Articles
Science Matters: Research Summary of the Left Atrial Appendage Closure After Ablation for Atrial Fibrillation
About the Author: Michael Katsnelson MD, PhD, FACC is currently a research fellow at Washington University in St. Louis School of Medicine. He specializes in advanced heart failure/transplant cardiology, and his main research interest lies in studying the role of the innate immune system in the progression of ischemic cardiomyopathy. In this article he provides a summary of a recent JACC publication.
Background: Catheter ablation is an effective method for achieving rhythm control and managing symptomatic atrial arrhythmias. Current guidelines recommend that even following a successful ablation procedure, patients with atrial fibrillation at moderate or high risk of stroke remain on oral anticoagulation due to the risk of recurrent atrial fibrillation. However, long term systemic anticoagulation carries the risk of serious bleeding events as well as high financial cost for patients. Catheter based closure of the left atrial appendage (LAA) provides an alternative strategy for stroke prevention in patients at elevated risk for cerebrovascular events following ablation. It is currently unclear whether the benefit of stroke prevention with a LAA occlusion device following an ablation is outweighed by the risk of procedure-related complications or device thrombosis. The authors of the OPTION trial sought to answer the question whether LAA closure could decrease the incidence of bleeding when compared to oral anticoagulation while maintaining a low risk of stroke and other embolic events in a patient population that is at moderate-high risk for stroke following catheter ablation.
Materials and Methods: OPTION was a multicenter randomized clinical trial which included patients who had undergone ablation for atrial fibrillation 90-180 days prior to randomization or if the procedure was scheduled to be performed within 10 days of randomization. Patients were included if they had a CHADS2-VaSC score of at least 2 for men and 3 for women. Patients were randomized in a 1:1 manner to either LAA closure or to oral anticoagulation. Patients were followed up to 36 months following randomization. The primary safety endpoint was a combination of non-procedure related major bleeding or clinically relevant nonmajor bleeding (requiring medical intervention). The primary efficacy endpoint was a combination of death from any cause, stroke, or systemic embolism. The trial included 803 patients in the LAA closure device group and 797 patients in the oral anticoagulation group.
Results: The authors found that LAA closure was superior to oral anticoagulation in reducing the risk of non-procedure related major bleeding and nonmajor bleeding requiring clinical intervention. Bleeding events occurred in 65 patients (8.5%) in the LAA occlusion group and 137 patients (18.1%) in the systemic anticoagulation group. The primary efficacy outcome including death from any cause, stroke or systemic embolism occurred in 41 patients in the LAA occlusion group and 44 patients in the systemic anticoagulation group, meeting the criterion for noninferiority. The secondary endpoint, which incorporated all ISHT major bleeding events including procedure related bleeding, met the criterion for noninferiority but not superiority.
Discussion: The results of the trial suggest that in a patient population at moderate-high risk of stroke following atrial fibrillation ablation, device closure of the LAA was associated with a lower risk of non-procedure related bleeding and had a noninferior efficacy profile with respect to prevention of all cause mortality, stroke and systemic embolism when compared with oral anticoagulation. However, the design of the trial was biased towards LAA closure because the safety endpoint specifically excluded procedural bleeding. When total ISHT major bleeding events (which included procedure-related bleeding) were analyzed, device closure of the LAA was found to be noninferior but not superior to oral anticoagulation. The overall incidence of ischemic stroke in both the LAA closure and systemic anticoagulation arm were low (1.2% and 1.3% respectively). By enrolling a population which is at a relatively low risk of events, the authors made it more likely that noninferiority between the two arms of the trial would be established. Patients with an LVEF<30%, who are at increased risk of atrial fibrillation and other arrhythmias, were specifically excluded from the trial. The results of the trial will assist with informing patients about the risks and benefits of LAA closure vs remaining on oral anticoagulation. The findings of this study and current clinical practice guidelines indicate that both options have an acceptable risk profile and that the decision on which course to take should be left to an informed discussion between the healthcare provider and the patient.
Link to article: https://www.nejm.org/doi/full/10.1056/NEJMoa2408308
