Preoperative left atrial strain abnormalities are associated with the development of postoperative atrial fibrillation following isolated coronary artery bypass surgery

Objective: Postoperative atrial fibrillation (POAF) is a common complication after coronary artery bypass grafting (CABG). Currently, there is no reliable way to determine preoperatively which patients will develop POAF following CABG. The aim of this study was to determine whether preoperative left atrial (LA) strain analysis might identify patients destined to develop POAF following CABG.

Methods: From 2016 to 2018, 211 patients who had a preoperative left ventricular ejection fraction >50% and adequate preoperative, predischarge, and follow-up echo images for interpretation underwent isolated CABG surgery. Postoperatively, patients had continuous rhythm monitoring until hospital discharge. Retrospective speckle-tracking analysis of preoperative echocardiograms was performed to calculate preoperative left ventricular global longitudinal strain and LA compliance and contraction strains in 92 matched patients. Multivariate logistic regression and Cox proportional hazards models were used to determine the predictors of POAF after CABG.

Results: POAF occurred in 50 patients (24%). They were older, had longer intensive care unit and hospital stays, and a slightly greater 30-day mortality (P = .07). Preoperative LA volume index was larger in the patients with POAF but still "normal" as defined by current guidelines. However, preoperative LA compliance and contraction strains were significantly lower in patients who developed POAF after CABG.

Conclusions: Decreased preoperative LA strain measurements, especially LA-fractional area change, LA-emptying fraction, and LA-reservoir strain, taken jointly, are more specific and sensitive than other preoperative parameters in identifying patients who will develop POAF following CABG. The ability to identify patients preoperatively who are destined to develop POAF following CABG provides a basis for limiting POAF prophylactic therapy to only those patients undergoing CABG who are most likely to benefit from it rather than to all patients undergoing CABG.