HFpEF is not itself a stage of heart failure. It is a type of heart failure, classified by how well the heart pumps, and it can occur at multiple stages of the disease. This is a common point of confusion because heart failure uses two separate classification systems at the same time: one based on pumping ability (ejection fraction) and another based on disease progression (stages A through D). HFpEF describes the first; your stage depends on how far the disease has advanced.
How HFpEF Fits Into Heart Failure Classification
Heart failure is divided into types based on left ventricular ejection fraction, which is the percentage of blood your heart pumps out with each beat. According to the 2022 guidelines from the American College of Cardiology, AHA, and Heart Failure Society of America, there are four categories:
- HFrEF (reduced ejection fraction): 40% or lower
- HFimpEF (improved ejection fraction): previously 40% or lower, now above 40%
- HFmrEF (mildly reduced ejection fraction): 41% to 49%
- HFpEF (preserved ejection fraction): 50% or higher
In HFpEF, the heart squeezes normally, pushing out a healthy percentage of blood. The problem is that the heart muscle has become stiff and doesn’t relax properly between beats, so it can’t fill with enough blood in the first place. The result is the same fluid buildup and shortness of breath that other types of heart failure cause, even though the pumping percentage looks fine on imaging.
The Four Stages of Heart Failure
Separately from the ejection fraction types, heart failure is staged A through D based on how far the condition has progressed. These stages apply to all types, including HFpEF.
Stage A means you’re at risk for heart failure but don’t have structural heart disease or symptoms. This includes people with high blood pressure, diabetes, or obesity who haven’t yet developed heart problems.
Stage B is pre-heart failure. There may be structural changes in the heart (like thickening of the walls) or elevated biomarkers, but no symptoms yet.
Stage C is where most people with a HFpEF diagnosis land. At this stage, you have both the structural or functional heart changes and current or previous symptoms like shortness of breath, fatigue, or fluid retention.
Stage D is advanced heart failure. Symptoms are severe and persist despite treatment, often interfering with daily life and requiring specialized interventions.
These stages only move in one direction. Once you’re classified as Stage C, you stay Stage C even if your symptoms improve with treatment. The system is designed to reflect cumulative disease progression, not how you feel on a given day.
NYHA Classes Measure Day-to-Day Symptoms
On top of staging, doctors also use the New York Heart Association functional classification to describe how limited you are by symptoms right now. Unlike the A-through-D stages, NYHA class can change over time as symptoms improve or worsen.
- Class I: No limitations. Normal activity doesn’t cause fatigue or shortness of breath.
- Class II: Slight limitation. You’re comfortable at rest, but ordinary activities like climbing stairs or walking uphill cause symptoms.
- Class III: Marked limitation. Even light activity triggers fatigue or breathlessness, though rest still feels fine.
- Class IV: Symptoms at rest. Any physical activity makes them worse.
A person with HFpEF at Stage C might be anywhere from NYHA Class I to Class IV depending on how well their condition is managed. So when someone asks “what stage is HFpEF,” the honest answer is: it depends on the individual patient, and it depends on which classification system you’re asking about.
Who Gets HFpEF
HFpEF accounts for roughly 50% of all heart failure cases, and that proportion is growing. It is overwhelmingly a disease of older adults, particularly women. In people under 50, prevalence is around 1% in women and nearly zero in men. By age 80 and older, it reaches 8 to 10% in women and 4 to 6% in men.
The typical person with HFpEF has several overlapping conditions. Hypertension is present in over 90% of cases. Atrial fibrillation, obesity, diabetes, chronic kidney disease, and sleep apnea are all extremely common. These aren’t just coincidences. Obesity, for example, drives HFpEF through increased blood volume, chronic inflammation, and direct effects on the heart muscle. Fat tissue releases signaling molecules that promote thickening and scarring of the heart walls, making them stiffer and harder to fill. High blood pressure forces the heart to work harder with each beat, gradually thickening the muscle over years.
This cluster of conditions is so consistent that researchers now describe a distinct “obese HFpEF” phenotype, where excess weight is the central driver of the heart’s stiffening. Early evidence suggests that significant weight loss can improve both the structural changes in the heart and symptom burden.
How HFpEF Is Diagnosed
Diagnosing HFpEF is trickier than diagnosing heart failure with a weak pump, because the ejection fraction looks normal. Doctors rely on a combination of imaging, blood tests, and clinical scoring systems.
A key blood marker is NT-proBNP, a protein released when the heart is under strain. UK guidelines use a threshold of 400 ng/L to trigger further testing with echocardiography. Levels between 400 and 2,000 ng/L call for an echocardiogram within six weeks; above 2,000 ng/L warrants one within two weeks. In patients with severe diastolic dysfunction (the hallmark of HFpEF), median NT-proBNP levels can reach above 4,000 ng/L.
Doctors also use clinical scoring tools like the H2FPEF score, which assigns points for six factors: history of atrial fibrillation (3 points), BMI over 30 (2 points), treatment with two or more blood pressure medications (1 point), elevated pressure in the lung arteries on ultrasound (1 point), age over 60 (1 point), and a specific measure of how stiff the heart appears on echocardiography (1 point). Scores range from 0 to 9, with higher scores making HFpEF more likely.
Treatment and Outlook
For years, HFpEF had no proven drug therapy, which set it apart from heart failure with reduced ejection fraction. That changed with the approval of SGLT2 inhibitors, a class of medications originally developed for diabetes. These drugs reduce hospitalizations and improve symptoms in HFpEF, and the 2024 ACC guidelines now include them as a core part of treatment for both HFpEF and HFrEF. They can be started early, even before or alongside other heart failure medications.
Beyond medication, managing the conditions that drive HFpEF is central to treatment. Controlling blood pressure, managing fluid retention with diuretics, treating atrial fibrillation, and losing weight all directly address the underlying mechanics that stiffen the heart.
One finding that surprises many people: after adjusting for risk factors, five-year mortality for HFpEF is essentially the same as for heart failure with a reduced ejection fraction, around 75% in a large registry study. The perception that a “preserved” ejection fraction means milder disease is misleading. HFpEF carries serious risk, which is part of why early identification, aggressive management of comorbidities, and newer drug therapies matter so much.