Prognostic Impact of New-Onset Left Bundle Branch Block After TAVR According to Preoperative Diastolic Dysfunction Severity

Background and Aims The prognostic impact of new-onset left bundle branch block (LBBB) after transcatheter aortic valve replacement (TAVR) remains unclear. We aimed to investigate whether its impact differs according to preoperative diastolic dysfunction (DD) severity. Methods Among 2006 patients who underwent TAVR between January 2016 and December 2021 at eight Japanese centers, 853 were classified as having grade 1 to 3 DD according to the American Society of Echocardiography guidelines. Patients were stratified into grade 1 DD (n = 348, 40.8%) and grade 2–3 DD cohorts (n = 505, 59.2%). The primary endpoint was 3-year all-cause death or rehospitalization for heart failure or arrhythmia. Results Follow-up completeness at 3 years was 78.8% (672/853). Median age was 84 years (interquartile range, 81–87), and 511 patients (59.9%) were female. New-onset LBBB was observed in 146 patients (17.1%) and was associated with the primary endpoint (adjusted hazard ratio [aHR], 1.54; 95% confidence interval [CI], 1.10–2.17; P = 0.012). In the grade 2–3 DD cohort, new-onset LBBB was associated with the primary endpoint (aHR, 1.99; 95% CI, 1.35–2.94; P = 0.001), whereas no association was observed in the grade 1 DD cohort (aHR, 0.87; 95% confidence interval [CI], 0.39–1.96; P = 0.74). The association differed significantly by DD grade (P for interaction = 0.028). Conclusions New-onset LBBB was associated with worse outcomes after TAVR, especially in grade 2–3 DD. DD grading may help identify patients more susceptible to adverse impact of new-onset LBBB.