Heart failure with preserved ejection fraction (HFpEF) is a complex medical condition where the heart muscle pumps blood normally but is unable to relax and fill properly. This impaired relaxation, known as diastolic dysfunction, causes blood to back up into the lungs and body, leading to heart failure symptoms. HFpEF accounts for approximately half of all heart failure cases. It is particularly challenging to diagnose compared to heart failure with reduced ejection fraction (HFrEF), where the pumping function is clearly weakened. Diagnosis requires a systematic approach, moving from recognizing initial clinical signs to using advanced cardiac imaging and diagnostic algorithms.
Initial Clinical Assessment and History Taking
The diagnostic journey for HFpEF begins with recognizing the clinical presentation, which often overlaps with other heart and lung conditions. Patients typically report breathlessness (dyspnea), particularly with physical effort, and general fatigue. These symptoms are a frequent reason for seeking medical attention and often become more pronounced as the condition progresses.
A comprehensive patient history is important for identifying the risk factors strongly associated with HFpEF. The condition is closely linked to co-morbidities such as long-standing high blood pressure (hypertension), diabetes, and obesity. Other common factors include atrial fibrillation, chronic kidney disease, and obstructive sleep apnea.
The physical examination may reveal signs of fluid retention, such as swelling in the legs (peripheral edema) or an elevated jugular venous pressure. The presence of an S3 heart sound or a displaced apical impulse can increase the likelihood of heart failure. Clinicians use these initial findings—symptoms, co-morbidities, and physical signs—to establish a baseline suspicion for heart failure, which guides subsequent diagnostic testing.
Essential Non-Invasive Testing: Biomarkers and Echocardiography
Following the initial assessment, non-invasive testing confirms cardiac stress and determines the heart’s overall function. Measurement of natriuretic peptides, specifically B-type natriuretic peptide (BNP) or N-terminal pro-B-type natriuretic peptide (NT-proBNP), serves as a crucial blood test. These peptides are released by the heart muscle in response to stretching and wall stress, and elevated levels suggest heart failure.
While elevated natriuretic peptide levels support a heart failure diagnosis, the levels in HFpEF are often lower than those seen in HFrEF, making interpretation more nuanced. Factors like obesity can artificially lower these values, requiring clinicians to adjust expected thresholds based on the patient’s body mass index (BMI) and age.
Transthoracic echocardiography (Echo) is the primary imaging tool used to evaluate the heart’s structure and function. The Echo confirms that the left ventricular ejection fraction (LVEF), the percentage of blood pumped out with each beat, is preserved, typically measuring 50% or greater. This preserved LVEF is the defining characteristic separating HFpEF from HFrEF. The Echo also provides resting clues about the heart’s ability to relax and fill, such as the size of the left atrium and the thickness of the heart muscle, which are signs of chronic diastolic stress.
Advanced Methods for Confirming Diastolic Dysfunction
When initial testing is inconclusive, or when the patient’s symptoms are highly suspicious despite equivocal resting results, advanced methods are employed to confirm the underlying diastolic dysfunction. The gold standard for non-invasive assessment involves specific Doppler measurements during an Echo, such as the E/e’ ratio. This ratio compares the velocity of early mitral inflow (E wave) to the velocity of the tissue movement at the mitral annulus (e’ wave), providing an estimate of the left ventricular filling pressures.
A high E/e’ ratio suggests that the pressure in the left ventricle is elevated during filling. Other advanced Echo parameters, including the left atrial volume index and the velocity of the tricuspid regurgitation jet, are also analyzed to characterize the degree of pressure elevation and its impact on the rest of the heart.
A significant challenge in diagnosing HFpEF is that the elevated filling pressures may only manifest when the heart is stressed, a condition known as occult or latent HFpEF. To uncover this, clinicians may order an exercise echocardiography, where the patient performs physical activity while the heart is continuously imaged. A positive stress Echo involves documenting a substantial rise in the E/e’ ratio or the pulmonary artery systolic pressure during exercise, confirming that the heart cannot adequately handle the demands of physical exertion.
In the most challenging cases, invasive hemodynamic testing, usually a Right Heart Catheterization (RHC), is performed. This procedure directly measures the pressures within the heart chambers and pulmonary circulation, providing the most accurate assessment of left ventricular filling pressures, known as the pulmonary capillary wedge pressure (PCWP). RHC can be performed at rest and during exercise, definitively diagnosing HFpEF by demonstrating a PCWP greater than 20 mmHg during exertion. Advanced cardiac imaging, like Cardiac Magnetic Resonance Imaging (MRI), may also be used to rule out specific causes of HFpEF, such as infiltrative diseases like cardiac amyloidosis, which require specialized treatment.
Structured Scoring Systems for Final Diagnosis
Because the diagnosis of HFpEF is rarely confirmed by a single test, clinicians rely on structured scoring systems to synthesize clinical, biochemical, and imaging data. These algorithms formalize the diagnostic process, ensuring a standardized approach. Two prominent examples are the H2FPEF score and the Heart Failure Association of the ESC diagnostic algorithm (HFA-PEFF).
These scoring systems assign points based on factors such as patient age, BMI, history of atrial fibrillation, and specific echocardiographic findings like the E/e’ ratio. For example, the H2FPEF score incorporates six variables, with a total score ranging from 0 to 9; a score of 6 or higher is highly suggestive of HFpEF. The HFA-PEFF algorithm uses a multi-stage approach, first assigning points based on clinical and natriuretic peptide data, followed by echocardiographic parameters.
The total score places the patient into a probability category: low, intermediate, or high likelihood of having HFpEF. A low probability score typically excludes the diagnosis, while a high score confirms it. Patients in the intermediate probability range are those for whom advanced testing, such as exercise echocardiography or invasive hemodynamic studies, is most often recommended to reach a definitive conclusion.