Heart Failure with Mildly Reduced Ejection Fraction (HFmrEF) 

The following guidance applies to patients with heart failure with mildly reduced ejection fraction (HFmrEF) with a left ventricular ejection fraction (LVEF) 41-49%.

Introduction

HFmrEF is a recent classification for patients who may have some prognostic benefit from disease modifying treatments such as ACE inhibitors, beta blockers and mineralocorticoid receptor antagonist (MRAs) even though trial evidence is not definitive. Sodium-glucose co-transporter 2 (SGLT2) inhibitors are an effective treatment for HFmrEF.

Diagnosis

The diagnosis of HFmrEF requires the presence of symptoms and/or signs of heart failure, and a mildly reduced ejection fraction (EF) of 41-49%.

The presence of elevated natriuretic peptides (NT-proBNP) and other evidence of structural heart disease (e.g. increased left atrial size, left ventricular hypertrophy or echocardiographic measures of left ventricular filling) make the diagnosis more likely but are not mandatory for diagnosis if there is certainty regarding the measurement of LVEF.

General management and treatment options

• Treatment is a composite of Heart Failure with Preserved Ejection Fraction (HFpEF) and Heart Failure with Reduced Ejection Fraction (HFrEF) treatment.
• Holistic care is important, as described in the Heart Failure with Preserved Ejection Fraction (HFpEF) guideline.
• Diuretics, where indicated, to relieve fluid retention and congestion (including MRAs where appropriate).
• ACE inhibitors (or ARBs) and beta blockers should be used where possible.
• Consider a SGLT2 inhibitor - see guidance here. 

N.B. Patients with a history of HFrEF (EF <40%), who later present with LVEF >50%, should be considered to have heart failure with improved EF (rather than HFpEF). Continued treatment for HFrEF is recommended in these patients.