A retrospective study compared the incidence of post operative atrial fibrillation (POAF) in patients treated with the CorMatrix ECM for pericardial closure following isolated coronary artery bypass graft (CABG) versus patients not treated with the patch. The retrospective study comprised of 222 patients. 111 were treated with the CorMatrix ECM and the other 111 were not. Results showed POAF in 34 of 111 control patients but only 20 in 111 CorMatrix ECM treated patients, indicating a 54% decrease in the risk of POAF in the CorMatrix ECM treated patients. This study shows a statistically significant reduction in the risk of POAF in patients undergoing an isolated CABG with pericardial closure using the CorMatrix ECM.