THE CORONARY RISK OF UNSUSPECTED RENAL-ARTERY STENOSIS

Purpose: This study was designed to determine the prevalence of unsusp ected renal artery stenoses (RAS) in patients undergoing arteriography for evaluation of aneurysmal or occlusive vascular disease and whethe r symptomatic coronary artery disease (CAD) is more prevalent among pa tients with unsuspected RAS. Methods: We reviewed the arteriograms and medical records of 346 consecutive patients with aortic aneurysms or occlusive disease in whom RAS was unsuspected on clinical grounds. Res ults: Aortography revealed unsuspected RAS (50% or greater diameter lo ss) in 98 patients (28%). Patients with RAS had a higher prevalence of mild, controlled hypertension (p < 0.001) and mild renal insufficienc y (p < 0.001), but in no case was arteriography obtained to diagnose r enovascular hypertension or ischemic nephropathy. Fifty-seven patients (58%) with unsuspected RAS had clinically overt CAD (documented myoca rdial infarction, positive coronary catheterization, previous coronary revascularization, ischemic electrocardiography changes, or angina pe ctoris), compared with 96 patients (39%) without RAS (p = 0.002). The correlation between the prevalence of CAD and RAS severity was highly significant (p < 0.001), and the relative odds ratio of CAD was highes t for RAS measuring 75% or greater. Stepwise logistic regression analy sis demonstrated three variables to be significantly and independently associated with CAD: 75% or greater RAS (p = 0.001), aortic aneurysm disease (p = 0.01), and hypertension (p = 0.001). RAS measuring 75% or greater diameter loss was associated with the highest estimated odds ratio: patients with this degree of RAS had a fourfold increase in the prevalence of clinically overt CAD. We also evaluated the relationshi p between RAS, mesenteric artery stenosis, and CAD; although RAS was m ore frequent among patients with mesenteric artery stenoses, mesenteri c artery stenoses were not associated with CAD. Conclusions: Unsuspect ed RAS is common among patients with peripheral vascular disease and s hould be considered an independent marker for CAD.