Risk Stratification Scores in Pulmonary Arterial Hypertension

An evaluation of 3 risk assessment tools for pulmonary arterial hypertension (PAH) found that each of the tools had value in predicting survival up to 5 years from baseline, and that the predictive value of these tools improved with evaluations done after 1 year of treatment for PAH. Findings of the evaluation were recently published in Respiration.

In the current study, investigators compared the predictive value with respect to transplant-free survival (TFs) in PAH for 3 risk assessment tools: 1) Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) risk score version 2.0; 2) Swedish/Comparative Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (PH) (COMPERA) score; and 3) French PH Network Registry (FPHR) score. The researchers retrospectively assessed these tools’ predictive value for predicting survival at 3 and 5 years post PAH diagnosis in a cohort of 50 patients. The investigators also assessed whether patients’ initial stratification changed when patients were evaluated with each tool 1 year after initiation of PAH treatment.

In the analysis, each tool was used to divide the 50 patients studied into low, intermediate, and high mortality risk groups at baseline and 1 year. At baseline, transplant-free survival rates at 3 years were predicted, with an area under the curve (AUC) of 0.73 for REVEAL, 0.73 for COMPERA, and 0.77 for FPHR. After 1 year of treatment, this predictive value increased, with AUCs of 0.91 for REVEAL, 0.89 for COMPERA, and 0.78 for FPHR. Importantly, low-risk status on any test was strongly associated with excellent transplant-free survival rates.

COMPERA and FPHR better predicted risk at 5 years compared with REVEAL 2.0. This finding is unexpected because REVEAL involves more variables. The authors hypothesized, however, that the extra variables could have confounded the predictive value after 3 years.

The authors highlighted that the choice of treatment at the time of diagnosis was partially associated with the initial severity of the disease. Overall, 50% of patients were administered monotherapy, with the other half receiving combination treatment within 3 months of diagnosis.

Limitations of the current study include a small sample size, which makes it difficult to extrapolate results to other populations. Another limitation was the retrospective nature of the study, with a paucity of certain variables. The study was also conducted over an extended interval of time during which new drugs and guidelines were introduced.

“Further investigation is necessary for the evaluation of potential new variables that could improve the prediction of the 3 risk assessment tools,” concluded the authors. “For example, peak oxygen uptake measured during cardiopulmonary exercise testing would be a potential candidate marker. Finally, as individual response to treatment has a major impact for prognosis, score calculation after 6 and/or 12 months should be strongly recommended.”

Reference

Vraka A, Yerly P, Aubert JD. Comparison of Risk Stratification Scores in Pulmonary Arterial Hypertension: A Monocentric Retrospective Study at Lausanne University Hospital. Respiration. Published online January 19, 2022. doi:10.1159/000520886.