Echocardiographic assessment for cardiopulmonary function in patients with congenital heart disease-related pulmonary arterial hypertension

Abstract

Background

For patients with congenital heart disease-related pulmonary arterial hypertension (CHD-PAH), cardiopulmonary exercise testing (CPET) can reflect cardiopulmonary reserve function. However, CPET may not be readily accessible for patients with high-risk conditions or limited mobility due to disability. Echocardiography, on the other hand, serves as a widely available diagnostic tool for all CHD-PAH patients. This study was aimed to identify the parameters of echocardiography that could serve as indicators of cardiopulmonary function and exercise capacity.

Methods

A cohort of 70 patients contributed a total of 110 paired echocardiogram and CPET results to this study, with 1 year interval for repeated examinations. Echocardiography and exercise testing were conducted following standardized procedures, and the data were collected together with clinically relevant indicators for subsequent statistical analysis. Demographic comparisons were performed using t-tests and chi-square tests. Univariate and multivariate analyses were conducted to identify potential predictors of peak oxygen uptake (peak VO₂) and the carbon dioxide ventilation equivalent slope (VE/VCO₂ slope). Receiver operating characteristic (ROC) analysis was used to assess the performance of the parameters.

Results

The ratio of tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) was found to be the only independent indicator significantly associated with both peak VO₂ and VE/VCO₂ slope (both p < 0.05). Additionally, left ventricular ejection fraction (LVEF) and right ventricular fractional area change (FAC) were independently correlated with the VE/VCO₂ slope (both p < 0.05). TAPSE/PASP showed the highest area under the ROC curve (AUC) for predicting both a peak VO₂ ≤ 15 mL/kg/min and a VE/VCO₂ slope ≥ 36 (AUC = 0.91, AUC = 0.90, respectively). The sensitivity and specificity of TAPSE/PASP at the optimal threshold exceeded 0.85 for both parameters.

Conclusions

TAPSE/PASP may be a feasible echocardiographic indicator for evaluating exercise tolerance.