Baseline Demographics and Clinical Characteristics of Patients Undergoing Implantation of Left Atrial Appendage Occlusion Device

Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. One of its most devastating complications is the development of thromboembolism, leading to fatal or disabling stroke. Besides oral anticoagulation, Percutaneous left atrial appendage occlusion (LAAO) is an alternative option, which should be considered in patients with non-valvular AF with high stroke risk and contraindications to OAC.

Objectives: Our study aims to describe the baseline and clinical characteristics of a real-world cohort consisting of patients undergoing that procedure.

Methods: The cohort consisted of 209 consecutive patients who underwent LAAO at Sheba medical center. We prospectively evaluated periprocedural clinical, laboratory, and imaging data. All patients were followed by scheduled in-clinic visits. Outcome data were collected from medical recorders and the national mortality registry.

Results: The mean age in our cohort was 75.5(±8.1) years. 64(31%) were female. Median CHADS₂ and CHA₂DS₂-Vasc scores were 3 [2- 4] and 5 [4- 6], respectively. Paroxysmal AF was present in fifty-two percent of the cohort, while one-third had permanent AF. Based on echocardiography and computed tomography analysis, "chicken wing" morphology was present in nearly half of the patients. Previous hemorrhagic stroke (30%) and previous GI bleeding (40%) were among the leading etiologies that led to LAAO implantation. Malignant LAA and LAA thrombus formation despite adequate OAC accounted for 3.8 and 1.4 percent of the etiologies in the entire cohort. Periprocedural major complications leading to mortality occurred in three patients(1.5%). At discharge, nearly 70% of patients were put on dual antiplatelet therapy, while 20% were put on a single antiplatelet agent, and 8% were discharged with anticoagulant therapy. During one year of clinical follow-up, only five patients(2.3%) sustained a systemic thromboembolic event (STE) , and a total of twenty-three patients (11%) have died.

Conclusions: In this high-risk cohort, LAAO implantation was performed with a low rate of procedural complications. Rates of STE were lower than expected, yet all-cause mortality remained common.