Bundle branch block patterns during atrial fibrillation rhythm for heart failure events

Aims

The clinical significance of bundle branch block (BBB) during atrial fibrillation (AF) rhythm in relation to heart failure (HF) events remains to be elucidated. This study aimed to explore the associations between BBB patterns and HF in AF patients.

Methods and results

We enrolled 2721 AF patients whose baseline electrocardiography during AF rhythm was available from a community-based prospective survey, the Fushimi AF Registry. Associations between complete left or right BBB (CLBBB/CRBBB) and the composite HF endpoint (a composite of hospitalization due to HF or cardiac death) were examined. CLBBB and CRBBB were observed in 31 patients (1.2%) and 218 patients (8.2%), respectively. Patients with BBB were older, and had a higher prevalence of chronic kidney disease, pre-existing HF, and lower left ventricular function than those without BBB. During a median follow-up period of 6.0 (2.2–9.0) years, the incidence of the primary composite HF endpoint was significantly higher in patients with CLBBB and CRBBB than those without BBB (CLBBB: 10.2% versus 3.5% per patient-year, log-rank P < 0.001; CRBBB: 6.5% versus 3.5% per patient-year, log-rank P < 0.001). In multivariable analysis, both CLBBB and CRBBB were independent predictors of the primary composite HF endpoint (adjusted hazard ratio 1.83 and 1.46, respectively).

Conclusions

CRBBB as well as CLBBB during AF rhythm were associated with higher risk of HF events in AF patients.