Lower extremity peripheral arterial disease in individuals with coronary artery disease: Prognostic importance, care gaps, and impact of therapy

Background Our objective was to examine the effect of concomitant lower extremity peripheral arterial disease (PAD) on long-term prognosis and pharmacotherapy in patients with coronary artery disease (CAD). Methods Prospective cohort study enrolling all patients with angiographically proven CAD between April 1, 2000, and December 31, 2004, in Alberta, Canada. Results Of 28 649 patients (mean age 64 years) with CAD, 2509 (9%) had a physician-assigned diagnosis of lower extremity PAD. Mortality was higher in the patients with CAD and PAD over a mean follow-up of 3.1 years, even after adjusting for the fact that patients with PAD had more severe CAD and more comorbidities (adjusted hazard ratio [HR] 1.41, 95% CI 1.28-1.55). Fewer patients with CAD and PAD received antiplatelet agents (83% vs 86%, odds ratio 0.86, 95% CI 0.77-0.97) or β-blockers (63% vs 67%, odds ratio 0.89, 95% CI 0.82-0.98), but users of these agents exhibited lower mortality (adjusted HR 0.68, 95% CI 0.60-0.77, for antiplatelet agents and adjusted HR 0.72, 95% CI 0.64-0.80, for β-blockers). Approximately half of these patients were prescribed statins or angiotensin-converting enzyme inhibitors, and 27% were using all 3 evidence-based anti-atherosclerotic therapies (antiplatelets, statin, and angiotensin-converting enzyme inhibitor). Conclusions In patients with CAD, lower extremity PAD is independently associated with poorer outcomes. Although all evidence-based therapies are underused in patients with CAD, patients with concomitant PAD are less likely to be prescribed antiplatelet agents or β-blockers—both agents are associated with improved survival in patients with CAD and PAD.