Echocardiographic Estimation of Mean Pulmonary Artery Pressure: Head-to-Head Comparison of 5 Methods

Transthoracic echocardiography is recommended for the initial evaluation of patients with suspected pulmonary hypertension (PH), while right heart catheterization (RHC) is indicated to measure mean pulmonary artery pressure (mPAP). Although different echocardiographic algorithms have been proposed to estimate mPAP, these are based on limited validation, often in small or selected populations, and all predate the revised PH diagnostic threshold (mPAP >20 mm Hg). This study aimed to evaluate and compare the diagnostic performance of 5 echocardiographic formulas for estimating mPAP in a large cohort of patients referred to RHC.

Consecutive patients undergoing clinically indicated RHC and transthoracic echocardiograph within 7 days were prospectively enrolled from a PH referral center over a 10-year period. Echocardiographic mPAP estimates were calculated using 5 previously proposed formulas derived from tricuspid regurgitation (TR), pulmonary regurgitation (PR), and pulmonary flow acceleration time. Diagnostic accuracy was assessed through correlation analysis, Bland-Altman plots, and receiver operating characteristic curves, applying the updated PH definition (mPAP >20 mm Hg).

Out of 571 patients included (age 68 ± 13 years, 50% male), 450 (79%) were diagnosed with PH. All echocardiographic formulas showed significant correlation with invasive mPAP (P < .001). The formula based on minimal end-diastolic PR pressure showed the best correlation (mPAP_DPmin; R = 0.92) and diagnostic accuracy (area under the curve, 0.96 [0.95-0.98]), outperforming mPAP derived from TR velocity (area under the curve, 0.91 [0.89-0.93]) and other formulas (all P < .001). The mPAP_DPmin value also showed minimal bias (+1.21 mm Hg) with narrow limits of agreement (-7.14 to +9.56 mm Hg) and high accuracy at the fixed 20 mm Hg threshold (sensitivity, 99%; specificity, 82%).

Echocardiographic estimation of mPAP using the mPAP_DPmin formula provides excellent diagnostic accuracy for PH, outperforming other established echocardiographic algorithms.