ACE and congestive heart failure: We assessed the statistical significance of the following established clinical risk factors [3,15] for POAF in our cohort: age, sex, body mass index (BMI), history of paroxysmal AF, hypertension, diabetes mellitus, congestive heart failure, preoperative angiotensin-converting enzyme-inhibitor (ACEI) use, preoperative angiotensin receptor blocker (ARB) use, preoperative beta blocker use and valve surgery.