Abstract 3046: Protective Effect Of Preoperative Angiotensin Converting Enzyme Inhibitors On Renal Outcome Following Coronary Artery Bypass Graft Surgery. A Propensity Score-adjusted Analysis

Abstract

Introduction: A large number of patients undergoing coronary artery bypass graft (CABG) surgery are treated with angiotensin converting enzyme (ACE) inhibitors before the operation. Since ACE inhibitors decrease glomerular perfusion pressure, it is still believed that their withdrawal before surgery on cardiopulmonary bypass may reduce postoperative renal adverse events. However, no previous study has attempted to address this issue. We aimed to evaluate the impact of preoperative ACE inhibitors on renal outcome in patients undergoing on pump CABG surgery using a risk adjusted approach. Methods and Results: A propensity score-based analysis of 531 patients undergoing elective isolated CABG surgery on cardiopulmonary bypass. Patients with preoperative end-stage renal failure requiring dialysis were excluded. Of those 531 patients, 204 were treated with ACE inhibitors before the operation and 327 were not treated with ACE inhibitors. Renal adverse outcome following surgery was defined as 20% decrease in creatinine clearance from preoperative or post-operative mechanical renal support. After adjusting for propensity score and covariates, multivariate analysis showed that preoperative ACE inhibitors had a protective effect against renal adverse outcome following CABG surgery (odds ratio [OR], 0.8; 95% confidence interval [CI],0.5 to 0.9; P <0.01). Other independent predictors of adverse renal outcome were age (OR 1.17 per 1 years; 95% CI 1.01 to 1.39; P <0.001), female sex (OR 0.72; 95% CI 0.51 to 0.93; P <0.001); left ventricular ejection fraction less than 0.30 (OR 2.12; 95% CI 1.92 to 2.85; P <0.01); pre-operative creatinine clearance (OR 1.23 per 10ml/min decrease; 95% CI 1.01 to 1.31; P <0.001); diabetes (OR 1.80; 95% CI 1.25 to 2.24; P <0.01); aortic cross clamp time (OR 1.31 per 10 min increase; 95% CI 1.11 to 1.61; P <0.01). Operative mortality was not statistically different between groups (2.4% versus 4.0% in patients with and without preoperative ACE inhibitors; P =0.45) Conclusions: Preoperative ACE inhibitors are associated with better renal outcome in patients undergoing on pump CABG surgery. No clinical evidences support ACE inhibitors withdrawal before surgery