Right ventricular myocardial performance score predicts 1 year mortality in pulmonary arterial hypertension

Background Multiparametric risk stratification is essential to determine prognosis and treatment in pulmonary arterial hypertension (PAH). Aside from right atrial pressure, traditional hemodynamic variables at diagnosis have an inconsistent association with prognosis in contemporary PAH cohorts. Hemodynamic indices of right ventricular-pulmonary artery (RV-PA) coupling may be better markers of prognosis but require further study. The right ventricular myocardial performance score (RV-MPS) was recently shown to estimate RV contractility, RV mechanical efficiency, RV-PA coupling and predict adverse outcomes at 1 year in patients with advanced left ventricular failure. The utility of RV-MPS in other etiologies of RV failure, such as PAH, is unknown. Purpose Assess the prognostic value of a novel hemodynamic metric, RV-MPS, in patients with WHO group 1 PAH. Methods Single center retrospective study of patients diagnosed with WHO Group 1 PAH between 1986 and 2024. Subjects were required to have complete hemodynamic data at the time of initial right heart catheterization. Congenital heart disease etiology was excluded. Advanced hemodynamic parameters calculated included pulmonary artery pulsatility index (PAPI), RV cardiac power output (RV-CPO) and RV-MPS. RV-MPS was calculated as (3 x PAPI x RV-CPO) / 2. The primary outcome was defined as a composite endpoint of death or lung transplant at 1 year. Results 335 patients were included in the study (51.8±15 years, 83.9% female, 53.4% white). The most common etiologies were connective tissue disease (40%) and idiopathic (36%). Baseline clinical characteristics: NT-proBNP 1374 (IQR: 280, 3936) pg/mL, 6-minute walk distance 302 (IQR: 230, 376) meters, WHO functional class II (38.3%) and III (41.3%), systolic blood pressure 123±20 mmHg, heart rate 82±14 bpm and eGFR 61 (IQR: 42,82) mL/min/1.73m² which correlates with a REVEAL Lite 2 score between 8 and 9. Baseline RV-MPS was 3.05 (IQR: 1.60-5.46), PAPI 5.4 (IQR: 3.6-9.2) and RV-CPO 0.35 (IQR: 0.25-0.46). Additional baseline hemodynamics are listed in Table 1. 57 (17.0%) patients died or underwent lung transplant at 1 year. In multivariate analysis, RV-MPS (OR 0.988 per 0.1 increase, 95% CI 0.97-0.99; p = 0.028) and eGFR (OR 0.84 per 10 increase, 95% CI 0.73-0.98; p = 0.023) were independent predictors of death or lung transplantation at 1 year. Other traditional and advanced hemodynamic parameters were not significant predictors of the primary outcome on multivariable analysis. Receiver operator characteristic analysis specified an optimal cutpoint of 3 for RV-MPS. Kaplan-Meier analysis indicated an association of RV-MPS with the primary outcome (87.5% for RV-MPS >3 vs 78.4% for RV-MPS ≤ 3; p <0.02) (Figure 1). Conclusion RV-MPS is a novel hemodynamic marker of RV-PA coupling that predicts death or need for lung transplant at 1 year from diagnosis in WHO group 1 PAH. A RV-MPS value of >3 was associated with improved prognosis.