Clinical Characteristics, Comorbidities, and Prognosis in Patients with Heart Failure with Unknown Ejection Fraction

Heart Failure (HF) is a frequent cause of mortality and recurrent hospitalization. Although HF databases are assembled based on left ventricular (LV) ejection fraction, patients without LV ejection fraction determination are not further analyzed.

The purpose of this study is to characterize patient attributes and outcomes in this group-HF with unknown Ejection Fraction (HFunEF).

We queried the electronic medical record from a community-based university practice for patients with a HF diagnosis. We included patients with >60 days follow-up and had interpretable Doppler-echocardiograms. We recorded demographic, Doppler-echocardiographic, and outcome variables (up to 2083 days).

There were 820 patients: 269 with HF with preserved Ejection Fraction (HFpEF), 364 with HF with reduced Ejection Fraction (HFrEF), of which 231 had a LV ejection fraction=40-49% and 133 had a LV ejection fraction<40%, and 187 with HFunEF. As compared to patients with HFunEF, HFpEF patients were younger, had a higher coronary disease and hyperlipidemia prevalence. Patients with HFrEF had more prevalent coronary disease, myocardial infarction, and hyperlipidemia. Patients with HFunEF were more likely to be seen by non-cardiology providers. All-cause mortality (ACM) was greater in HFunEF patients than patients with HFpEF (Hazard Ratio (HR)=1.60 (1.16-2.29), p=0.004). Furthermore, HF readmission rates were lower in HFunEF as compared to HFpEF (HR=0.33 (0.27-0.54), p<0.0001) and HFrEF (HR=0.30 (0.028-0.50), p<0.0001).

Patients with HFunEF have greater ACM and lower HF re-admission than other HF phenotypes. Adherence to core measures, including LV ejection fraction assessment, may improve outcomes in this cohort of patients.