An echocardiogram showing a normal ejection fraction number can reassure both doctor and patient that the heart is pumping fine. According to a landmark 2026 consensus document from the world’s leading cardiology organizations, that reassurance may not always be warranted.
The test in question is the left ventricular ejection fraction (LVEF), which measures the percentage of blood the heart pumps out with each beat. Some people with a normal ejection fraction also have heart failure – a condition known as heart failure with preserved ejection fraction, or HFpEF. The heart still squeezes adequately, so the number looks reassuring. But when the heart muscle stiffens, and the left ventricle can’t relax and fill properly between beats, the left ventricle holds a lower volume of blood, often because thick or stiff heart tissue reduces the ventricle size. The pump looks fine on paper while the patient still has heart failure.
In June 2026, the American Heart Association, the American College of Cardiology, the European Society of Cardiology, and the World Heart Federation jointly published the Second Universal Definition of Heart Failure – the most comprehensive revision of how this condition is defined, classified, and diagnosed in over five years. The document landed simultaneously in four major journals and sent a clear message: the way clinicians have been measuring and categorizing heart failure is both too narrow and too rigid.
Why the Old Definition Was Failing Patients
For selecting medical treatment, individuals with heart failure have commonly been grouped by LVEF into those with preserved or mildly reduced ejection fraction and those with reduced ejection fraction. Categorizing heart failure by ejection fraction alone, or by specific cutoff values, has well-documented limitations.
Clinical trials investigating new heart failure therapies have long required patients to have LVEF readings within a very narrow range just to qualify for enrollment. That practice has shaped treatment evidence for decades and may have excluded large numbers of patients who could have benefited. Subjectivity and ambiguity in the definition of heart failure have also limited global surveillance and prevention programs.
LVEF readings are not uniform across all people. A 2026 meta-analysis found that in healthy adults, the lower limit of normal LVEF is approximately 53% for women and 52% for men – and that figure itself varies. Individuals of Asian origin show 2 to 3 percentage points higher LVEF than Black or White individuals. A cutoff treated as universal is, in practice, neither universal nor equally meaningful across different populations.
The 2026 consensus document published in Circulation confronts this directly. Its authors argue that LVEF cutoffs used in previous definitions were arbitrary – and that leaning too heavily on a single number has been distorting how heart failure is identified, studied, and treated.
Three Categories, Not a Spectrum With One Dividing Line
The Second Universal Definition of Heart Failure groups heart failure into three categories: reduced ejection fraction, preserved ejection fraction, and improved ejection fraction. Each reflects a meaningfully different clinical picture, and each may require a different treatment approach.
Heart failure with reduced ejection fraction (HFrEF) is what most people picture when they hear the diagnosis: the heart pumps less blood than it should, typically measured as an LVEF at or below 40%. This form has the most established drug therapies and the longest trail of clinical trial evidence. Heart failure with preserved ejection fraction (HFpEF) is the form most likely to be missed on a routine test. The LVEF looks normal, but the heart has become stiff and can’t fill or relax properly, producing the same debilitating symptoms – shortness of breath, fluid buildup, severe fatigue – as reduced EF heart failure. The prevalence of HFpEF is increasing, driven by aging populations and rising rates of hypertension, diabetes, and obesity.
The third category – heart failure with improved ejection fraction (HFimpEF) – is a consequential addition. Current guidelines recognize a separate subgroup of individuals whose ejection fraction increases with time and medical intervention, while emphasizing that these individuals may still be at risk for heart failure events. A patient whose LVEF improves with treatment is not cured; the underlying disease remains, and stopping medication can trigger relapse. The 2026 definition makes this explicit in a way previous frameworks did not.
The document also addresses the dynamic trajectories of heart failure – improvement, remission, and recovery – and highlights the impact of social determinants and geographic variation on heart failure risk and outcomes. Heart failure is no longer presented as a one-way escalation; it is a condition that can move in multiple directions depending on treatment, behavior, and underlying cause.
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A New Map of Causes
One of the most clinically significant changes in the 2026 document is its approach to etiology – the underlying cause of why a patient developed heart failure in the first place.
In clinical practice, the cause of heart failure has often been placed into just two categories: ischemic and non-ischemic cardiomyopathy (ischemic meaning caused by reduced blood supply to the heart; non-ischemic covering everything else). Ischemic heart disease remains the leading cause of heart failure in the Western world, according to a 2022 guideline published in the Journal of the American College of Cardiology – but the picture globally is far more varied.
