Relation of intraventricular conduction delay to risk of new-onset heart failure and structural heart disease in the general population.

BACKGROUND

Intraventricular conduction delays (IVCDs) are hallmarks of heart failure (HF) and structural heart disease (SHD) but their prognostic value for HF and SHD is unclear.

METHODS

Relation of eight IVCDs and the incidence of first-time HF or SHD was studied in a nationally representative random sample of 6080 Finnish subjects aged ≥ 30 years (mean age 52.1, SD 14.5 years) who participated in the health examination including 12-lead ECG.

RESULTS

During 16.5 years' follow up, half of the subjects with left bundle branch block (LBBB) and one third of the subjects with non-specific IVCD developed HF. After controlling for known clinical risk factors the hazard ratio (HR) for new-onset HF for LBBB was 3.29 (95% confidence interval 1.93-5.63, P < 0.001) and 3.53 for non-specific IVCD (1.65-7.55, P = 0.001). In corresponding analysis, LBBB predicted SHD with HR 2.60 (1.21-5.62, P = 0.015). Excluding subjects with history of heart disease, including coronary heart disease, did not have impact on results. Right bundle branch block and other IVCDs displayed no relation to endpoints.

CONCLUSION

LBBB and non-specific IVCD were associated with more than three-fold risk of new-onset HF. Furthermore, LBBB was associated with novel SHD. Their presence should alert clinician even in subjects free from any known heart disease.