Identifying consistent echocardiographic thresholds for risk stratification in pulmonary arterial hypertension.

Several indices of right heart remodeling and function have been associated with survival in pulmonary arterial hypertension (PAH). Outcome analysis and physiological relationships between variables may help develop a consistent grading system. Patients with Group 1 PAH followed at Stanford Hospital who underwent right heart catheterization and echocardiography within 2 weeks were considered for inclusion. Echocardiographic variables included tricuspid annular plane systolic excursion (TAPSE), right ventricular (RV) fractional area change (RVFAC), free wall strain (RVFWS), RV dimensions, and right atrial volumes. The main outcome consisted of death or lung transplantation at 5 years. Mathematical relationships between variables were determined using weighted linear regression and severity thresholds for were calibrated to a 20% 1-year mortality risk. PAH patients ( n  = 223) had mean (SD) age of 48.1 (14.1) years, most were female (78%), with a mean pulmonary arterial pressure of 51.6 (13.8) mmHg and pulmonary vascular resistance index of 22.5(6.3) WU/m ² . Measures of right heart size and function were strongly related to each other particularly RVFWS and RVFAC ( R ²  = 0.82, p  < 0.001), whereas the relationship between TAPSE and RVFWS was weaker ( R ²  = 0.28, p  < 0.001). Death or lung transplantation at 5 years occurred in 78 patients (35%). Guided by outcome analysis, we ascertained a uniform set of parameter thresholds for grading the severity of right heart adaptation in PAH. Using these quantitative thresholds, we, then, validated the recently reported REVEAL-echo score (AUC 0.68, p  < 0.001). This study proposes a consistent echocardiographic grading system for right heart adaptation in PAH guided by outcome analysis.
Competing Interests: Bettia Celestin, Shadi P. Bagherzadeh, Kenzo Ichimura, Everton J. Santana, Andrew John Sweatt and Pablo Amador Sanchez, have no conflicts to report. Francois Haddad has received funding from Janssen Inc. to conduct the research. Tobore Tobore is a senior director of Medical Affairs at Janssen. Anton Vonk Noordegraaf is supported by the Netherlands CardioVascular Research Initiative (CVON‐2012‐08 PHAEDRA, CVON‐2017‐10 DOLPHIN‐GENESIS) and the Netherlands Organization for Scientific Research (NWO‐VICI: 918.16.610). In addition, his institute received speakers money from Johnson & Johnson, MSD, Actelion, Bayer and Ferrer in the past 3 years. Finally, he served as a member of the scientific advisory board of Morphogen‐X, Ferrer, Gosammer Bio Services Inc, Altavant, MSD and Johnson & Johnson. The remaining authors declare no conflict of interest.
(© 2024 The Authors. Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of Pulmonary Vascular Research Institute.)