Risk assessment is essential in pulmonary arterial hypertension (PAH) management. We investigated the effect of riociguat on REVEAL Lite 2 score, an abridged version of the REVEAL risk score, and its association with long-term outcomes in PATENT. PATENT-1 was a randomized, double-blind study of riociguat vs placebo in patients with PAH. In the PATENT-2 open-label extension, all patients received riociguat up to 2.5mg three times daily (n=396). REVEAL Lite 2 scores were calculated at baseline, PATENT-1 Week 12, and PATENT-2 Week 12, with patients stratified as low- (1-5), intermediate- (6-7), or high-risk (≥8). Kaplan-Meier and Cox proportional hazards analyses assessed association of riociguat with survival and clinical worsening-free survival (CWFS). REVEAL Lite 2 score improved with riociguat 2.5mg at PATENT-1 Week 12 (least-squares mean difference vs placebo: -0.8; p=0.0004). More patients receiving riociguat 2.5 mg stabilized or improved risk stratum at PATENT-1 Week12 vs placebo (p=0.0005) and achieved low-risk status. REVEAL Lite 2 score at baseline and PATENT-1 Week 12 were associated with survival and CWFS (all p < 0.0001), as was change in score from baseline to Week12 (p=0.0002 and p < 0.0001, respectively). Survival and CWFS differed between risk strata at baseline (p < 0.0001) and PATENT-1 Week 12 (p < 0.0001). This analysis confirms the risk-reduction benefits of riociguat in patients with PAH and further contributes to the validation of REVEAL Lite 2 in facilitating PAH risk assessment.