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LAA Morphology and Thromboembolic Risk After Ablation for AF | Journal Scan
Study Questions:
Is the anatomy and/or the morphology of the left atrial appendage (LAA) associated with thromboembolism (TE) in patients with atrial fibrillation (AF)?
Methods:
Among 2,069 patients who underwent catheter ablation of AF, 31 (1.5%) suffered a TE even during follow-up. Sixteen of these patients experienced TE within 30 days of the procedure, and were excluded. The clinical and anatomic characteristics of the remaining 15 patients were compared against a control group of patients (n = 115, matched for CHA2DS2-VASc) who underwent catheter ablation, but did not experience TE. Patients were treated with oral anticoagulation after the procedure based on the CHADS2 or CHA2DS2-VASc score. Cardiac computed tomography was performed prior to the ablation procedure.
Results:
The study patients (n = 130, mean age = 64 years, paroxysmal AF in approximately 50%) underwent a mean of 1.4 ablation procedures and were followed up for a median of 24 months. AF was eliminated in two-thirds of the patients. The mean international normalized ratio at the time of the TE event was 2.4. Patients who experienced TE were more likely to experience AF recurrence than controls (73% vs. 28%; p = 0.001). Multivariate analysis revealed that patients with TE were more likely to experience recurrent AF (hazard ratio [HR], 6.2; 95% confidence interval [CI], 2.0-20; p = 0.002) and to have an LAA takeoff above the level of the left superior pulmonary vein (HR, 4.9; 95% CI, 1.4-17; p = 0.014). The morphological characteristics of the LAA were not associated with TE.
Conclusions:
The authors concluded that TE after catheter ablation of AF is associated with arrhythmia recurrence and a higher LAA takeoff.
Perspective:
It is not clear whether elimination of AF with catheter ablation is associated with a reduction of TE risk. It is possible that AF may merely be a marker versus a direct cause of TE. The current recommendation is to continue oral anticoagulation in high-risk patients even in the absence of AF recurrence following catheter ablation. The results of the current study suggest that AF recurrence may be associated with TE; however, the results of this observational study with a very low event rate (0.7%) cannot be considered definitive. Anatomic variation of the LAA origin, as it relates to TE, also needs to be evaluated further.
Keywords: Anatomic Variation, Anticoagulants, Arrhythmias, Cardiac, Atrial Appendage, Atrial Fibrillation, Catheter Ablation, Control Groups, Follow-Up Studies, Incidence, International Normalized Ratio, Multivariate Analysis, Pulmonary Veins, Recurrence, Thromboembolism, Tomography
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