RBBB in TAVR Recipients
What is the influence of baseline right bundle branch block (RBBB) on all-cause and cardiovascular mortality as well as sudden cardiac death (SCD) among patients undergoing transcatheter aortic valve replacement (TAVR)?
The investigators evaluated a total of 3,527 patients (mean age 82 ± 8 years, 50.1% men) according to the presence of RBBB on baseline electrocardiography (ECG). Intraventricular conduction abnormalities were classified according to the American Heart Association, American College of Cardiology Foundation, and Heart Rhythm Society recommendations for standardization and interpretation of the ECG. TAVR complications and causes of death were defined according to Valve Academic Research Consortium 2 definitions. Survival rates were summarized using Kaplan-Meier estimates, and log-rank tests were used to compare groups.
RBBB was present on baseline ECG in 362 patients (10.3%) and associated with higher 30-day rates of permanent pacemaker implantation (PPI) (40.1% vs. 13.5%; p < 0.001) and death (10.2% vs. 6.9%; p = 0.024). At a mean follow-up of 20 ± 18 months, pre-existing RBBB was independently associated with all-cause mortality (hazard ratio [HR], 1.31; 95% confidence interval [CI], 1.06-1.63; p = 0.014) and cardiovascular mortality (HR, 1.45; 95% CI, 1.11-1.89; p = 0.006), but not with SCD (HR, 0.71; 95% CI, 0.22-2.32; p = 0.57). Patients with pre-existing RBBB and without PPI at discharge from the index hospitalization had the highest 2-year risk for cardiovascular death (27.8%; 95% CI, 20.9%-36.1%; log-rank p = 0.007). In a subanalysis of 1,245 patients without PPI at discharge from the index hospitalization and with complete follow-up regarding the need for PPI, pre-existing RBBB was independently associated with the composite of SCD and PPI (HR, 2.68; 95% CI, 1.16-6.17; p = 0.023).
The authors concluded that pre-existing RBBB was found in 10% of TAVR recipients and was associated with poorer clinical outcomes.
This multicenter registry study reports a prevalence of RBBB of 10.3% among TAVR candidates, the presence of which was associated with higher 30-day permanent pacemaker implantation and mortality rates. Furthermore, RBBB was an independent predictor of midterm all-cause and cardiovascular mortality. Additional studies are indicated to evaluate strategies directed at optimal management of those with RBBB undergoing TAVR, and the early detection of patients at risk for late development of high-degree atrioventricular block. At this time, prolonged monitoring or prophylactic pacemaker may be considered in selected TAVR cases with pre-existing RBBB.
Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Geriatric Cardiology, Invasive Cardiovascular Angiography and Intervention, Prevention, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Cardiac Surgery and Arrhythmias
Keywords: Arrhythmias, Cardiac, Bundle-Branch Block, Death, Sudden, Cardiac, Electrocardiography, Geriatrics, Pacemaker, Artificial, Primary Prevention, Survival Rate, Transcatheter Aortic Valve Replacement
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