Effects of Angiotensin-Converting Enzyme Inhibitor Therapy on Clinical Outcome in Patients Undergoing Coronary Artery Bypass Grafting

OBJECTIVES: This study evaluates the effect of pre-operative angiotensin-converting enzyme inhibitor (ACEI) therapy on early clinical outcomes after coronary artery bypass grafting (CABG). BACKGROUND: Therapy with ACEIs has been shown to reduce the rate of mortality and prevent cardiovascular events in patients with coronary artery disease. However, their pre-operative use in patients undergoing CABG is still controversial. METHODS: A retrospective, observational, cohort study was undertaken of prospectively collected data on 10,023 consecutive patients undergoing isolated CABG between April 1996 and May 2008. Of these, 3,052 patients receiving pre-operative ACEI were matched to a control group by propensity score analysis. RESULTS: Overall rate of mortality was 1%. Pre-operative ACEI therapy was associated with a doubling in the risk of death (1.3% vs. 0.7%; odds ratio [OR]: 2.00, 95% confidence interval [CI]: 1.17 to 3.42; p = 0.013). There was also a significant difference between the ACEI and control group in the risk of post-operative renal dysfunction (PRD) (7.1% vs. 5.4%; OR: 1.36, 95% CI: 1.1 to 1.67; p = 0.006), atrial fibrillation (AF) (25% vs. 20%; OR: 1.34, 95% CI: 1.18 to 1.51; p <0.0001), and increased use of inotropic support (45.9% vs. 41.1%; OR: 1.22, 95% CI: 1.1 to 1.36; p <0.0001). In a multivariate analysis, pre-operative ACEI treatment was an independent predictor of mortality (p = 0.04), PRD (p = 0.0002), use of inotropic drugs (p <0.0001), and AF (p <0.0001). CONCLUSIONS: Pre-operative therapy with ACEI is associated with an increased risk of mortality, use of inotropic support, PRD, and new onset of post-operative AF.