Impact of Tricuspid Regurgitation Severity on Accuracy of Echocardiographic Estimation of Systolic Pulmonary Artery Pressure in Patients With Pulmonary Arterial Hypertension

Objective: This study aims to investigate the impact of tricuspid regurgitation (TR) severity on the accuracy of echocardiographic estimation of systolic pulmonary arterial pressure (sPAP) in patients with pulmonary arterial hypertension (PAH). Methods: Patients who were diagnosed with PAH and had a right heart catheterization (RHC) and echocardiography examination were selected retrospectively from May 2018 to December 2021. sPAP measured by RHC is used as the gold standard. A difference in sPAP of less than 10 mmHg between echocardiographic estimation by peak TR velocity and RHC measurement was defined as accurate, with a difference >= 10 mmHg considered inaccurate. The factors affecting the accuracy of echocardiographic sPAP estimation were analyzed by univariate and multivariate analysis. Results: A total of 138 patients aged (45.57 +/- 15.97) years with PAH were enrolled. sPAP measured by echocardiography and RHC were (80.83 +/- 23.46) and (81.62 +/- 30.05) mmHg, respectively. The values of the 2 methods were highly correlated (r = 0.809, P < 0.01) and Bland-Altman plots showed good consistency. The accuracy rate of sPAP estimation by echocardiography was 42.03% (58/138). In the 57.97% (80/138) of patients where echocardiography was inaccurate, sPAP was overestimated in 28.26% (39/138) and underestimated in 29.71% (41/138). Univariate analysis showed that there was a statistically significant difference between the accurate and inaccurate groups in World Health Organization-Function Class, N-terminal pro-B-type natriuretic peptide, severity of TR, tricuspid annular plane systolic excursion (TAPSE), sPAP-RHC, mean pulmonary artery pressure, pulmonary vascular resistance (P < 0.05). Multivariate logistic regression analyses identified the TR severity (odds ratio = 2.292, 95% confidence interval: 1.126-4.667, P = 0.022) and TAPSE (odds ratio = 0.733, 95% confidence interval: 0.621-0.865, P < 0.001) as independent predictors for the accuracy of echocardiographic sPAP estimation. Conclusion: Higher TR severity and lower TAPSE values reduce the accuracy of sPAP estimated by echocardiography. Therefore, TR severity and right heart function should be considered when echocardiography is used to estimate sPAP by the TR velocity.