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

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Research

Background:

• Bundle branch block (BBB) is a common electrocardiographic finding.
• The prognostic implications of BBB in patients with atrial fibrillation (AF) concerning heart failure (HF) are not fully understood.
• Identifying risk factors for HF events in AF patients is crucial for clinical management.

Purpose of the Study:

• To investigate the association between different patterns of BBB and the risk of heart failure (HF) events in patients diagnosed with atrial fibrillation (AF).
• To determine if complete left bundle branch block (CLBBB) or complete right bundle branch block (CRBBB) during AF rhythm predict future HF outcomes.

Main Methods:

• Analysis of baseline electrocardiography data from 2721 AF patients in the Fushimi AF Registry.
• Examination of associations between CLBBB/CRBBB and a composite HF endpoint (hospitalization for HF or cardiac death).
• Multivariable analysis to identify independent predictors of HF events, adjusting for other risk factors.

Main Results:

• CLBBB was present in 1.2% and CRBBB in 8.2% of the AF cohort.
• Patients with BBB were older and had more comorbidities, including pre-existing HF and chronic kidney disease.
• Both CLBBB and CRBBB were significantly associated with a higher incidence of HF events during follow-up (CLBBB: 10.2% vs. 3.5%; CRBBB: 6.5% vs. 3.5% per patient-year).
• CLBBB and CRBBB independently predicted the composite HF endpoint (aHR 1.83 and 1.46, respectively).

Conclusions:

• Both complete left bundle branch block (CLBBB) and complete right bundle branch block (CRBBB) occurring during atrial fibrillation (AF) rhythm are associated with an elevated risk of heart failure (HF) events.
• These findings underscore the clinical significance of recognizing BBB patterns in AF patients for risk stratification and management of HF.