Prevalence and prediction of previously unrecognized peripheral arterial disease in patients with coronary artery disease: The peripheral arterial disease in Interventional Patients Study

BACKGROUND: Peripheral arterial disease (PAD) is under diagnosed in primary care practices, yet the extent of unrecognized PAD in patients with coronary artery disease (CAD) is unknown. OBJECTIVE: To assess the prevalence of previously unrecognized PAD in patients undergoing coronary angiography and/or intervention and to determine the relationship between presence of PAD and severity of CAD. METHODS: The Peripheral Arterial Disease in Interventional Patients Study (PIPS) is a prospective cohort study conducted at an inpatient service of a tertiary referral center. A total of 800 patients referred for coronary angiography without prior diagnosis of PAD aged 70 years or older or aged 50-69 years with a history of tobacco use and/or diabetes mellitus were included. Evaluation involved a medical history, a questionnaire to assess symptoms and functional status, and measurement of the ankle-brachial index (ABI). PAD was considered present if the ABI was 0.90 or less. RESULTS: The prevalence of previously unrecognized PAD was 15%, 95% CI (12.6-17.7) and was highest among patients over 70 years of age (25.2%) and in women (23.3%). Among patients with CAD, those with PAD had higher prevalence of left main and multivessel coronary artery disease (87.2% vs. 75.5%, P = 0.006). Alternatively, patients with multivessel CAD had a twofold higher risk of being diagnosed with previously unrecognized PAD compared with those with single vessel CAD adjusted OR = 2.02, (95% CI 1.03-3.98). CONCLUSIONS: PAD is often overlooked even in patients with known ischemic heart disease under specialist cardiovascular care. Overlooked PAD in this population increases in frequency with advanced age, in women, and in the presence of other traditional cardiovascular risk factors. Furthermore, the presence of PAD in this population identifies a subgroup with more severe form of CAD.