Pericardial Effusion Requiring Intervention in Patients Undergoing Percutaneous Left Atrial Appendage Occlusion: Prevalence, Predictors and Associated In-hospital Adverse Events from 17,700 Procedures in the United States.

Abstract: Background Left atrial appendage occlusion has shown promise in mitigating risk of stroke in selected patients with atrial fibrillation. Objective To determine the real-world prevalence and in-hospital outcomes in left atrial appendage occlusion (Watchman) recipients complicated by pericardial effusion requiring percutaneous drainage or open cardiac surgery based intervention. Methods Data were derived from National Inpatient Sample database from January 2015 to December 2017. The primary outcomes assessed were the prevalence of pericardial effusion requiring intervention and in-hospital outcomes including mortality, other major complications, hospital stay >1 day, and hospitalization costs. Predictors of pericardial effusion requiring intervention were also analyzed. Results Pericardial effusion requiring intervention occurred in 220 (1.24%) total patients. After multivariable adjustment, pericardial effusion requiring intervention was associated with in-hospital mortality (adjusted odds ratio [aOR] 511.6, 95% CI 122-2145.3), other Watchman-related major complications (aOR 1.35, 95% CI 0.83-2.19), length of stay > 1 day (aOR 17.64, 95% CI 12.56-24.77) and hospitalization cost above the median $24,327$ (aOR 3.58, 95% CI 2.61-4.91). Independent patient predictors of pericardial effusion requiring intervention from the procedure included advanced age (aOR 1.029 per 1-year increase, 95% CI 1.009-1.05), a higher CHA₂DS₂-VASc score (aOR 1.221 per 1-point increase, 95% CI 1.083-1.377) and obesity (aOR 2.033, 95% CI 1.464-2.823). Conclusion In a large, contemporary real-world cohort of Watchman recipients in United States practice, the prevalence of pericardial effusion requiring intervention was 1.24%. Pericardial effusion requiring intervention was associated with several adverse events including increased in-hospital mortality, other major complications, prolonged hospital stay, and hospitalization costs.