Heart failure with recovered ejection fraction and the utility of defibrillator therapy: a review

Abstract

Heart failure with recovered ejection fraction (HFrecEF) involves those who have previously had reduced cardiac function that has subsequently improved. However, there is not a single definition of this phenomenon and recovery of cardiac function in terms of left ventricular ejection fraction (LVEF) itself does not necessarily correlate with remission from the detrimental physiology of heart failure (HF) and its consequences. There is also the question of the utility of defibrillators in these patients, and whether they should be replaced at the time of battery depletion. To address this, several studies have shown specific predictors of ensuing LVEF recovery, including patient demographics, co-morbidities, and medication use, as well as predictors of ventricular arrhythmias (VA) following LVEF recovery. Recent studies have also shown novel imaging parameters that may aid in predicting which patients would have a higher risk of these arrhythmias. Additional data describe a small, yet appreciable risk of VA, in addition to appropriate shocks as well. In this review, we describe predictors of LVEF recovery, carefully analyse and characterize the continued risk for VA and appropriate shocks following LVEF recovery, and explore additional novel modalities that may aid in decision-making.

Keywords: Defibrillator; Ejection fraction; Heart failure; Recovered; Sudden cardiac death.

Figure 1

Heart failure with recovered ejection fraction as a distinct clinical entity and continued benefit from defibrillator therapy. Heart failure with recovered ejection fraction is a clinical entity that is distinct from other types of heart failure with its unique biomarkers and outcomes. Patients start with having a low EF, defined at <40%, but then there is great heterogeneity in defining recovery. Certain patient demographics and co‐morbidities have been identified as either positively or negatively predictive of recovery. It is a frequent occurrence for ICD to be placed when EF ≤ 35%, but it is unclear the benefit of reducing SCD when it is time to replace the generator in those with defibrillators with HFrecEF. There is mortality benefit from ICDs in HFrecEF, and new technology may be able to guide these decisions further. ACEi, angiotensin‐converting enzyme inhibitor; ARB, angiotensin receptor blocker; BB, beta‐blocker; BNP, brain natriuretic peptide; EF, ejection fraction; HFrecEF, heart failure with recovered ejection fraction; HFrEF, heart failure with reduced ejection fraction; ICD, implantable cardioverter‐defibrillator; NYHA, New York Heart Association; SCD, sudden cardiac death.

Figure 2

Differences between heart failure with reduced ejection fraction and heart failure with recovered ejection fraction in select baseline characteristics. Three sources, Agra Bermejo et al., Lupón et al., and Park et al., provided the past medical history of patients in different heart failure cohorts. The conditions that all three papers included were combined to produce average per cent representation of the specific demographics provided in the figure. HF, heart failure; HFrecEF, heart failure with recovered ejection fraction; HFrEF, heart failure with reduced ejection fraction; LVEF, left ventricular ejection fraction.