Abstract 16843: Black Race is Linked to Lower Occurrence of Postoperative Atrial Fibrillation after Cardiac Surgery
Objective: To investigate differences in occurrence of atrial fibrillation (AF) after cardiac surgery between black and white patients, because genetic predisposition for non-surgical AF has been suggested and could also affect postoperative AF.
Methods: Between 1995-2005, 21,458 patients of self-reported black or white race underwent CABG and/or valve surgery in sinus rhythm. To adjust for patient confounders, including socioeconomic position, we propensity-matched black with white patients and studied occurrence of postoperative AF and other postoperative arrhythmic and non-arrhythmic complications. Multivariable logistic regression identified predictors of postoperative AF in black patients.
Results: Of 20,282 white patients 7,093 (35%) developed postoperative AF, compared to 255 (22%) of 1,176 black patients (p <0.0001). Blacks were younger and had lower socioeconomic position. Their body mass index and preoperative creatinine levels were greater; hypertension and congestive heart failure were more prevalent and left atrial size was smaller among blacks. Procedural differences were less aortic valve, but more mitral valve replacements in black patients. In 847 propensity-matched patient pairs these confounding characteristics were well balanced. Propensity-adjusted analyses demonstrated lower occurrence of postoperative AF in black verses white patients (OR 0.76, 95% CI 0.61-0.95). A sensitivity analysis suggested a hidden confounder had to change the odds of blacks developing postoperative AF by 0.61 to explain our results alternatively. Other than higher occurrence of bradycardia and re-intubation in whites, there were no differences in postoperative complications or hospital mortality. Independent risk factors for postoperative AF in black patients were older age, more severe tricuspid regurgitation, more blood transfusions and valve replacement.
Conclusion: In this propensity-matched study black patients had lower occurrence of postoperative AF after cardiac surgery, when compared to whites. These results have novel mechanistic implications: genetic predisposition may play an important role in the development of AF after cardiac surgery.
- © 2010 by American Heart Association, Inc.