Cardiopulmonary exercise test to detect cardiac dysfunction from pulmonary vascular disease

Area of Science:

• Cardiology
• Pulmonary Medicine
• Exercise Physiology

Background:

• Pulmonary vascular disease can cause cardiac dysfunction, leading to characteristic findings on cardiopulmonary exercise testing (CPET).
• Assessing stroke volume (SV) augmentation during exercise is crucial for identifying cardiac limitations in patients with pulmonary vascular disease.

Approach:

• Correlated CPET-derived O2·pulse ratio (O2·pulseAT/O2·pulserest) with right heart catheterization (RHC)-derived SV ratio (SVAT/SVrest) in patients with suspected pulmonary vascular disease.
• Evaluated the sensitivity and specificity of the O2·pulse ratio to detect diminished SV augmentation, comparing it with echocardiography-derived peak tricuspid regurgitant velocity (TRVpeak).

Key Points:

• CPET-derived O2·pulseAT/O2·pulserest strongly correlated with RHC-derived SVAT/SVrest (r=0.72, p<0.0001).
• The O2·pulse ratio demonstrated superior accuracy (AUROC 0.92) in detecting deficient SV augmentation compared to TRVpeak (AUROC 0.69).
• An O2·pulseAT/O2·pulserest ratio below 2.6 showed 92.6% sensitivity and 66.7% specificity for inadequate SV augmentation.

Conclusions:

• CPET is more accurate than echocardiography for detecting impaired SV augmentation in pulmonary vascular disease.
• CPET-derived O2·pulse ratio serves as a valuable noninvasive tool for screening patients at risk for pulmonary vascular disease, including those with persistent dyspnea post-pulmonary embolism.