Prognostic impact of right bundle branch block in hospitalized patients with idiopathic dilated cardiomyopathy: a single-center cohort study

Abstract

Objective Idiopathic dilated cardiomyopathy (IDCM) is a primary myocardial disease resulting in symptoms of heart failure. Right bundle branch block (RBBB) is associated with increased cardiovascular risk and all-cause mortality. Therefore, the present study was performed to identify the prognostic impact of RBBB in patients with IDCM. Methods In total, 165 hospitalized patients with IDCM were evaluated. Receiver operating characteristic curve analysis was used to determine the cutoff point, and Cox regression was used to assess risk factors. Results After a median follow-up of 73.1 months (interquartile range, 36.1–88.7 months), 59 (35.8%) patients had died. All-cause mortality was significantly higher in patients with than without RBBB (log-rank χ 2 = 9.400), P<0.05. Significant independent predictors of all-cause mortality in patients with IDCM were RBBB (hazard ratio, 2.898; 95% confidence interval, 1.201–6.995) and the left ventricular end-diastolic dimension (LVEDD) (hazard ratio, 1.034; 95% confidence interval, 1.004–1.066) at admission. Patients with RBBB and an LVEDD of ≥63 mm had the highest mortality (log-rank χ 2 = 14.854), P<0.05. Conclusion RBBB was an independent predictor of all-cause mortality, and the combination of RBBB and LVEDD provided more clinically relevant information than RBBB alone for assessing the risk of all-cause mortality in patients with IDCM.