Abstract 4144961: Validation of Right Ventricle and Pulmonary Artery Decoupling via Non-Invasive and Invasive Measurements in Pulmonary Arterial Hypertension: Significance and Considerations for Early Detection and Prognostic Stratification

Backgrounds: The ratio of tricuspid annular plane systolic excursion over the estimated pulmonary artery systolic pressure (TAPSE/PASP) has shown as a parameter of coupling between right ventricle and pulmonary artery. Despite its importance, the accuracy of estimating PASP in echocardiography and the diagnostic/prognostic value of TAPSE/PASP are not fully understood. Methods: We examined 697 pairs of right heart catheterization and echocardiography performed in 264 patients who were suspected to have pulmonary arterial hypertension (PAH). We excluded the data of echocardiogram with no TR (n = 6). The correlation of PASP measured by right heart catheterization and echocardiography was analyzed according to the severity of tricuspid regurgitation (TR). The accuracies of predicting the presence of PAH by TAPSE/PASP were examined by receiver operating characteristic (ROC) curve analysis. The severity of TAPSE/PASP was categorized in three groups according to the current guideline (low: < 0.19, intermediate: 0.19 - 0.31, high: > 0.31 mm/mmHg), and the association between TAPSE/PASP and composite prognosis of cardiovascular death or lung transplantation was evaluated by Kaplan-Meier analysis. Results: At baseline, median age was 57 [interquartile range: 42, 71], 188 (71.2%) of the patients were female, median TRPG was 50.7 [35.0, 69.3] mmHg, median TAPSE was 18.0 [14.9, 23.0] mm, and median mean PAP was 34 [21, 46] mmHg. Trivial TR was identified in 159 (23.0%) echocardiography, and PASP was likely to be underestimated in patients with trivial TR (panel A). TAPSE/sPAP was inversely correlated with pulmonary vascular resistance (panel B), and ROC curve analysis demonstrated that TAPSE/PASP 0.55 was the best threshold in predicting the presence of PAH, but the threshold was higher in trivial TR (panel C). The Kaplan-Meier analysis demonstrated that patients whose TAPSE/PASP were under 0.19 mm/mmHg had significant worse prognosis in contemporary intensive treatment of pulmonary vasodilators (panel D). Conclusions: PASP measured by echocardiography is an accurate noninvasive parameter to estimate the hemodynamics and prognosis in patients with PAH. Since the trivial TR may underestimate the PASP, presence of other echocardiographic signs of PAH should be evaluated especially in patients with trivial TR.