Abstract 60: Mortality Following Heart Failure Hospitalization By QRS Duration In Patients With Preserved Ejection Fraction

Background: Heart failure with preserved ejection fraction (HFpEF) comprises almost half of all heart failure (HF) diagnoses. Similar to HF with reduced ejection fraction (HFrEF), HFpEF carries up to a 75% 5-year mortality following HF hospitalization. However, unlike its corollary, HFpEF has exceedingly limited therapeutic options to alter its natural history. While QRS prolongation (QRS > 120 msec) carries prognostic significance in HFrEF, less is known about the implications of this conduction abnormality in HFpEF. Objective: To determine the association of QRS prolongation with survival among patients with HFpEF following HF hospitalization. Methods: A retrospective review of 1,454 patients with left ventricular EF ≥ 45% discharged from the Minneapolis VA Medical Center between 2015 and 2019 from a HF hospitalization. All patients’ electrocardiograms (ECG) were classified by QRS duration as either prolonged (QRS >120 msec) or narrow complex (QRS ≤120 msec). Those with prolonged QRS were further subtyped as: left bundle branch block (LBBB), right bundle branch block (RBBB), intraventricular conduction delay (IVCD), or ventricular paced (VP) rhythm. Results: Of the 1,454 patients (mean age 75.1 ± 10.8 years, 97.7% male, and mean EF 58.5% ± 10.2%), 545 (37.5%) had QRS prolongation. Specifically, 61 (4.2%) had LBBB, 266 (18.3%) had RBBB, 77 (5.3%) had IVCD and 141 (9.7%) had VP. Over 4.09 ± 1.00 years of follow up, 769 (52.9%) of the patients died (Table). Patients with a narrow QRS had a similar survival relative to those with a QRS >120 msec with an age and sex adjusted hazard ratio of 1.01 (95% CI: 0.87-1.17, p = 0.16) (Figure). Conclusions: The mortality rate is exceedingly high in patients with HFpEF discharged after a HF hospitalization. While the QRS interval was not significantly associated with near-term survival in this analysis, these data suggest that studies with greater statistical power and follow-up duration are warranted.