Effect of preoperative angiotensin converting enzyme inhibitor or angiotensin receptor blocker use on the frequency of atrial fibrillation after cardiac surgery: a cohort study from the atrial fibrillation suppression trials II and III.

BACKGROUND: Two recent meta-analyses demonstrated that angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) reduce the risk of developing new-onset atrial fibrillation (AF) by nearly 50%. However, the ability of ACEIs or ARBs to prevent postoperative atrial fibrillation (POAF) after cardiac surgery has not been adequately evaluated.

OBJECTIVE: To evaluate the impact of preoperative ACEI or ARB use on the incidence of POAF after cardiac surgery.

METHODS: Patients undergoing coronary artery bypass grafting and/or valvular surgery from the (atrial fibrillation suppression trials II and III (AFIST II and III) randomized, controlled trials were evaluated in this cohort evaluation. Data in respect to patient demographics, surgical characteristics, medication utilization and the incidence of POAF (defined as AF lasting at least 5 min in duration documented by telemetry) were all uniformly and prospectively collected as part of AFIST II and III. Multivariate logistic regression was utilized to calculate adjusted odds ratios with 95% confidence intervals.

RESULTS: A total of 338 patients were evaluated of which 175 (51.8%) received an ACEI or ARB preoperatively and 163 (48.2%) did not. The study population was 65.7+/-9.1 years of age, 77.8% were male, 11.2% underwent valve surgery, 3.6% had prior AF, 10.1% had heart failure and 84.0 and 37.9% received postoperative beta-blockade and prophylactic amiodarone, respectively. In total, 110 (32.5%) patients developed POAF. Upon multivariate logistic regression, the preoperative use of an ACEI or ARB was not found to be associated with a statistically significant reduction in POAF (adjusted odds ratio; 0.71, 95% CIs 0.42-1.20).

CONCLUSIONS: Although preoperative ACEI or ARB use reduced the odds of developing POAF by 29%, this association with not found to be statistically significant. A study with approximately 600 subjects would be needed to discern if ACEIs or ARBs truly impact POAF.