Prognostic impact of left ventricular dilatation in heart failure with mildly reduced ejection fraction

This study investigated the prognostic value of left ventricular (LV) dilatation in patients with heart failure with mildly reduced ejection fraction (HFmrEF). Adverse cardiac remodeling may lead to LV dilatation and impaired prognosis in heart failure with reduced ejection fraction (HFrEF). Its significance in HFmrEF remains unclear. Patients hospitalized with HFmrEF (2016-2022) were included and stratified by the presence or absence LV dilatation (males: LV end-diastolic diameter (LVEDD) >58 mm; females: >52 mm). Kaplan-Meier and multivariable Cox regression analyses assessed 30-month all-cause mortality and HF-related rehospitalization. Among 2154 patients (median LVEDD 49.0 mm), 290 (13.5 %) had LV dilatation. These patients were younger (73 vs. 76 years; p = 0.001), less often males (42.2 % vs. 67.2 %; p = 0.001), and more likely to have non-ischemic cardiomyopathy (10.0 % vs. 6.3 %; p = 0.019). LV dilatation was not associated with 30-month all-cause mortality (29.7 % vs. 31.4 %; HR = 0.933; 95 % CI 0.744-1.171; p = 0.548) but was linked to higher HF-related rehospitalization risk (19.1 % vs. 12.5 %; HR = 1.606; 95 % CI 1.193-2.161; p = 0.003), even after multivariable adjustment (HR = 1.613; 95 % CI 1.163-2.238; p = 0.004). In HFmrEF, LV dilatation independently predicts HF-related rehospitalization but not all-cause mortality.