Ejection Fraction
Key result
Ejection fraction is a flawed measure of myocardial contractility and should be abandoned as the primary means of categorizing heart failure in favor of underlying pathophysiology.
Key Points
- To re-evaluate the physiological validity of ejection fraction as a measure of myocardial contractility and assess whether heart failure categorization should move away from ejection fraction thresholds.
- Physiological analysis of ventricular pressure-volume relationships under varying preload and afterload conditions.
- Evaluation of ventricular remodeling models comparing stroke volume and end-diastolic volume variations across dilated and hypertrophic cardiomyopathies.
- Ejection fraction reflects stroke volume normalized to end-diastolic volume and is heavily confounded by ventricular preload, afterload, and chamber remodeling rather than intrinsic contractility alone.
- In cardiac remodeling models where stroke volume is equally reduced to 25 mls, ejection fraction is markedly lower in dilated cardiomyopathy (19%) than in hypertrophic cardiomyopathy (28%) purely due to differences in end-diastolic volume.
- Categorizing heart failure solely as preserved versus reduced ejection fraction fails to define underlying etiologies and has contributed to neutral clinical trials, supporting replacement with disease-specific constructs such as metabolic-senile cardiovascular disease.
PICO
P
Population
Heart failure
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
JTJohn TeerlinkHeart failure specialist, UCSF Medical Center
“The static categorization of heart failure based on a single LVEF cut-off doesn't capture the dynamic progression or response to therapy in many patients. By focusing on LVEF trajectories, clinicians can make more informed treatment decisions and provide more personalized care. Additionally, there are beneficial therapies that can be initiated in patients with heart failure without knowledge of the LVEF.”
MAMarianna AdamoAssociate professor of cardiology, University of Brescia
“The mildly reduced LVEF phenotype was introduced in previous guidelines to focus on patients not usually included in clinical trials. However, we know that these patients share similar pathophysiology — and benefit from similar treatments — as those with reduced LVEF.”
“We've shifted away from rigid definitions of specific ejection fractions to define a specific type of heart failure. The updated definition takes into account differences in LVEF based on sex, age, and some differences with ethnicity.”
Implication
The authors argue that classifying heart failure based on ejection fraction is misguided and propose focusing on underlying pathophysiology, such as metabolic-senile cardiovascular disease (MetS-CVD).
Abstract
The long-standing emphasis on ejection fraction (EF) is misguided. EF is erroneously assumed to be a measure of myocardial contractility. Of greater concern is the widespread classification of patients with heart failure (HF) based on whether EF is preserved (HFpEF) or reduced (HFrEF). In fact, EF does not provide any specific information on causation or underlying mechanisms. We believe that a revision or abandonment of this nomenclature is warranted, and categorization of patients with HF should more strongly emphasize underlying pathophysiology EF is a characterization of ventricular ejection: the stroke volume (SV) expressed as a fraction of end-diastolic volume (EDV). Knowledge of EDV is essential to translate SV expressed as a percentage (EF) into absolute SV, a quantity of more physiological and clinical significance, hence our admonition that no one should ever mention EF without, in the same breath, diastolic volume. In the 1950s, physiologists used the instantaneous change in SV/EDV (ie, the change in EF) as a measure of change in contractility under conditions of constant load. Over time we have largely forgotten that (1) EF is influenced by both preload (diastolic) and afterload (systolic) and cannot be interpreted as an index of contractility without knowledge of left ventricular (LV) loads; and (2) structural changes leading to increases or decreases in LVEDV will strongly influence the EF at a given level of contractility and SV. So EF is twice removed from an …
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Cite This Study
Konstam et al. (2017) conducted an editorial in Heart failure. Ejection fraction is a flawed measure of myocardial contractility and should be abandoned as the primary means of categorizing heart failure in favor of underlying pathophysiology.