Peripheral artery disease and outcomes in patients with acute myocardial infarction

Aim To describe the population of patients with previously diagnosed peripheral artery disease (PAD) experiencing a myocardial infarction (MI) and to investigate 1-year major adverse cardiac events (MACE: all-cause mortality, reinfarction, stroke and heart failure hospitalisation) following MI. Background MI patients with PAD constitute a high-risk population with adverse cardiac outcomes. Contemporary real-life data regarding the clinical characteristics of this patient population and clinical event rates following MI remain scarce. Methods This observational study included all MI patients presenting with ST-elevation MI or non-ST-elevation MI between 01 January 2005 and 31 December 2014 with (n=4213) and without (n=106 763) a concurrent PAD diagnosis, identified in the nationwide Swedish Websystem for Enhancement and Development of Evidencebased care in Heart disease Evaluated According to Recommended Therapies registry and the National Patient Registry (PAD prevalence: 3.8%). Cox proportional hazard models were applied to compare the outcome between the two populations. Results MI patients with PAD were older and more often burdened with comorbidities, such as diabetes, hypertension and previous MI. After adjustments, PAD was significantly associated with higher rates of MACE (HR 1.35, 95% CI 1.27 to 1.44), mortality (HR 1.59, 95% CI 1.43 to 1.76), reinfarction (HR 1.48, 95% CI 1.32 to 1.66), stroke (HR 1.27, 95% CI 1.05 to 1.53), heart failure (HR 1.29, 95% CI 1.20 to 1.40) and bleeding (HR 1.26, 95% CI 1.09 to 1.47) at 1 year. Conclusion A concurrent PAD diagnosis was independently significantly associated with higher rates of adverse outcomes following MI in a nationwide real-life MI population. The low prevalence of PAD compared with previous studies suggests significant underdiagnosing. Future studies should investigate if PAD screening with ankle-brachial index may increase diagnosing and subsequently lead to improved treatment of polyvascular disease