A comprehensive population-based characterization of heart failure with mid-range ejection fraction

Area of Science:

• Cardiology
• Clinical Medicine
• Heart Failure Research

Background:

• Heart failure is classified by ejection fraction (EF) into reduced (HFrEF, EF <40%), preserved (HFpEF, EF ≥50%), and a newly recognized mid-range EF (HFmrEF, EF 40-49%).
• Understanding the distinct clinical features and prognostic implications of HFmrEF is crucial for accurate patient management and therapeutic strategies.

Purpose of the Study:

• To compare the clinical characteristics and outcomes of patients with HFmrEF against those with HFrEF and HFpEF.
• To investigate the association between baseline characteristics, EF group, and all-cause mortality.

Main Methods:

• Analysis of data from the Swedish Heart Failure Registry, including 42,061 patients.
• Utilized multivariable logistic regressions to assess baseline characteristics and EF group associations.
• Employed multivariable Cox regressions to determine the association between EF group and all-cause mortality.

Main Results:

• HFmrEF patients (21%) exhibited intermediate characteristics between HFrEF (56%) and HFpEF (23%).
• Coronary artery disease (CAD) was more prevalent in HFrEF and HFmrEF compared to HFpEF.
• Adjusted all-cause mortality for HFmrEF was similar to HFpEF, but higher in HFrEF. However, CAD increased mortality risk in HFmrEF.

Conclusions:

• HFmrEF represents an intermediate phenotype, distinct from HFrEF and HFpEF.
• While HFmrEF shares some features with HFrEF, its adjusted mortality risk is comparable to HFpEF.
• The presence of CAD significantly impacts the prognosis of HFmrEF, increasing mortality risk.