121 Imaging of improved right ventricular function and risk status in pulmonary arterial hypertension

Aims Right ventricular function adaptation to afterload as assessed by the ratio of tricuspid annular plane excursion (TAPSE) to systolic pulmonary artery pressure (PASP) has been shown to be of prognostic relevance in pulmonary arterial hypertension (PAH). To test the hypothesis that improvement in TAPSE/PASP under targeted therapies is associated with the likelihood to achieve a better prognostic low-risk status in PAH. Methods and results The study retrospectively enrolled 677 PAH patients (55% idiopathic) with follow-up clinical, right heart catheterization, and echocardiographic evaluations within 12 months [interquartile range (IQR): 180–344 days] after initiation of targeted therapies from 2005 to 2017 in 11 Italian centres. European guidelines-derived and United States Registry to Evaluate Early and Long-Term PAH Disease Management registry REVEAL 2.0 risk scores were assessed at baseline and follow-up. The patients improved their functional class and 6-min walk distance, but a minority of them achieved or maintained the low risk status as assessed either with the European or the REVEAL 2.0 score (30% and 27%, respectively). The TAPSE/PASP ratio increased curvilinearly in proportion to decreased pulmonary vascular resistance (PVR) by more than 50%. Patients at low risk were, respectively, 4.93 and 3.37 times more likely to have TAPSE/PASP ≥0.35 mm/mmHg than those at intermediate or high risk, according to the ESC/ERS [odds ratio: (OR) 4.93, confidence interval (CI): 3.40–7.14; P = 0.0001] and the REVEAL 2.0 score (OR: 3.37, CI: 2.32–4.90; P = 0.0001). Conclusions Improvement of TAPSE/PASP under targeted therapies in PAH is associated with a low risk status, marked reduction in PVR, and improved outcome.