Abstract
Right ventricular (RV) dysfunction is a critical yet often underrecognized determinant of prognosis in patients with advanced interstitial lung disease (ILD) undergoing lung transplant evaluation. The tricuspid annular plane systolic excursion to pulmonary arterial systolic pressure (TAPSE/PASP) ratio has emerged as a promising noninvasive echocardiographic surrogate of RV-pulmonary arterial (RV-PA) coupling, offering a dynamic estimate of RV function relative to afterload. In this single-center retrospective cohort study, we assessed the prognostic association of the TAPSE/PASP ratio in 65 lung transplant candidates with advanced ILD. All patients underwent comprehensive transthoracic echocardiography and right heart catheterization as part of pre-transplant evaluation. The primary endpoint was a composite of all-cause mortality or lung transplantation. Over a median follow-up of 24 months, 33 patients (50.8%) reached this endpoint. Receiver operating characteristic (ROC) curve analysis identified an optimal TAPSE/PASP cutoff value of 0.55 (AUC: 0.763, p < 0.001), with a sensitivity of 70% and specificity of 75% for predicting adverse outcomes. Patients with TAPSE/PASp < 0.55 exhibited significantly worse transplant-free survival (log-rank p = 0.0057), more pronounced RV structural and functional impairment, and elevated pulmonary vascular resistance. In multivariable Cox regression analysis, TAPSE/PASP was the sole independent predictor of the primary outcome (HR: 0.09, p = 0.01). These findings suggest that the TAPSE/PASP ratio may constitute a feasible and reproducible noninvasive surrogate of RV-pulmonary arterial uncoupling and could facilitate the identification of high-risk individuals among lung transplant candidates with advanced interstitial lung disease. However, in light of the retrospective and single-center nature of this study, the results should be interpreted with caution as hypothesis-generating, and further validation in large-scale, prospective, multicenter cohorts is warranted.