Aims: To evaluate the long-term mortality rate and to determine independent mortality risk factors in patients with bifascicular block (BFB). Patients with BFB are known to have a higher mortality risk than the general population, not only related to progression to atrio-ventricular block but also due to the presence of malignant ventricular arrhythmias. Previous observational and epidemiological studies including a high proportion of patients with structural heart disease have shown an important cardiac mortality rate and may not reflect the real outcome of patients with BFB.
Methods and results: From March 1998 until December 2006, we prospectively studied 259 consecutive BFB patients, 213 (82%) of whom presenting with syncope/pre-syncope, undergoing electrophysiological study. After a median follow-up of 4.5 years (P25:2.16-P75:6.41), 53 patients (20.1%) died, 19 (7%) of whom due to cardiac aetiology. Independent total mortality predictors were age [hazard ratio (HR) 1.04, 95% confidence interval (CI) 1.01-1.09], NYHA class>or=II (HR 2.17, 95% CI 1.05-4.5), atrial fibrillation (HR 2.96, 95% CI 1.1-7.92), and renal dysfunction (HR 4.26, 95% CI 2.04-9.01). An NYHA class of >or=II (HR 5.45, 95% CI 2.01-14.82) and renal failure (HR 3.82, 95% CI 1.21-12.06) were independent predictors of cardiac mortality. No independent predictors of arrhythmic death were found.
Conclusion: Total mortality, especially of cardiac cause, is lower than previously described in BFB patients. Advanced NYHA class and renal failure are predictors of cardiac mortality.