Abstract Body (Do not enter title and authors here): Background: The growing epidemiologic burden of heart failure (HF) poses a significant public health challenge. The development of conduction abnormalities influences HF outcomes, with left bundle branch block (LBBB) established as an independent mortality predictor. However, the impact of right bundle branch block (RBBB) on HF mortality is still controversial. The aim of this study is to compare survival in HF patients with and without RBBB.
Methods: A comprehensive search was conducted on PubMed, Scopus, Web of Science, and Cochrane Library from inception to 12 October 2024. Raw data coordinates were extracted from Kaplan–Meier curves and merged into one dataset to reconstruct individual patient data. Hazard ratios (HR) with 95% confidence intervals (CI) were estimated using the Cox regression model. Dichotomous outcomes were pooled as risk ratios (RR) with 95% confidence interval (CI) using a random-effects model.
Results: 13 studies incorporating 25714 HF patients were included in our analysis. Patients with RBBB had a significantly lower median survival of 41.0 months (95% CI: 39.0 – 44.8) compared to 51.2 months (95% CI: 49.2 – 52.8) in patients without RBBB. Survival at 1,3, and 5 years in RBBB patients was 74.2%, 54.0%, and 39.4%, respectively, compared to 77.2%, 58.1%, and 45.4% in patients without RBBB. The HR for mortality was 0.87 (95% CI: 0.83 – 0.91, p < 0.001), indicating a 13% lower risk of death in patients without RBBB compared to those with RBBB. There was no significant difference in cardiovascular mortality between groups (RR: 1.34; 95% CI: 0.88 – 2.05; p = 0.17).
Conclusion: RBBB was associated with an increased risk of mortality in HF patients. These findings support the use of RBBB as a potential marker for risk stratification in HF. Further research with stricter inclusion criteria is warranted to better understand how the observed association is influenced by preserved versus reduced ejection fraction.