, and procedural data such as crossing times, radiation dose area product, and absence of patients with drug-coated peripheral stents. These limitations are being addressed as part of the ongoing XLPAD registry data capture.
Despite these limitations, the findings of this study provide important insights regarding contemporary use of stent and non-stent based treatments for endovascular treatment of infrainguinal PAD in the United States.