Heart Failure with Improved Ejection Fraction: Insight into the Variable Nature of Left Ventricular Systolic Function

Abstract

The progress of contemporary cardiovascular therapy has led to improved survival in patients with myocardial disease. However, the development of heart failure (HF) represents a common clinical challenge, regardless of the underlying myocardial pathology, due to the severely impaired quality of life and increased mortality comparable with malignant neoplasms. Left ventricular ejection fraction (LVEF) is the main index of systolic function and a key predictor of mortality among HF patients, hence its improvement represents the main indicator of response to instituted therapy. The introduction of complex pharmacotherapy for HF, increased availability of cardiac-implantable electronic devices and advances in the management of secondary causes of HF, including arrhythmia-induced cardiomyopathy, have led to significant increase in the proportion of patients with prominent improvement or even normalization of LVEF, paving the way for the identification of a new subgroup of HF with an improved ejection fraction (HFimpEF). Accumulating data has indicated that these patients share far better long-term prognoses than patients with stable or worsening LVEF. Due to diverse HF aetiology, the prevalence of HFimpEF ranges from roughly 10 to 40%, while the search for reliable predictors and genetic associations corresponding with this clinical presentation is under way. As contemporary guidelines focus mainly on the management of HF patients with clearly defined LVEF, the present review aimed to characterize the definition, epidemiology, predictors, clinical significance and principles of therapy of patients with HFimpEF.

Heart failure with preserved ejection fraction and atrial fibrillation: recent advances and open questions

“…We think that two main reasons possibly overlapping may explain this profile. The first one is the setting where medical drugs indicated for HFpEF were able to improve LVEF, a scenario that may be seen for around 1/3 of patients with HFrEF (compared to grossly 1/3 with stable LVEF and 1/3 with worsening LVEF in spite of optimal drug therapy) [ 9 ]. The other possibility is that HFrEF was related to a transient or a curable cause that may include for example ischemic aetiology with efficient revascularisation or valve disease treated with surgery or percutaneous intervention [ 2 , 9 ].…”

“…The first one is the setting where medical drugs indicated for HFpEF were able to improve LVEF, a scenario that may be seen for around 1/3 of patients with HFrEF (compared to grossly 1/3 with stable LVEF and 1/3 with worsening LVEF in spite of optimal drug therapy) [ 9 ]. The other possibility is that HFrEF was related to a transient or a curable cause that may include for example ischemic aetiology with efficient revascularisation or valve disease treated with surgery or percutaneous intervention [ 2 , 9 ]. However, one of the most striking examples of HFrEF with complete recovery is cardiomyopathy directly and purely induced by persistent arrhythmias (so-called tachycardiomyopathy) among which AF is the most common cause [ 2 , 9 , 10 ].…”

“…The other possibility is that HFrEF was related to a transient or a curable cause that may include for example ischemic aetiology with efficient revascularisation or valve disease treated with surgery or percutaneous intervention [ 2 , 9 ]. However, one of the most striking examples of HFrEF with complete recovery is cardiomyopathy directly and purely induced by persistent arrhythmias (so-called tachycardiomyopathy) among which AF is the most common cause [ 2 , 9 , 10 ]. When AF causes HF, the clinical course may be more favourable than with other causes of HF although patients may not have a complete healing and may shift from HFrEF to HFpEF.…”

Acute heart failure: How can we predict subsequent improvement in systolic function?

“…The most accepted HFiEF definition comprises an initial LVEF < 40% and an increase of ≥10% and a follow-up measurement >40%. 7 Alternatively HFiEF has been categorized by some authors as a LVEF normalization (usually >50%), regardless of the percentage change of the parameter of interest over time. Further simplified approaches defined improvement as a recovery in LVEF from <35% or <40% to >50%.…”

“…This evidence is consistent across the various studies despite the different definitions used in phenotyping this entity. The most accepted HFiEF definition comprises an initial LVEF < 40% and an increase of ≥10% and a follow‐up measurement >40% 7 . Alternatively HFiEF has been categorized by some authors as a LVEF normalization (usually >50%), regardless of the percentage change of the parameter of interest over time.…”