Cardiac troponins predict mortality and cardiovascular outcomes in patients with peripheral artery disease: A systematic review and meta-analysis of adjusted observational studies

Background A significant proportion of patients (pts) with peripheral artery disease (PAD) have concomitant coronary artery disease and polyvascular involvement contributes to increased risk of death and unfavorable cardiovascular events. Hypothesis Cardiac troponins are associated with adverse cardiovascular outcomes in PAD pts. Methods We systematically searched Medline and Scopus to identify all observational cohort studies published before June 2021 (combining terms "troponin," "peripheral artery disease," "peripheral arterial disease," "intermittent claudication," and "critical limb ischemia") that evaluated the prognostic impact of troponin rise on admission on all-cause mortality and/or major cardiovascular events (MACEs; composite of myocardial infarction, stroke, and cardiovascular death) in PAD pts followed up at least 6 months. A meta-analysis was conducted using the generic inverse variance method. Heterogeneity between studies was investigated using Cochrane's Q test and I-2 statistic. Results Eight studies were included in the final analysis (5313 pts) with a median follow-up of 27 months (interquartile range: 12-59 months). The prevalence of troponin positivity was 5.3% (range: 4.4%-8.7%) in pts with intermittent claudication, and 62.6% (range: 33.6%-85%) in critical limb ischemia. Elevated troponins were significantly associated with an increased risk of all-cause mortality (hazard ratio [HR]: 2.85, 95% confidence interval [CI]: 2.28-3.57; I-2 = 50.97%), and MACE (HR: 2.58, 95% CI: 2.04-3.26; I-2 = 4.00%) without publication bias (p = .24 and p = .10, respectively). Conclusion Troponin rise on admission is associated with adverse long-term cardiovascular outcomes in symptomatic PAD.