Left Atrial Appendage Remodeling After Lariat Left Atrial Appendage Ligation.

BACKGROUND Left atrial appendage (LAA) ligation with the Lariat device is being used for stroke prevention in atrial fibrillation. Residual leaks into the LAA are commonly reported after the procedure. Little is known about the anatomic LAA remodeling after Lariat ligation. METHODS AND RESULTS In an exploratory study, we evaluated LAA 3-dimensional geometry via computed tomographic scan in 31 consecutive patients before Lariat closure and after a minimum of 30 days post procedure. Thirteen patients were classified as unfavorable cases based on anatomic criteria. Our population had an average age of 70±12 years, a mean CHADS2 (congestive heart failure, hypertension, age>75, diabetes mellitus, history of stroke) score of 3.2±1.2, a mean CHADS2VASC (CHADS2 in addition to female sex, ages 65-75, as well as double impact of age >75, vascular disease) of 4.2±1.5, and a mean HASBLED (hypertension, abnormal renal/liver function, stroke, bleeding predisposition/history, labile international normalized ratio, elderly, drugs/alcohol) bleeding score of 4.0±1.1. Successful suture deployment was achieved in all cases, but 3 patients had intraprocedural residual flow into the LAA (leak). On follow-up, 10 patients (32%) had recanalized residual LAA cavities, which were morphologically similar to the original LAA, albeit significantly smaller in volume (22.5±13.3% of the original volume). Recanalization was not associated with age, sex, comorbid conditions, stroke or bleeding risk scores, follow-up interval, baseline LAA volume, or morphology. Unfavorable cases had anatomic outcomes comparable with those of the anatomically favorable population. No patients have exhibited thromboembolism after 842±338 days post ligation. CONCLUSIONS Incomplete LAA ligation after Lariat is common. However, the remodeled LAA cavity is dramatically reduced. Diminished cavity size and tightening of the LAA orifice may play a role in the reduction of thrombus formation.