Impact of Left Atrial Appendage Closure During Cardiac Surgery on the Occurrence of Early Postoperative Atrial Fibrillation, Stroke, and Mortality: A Propensity Score Matched Analysis of 10,633 Patients

BACKGROUND—: Prophylactic exclusion of the left atrial appendage (LAA) is often performed during cardiac surgery ostensibly to reduce the risk of stroke. However, the clinical impact of LAA closure in humans remains inconclusive. METHODS—: Out of 10,633 adults who underwent CABG and/or valve surgery between January 2000 and December 2005, 9,792 patients with complete baseline characteristics, surgery procedure and follow-up data were included in this analysis. A propensity-score matching analysis based on 28 pretreatment covariates was performed and 461 matching pairs were derived and analyzed to estimate the association of LAA closure with early postoperative atrial fibrillation (POAF) (AF ≤30 days of surgery), ischemic stroke and mortality. RESULTS—: In the propensity-matched cohort, the overall incidence of POAF was 53.9%. In this group, the rate of early POAF among the patients who underwent LAA closure was 68.6% vs 31.9% for those who did not undergo the procedure (P<.001). LAA closure was independently associated with an increased risk of early POAF (adjusted OR [95% CI], 3.88 [2.89-5.20]), but did not significantly influence the risk of stroke (adjusted HR [95% CI], 1.07 [0.72-1.58]) or mortality (adjusted HR [95% CI], 0.92 [0.75-1.13]). CONCLUSIONS—: After adjustment for treatment allocation bias, LAA closure during routine cardiac surgery was significantly associated with an increased risk of early POAF, but did not influence the risk of stroke or mortality. It remains uncertain whether prophylactic exclusion of the LAA is warranted for stroke prevention during non–AF-related cardiac surgery.