The 2026 consensus replaces that two-category system with a standardized etiologic taxonomy spanning 18 categories of causes, including ischemic disease, hypertension, valve disease, arrhythmias, infiltrative disorders, metabolic and nutritional conditions, pregnancy-related cardiomyopathy, extreme psychological stress (known as Takotsubo syndrome), and cancer treatment-related heart damage. It also includes a category for infective cardiomyopathy, covering viral myocarditis, Chagas disease, HIV, and Lyme disease – causes that are far more prevalent in parts of Latin America, sub-Saharan Africa, and Southeast Asia than in North America or Europe.
The 2026 update introduces a universal classification of heart failure causes with explicit acknowledgment of geographic variation. A cardiologist in Brazil and one in Germany may be looking at the same diagnosis but different underlying drivers. The new taxonomy gives both clinicians a shared vocabulary that does not erase those differences.
Identifying the specific cause of heart failure may open doors to treatments that a generic diagnosis would never suggest. A patient with Chagas-related cardiomyopathy needs different management than one with hypertension-driven HFpEF. A patient whose heart failure was triggered by a chemotherapy drug may respond very differently to therapy than someone whose arteries are obstructed.
The Scope of the Problem
More than 64 million adults globally have heart failure, according to the American Heart Association, and prevalence continues to rise, driven in part by aging populations and increasing rates of obesity, Type 2 diabetes, and high blood pressure.
Heart failure is the world’s leading cause of hospitalization – a burden that falls disproportionately on older adults, those with multiple chronic conditions, and communities with limited access to specialist care. The AHA’s news release on the new consensus notes that the condition remains severely underrecognized, with awareness gaps among patients, families, community health workers, and policymakers.
The growing prevalence of heart failure is driven in part by increasing numbers of individuals with HFpEF – precisely the form most likely to return a normal ejection fraction result and go undiagnosed. HFpEF has become one of the dominant presentations of the disease, not an outlier.
A population-based study published in the European Journal of Heart Failure found that approximately 84% of individuals with heart failure had at least one identifiable risk factor amenable to preventive treatment in the five years preceding their diagnosis. For the vast majority of people eventually diagnosed with heart failure, there was a window – years, not months – during which targeted intervention could have changed the course of the disease.
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What the 2026 Definition Means in Practice
The second universal definition does not replace clinical guidelines – those are being updated separately – but it gives clinicians and researchers a common framework that the previous patchwork of regional and organizational definitions never provided. The document aims to improve prevention, early detection, and management of heart failure worldwide.
Breathlessness climbing stairs, ankles that swell by evening, fatigue that doesn’t resolve with rest – these symptoms in someone whose ejection fraction came back normal are precisely the kind of presentation the 2026 framework addresses. There is evolving evidence for the efficacy and safety of therapies across different ejection fraction ranges, which means a normal LVEF no longer rules out treatment. Imaging, blood biomarkers such as BNP (brain natriuretic peptide, a protein released when the heart is under stress), and in some cases genetic testing all contribute to a fuller picture than a single echocardiogram number can provide.
Cardiology’s approach to heart failure staging has also evolved. Progression from one heart failure stage to another was initially understood as unidirectional; once clinical heart failure developed, a return to preclinical stages was considered unlikely. The first Universal Definition’s staging system introduced heart failure “remission” with guideline-directed medical therapy and risk factor modification. The 2026 update expands on this, formally recognizing trajectories of improvement and recovery as distinct outcomes worth pursuing.
What to Do With This Information
If you have been told your heart function tests are normal but continue to experience unexplained breathlessness, fluid retention, or exercise intolerance, ask your doctor whether HFpEF has been considered. Under the 2026 framework, a normal ejection fraction reading does not exclude a heart failure diagnosis. Additional assessments – diastolic function measurements on echocardiogram, blood biomarker testing, or cardiac MRI – may be warranted.
Special attention should be given to cardiometabolic risk factors, including overweight, obesity, chronic kidney disease, and diabetes, because their prevalence is increasing globally and there are promising opportunities for the prevention of heart failure in these conditions. Managing blood pressure, blood sugar, and body weight have direct, documented effects on heart failure risk – not just general health benefits.
For patients at risk of heart failure in the primary care setting, primary prevention is critical to prevent progression. Elevated systolic and diastolic blood pressure is a major risk factor for the development of symptomatic heart failure, and it is a lever patients and clinicians can act on now, without waiting for guidelines to be updated.
For anyone living with heart failure, at risk of it, or currently navigating a borderline result, the core message is clear: one normal number doesn’t tell the whole story, and the cardiology community is formally acknowledging that.
Disclaimer: This information is not intended to be a substitute for professional medical advice, diagnosis, or treatment and is for information only. Always seek the advice of your physician or another qualified health provider with any questions about your medical condition and/or current medication. Do not disregard professional medical advice or delay seeking advice or treatment because of something you have read here.
AI Disclaimer: This article was created with the assistance of AI tools and reviewed by a human editor.
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