RCT: Left Atrial Appendage Closure May Reduce Bleeding Without Increasing Stroke Risk After AF Ablation

Background: Catheter ablation is an effective treatment for symptomatic atrial fibrillation (AF), but patients at high risk for stroke require ongoing oral anticoagulation (OAC) due to the potential for asymptomatic AF recurrence. Left atrial appendage closure (LAAC) is a mechanical alternative to OAC, but its efficacy and safety post-AF ablation are not well established.

Objective: To compare the safety and efficacy of LAAC versus continued OAC in patients with AF undergoing catheter ablation.

Methods: In this international, randomized trial, 1,600 patients with AF and elevated CHA₂DS₂-VASc scores (≥2 in men, ≥3 in women) who underwent or were scheduled for catheter ablation were assigned to either LAAC (n=803) or OAC (n=797). The primary safety endpoint was non–procedure-related major bleeding or clinically relevant nonmajor bleeding through 36 months. The primary efficacy endpoint was a composite of death from any cause, stroke, or systemic embolism at 36 months. The secondary endpoint was major bleeding, including procedure-related bleeding.

Results: At 36 months, bleeding events occurred in 8.5% of the LAAC group versus 18.1% of the OAC group (P<0.001 for superiority). The primary efficacy endpoint occurred in 5.3% of the LAAC group and 5.8% of the OAC group (P<0.001 for noninferiority). Major bleeding, including procedure-related bleeding, occurred in 3.9% of the LAAC group and 5.0% of the OAC group (P<0.001 for noninferiority). Device-related complications occurred in 23 patients, and incomplete device closure was noted in up to 20% of patients.

Conclusions: Among patients undergoing AF ablation, LAAC reduced the risk of bleeding compared to OAC without increasing the risk of death, stroke, or systemic embolism over 36 months.

Implications for Practice: LAAC may be considered as an alternative to long-term OAC in patients undergoing AF ablation who are at moderate to high risk of stroke. However, clinicians should exercise caution due to potential device-related complications, such as incomplete closure and peri-device leaks, which may increase stroke risk. The decision to use LAAC should involve a thorough discussion with the patient about the benefits and risks.

Study Strengths and Limitations: Strengths include the randomized design and large sample size. Limitations involve the exclusion of procedure-related bleeding from the primary safety endpoint, potentially underestimating the true bleeding risk of LAAC. The inclusion of all-cause mortality in the primary efficacy endpoint may dilute the ability to detect differences in stroke risk. Additionally, missing data and a significant rate of incomplete device closure raise concerns about the generalizability and safety of LAAC.

Future Research: Further large-scale, randomized trials are needed to address these limitations, especially to assess stroke risk adequately and the impact of procedural complications. Studies should also evaluate long-term outcomes and the cost-effectiveness of LAAC compared to OAC in diverse patient populations.

References:

1. Wazni OM, Saliba WI, Nair DG, et al. Left Atrial Appendage Closure after Ablation for Atrial Fibrillation. New England Journal of Medicine. Published November 16, 2024. DOI: http://doi.org/10.1056/NEJMoa2408308
2. Mandrola J. Electrophysiology is on the brink of a possible disaster. November 19, 2024. Available at: https://johnmandrola.substack.com/p/electrophysiology-is-on-the-brink