The coronary risk of unsuspected renal artery stenosis.

PURPOSE: This study was designed to determine the prevalence of unsuspected renal artery stenoses (RAS) in patients undergoing arteriography for evaluation of aneurysmal or occlusive vascular disease and whether symptomatic coronary artery disease (CAD) is more prevalent among patients 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.

RESULTS

Aortography revealed unsuspected RAS (50% or greater diameter loss) in 98 patients (28%). Patients with RAS had a higher prevalence of mild, controlled hypertension (p < 0.001) and mild renal insufficiency (p < 0.001), but in no case was arteriography obtained to diagnose renovascular hypertension or ischemic nephropathy. Fifty-seven patients (58%) with unsuspected RAS had clinically overt CAD (documented myocardial infarction, positive coronary catheterization, previous coronary revascularization, ischemic electrocardiography changes, or angina pectoris), 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 highest for RAS measuring 75% or greater. Stepwise logistic regression analysis 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 relationship between RAS, mesenteric artery stenosis, and CAD; although RAS was more frequent among patients with mesenteric artery stenoses, mesenteric artery stenoses were not associated with CAD.

CONCLUSIONS

Unsuspected RAS is common among patients with peripheral vascular disease and should be considered an independent marker for CAD.