Renal failure predisposes patients to adverse outcome after coronary artery bypass surgery

Methods. We analyzed a Veterans Affairs database obtained The presence of impaired renal function potentially prospectively from 1992 through 1996 at 14 of 43 centers per- results in several physiologic abnormalities that could forming heart surgery. We compared the outcome after CABG contribute to adverse operative outcome. Indeed, the in patients with a baseline serum creatinine of less than 1.5 mg/dl (median 1.1 mg/dl, N 5 3271) to patients with a baseline absence of renal function has been well documented to serum creatinine of 1.5 to 3.0 mg/dl (median 1.7, N 5 631). be associated with relatively high morbidity and mortalResults. Univariate analysis revealed that patients with a ity after surgery, including cardiac surgery, despite renal serum creatinine of 1.5 to 3.0 mg/dl had a higher 30-day mortal- replacement therapy [13‐15]. There is, however, limited ity (7% vs. 3%, P , 0.001) requirement for prolonged mechanical ventilation (15% vs. 8%, P 5 0.001), stroke (7% vs. 2%, information on the effects of lesser degrees of renal failP , 0.001), renal failure requiring dialysis at discharge (3% ure on CABG outcome [1, 4, 5, 11, 12]. vs. 1%, P , 0.001), and bleeding complications (8% vs. 3%, This study was therefore undertaken to test the hyP , 0.001) than patients with a baseline serum creatinine of pothesis that mild-to-moderate renal failure (defined as less than 1.5 mg/dl. Multiple logistic regression analyses found a serum creatinine concentration of 1.5 to 3.0 mg/dl) is that patients with a baseline serum creatinine of less than 1.5 mg/dl had significantly lower (P , 0.02) 30-day mortality and an independent risk factor for adverse outcome after postoperative bleeding and ventilatory complications than pa- CABG. To test this hypothesis, we used a large Veterans tients with a serum creatinine of 1.5 to 3.0 mg/dl when control- Affairs (VA) database. This database contained extenling for all other variables. sive data on comorbid conditions, preoperative status, Conclusion. These results demonstrate that mild renal failure and post-CABG complications collected on more than is an independent risk factor for adverse outcome after CABG. 3900 patients. Our multivariate analysis results demonstrate that mild-to-moderate renal failure is an independent risk factor for adverse outcome after CABG when More than 600,000 patients undergo coronary artery all other risk factors are held constant. Our results also bypass grafting (CABG) annually in the United States. delineate some of the specific post-CABG complications Many of these patients have comorbid conditions, such associated with mild-to-moderate renal failure.