Vessel Calcification as a Risk Factor for In-Stent Restenosis in Complex Femoropopliteal Lesions After Zilver PTX Paclitaxel-Coated Stent Placement.

Purpose: To evaluate the effect of vessel calcification on in-stent restenosis (ISR) after drug-coated stent (DCS) placement in the femoropopliteal segment. Materials and Methods: A retrospective multicenter study was undertaken involving 220 consecutive symptomatic patients (mean age 73.1±8.3 years; 175 men) with femoropopliteal lesions in 230 limbs treated with the Zilver PTX DCS and having duplex surveillance after the endovascular procedures. Mean lesion length was 16.4±9.8 cm (range 2-40); there were 104 (45.2%) total occlusions and 68 (29.6%) in-stent restenoses (ISR). Twenty (8.7%) vessels had no runoff. The majority of lesions (148, 64.3%) were calcified according to the peripheral arterial calcium scoring system (PACSS). Primary patency was evaluated by duplex. Lesions were classified as either PACSS 0-2 (none or unilateral wall calcification) or PACSS 3 and 4 (bilateral wall calcification). Multivariate analysis was performed to identify variables associated with ISR; the results are given as the hazard ratio (HR) and 95% confidence interval (CI). Results: The 1-, 2-, and 5-year primary patency and freedom from clinically-driven target lesion revascularization estimates were 75.9%, 63.6%, and 45.0%, and 84.7%, 73.7%, and 54.2%, respectively. Major amputations were performed on 4 limbs during follow-up. In multivariate analysis, vessel calcification (adjusted HR 1.718, 95% CI 1.035 to 2.851, p=0.036) was significantly correlated with the occurrence of ISR, along with lesion length (adjusted HR 1.041, 95% CI 1.013 to 1.070, p=0.003), and cilostazol administration (adjusted HR 0.476, 95% CI 0.259 to 0.876, p=0.017). Conclusion: This study suggested that bilateral vessel wall calcification was an independent risk factor for ISR in complex femoropopliteal lesions after Zilver PTX DCS placement, along with lesion length; cilostazol administration had a protective effect.