Severity of renal vascular disease predicts mortality in patients undergoing coronary angiography

Background. Renal artery stenosis (RAS) is a relatively uncommon but potent ially reversible cause of renal failure. In a previous report, we demonstra ted that the presence of RAS is independently associated with mortality in a group of patients undergoing coronary angiography. Our current study expa nds on this cohort, investigating the effect of the severity of RAS on all- cause mortality. Methods. A total of 3987 patients underwent abdominal aortography immediate ly following coronary angiography. For the purpose of survival analysis, si gnificant RAS was defined as greater than or equal to 75% narrowing in the luminal diameter. Results. Significant RAS was present in 4.8% of patients studied and was bi lateral in 0.8%. Factors associated with the presence of RAS included femal e gender, older age, hypertension. congestive heart failure, elevated serum creatinine, and congestive heart failure. The four-year unadjusted surviva ls for patients with and without significant RAS were 57 and 89%, respectiv ely (P < 0.001). Using the Cox proportional hazards model. the factors inde pendently associated with decreased survival were the presence of RAS. incr eased age, the severity of coronary artery disease, the presence of comorbi d disease, reduced ejection fraction, symptoms of congestive cardiac failur e. and the mode of treatment of coronary artery disease . In the multivaria te model. the presence of RAS conferred a hazard ratio of 2.01 (95% CI, 1.5 1 to 2.67, P < 0.001). We demonstrated an incremental effect on mortality a ccording to the severity of RAS at baseline. Four-year adjusted survival fo r patients with 50%. 75%. and greater than or equal to 95% stenosis was 70% . 68%. and 48%. respectively. In addition, bilateral disease was associated with four-year survival of 47% as compared with 59% for patients with unil ateral disease (P < 0.001). The impact of RAS on survival remained robust r egardless of the manner of treatment of coronary artery disease [that is, m edical, percutaneous transluminal coronary angioplasty (PTCA), or coronary artery bypass graft (CABG)]. Conclusions. In this patient population. the presence of RAS is a strong in dependent predictor of mortality. Increasing severity of RAS has an increme ntal effect on survival probability.