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 beta-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 beta-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 beta-blockers--both agents are associated with improved survival in patients with CAD and PAD.