Prophylactic Left Atrial Appendage Ligation During Coronary Artery Bypass Graft Surgery Allows Safe Avoidance of Anticoagulation Regardless of Postoperative Atrial Fibrillation

Abstract

Background New-onset postoperative atrial fibrillation (POAF) is the most common arrhythmia following cardiac surgery. POAF increases the risk of thromboembolism and stroke, as well as morbidity and mortality more generally. Despite evidence from the landmark PROTECT-AF and PREVAIL trials, left atrial appendage ligation (LAAL) is not routinely performed for thromboembolism prophylaxis in POAF, and anticoagulation remains the standard of care along with dual antiplatelet therapy. This study evaluated the efficacy of concomitant LAAL in eliminating the need for postoperative anticoagulation, regardless of POAF development, in patients undergoing coronary artery bypass grafting (CABG). Methods Between 2019 and 2021, 130 patients were selected to undergo concomitant LAAL while undergoing CABG surgery. Patients were then monitored for the incidence of new-onset POAF, and anticoagulation was strictly avoided for this indication. Demographic and outcome data were collected, with endpoints including transient ischemic attack (TIA) or stroke, death, and readmission within one year, as well as the length of hospital and intensive care unit (ICU) admissions. Results POAF occurred in 37 patients (28.5%), consistent with previous reports. However, none of the POAF patients experienced TIA or stroke during the one-year follow-up period, compared to 2 (2.15%) in the non-POAF group, a typical rate of postoperative stroke in such a patient population. No significant differences were observed between POAF and non-POAF cohorts in one-year stroke, all-cause mortality, readmission rates, or total hospital stay. Interestingly, the POAF cohort had a significantly longer mean ICU stay (4.24 vs 3.37 days, p = 0.0219), possibly due to the time required for arrhythmia control before discharge. The study population had a high mean CHA₂DS₂-VASc score (2.81), indicating an increased risk of thromboembolism, and a high mean HAS-BLED score, suggesting an elevated bleeding risk with anticoagulation. Conclusions LAAL appears to be an effective adjunct to CABG for thromboembolism prophylaxis in POAF. Formal anticoagulation was avoided in this study, with no significant differences in adverse events between POAF and non-POAF groups, suggesting that LAAL may be a suitable alternative to anticoagulation, especially in high-risk patients (e.g., those with elevated CHA₂DS₂-VASc or HAS-BLED scores). The safety and efficacy of this approach should be corroborated by larger randomized studies, such as the ongoing LeAAPS trial. LAAL during CABG may help reduce the risk of bleeding complications associated with anticoagulation while maintaining protection against thromboembolic events in patients who develop POAF.

Keywords: anticoagulation; coronary artery bypass grafting; left atrial appendage ligation; postoperative atrial fibrillation; stroke.

Figure 1. The AtriClip® delivery device and pre-loaded left atrial appendage clip.

The 35 mm model is shown here, featuring a malleable 25 cm shaft, end effector with 180 degrees total head articulation, and thumb lever deployment. Image used with permission of AtriCure, Inc., Mason, OH, USA.

Figure 2. Cohort distribution segregated by the development of postoperative atrial fibrillation (POAF).

Distribution of patients within the study who developed new-onset postoperative atrial fibrillation (n = 37), compared to the control cohort who remained in normal sinus rhythm postoperatively (n = 93).

Figure 3. Demographic variables and risk scores.

The POAF cohort was significantly older than the control cohort. Otherwise, groups were similar. Cohort differences in continuous variables were compared using t-tests, and categorical variables were compared using Fisher's exact test between POAF and non-POAF patients. POAF: Postoperative atrial fibrillation

Figure 4. Primary endpoints of stroke, death, or readmission within one year: groups had similar outcomes.

Primary endpoints: No significant differences were observed at one year between the two cohorts. Cohort differences in continuous variables were compared using t-tests, and categorical variables were compared using Fisher's exact test between POAF and non-POAF patients. N/A: Not applicable; POAF: postoperative atrial fibrillation

Figure 5. Postoperative length of stay and ICU stay stratified by POAF occurrence.

Secondary endpoints: There was a significantly longer length of ICU admission in the POAF cohort than in the Control cohort, the total length of hospital admission was not significantly different. Cohort differences in continuous variables were compared using t-tests, and categorical variables were compared using Fisher's exact test between POAF and non-POAF patients. LOS: Length of stay; ICU: intensive care unit; POAF: postoperative atrial fibrillation