Pulmonary Capillary Wedge Pressure Patterns During Exercise Predict Exercise Capacity and Incident Heart Failure

Area of Science:

• Cardiology
• Exercise Physiology
• Heart Failure Research

Background:

• Resting left ventricular filling pressures lack sensitivity for diagnosing heart failure with preserved ejection fraction (HFpEF) in patients with dyspnea.
• Exercise hemodynamic monitoring may offer a more sensitive approach to diagnose HFpEF and predict outcomes.

Purpose of the Study:

• To investigate if exercise-induced changes in pulmonary capillary wedge pressure (PCWP) indexed to cardiac output (CO) can differentiate HFpEF from other causes of dyspnea.
• To assess if the PCWP/CO slope during exercise reflects aerobic capacity and predicts heart failure outcomes in patients with normal resting PCWP.

Main Methods:

• 175 patients (controls, HFpEF, dyspnea with normal resting PCWP) underwent cardiopulmonary exercise testing with hemodynamic monitoring.
• Regression techniques defined normative PCWP/CO slope bounds in controls.
• The association of PCWP/CO slope with exercise capacity and cardiac outcomes was analyzed in the dyspnea group.

Main Results:

• Patients with HFpEF exhibited a significantly higher PCWP/CO slope (3.4±1.9 mm Hg/L/min) compared to controls (1.2±0.4 mm Hg/L/min).
• An abnormal PCWP/CO slope (>2 mm Hg/L/min) was observed in 45% of patients with dyspnea and normal resting PCWP.
• Elevated PCWP/CO slope was linked to reduced exercise capacity (peak Vo2) and increased risk of adverse cardiac events (HR 3.47, P=0.03).

Conclusions:

• Elevated PCWP/CO slope during exercise is prevalent in patients with dyspnea and normal resting pressures.
• Exercise PCWP/CO slope is a valuable predictor of exercise capacity and long-term heart failure outcomes.
• Assessing exercise PCWP/CO slope may improve early diagnosis of HFpEF, complementing resting measurements.