Changes in REVEAL Lite 2 risk status are associated with long-term outcomes in patients with pulmonary arterial hypertension: a post-hoc analysis of the GRIPHON study

Background: Mortality risk assessment informs clinical management of pulmonary arterial hypertension (PAH). The Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) Lite 2 is a simplified risk calculator discriminating 1-year mortality risk. Methods: This post-hoc analysis of the phase 3 GRIPHON study assessed changes in REVEAL Lite 2 risk score with selexipag versus placebo, and whether changes were prognostic or predictive of time to first morbidity/mortality (M/M) event. Results: REVEAL Lite 2 risk category discriminated M/M risk (landmark concordance indices: 0.68-0.76, selexipag; 0.65-0.70, placebo). Across baseline risk categories, hazard ratios supported a lower risk of M/M events with selexipag versus placebo: low, 0.573 (95% confidence interval [CI] 0.361-0.908; p = 0.0178); intermediate, 0.423 (95% CI 0.274-0.655; p = 0.0001); high, 0.711 (9% CI 0.520-0.972; p = 0.0326). Odds ratios for risk improvement were 2.0 (95% CI 1.50-2.65), 1.8 (95% CI 1.38-2.43), and 2.0 (95% CI 1.43-2.72) for selexipag versus placebo at 16, 26, and 52 weeks, respectively (all p < 0.001). REVEAL Lite 2 risk improvement at Week 16 explained 19.1% of the treatment effect in all patients and 47.0% in patients with REVEAL Lite 2 baseline risk score of ≥ 7. Conclusions: REVEAL Lite 2 can monitor PAH M/M risk and facilitate treatment optimization. Baseline REVEAL Lite 2 risk score was prognostic of M/M risk in patients with PAH and mediates treatment effect up to 47% for those at higher risk. Lower M/M risk with selexipag versus placebo occurred irrespective of baseline risk category. (ClinicalTrials.gov identifier: NCT01106014).