Epidemiology and Treatment Patterns of Pulmonary Arterial Hypertension (PAH) Patients Across US Regions Using Real-World Data from OPUS/OrPHeUS

Rationale: Management of PAH in the US is decentralized, with potential healthcare differences across regions. We used real-world data from OPUS/OrPHeUS to describe PAH patient characteristics and treatment patterns across four US regions. Methods: OPUS (NCT02126943) was a prospective, multicenter, long-term, US observational drug registry, (April 2014-April 2020). OrPHeUS (NCT03197688) was a retrospective, multicenter, US medical chart review (October 2013-March 2017); data cut-off was February 2020. This analysis describes baseline characteristics and treatment patterns in PAH patients newly initiated on macitentan in the combined OPUS/OrPHeUS dataset in four US regions: West, Midwest, Northeast and South. Results: By February 2020, 4540 PAH patients had follow-up data in the combined dataset. Of these, 4456 patients were from one of four US regions: West (N=928), Midwest (N=980), Northeast (N=690), and South (N=1858). Patient characteristics at macitentan initiation are shown in the table. Median age ranged from 57 years in West to 63 years in South. Compared to other regions, the proportion of patients with idiopathic PAH was higher in South; the proportion of PAH associated with connective tissue disease was higher in Midwest and Northeast; while the proportions of drug and toxininduced PAH and PAH associated with congenital heart diseases were higher in West. The majority of patients in all regions had prevalent disease and were in World Health Organization functional class (WHO FC) III/IV. Median 6-minute walk distance was lowest in Northeast and highest in West. Median (Q1, Q3) macitentan exposure in months was 14.6 (5.6, 28.6) in West, 15.3 (4.8, 30.5) in Midwest, 15.2 (5.4, 30.7) in Northeast and 13.4 (5.1, 27.4) in South. Percentages of patients receiving mono/double/triple therapy at macitentan initiation, respectively, were: 36%/48%/15% in West; 31%/51%/18% in Midwest; 44%/45%/11% in Northeast; 43%/45%/12% in South. At 2 years, across regions, 52-60% of patients who had initiated on monotherapy were still receiving monotherapy. Conclusions: Baseline characteristics and treatment patterns in PAH patients initiating macitentan were comparable across the four US regions. The majority of patients had prevalent disease, were in WHO FC III/IV and initiated macitentan as part of a combination therapy regimen, with a slightly higher proportion of patients receiving combination therapy at macitentan initiation in West and Midwest. Despite recommendations for use of combination therapy, across all regions a considerable proportion of patients were initiated and maintained on monotherapy, and the proportion of patients receiving triple therapy was low.