Cardiovascular outcomes for patients with symptomatic peripheral artery disease: A cohort study in The Health Improvement Network (THIN) in the UK

Background Few data are available on risk factors and associations with outcomes in symptomatic peripheral artery disease (PAD) populations in primary care. We assessed characteristics and cardiovascular outcomes in patients with and those without symptomatic peripheral artery disease in UK primary care, and quantified risk factors for cardiovascular outcomes in patients with peripheral artery disease. Methods Among patients in The Health Improvement Network (THIN) aged 50-89 years in 2000-2010, a symptomatic peripheral artery disease cohort (n=28,484) and a matched comparison cohort without peripheral artery disease (n=113,940) were identified using Read codes. Cox proportional hazard ratios (HRs) and 95% confidence intervals (CIs) for cardiovascular outcomes were calculated, adjusted for potential confounders. Results The incidence of all-cause death per 1000 person-years was 83.22 and 50.46 in the peripheral artery disease and non-peripheral artery disease cohort, respectively (HR 1.41; 95% CI 1.68-1.43). The incidence of composite cardiovascular outcome (myocardial infarction, ischaemic stroke or cardiovascular-related death) per 1000 person-years was 31.87 and 14.63 in the peripheral artery disease and non-peripheral artery disease cohort, respectively (HR 1.71; 95% CI 1.65-1.77). Risk factors for composite cardiovascular outcome in patients with peripheral artery disease were older age (75 years vs. 50-64 years: HR 2.37; 95% CI 2.20-2.55), current smoking (1.26; 1.17-1.35), comorbid diabetes (1.42; 1.32-1.52), heart failure (1.31; 1.20-1.44), atrial fibrillation (1.32; 1.18-1.47, previous myocardial infarction (1.29; 1.20-1.39) and previous ischaemic stroke (1.77; 1.63-1.93). Conclusion Patients with symptomatic peripheral artery disease in a clinical practice population have a high risk of death and cardiovascular-related outcomes. Minimising risk is important in the ongoing management of these patients.