Epidemiological and evolutionary characteristics of heart failure in patients with left bundle branch block – A Moroccan center-based study

BackgroundIn patients with heart failure, left bundle branch block (LBBB) seems to be associated with an increased risk of cardiovascular mortality.PurposeThe purpose of this study is to determine the in-hospital outcome of congestive heart failure patients with LBBB versus those without.MethodsWe conducted a prospective observational study at the Department of Intensive Care and Rhythmology at the Mohammed V Military Hospital of Rabat, where 330 patients were admitted for heart failure between January 2008 and September 2012. Screening out patients with missing data yielded a cohort of 274 patients. Among the 274 patients, only 110 had LBBB and a left ventricular ejection fraction lower than 50%. We randomly selected a subset of 110 patients diagnosed as non-LBBB to ensure a significant statistical comparison between LBBB and non-LBBB patients. We therefore considered two groups in our analysis: 110 heart failure (HF) patients with LBBB and 110 HF patients without LBBB. Patients with incomplete records were excluded.ResultsMale gender was dominant in both groups (82.7% vs. 66.7%, p = 0.005). Patients with LBBB had a higher prevalence of idiopathic dilated cardiomyopathy (39.1% vs. 4.8%, p < 0.001); and a higher prevalence of previous hospitalization for heart failure (64.5% vs. 23.3%, p < 0.001). The left ventricular ejection fraction was significantly lower in the group with LBBB (25.49% vs. 39.53%, p < 0.001). Age, cardiovascular risk factors, rhythmic and thromboembolic complications did not significantly differ. In patients with LBBB, 61.8% received cardiac resynchronization therapy performed both during the index hospital stay (50.9%) and previously (10.9%). Hospital outcome was marked by 20 in-hospital deaths in the group with LBBB and eight deaths in the group without LBBB (p = 0.008).ConclusionOur analysis emphasizes increased in-hospital mortality and higher disease severity, over a short period of stay, in heart failure patients with left bundle branch block.