Immediate vs delayed left bundle branch block after transcatheter aortic valve replacement: incidence and risk factors for permanent pacemaker implantation

Characteristics of patients with delayed compared to immediate new onset left bundle branch block (LBBB) after transcatheter aortic valve replacement (TAVR) are poorly defined. To describe the incidence and features of patients with delayed post TAVR LBBB as well as risk factors for permanent pacemaker implantation (PPI). 1469 consecutive TAVR patients were screened for the occurrence of new onset LBBB. ECG was performed within 1 week before the procedure, immediately post procedure, and daily thereafter until discharge. According to the immediate post TAVR ECG, patients were divided into 2 groups, immediate and delayed new onset LBBB. Both groups were followed for the occurrence of PPI and mortality. Among patients who underwent TAVR, 296 (20.1%) developed new-onset LBBB, of whom, 282 were included the present study. LBBB occurred immediately after the procedure in 249 patients (88.3%) and was delayed in 33 patients (11.7%). Rates of both early PPI within 2 weeks as well as long term PPI and mortality were comparable between patients with immediate vs. delayed onset LBBB. In patients with immediate LBBB, QRS width correlated with a need for PPI, while in patients with delayed LBBB, PR prolongation of ≥ 115 ms differentiated between patients with and without PPI. The appearance of new onset post TAVR LBBB may be delayed in ~ 12% of patients. These patients exhibit similar rates of PPI need and mortality; however different ECG parameters signify high risk for PPI need among these patients.