Cardiopulmonary Exercise Test to Detect Cardiac Dysfunction from Pulmonary Vascular Disease

Abstract 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 2 ·pulse AT /O 2 ·pulse rest with RHC-determined SV AT /SV rest . We evaluated the sensitivity and specificity of O 2 ·pulse AT /O 2 ·pulse rest to detect SV AT /SV rest below the lower limit of normal (LLN). For comparison, we performed similar analyses comparing echocardiographically-measured peak tricuspid regurgitant velocity (TRV peak ) with SV AT /SV rest . Results From July 2018 through February 2023, 83 simultaneous RHC and CPET were performed. Thirty-six studies measured O 2 ·pulse and SV at rest and at AT. O 2 ·pulse AT /O 2 ·pulse rest correlated highly with SV AT /SV rest (r = 0.72, 95% CI 0.52, 0.85; p < 0.0001), whereas TRV peak did not (r = -0.09, 95% CI -0.47, 0.33; p < 0.69). The AUROC to detect SV AT /SV rest below the LLN was significantly higher for O 2 ·pulse AT /O 2 ·pulse rest (0.92, SE 0.04; p = 0.0002) than for TRV peak (0.69, SE 0.10; p = 0.12). O 2 ·pulse AT /O 2 ·pulse rest 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 AT /SV rest . Conclusions CPET detected deficient SV augmentation more accurately than echocardiography. CPET-determined O 2 ·pulse AT /O 2 ·pulse rest 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.