Interest of TAPSE/sPAP ratio for noninvasive pulmonary arterial hypertension risk assessment

Background: Although ventriculoarterial coupling is associated with better survival in pulmonary arterial hypertension (PAH), existing PAH risk assessment method has not considered echocardiographic criteria of right ventricular to pulmonary artery coupling. We aimed to test the prognostic value of the echocardiographic tricuspid annular plane systolic excursion/systolic pulmonary artery pressure (TAPSE/sPAP) ratio for noninvasive PAH risk assessment.

Methods: We retrospectively studied a cohort of 659 incident PAH patients from 4 independent French PH centers (training cohort: n = 306, validation cohort n = 353) who underwent follow-up TAPSE/sPAP measurement in addition to previously validated noninvasive risk stratification variables. The primary composite outcome was 3-year all-cause mortality or lung transplantation from re-evaluation.

Results: Mean age was 55 ± 17 years-old with a majority of female (66%). The three main PAH causes were connective tissue disease (26%), idiopathic (24%) and porto-pulmonary (19%). The primary composite outcome occurred in 71 (23%) patients. Multivariable Cox regression analysis retained 3 noninvasive low-risk criteria as associated with the primary composite outcome: NYHA I-II (p = 0.001), NTproBNP <300 ng/L or BNP <50 ng/L (p = 0.004), and TAPSE/sPAP >0.33 mm/mmHg (p = 0.004). The more the low-risk criteria achieved at follow-up, the better the event-free survival both in the training and validation cohort (log-rank p < 0.001). In the training cohort, the c-index for these 3 criteria, for COMPERA 2.0 and for the noninvasive French Pulmonary Hypertension Network method were 0.75, 95%CI(0.70-0.82), 0.72 95%CI(0.66-0.75), 0.71 95%CI(0.62-0.73), respectively.

Conclusion: The 3 following dichotomized low-risk criteria: TAPSE/sPAP >0.33 mm/mmHg, NYHA I-II and NTproBNP <300 ng/L or BNP <50 ng/L allow to identify low-risk PAH patients at follow-up.