Wider means worsen? Influence of QRS duration of left bundle branch block on prognosis of patients after transcatheter aortic valve replacement

The impact of QRS duration on postoperative LBBB and its implications for the prognosis of patients undergoing transcatheter aortic valve replacement (TAVR) remained uncertain. This study enrolled consecutive patients who underwent TAVR with self-expanding prostheses in our department from September 2017 to January 2021. Based on the pro-discharge electrocardiogram, patients were categorized into 3 groups: Group-NCD (no conduction disorder), Group-sLBBB (LBBB, QRS ≥ 150 ms), and Group-mLBBB (LBBB, QRS < 150 ms). Basic characteristics were compared among these groups. Furthermore, differences in left ventricular ejection fraction (LVEF), survival rates, and clinical events were assessed at baseline, discharge, and during a one-year follow-up period. A total of 56 patients were included in the study. With 17 (30.36%) experiencing new-onset LBBB, of which eleven had a QRS duration ≥ 150 ms. Group-sLBBB exhibited a longer left ventricular end-diastolic diameter at baseline. At a one-year follow-up, the LVEF improved in Group-NCD, but not in the LBBB groups. At discharge, the LVEF of Group-sLBBB was lower than that of Group-NCD (52.82 ± 11.48 vs 61.48 ± 10.10, P = .036) and remained lower at follow-up (57.10 ± 9.49 vs 65.85 ± 7.58, P = .011). Additionally, the LVEF of Group-sLBBB was lower than that of Group-mLBBB at discharge (52.82 ± 11.48 vs 63.17 ± 4.31, P = .018). However, there were no significant differences in survival and event-free survival among the groups. The study revealed a notable occurrence of new-onset LBBB following TAVR, with a majority of cases exhibiting a significantly prolonged QRS duration (≥150 ms). While the presence of LBBB did not impact one-year survival or clinical events, it did exert adverse effects on LVEF. Notably, when QRS duration was markedly prolonged, these adverse effects manifested earlier and were more pronounced.