Diagnostic Criteria for HFrEF vs HFpEF
HFrEF is diagnosed when LVEF is ≤40%, while HFpEF requires LVEF ≥50% PLUS evidence of elevated left ventricular filling pressures (either spontaneous or provokable). 1
HFrEF Diagnostic Criteria
The diagnosis of HFrEF is straightforward and requires:
- Clinical signs and symptoms of heart failure (dyspnea, fatigue, edema, orthopnea, paroxysmal nocturnal dyspnea)
- LVEF ≤40% on echocardiography or other cardiac imaging 1
That's it. The LVEF threshold alone, combined with HF symptoms, establishes the diagnosis.
HFpEF Diagnostic Criteria
HFpEF diagnosis is more challenging and requires ALL of the following 1:
- Clinical signs and symptoms of heart failure
- LVEF ≥50%
- Objective evidence of elevated LV filling pressures, demonstrated by at least one of:
- Elevated natriuretic peptides (BNP or NT-proBNP)
- Echocardiographic evidence: E/e′ ratio ≥15
- Invasive hemodynamic measurements showing elevated pulmonary capillary wedge pressure or LV end-diastolic pressure
- Evidence during provocative testing (exercise echocardiography or fluid challenge)
Supporting Structural Evidence for HFpEF
While not absolutely required, structural heart disease findings strengthen the HFpEF diagnosis 1:
- Increased left atrial volume index
- Increased LV mass index
- Other LV structural or functional alterations
The Middle Ground: HFmrEF
Patients with LVEF 41-49% are classified as HFmrEF (heart failure with mildly reduced ejection fraction). These patients require the same additional evidence of elevated filling pressures as HFpEF patients 1.
Critical pitfall: A single LVEF measurement in the mildly reduced range (41-49%) is insufficient—you must assess the trajectory over time. These patients are typically either improving from HFrEF or deteriorating toward it 1.
Key Diagnostic Nuances
Why HFpEF Needs More Than Just LVEF
The writing committee emphasizes that HF symptoms are nonspecific and overlap with many conditions. Normal natriuretic peptide levels do NOT exclude HFmrEF or HFpEF 1. This is why objective measures of cardiac dysfunction are mandatory for diagnostic specificity in preserved or mildly reduced EF categories.
When Diagnosis Remains Uncertain
If the diagnosis is still unclear after initial evaluation:
- Exercise stress echocardiography with diastolic parameter assessment
- Invasive hemodynamics at rest or with exercise, measuring pulmonary capillary wedge pressure, LV end-diastolic pressure, PA pressures, stroke volume, and cardiac output 1
The H2FPEF Score
For challenging HFpEF cases, the H2FPEF clinical composite score integrates 1:
- Obesity
- Atrial fibrillation
- Age >60 years
- Treatment with ≥2 antihypertensive medications
- E/e′ ratio >9
- PA systolic pressure >35 mm Hg
The score ranges 0-9, with odds of HFpEF doubling for each point increase.
Improved EF Category
Important distinction: Patients with previous LVEF ≤40% who improve to >40% are classified as HFimpEF (heart failure with improved ejection fraction), NOT as HFpEF, even if LVEF reaches >50% 1. These patients should continue HFrEF treatment, as EF can decrease after medication withdrawal.