Cardiopulmonary exercise test to detect cardiac dysfunction from pulmonary vascular disease.

BACKGROUND

Cardiac dysfunction from pulmonary vascular disease causes characteristic findings on cardiopulmonary exercise testing (CPET). We tested the accuracy of CPET for detecting inadequate stroke volume (SV) augmentation during exercise, a pivotal manifestation of cardiac limitation in patients with pulmonary vascular disease.

METHODS

We reviewed patients with suspected pulmonary vascular disease in whom CPET and right heart catheterization (RHC) measurements were taken at rest and at anaerobic threshold (AT). We correlated CPET-determined O·pulse/O·pulse with RHC-determined SV/SV. We evaluated the sensitivity and specificity of O·pulse/O·pulse to detect SV/SV below the lower limit of normal (LLN). For comparison, we performed similar analyses comparing echocardiographically-measured peak tricuspid regurgitant velocity (TRV) with SV/SV.

RESULTS

From July 2018 through February 2023, 83 simultaneous RHC and CPET were performed. Thirty-six studies measured O·pulse and SV at rest and at AT. O·pulse/O·pulse correlated highly with SV/SV (r = 0.72, 95% CI 0.52, 0.85; p < 0.0001), whereas TRV did not (r = -0.09, 95% CI -0.47, 0.33; p = 0.69). The AUROC to detect SV/SV below the LLN was significantly higher for O·pulse/O·pulse (0.92, SE 0.04; p = 0.0002) than for TRV (0.69, SE 0.10; p = 0.12). O·pulse/O·pulse of less than 2.6 was 92.6% sensitive (95% CI 76.6%, 98.7%) and 66.7% specific (95% CI 35.2%, 87.9%) for deficient SV/SV.

CONCLUSIONS

CPET detected deficient SV augmentation more accurately than echocardiography. CPET-determined O·pulse/O·pulse may have a prominent role for noninvasive screening of patients at risk for pulmonary vascular disease, such as patients with persistent dyspnea after pulmonary embolism.