COMPERA 2.0: A refined 4-strata risk assessment model for pulmonary arterial hypertension

Abstract

BACKGROUND Risk stratification plays an essential role in the management of patients with pulmonary arterial hypertension (PAH). The current European guidelines propose a 3-strata model to categorise risk as low, intermediate, or high, based on the expected 1-year mortality. However, with this model, most patients are categorised as intermediate risk. We investigated a modified approach based on 4 risk categories with intermediate risk subdivided into intermediate-low and intermediate-high risk. METHODS We analysed data from COMPERA, a European pulmonary hypertension registry, and calculated risk at diagnosis and first follow-up based on functional class (FC), 6 min walking distance (6 MWD) and serum levels of brain natriuretic peptide (BNP) or N-terminal fragment of pro-BNP (NT-proBNP), using refined cut-off values. Survival was assessed with Kaplan-Meier analyses, log-rank testing, and Cox proportional hazards models. RESULTS Data from 1,655 patients with PAH were analysed. Using the 3-strata model, most patients were classified as intermediate risk (76.0% at baseline and 63.9% at first follow-up). The refined 4-strata risk model yielded a more nuanced separation and predicted long-term survival, especially at follow-up assessment. Changes in risk from baseline to follow-up were observed in 31.1% of the patients with the 3-strata model and in 49.2% with the 4-strata model. These changes, including those between the intermediate-low and intermediate-high strata, were associated with changes in long-term mortality risk. CONCLUSIONS Modified risk stratification using a 4-strata model based on refined cut-off levels for FC, 6MWD and BNP/NT-proBNP was more sensitive to prognostically relevant changes in risk than the original 3-strata model