Heart Failure With Stable Mildly-reduced Ejection Fraction: Prognosis and Predictors of Outcomes

Area of Science:

• Cardiology
• Internal Medicine

Background:

• Heart failure with mildly-reduced ejection fraction (HFmrEF), defined as LVEF 40%-49%, is an under-recognized clinical entity.
• The long-term prognosis and outcome predictors for stable HFmrEF remain unclear.

Purpose of the Study:

• To investigate the clinical outcomes and predictors of mortality, HF hospitalization, and hospital length of stay in patients with stable HFmrEF over one year.
• To compare clinical outcomes between stable HFmrEF, HFrEF, and HFpEF groups.

Main Methods:

• Retrospective study including 609 patients with stable left ventricular ejection fraction (LVEF) for at least one year.
• Patients were categorized into three groups based on LVEF: HFmrEF (40-49%), HFrEF (≤40%), and HFpEF (≥50%).
• Clinical outcomes assessed included all-cause mortality, cardiac mortality, and HF hospitalization (HFH). Predictors of outcomes and hospital length of stay (LOS) were analyzed.

Main Results:

• Stable HFmrEF patients exhibited a lower HFH rate compared to HFrEF (HR=0.52) and a higher HFH rate compared to HFpEF (HR=1.23).
• All-cause and cardiac mortality rates were similar across the three groups.
• In stable HFmrEF patients, beta-blocker use was associated with lower cardiac mortality, while chronic kidney disease (CKD) was linked to fewer HFH. Loop diuretics predicted mortality, and higher NYHA class predicted HFH. Smoking and CKD predicted longer hospital LOS. Patients with prior HF admissions had higher mortality.

Conclusions:

• Stable HFmrEF represents an intermediate phenotype between HFrEF and HFpEF regarding HF hospitalization rates.
• CKD, NYHA class, beta-blockers, and loop diuretics are significant predictors of clinical outcomes in stable HFmrEF.
• Smoking and CKD are associated with prolonged hospital stays in this population.