Characterization of pleural effusion after left atrial appendage exclusion using the lariat procedure

Background The Lariat procedure is increasingly used for the exclusion of the left atrial appendage (LAA) in atrial fibrillation (AF) patients. There are anecdotal reports of pleural effusions after the Lariat procedure. However, the incidence, demographics, and pathophysiology of these effusions are largely unknown. Objective Characterization of pleural effusions in patients who underwent LAA exclusion using the Lariat procedure. Methods We report the incidence, demographics, and clinical and laboratory characteristics of patients from a multicenter prospective registry who underwent the Lariat procedure and subsequently developed pleural effusions. Results A total of 10 out of 310 (3.2%) patients developed significant pleural effusions after the Lariat procedure. The mean age of these patients was 67 ± 9, ranging from 52 to 78 years and included 5 (50%) males. Nine patients had persistent AF with median CHADS₂ score of 2.7 ± 1.2. The LAA was successfully ligated in all these patients. Post-Lariat procedure, 6 patients developed bilateral and 4 patients developed left-sided pleural effusions. Pleural tap revealed transudative in 2 and exudative in 6 patients. The remaining 2 patients responded to active diuresis and behaved clinically like transudative effusions. There is a statistically significant difference between the onset of pleural effusion after the Lariat procedure between tPLE versus ePLE groups (14 ± 1.2 vs. 6 ± 6, P = 0.05). Conclusion Incidence of clinically significant pleural effusion is uncommon after the Lariat procedure and can be either exudative or transudative in nature depending on the underlying mechanisms. More prospective studies are needed to study the pathophysiologic basis of development of pleural effusions after the Lariat procedure.