Assessment of right ventricle–to–pulmonary artery coupling by three-dimensional echocardiography in pre-capillary pulmonary hypertension: comparison with tricuspid annular plane systolic excursion /systolic pulmonary artery pressure ratio

BACKGROUND: The tricuspid annular plane systolic excursion/systolic pulmonary artery pressure ratio (TAPSE/sPAP) has limitations in evaluating right ventricle-to-pulmonary artery (RV-PA) coupling, particularly when pulmonary artery pressure cannot be accurately estimated by tricuspid regurgitation or when TAPSE cannot accurately reflect right ventricular systolic function in certain scenarios. Therefore, this study aimed to explore the value of three-dimensional echocardiography (3DE) coupling parameters in assessing RV-PA coupling in patients with pre-capillary pulmonary hypertension (PH). METHODS: Fifty-nine patients with pre-capillary PH were retrospectively recruited. The surrogate "gold standard" of RV-PA coupling was derived from right heart catheterization (RHC) and cardiac magnetic resonance imaging (CMR). The relationships between echocardiographic RV-PA coupling parameters and RHC-CMR coupling standard were analyzed by Pearson's test and Bland‒Altman test. Additionally, 24 chronic thromboembolic pulmonary hypertension (CTEPH) patients were enrolled to explore the changes in echocardiographic RV-PA coupling parameters before and after PEA. Multivariate ordinal regression analysis was performed to identify echocardiographic parameters associated with prognostic risk stratification in pre-capillary PH patients. RESULTS: 3DE coupling parameters demonstrated strong correlation and good agreement with the RHC-CMR coupling standard. In contrast, TAPSE/sPAP was moderately correlated to the RHC-CMR coupling standard, but showed poor consistency, with a significant bias of 0.44 (95% CI: 0.374, 0.511). Before and after PEA, stroke volume/end-systolic volume (SV/ESV) derived by 3DE remained moderately correlated with pulmonary vascular resistance (PVR) and mean pulmonary artery pressure (mPAP) (r =-0.614, -0.655, P < 0.001), whereas TAPSE/sPAP was only associated with PVR and mPAP in CTEPH patients before PEA (r=-0.605, -0.758, P < 0.001). Multivariate regression analysis revealed TAPSE/sPAP as the strongest predictor of prognostic risk. CONCLUSIONS: 3DE-derived coupling parameters offer a noninvasive and reliable approach for assessing RV-PA coupling in patients with pre-capillary PH, especially for patients who cannot accurately estimate pulmonary artery pressure or have undergone cardiac surgery. 3DE SV/ESV is superior to TAPSE/sPAP for assessing postoperative RV-PA coupling in CTEPH patients, TAPSE/sPAP remains a valuable parameter for prognostic risk stratification in pre-capillary PH patients. Echocardiography can provide valuable information for assessing RV-PA coupling and prognosis in patients with pre-capillary PH. However, the application of echocardiographic coupling parameters should be determined based on the specific clinical context.