Prognostic Implications of Right Bundle Branch Block in the General Population: A Systematic Review and Meta-Analysis.

Background: Because the prognostic significance of right bundle branch block (RBBB) in the general population remains uncertain, we conducted a systematic review and meta-analysis to evaluate the association of RBBB with clinical outcomes in general population cohorts. Methods and Results: We systematically searched major databases for population-based cohort studies reporting associations between RBBB and clinical outcomes. Hazard ratios (HRs) were pooled using a random-effects model. A total of 14 studies were included in the systematic review, of which 5 (all-cause mortality), 4 (cardiovascular mortality), and 2 studies (pacemaker implantation) were included in the meta-analyses. RBBB was associated with a modest increase in all-cause mortality (HR 1.08; 95% confidence interval (CI), 1.01-1.16), although the association was attenuated in the sensitivity analysis excluding the largest-weight study (HR 1.04; 95% CI, 0.87-1.24). No significant association was observed between RBBB and cardiovascular mortality (HR 1.20; 95% CI, 0.90-1.59). RBBB was associated with an increased risk of pacemaker implantation (HR 3.03; 95% CI, 1.70-5.38), although the number of studies was limited. Conclusions: RBBB was associated with a modest and partially unstable increase in all-cause mortality, but no significant association with cardiovascular mortality was observed. RBBB may reflect underlying risk profiles or progressive conduction system abnormalities, rather than serving as a strong independent predictor of mortality.