Relation Between Preoperative Renal Dysfunction and Cardiovascular Events (Stroke, Myocardial Infarction, or Heart Failure or Death) Within Three Months of Isolated Coronary Artery Bypass Grafting

Renal dysfunction is related to long-term mortality and myocardial infarction after coronary artery bypass grafting (CABG). We aimed to investigate the association between preoperative renal dysfunction and early risk of stroke, myocardial infarction, or heart failure after CABG. From the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies registry, we included all 36,284 patients who underwent primary isolated CABG from 2000 to 2008 in Sweden. The Swedish National Inpatient Registry was used to obtain the primary end point, which was rehospitalization for stroke, myocardial infarction, or heart failure ≤90 days after CABG. Logistic regression models were used to estimate the risk for the primary outcome and the secondary outcome of death from any cause, while adjusting for confounders. During 90 days of follow-up, there were 2,462 cardiovascular events and 617 deaths. In total, 17% of patients developed acute kidney injury postoperatively. Odds ratios with 95% confidence intervals for cardiovascular events after adjustment for age, gender, atrial fibrillation, left ventricular ejection fraction, diabetes mellitus, peripheral vascular disease, and history of myocardial infarction, heart failure, or stroke was 1.24 (1.06 to 1.45) in patients with an estimated glomerular filtration rate of 15 to 45 ml/min/1.73 m2 but became nonsignificant after acute kidney injury was introduced into the statistical model. The risk of death was significantly increased in patients with estimated glomerular filtration rate of 15 to 45 ml/min/1.73 m2 (odds ratio 1.76, 95% confidence interval 1.38 to 2.25) even after adjustment for all confounders. Renal dysfunction was associated with all-cause mortality but not with cardiovascular events during the first 3 postoperative months after primary isolated CABG.