Post-Pulmonary Embolism Phenotypes Described by Invasive Cardiopulmonary Exercise Testing

Area of Science:

• Cardiopulmonary Exercise Testing
• Pulmonary Hypertension
• Respiratory Medicine

Background:

• Post-pulmonary embolism (PE) dyspnea is a common and often debilitating condition.
• Previous studies suggest links to elevated right ventricular (RV) afterload, dead space ventilation, and deconditioning.
• Identifying distinct physiological underpinnings is crucial for targeted management.

Purpose of the Study:

• To determine if distinct physiological phenotypes of post-PE dyspnea exist.
• To characterize these phenotypes using invasive cardiopulmonary exercise testing (iCPET) parameters.
• To investigate the role of RV afterload, ventilatory efficiency, respiratory mechanics, and peripheral oxygen use.

Main Methods:

• A hierarchical cluster analysis was applied to iCPET data from patients with post-PE dyspnea.
• iCPET parameters including pulmonary hemodynamics, ventilation, and oxygen utilization were assessed.
• Patients were compared to iCPET control participants.

Main Results:

• Three distinct patient clusters emerged from the analysis.
• Cluster 1: Elevated RV afterload with impaired ventilatory efficiency.
• Cluster 2: Elevated RV afterload with compromised respiratory mechanics.
• Cluster 3: Mildly elevated RV afterload with reduced peak cardiac output.

Conclusions:

• Invasive cardiopulmonary exercise testing (iCPET) reveals significant heterogeneity in post-PE dyspnea.
• Three distinct phenotypes are characterized by varying degrees of RV afterload and associated functional limitations.
• These findings highlight the need for individualized assessment and treatment strategies for post-PE dyspnea.