Clinical impact of improvement in the ankle–brachial index after endovascular therapy for peripheral arterial disease

Predictive ability of changes in the ankle–brachial index (ABI) after revascularization for long-term clinical outcomes remains unclear. Pre- and postprocedural ABI were recorded for 1307 consecutive patients who underwent their first successful EVT for symptomatic aortoiliac (n = 710) or femoropopliteal (n = 597) lesions. The patients were divided into two groups according to the increase in ABI: ∆ABI ≥ 0.15 (n = 980) and ∆ABI < 0.15 (n = 327). We investigated the association between ABI improvement after EVT and long-term clinical outcomes. The clinical outcome measures included all-cause mortality, myocardial infarction, stroke, target limb revascularization, EVT for target lesion revascularization, major amputation of the target limb, and a composite endpoint that included both target limb revascularization and major amputation. All-cause mortality was significantly lower in the ∆ABI ≥ 0.15 group than in the ∆ABI < 0.15 group [crude hazard ratio (HR) 0.77, 95% confidence interval (CI) 0.60–0.98, P = 0.03]; however, this was no longer statistically significant after adjusting for baseline characteristics (adjusted HR 0.82, 95% CI 0.63–1.07, P = 0.14). A composite of target limb revascularization and major amputation was less often observed at 10 years in the ΔABI ≥ 0.15 group (258 patients, 38%) compared with the ΔABI < 0.15 group (112 patients, 59%; adjusted HR 0.54, 95% CI 0.42–0.68, P < 0.001), mainly because of a lower risk of target limb revascularization (adjusted HR 0.54, 95% CI 0.42–0.69, P < 0.001). No significant interactions were noted with regard to the locations of the treated lesions (P for the interaction, 0.13) or preprocedural ABI (P for the interaction, 0.40). An increase of ABI ≥ 0.15 after successful EVT was an independent predictor for freedom from a composite of target limb revascularization and major amputation, irrespective of the locations of the treated lesions and the preprocedural ABI.