BackgroundPatients treated with left atrial appendage occlusion (LAAO) are at high bleeding risk. Intensive antithrombotic treatment is recommended after the procedure to prevent device-related thrombosis. ObjectivesThis study sought to evaluate the incidence, consequences, and predictors of early nonprocedural bleeding after LAAO. MethodsThis was a multicenter study including 1,649 patients undergoing LAAO in 9 centers. Early nonprocedural bleeding was defined as bleeding unrelated to the procedure occurring within 3 months after device implantation. The severity of bleeding was defined by the Valve Academic Research Consortium-2 classification. A sensitivity analysis was performed at 45 days. ResultsA total of 121 (7.3%) patients experienced early nonprocedural bleeding events, and 69 (57.0%) were classified as major bleeding (4.2% of patients). Independent predictors of early nonprocedural bleeding were dual antiplatelet therapy (DAPT) at discharge (adjusted HR [aHR]: 1.61; 95% CI: 1.12-2.33; P = 0.01), prior gastrointestinal bleeding (aHR: 2.15; 95% CI: 1.38-3.35; P < 0.001), and multiple locations of prior bleeding (aHR: 2.33; 95% CI: 1.34-4.05; P < 0.001). DAPT at discharge was predictive of both all and major nonprocedural bleeding at 3 months and 45 days. After a median follow-up of 2.3 years (Q1-Q3: 1.1-4.1 years), early nonprocedural bleeding was independently associated with an increased risk of all-cause death (aHR: 1.53; 95% CI: 1.15-2.06; P < 0.001). This heightened mortality risk was similar at 45 days. ConclusionsEarly nonprocedural bleeding after LAAO occurred in ∼7% of patients within 3 months, with more than one-half being classified as major bleeding. Regardless of severity, early nonprocedural bleeding was associated with increased mortality. DAPT at discharge determined an increased risk of early nonprocedural bleeding after LAAO. These results emphasize the importance of bleeding risk for determining antithrombotic strategies after LAAO.