Noninvasive Assessment of Mean Pulmonary Artery Pressure: A Comparison of Doppler Echocardiographic Methods

Studies that directly and simultaneously compare each echocardiographic method of estimating mean pulmonary artery pressure (mPAP) to that of right heart catheterization (RHC) in the same population are limited. The purpose of this study was to compare the yield and agreement of each echocardiographic method for estimating mPAP to RHC in a real-world cohort.

We screened 122 consecutive patients scheduled to undergo RHC at California Pacific Medical Center. All volunteers underwent resting transthoracic echocardiogram within 24 hours of completing RHC. We compared 6 distinct noninvasive methods for estimating mPAP to RHC. We performed scatter plots with linear regression and Bland-Altman analyses. We analyzed the diagnostic performance of various combinations of noninvasive parameters for the diagnosis of pulmonary hypertension (mPAP >20 mm Hg).

By invasive investigation, the mean right atrial pressure (mRAP) was 11.4 ± 5.9 mm Hg, the mPAP was 33.1 ± 11.1 mm Hg, and the pulmonary vascular resistance (PVR) was 2.8 ± 1.6 Wood units. The noninvasive mPAP method using peak tricuspid regurgitation (TR) and end-diastolic pulmonary regurgitation (PR) gradients was most closely correlated with invasive mPAP (r = 0.70), while the method using pulmonary acceleration time was the least closely correlated with RHC mPAP (r = 0.33). Models using combined noninvasive TR and PR variables were better correlated with invasive mPAP (R² = 0.60) compared with using noninvasive TR or PR variables alone (R² = 0.48 and 0.47, respectively). The volunteers with an incomplete TR envelope had a more pronounced underestimation of systolic pulmonary artery pressure (52 vs 40 mm Hg, P < .001) compared wth ivolunteers with a complete TR envelope (55 vs 49 mm Hg). The utilization of multiple echocardiographic parameters improved the diagnostic accuracy of mean pulmonary hypertension (mPAP > 20 mm Hg) compared to RHC.

Noninvasive methods using the TR signal with inferior vena cava assessment were the most strongly correlated with invasive mPAP. The utilization of multiple echocardiographic parameters improved the diagnostic accuracy of mean pulmonary hypertension (mPAP > 20 mm Hg).