Diagnosing HFpEF in Patients With Unexplained Dyspnea by Using Invasive Left Ventricular Pressure-Volume Loops.

Area of Science:

• Cardiology
• Cardiovascular Physiology
• Diagnostic Medicine

Background:

• Diagnosing heart failure with preserved ejection fraction (HFpEF) presents significant clinical challenges.
• Noninvasive diagnostic algorithms for HFpEF require validation against invasive hemodynamic measurements, the current gold standard.

Purpose of the Study:

• To estimate the prevalence of HFpEF in euvolemic patients with unexplained exertional dyspnea using left ventricular (LV) pressure-volume loops (PVL).
• To validate the performance of noninvasive diagnostic algorithms against invasive LV PVL measurements.

Main Methods:

• Patients with unexplained exertional dyspnea and preserved LV ejection fraction were assessed using right-heart catheterization and real-time continuous LV PVL.
• HFpEF was defined by elevated LV filling pressures or impaired relaxation/increased LV stiffness.
• Diagnostic performance of H2FPEF and HFA-PEFF scores was compared between HFpEF and non-HFpEF groups.

Main Results:

• 93% of included patients (26 out of 28) were diagnosed with HFpEF based on invasive LV PVL.
• HFpEF was confirmed either by elevated filling pressures (11 patients) or by impaired relaxation/stiffness without elevated pressures (15 patients).
• Noninvasive diagnostic scores demonstrated high specificity but insufficient sensitivity for HFpEF detection.

Conclusions:

• A significant proportion of HFpEF patients (half) exhibited normal hemodynamics via right-heart catheterization but met HFpEF criteria through impaired relaxation or LV stiffness.
• Further investigation is warranted to understand the clinical significance of this subgroup and to enhance diagnostic and therapeutic strategies.