ANALYSIS OF RISK-FACTORS FOR DEVELOPMENT OF ATRIAL-FIBRILLATION EARLYAFTER CARDIAC VALVULAR SURGERY

Atrial fibrillation (AF) commonly develops after cardiac valvular surg ery. The objective of this study was to identify risk factors for post operative AF following valvular surgery. A cohort of 915 consecutive a dult patients undergoing isolated valvular surgery with preoperative s inus rhythm was analyzed. Univariate and independent multivariate risk factors for postoperative AF were determined. A second cohort of 305 patients with the same inclusion criteria was used to validate the mul tivariate predictors. Patients studied had a mean age of 56.1 +/- 14.7 years, 57.9% were men, 79.6% had a normal left ventricular ejection f raction, and their mean left atrial size was 46.2 +/- 9.3 mm. The inci dence of postoperative AF was 36.7%. Independent predictors of postope rative AF included: advanced age (odds ratio [OR] 1.506 per decade, 95 % confidence interval, [CI] 1.35 to 1.68, p = 0.0001); mitral stenosis (OR 2.066, CI 1.21 to 3.52, p = 0.0077); left atrial enlargement (OR 1.468, CI 1.07 to 2.01, p = 0.0165); use of systemic hypothermia (OR 0 .572, CI 0.422 to 0.776, p = 0.0003); and a history of cardiac surgery (OR 0.676, CI 0.465 to 0.981, p = 0.0393). Among these variables, adv anced age, mitral stenosis, and left atrial enlargement were confirmed as independent risk factors in the validation cohort. (C)1998 by Exce rpta Medica, Inc.