Functional capacity improvement and cardiovascular events after lower extremity revascularization

BACKGROUND: Functional status predicts outcomes in peripheral artery disease (PAD), but the relevance of changes in functional capacity after lower extremity revascularization (LER) and long-term events is unclear. METHODS: In an IRB-approved prospective cohort, we evaluated adjudicated major adverse cardiovascular and limb events (MACLE: death, myocardial infarction, stroke, major amputation, or acute limb ischemia requiring revascularization) among patients with severe PAD undergoing LER. Functional capacity was assessed using the Duke Activity Status Index (DASI) prior to and at 6 months post-LER. Participants were categorized as: Lower-to-Lower (DASI below cohort pre-LER median [15.95] at both time points), Higher-to-Higher (above median at both), or Lower-to-Higher (below at baseline, above at 6 months). Landmark analyses examined MACLE and all-cause mortality from 6 months onward, with Cox models adjusted for demographic and clinical covariates. RESULTS: Overall, 143 participants had DASI data from before and 6 months after LER (median age 74 years; 36.4% female; 40.6% non-White). Baseline ankle-brachial index (0.56 [0.41, 0.82]) did not differ between groups. The Lower-to-Higher group (n = 28) increased DASI by 17.0 [11.8, 27.0] points (~2.1 METs). MACLE (p < 0.01) and mortality (p < 0.05) differed significantly across groups. Persistently lower DASI was associated with higher adjusted risks of MACLE (HR = 2.03, p = 0.09) and death (HR = 6.78, p = 0.01) relative to persistently higher DASI. Patients whose DASI improved (Lower-to-Higher) had risk similar to those who sustained DASI above the cohort pre-LER median (Higher-to-Higher group). CONCLUSIONS: Among patients with severe PAD undergoing LER with very low DASI, failure to improve functional capacity at 6 months post-LER was associated with higher rates of long-term MACLE and mortality, whereas patients making even modest gains in functional capacity post-LER experienced outcomes comparable to those with consistently greater than cohort average function. Trial Registration: ClinicalTrials.gov NCT02106429.