Objective: Diastolic dysfunction has been associated with development of atrial fibrillation (AF) in the community and recently in the postoperative setting. We hypothesized that abnormal left ventricular filling predicts AF after cardiac surgery, a common marker of poor outcomes.

Methods: Cohort study of 233 consecutive patients, who underwent coronary artery bypass grafting (CABG) and/or valve surgery. Early and late mitral inflow velocity (E, A) and deceleration time (DT) and early mitral annular velocity (e’) obtained from echo within 6 months before cardiac surgery and their association with postoperative AF.

Results: Postoperative AF occurred in 65 (28%) of patients, who were on average older, more likely to have had prior episodes of AF, had larger inferior vena cava diameter and shorter DT (189 ± 62ms vs. 214 ± 63ms, p=0.007).  Multivariable adjusted analyses demonstrated only DT (odds ratio [OR] 0.65 (95% confidence interval [CI] 0.40-0.97), older age (OR 2.62 (95% CI 1.68 - 4.10) and prior episodes of atrial fibrillation (OR 7.20, CI 1.41-36.8) to be independent predictors of postoperative AF. Patients with a DT ≤ 200ms (n=117) had a significantly longer length of hospital stay compared with those who had DT > 200ms (n=116) (median 7 days (interquartile range [IQR] 5-10) vs. 6 days (IQR 5-7, p=0.0002).

Conclusion: In patients who undergo cardiac surgery, a shorter DT of early mitral inflow identified greater risk for postoperative AF and a longer hospital stay. These results provide useful information for preoperative risk assessment and mechanistic understanding of postoperative AF.