Abstract
The associations of left bundle branch block (LBBB) and right bundle branch block
(RBBB) with cardiovascular (CV) outcomes compared with normal QRS in heart failure
patients with preserved ejection fraction (HFpEF) are unclear. We sought to determine
CV morbidity, mortality, and total costs associated with LBBB and RBBB in acute HFpEF
compared with those without BBB. A cross-sectional study using the 2019 NIS database
analyzed adult HFpEF hospitalizations for acute heart failure, categorizing patients
by LBBB, RBBB, or normal QRS. Clinical outcomes included atrial fibrillation (AF),
ventricular fibrillation (VF), complete heart block (CHB), sick sinus syndrome (SSS),
cardiac arrest (CA), hospitalization costs, and in-hospital mortality. Associations
between BBB types and outcomes were assessed using logistic and relative risk (RR)
models with propensity score weighting, validated by sensitivity analyses. A total
of 334,511 hospitalizations with HFpEF including LBBB (6,818, 2%) and RBBB (7,948,
2.4%) were analyzed. Compared with normal QRS duration, LBBB was associated with VF
(odds ratio [OR] = 2.47, p < 0.001), SSS (OR = 1.72, p < 0.001), CHB (OR = 2.77, p < 0.001) and greater hospitalization costs (RR = 1.15, p < 0.001) after adjusting for covariates in PS analysis. Similarly, RBBB was associated
with AF (OR = 1.30, p < 0.001), VF (OR = 1.59, p = 0.033), SSS (OR = 1.72, p < 0.001), CHB (OR = 2.81, p < 0.001), CA (OR = 1.19, p < 0.001), and higher hospitalization costs (RR = 1.08, p < 0.001). These associations remained unchanged in multiple validation analyses even
after additionally adjusting for obesity, hypertension, and diabetes. The length of
stay was shorter in HFpEF with RBBB and LBBB subgroups compared with normal QRS. In
hospitalizations of acute decompensated HFpEF, BBB was associated with an increased
risk of CV outcomes and hospitalization costs.
Keywords heart failure with preserved ejection fraction - left bundle branch block - right
bundle branch block - atrial fibrillation - ventricular arrhythmias - cardiovascular
disease outcomes