Impact of Operator Experience on Left Atrial Appendage Occlusion Outcomes

Background: The relationship between long-term outcomes and operator experience for left atrial appendage occlusion (LAAO) is still unknown. Objectives: This study sought to explore the association between operator LAAO experience and one-year clinical outcomes. Methods: The RECORD study (Registry to Evaluate Chinese Real-World Clinical Outcomes in Patients With AF Using the WATCHMAN Left Atrial Appendage Closure Technology; NCT03917563) was a multicenter, prospective registry that included patients with the WATCHMAN LAAO device (Boston Scientific) in China from April 1, 2019, to October 31, 2020. The current analyses included patients with solely LAAO from the registry; those who had concomitant LAAO and ablation/other procedures were excluded. The primary outcome was a composite endpoint of death, stroke, systemic embolism, and Bleeding Academic Research Consortium (BARC)-defined type 3 or 5 bleeding at 1 year. Results: A total of 1,547 LAAO patients and 111 operators were included. The mean CHA₂DS₂-VASc and HAS-BLED scores of patients were 4.0 ± 1.8 and 2.5 ± 1.1, respectively. The mean age of operators was 47.0 ± 7.2 years, 15 (13.5%) were female, and 52 (46.8%) were electrophysiologists. Utilizing maximally selected log-rank statistics, the thresholds to categorize an experienced operator were performing ≥32 LAAOs annually or ≥134 LAAOs in total. Performing ≥32 LAAOs annually is the better criterion than ≥134 LAAOs in total (absolute net reclassification index: 25.79%; P < 0.001). Compared with the ≥32 LAAO annually group, the <32 group was associated with a 1.8-fold (HR_adjusted: 1.79; 95% CI: 1.16-2.78; P = 0.009) increase in the risk of the primary endpoint, and such risk in the <32 group can be reduced by ∼12% after performing each additional 5 cases (HR_adjusted per 5 cases: 0.88; 95% CI: 0.78-0.99; P = 0.033). Conclusions: Performing ≥32 LAAOs annually could be a threshold to categorize an experienced operator. Before reaching this threshold, the risk of death, stroke, systemic embolism, and BARC-defined type 3 or 5 bleeding decreased by 12% after every 5 cases performed.