CORE-PH: A 3-Component Score for Long-Term Mortality Risk in a Pulmonary Arterial Hypertension Cohort.

Background/Objectives: Pulmonary arterial hypertension (PAH) risk tools do not jointly capture right ventricular adaptation, systemic oxygen balance, and nutritional reserve. We developed the three-component CORE-PH score and assessed its association with long-term mortality. Methods: This retrospective, single-center study included 105 treatment-naïve adults with group 1 PAH or group 4 chronic thromboembolic pulmonary hypertension who underwent diagnostic right heart catheterization in 2011-2025. One point each was assigned for Prognostic Nutritional Index ≤ 47.7, TAPSE/sPAP ≤ 0.4632 mm/mmHg, and mixed venous oxygen saturation ≤ 68.1%. Mortality associations were assessed using Cox regression. Discrimination was compared with COMPERA 2.0 and REVEAL Lite 2 using time-dependent AUCs at 12, 36, and 60 months. Bootstrap validation repeated threshold selection and score reconstruction. Results: Of 105 patients, 98 (93.3%) had PAH and 51 died during a median follow-up of 70.0 months. Each CORE-PH point was associated with greater mortality after adjustment for age and functional class (hazard ratio, 2.645; 95% confidence interval, 1.823-3.837; p < 0.001). The association persisted in the contemporary-definition sensitivity cohort (n = 84). Time-dependent AUCs were 0.779, 0.779, and 0.817 at 12, 36, and 60 months. AUCs were higher than those of COMPERA 2.0 at 36 and 60 months, while differences versus REVEAL Lite 2 were not statistically significant. The optimism-corrected C-index was 0.719, and the optimism-corrected calibration slope was 0.888. Conclusions: CORE-PH identified a mortality gradient in this predominantly PAH cohort. External validation is required before clinical use; applicability to other forms of precapillary pulmonary hypertension remains uncertain.