Right Ventricular–Pulmonary Arterial Coupling by Serial TAPSE/sPAP: A Noninvasive Predictor for Clinical Outcomes in Chronic Thromboembolic Pulmonary Hypertension

Abstract

ABSTRACT The ratio of tricuspid annular plane systolic excursion to systolic pulmonary artery pressure (TAPSE/sPAP) is a noninvasive surrogate of right ventricular–pulmonary arterial coupling, but its value for dynamic risk stratification in chronic thromboembolic pulmonary hypertension (CTEPH) remains uncertain. This multicenter prospective cohort enrolled adults with CTEPH between 2016 and 2023. Patients were stratified by quartile‐based baseline TAPSE/sPAP cutoffs into < 0.15, 0.15 to 0.30, and > 0.30. The primary outcome was clinical worsening (CW) within 12 months, comprising all‐cause death, hospitalization for worsening pulmonary hypertension, escalation of pulmonary hypertension‐targeted therapy, or a > 30% increase in pulmonary vascular resistance. Associations were examined using Kaplan–Meier, Cox regression, and time‐dependent Cox analyses. Among 949 patients, 868 had follow‐up and 212 (24.4%) experienced CW during a median follow‐up of 10.3 months (interquartile range, 5.4–12.2 months). Lower baseline TAPSE/sPAP was associated with worse functional and hemodynamic profiles, and CW‐free survival differed across strata (log‐rank p = 0.004). Each 0.1‐unit increase in baseline TAPSE/sPAP was associated with lower CW risk (adjusted HR, 0.89; 95% CI, 0.79–0.99; p = 0.039). Among 593 patients with serial measurements, higher time‐updated TAPSE/sPAP (adjusted HR, 0.66; 95% CI, 0.52–0.83; p < 0.001) and greater improvement from baseline (adjusted HR, 0.81; 95% CI, 0.71–0.92; p = 0.002) were associated with lower subsequent CW risk. Lower TAPSE/sPAP identifies greater disease severity and CW risk in CTEPH. Serial TAPSE/sPAP may support noninvasive dynamic risk stratification and residual risk assessment during follow‐up.