Exclusion versus preservation of the left atrial appendage in rheumatic mitral valve surgery

Clinical impacts of concomitant left atrial appendage occlusion during mitral valve surgery in patients with mitral regurgitation

Surgical occlusion of the left atrial appendage (LAA) during cardiac surgery in patients with atrial fibrillation (AF) is known to reduce thromboembolism. However, data on the clinical significance of LAA occlusion (LAAO) in patients with mitral regurgitation (MR) are lacking. A total of 237 AF patients with chronic severe MR who underwent mitral valve (MV) surgery were retrospectively analyzed. Patients were divided into two groups according to concomitant LAAO or LAA preservation. The primary outcome was a composite of all-cause death and thromboembolic events (ischemic stroke or systemic embolism). The LAA was surgically occluded in 98 (41%) patients and preserved in 139 (59%) patients. During the follow-up period (median, 37 months), 29 primary outcomes occurred. In the Kaplan-Meyer analysis, the LAA preservation group showed a greater cumulative incidence of the primary outcome (P = 0.002) and thromboembolic events (P = 0.003) than the LAAO group. In the univariate Cox regression analysis, coronary artery disease, CHA2DS2-VASc score, a cauliflower-shaped LAA, Maze, and no LAAO were significantly associated with the primary outcome. In the multivariate Cox regression analysis, concomitant LAAO was significantly linked to the primary outcome (hazard ratio [HR]: 0.30, 95% confidence interval [CI]: 0.10-0.91, P = 0.033) and thromboembolic events (HR: 0.19, 95% CI: 0.04-0.87, P = 0.032). These benefits from LAAO were consistent, even after propensity score-matched analysis. For patients undergoing surgery for chronic MR who also have AF, concomitant surgical LAAO is associated with favorable clinical outcome.

A Comparative Study of Thoracoscopic Left Atrial Appendage Clipping vs Stapled Resection

BACKGROUND

The left atrial appendage (LAA) is the predominant site of thrombus formation in atrial fibrillation (AF), which is associated with ischemic stroke. This study comparatively evaluated the complete LAA closure rates between LAA clipping and stapled resections.

METHODS

The study included 333 patients who underwent thoracoscopic operation with both preoperative and postoperative computed tomographic scans. Propensity score matching (4:1 ratio) was applied, matching 90 LAA clipping patients with 206 stapled resection patients. The primary end point was complete LAA closure, defined as a residual LAA depth of <1 cm on computed tomographic images obtained 1 year postoperatively.

RESULTS

No 30-day death was observed. Complete LAA closure was achieved in 85.9% (286 of 333) of patients. After propensity score matching, the clipping group demonstrated a significantly higher complete LAA closure rate than the stapled resection group (95.6% vs 83.0%, P = .003). The residual LAA stump depth was also shorter in the clipping group compared with the stapled resection group (2.9 vs 5.3 mm, P = .001). Two patients with a residual LAA stump exhibited an association with ischemic stroke during follow-up.

CONCLUSIONS

The clipping group demonstrated a higher rate of complete LAA closure compared with the stapled resection group. Close monitoring of patients with residual LAA stumps is essential. Further research with larger cohorts is needed to elucidate impact of the residual LAA stump on thromboembolic events.

Left atrial appendage preservation versus closure during surgical ablation of atrial fibrillation

OBJECTIVE

There is limited evidence regarding the effectiveness of left atrial appendage (LAA) closure during surgical ablation of atrial fibrillation (AF) in yielding superior clinical outcomes. This study aimed to evaluate the association of LAA closure versus preservation with the risk of adverse clinical outcomes among patients undergoing surgical ablation during cardiac surgery.

METHODS

We evaluated 1640 patients (aged 58.8±11.5 years, 898 women) undergoing surgical ablation during cardiac surgery (including mitral valve (MV), n=1378; non-MV, n=262) between 2001 and 2018. Of these, 804 had LAA preserved, and the remaining 836 underwent LAA closure. Comparative risks of stroke and mortality between the two groups were evaluated after adjustments with inverse-probability-of-treatment weighting (IPTW). Longitudinal echocardiographic data (n=9674, 5.9/patient) on transmitral A-wave and E/A-wave ratio were analysed by random coefficient models.

RESULTS

Adjustment with IPTW yielded patient cohorts well-balanced for baseline profiles. During a median follow-up of 43.5 months (IQR 19.0-87.3 months), stroke and death occurred in 87 and 249 patients, respectively. The adjusted risk of stroke (HR 0.85; 95% CI 0.52-1.39) and mortality (HR 0.80; 95% CI 0.61 to 1.05) did not differ significantly between the two groups. Echocardiographic data demonstrated higher transmitral A-wave velocity (group-year interaction, p=0.066) and lower E/A-wave ratio (group-year interaction, p=0.045) in the preservation group than in the closure group.

CONCLUSIONS

LAA preservation during surgical AF ablation was not associated with an increased risk of stroke or mortality. Postoperative LA transport functions were more favourable with LAA preservation than with LAA closure.