Left bundle branch block and mortality in patients with acute heart failure syndrome: a substudy of the EFICA cohort.

Objective: In patients with chronic heart failure (CHF), left bundle branch block (LBBB) is associated with an increased risk of cardiovascular mortality. We aimed to investigate the association of LBBB with short- and long-term outcome in patients discharged after a de novo episode of acute heart failure (AHF) or AHF complicating a mild CHF.

Results: Patients with no history of New York Heart Association class III and IV CHF, who were admitted for a severe AHF episode and enrolled in the prospective observational EFICA study (n = 403), were included. Left bundle branch block prevalence was 16%. Patients with LBBB had a higher prevalence of dilated cardiomyopathy (23 vs. 10%, P < 0.005), a higher percentage of AHF episodes without identified precipitating factor (15 vs. 2%, P < 0.001), and were less likely to present increased markers of cardiac injury (41 vs. 56%, P = 0.04). The 4-week mortality was 24.8% with no difference between LBBB and no LBBB patients. Left bundle branch block was however an independent predictor of 1-year mortality in the 4-week survivors [hazards ratio (95% confidence interval) = 2.01 (1.12-3.64), P = 0.02].

Conclusions: Long-term outcome of patients surviving a severe episode of de novo AHF or AHF complicating a mild CHF is worsened by LBBB. These patients may constitute a subgroup at high risk in whom specific therapeutic solutions should be investigated.