Objective: This study aims to investigate the prevalence and prognostic value of ischemic (ICMP) versus non-ischemic cardiomyopathy (NICMP) in patients hospitalized due to heart failure with mildly reduced ejection fraction (HFmrEF). 

Background: Limited data regarding the prevalence and prognostic impact of ICMP versus NICMP in patients with HFmrEF is available.

Methods: A large retrospective registry was used including all consecutive hospitalized patients with HFmrEF (i.e., left ventricular ejection fraction (LVEF) 41 – 49%) from 2016 to 2022 according to current European guidelines. The prognostic impact of ICMP was compared NICMP was invastigated. The primary endpoint was the first cardiovascular re-hospitalization at 36 months. Secondary endpoints were heart failure related re-hospitalization and in-hospital mortality. Kaplan-Meier, uni- and multivariable Cox regression analyses were applied for statistics.

Results: 803 consecutive HFmrEF patients were included. The prevalence of ICMP was 55%. In the ICMP group, only 254 patients (57%) underwent coronary angiography during index hospitalization. Of those, 22% presented with on-vessel, 23% with two-vessel and 54% with 3-vessel-disease, respectively. The levels of aminoterminal pro-B-type Natriuretic Peptide (NT-pro BNP) did not differ in both groups (7332 vs. 7408ng/l; p=0.964). HFmrEF patients who suffered from ICMP showed an increased risk of cardiovascular re-hospitalization compared to NICMP patients at 3 years (22% vs. 15%; log-rank p=0.013). Even after multivariable adjustment, the risk of cardiovascular re-hospitalization was still significantly higher in patients with ICMP (HR=1.512; 95% CI 1.067 – 2.142; p=0.02). Within patients presenting with ICMP, the presence of multi-vessel disease was associated with an increased risk for cardiovascular re-hospitalization (29% vs. 13%; HR=2.455; 95% CI 1.432 – 4.207; p=0.001). The risks of heart failure related re-hospitalization (9% vs 9%; p=0.832) and in-hospital mortality (3% vs 4%; p=0.344) were comparable between ICMP and NICMP HFmrEF patients.
Conclusions: HFmrEF patients with ICMP revealed higher rates of cardiovascular re-hospitalization and comparable rates of heart failure related re-hospitalization and in-hospital mortality compared to HFmrEF patients with NICMP.