OBJECTIVES: Prostacyclins improve symptomatology and survival among pulmonary arterial hypertension (PAH) patients; however, they are commonly reserved for later stage disease. The objective of this study was to explore the impact of prostacyclins on time to all-cause and PAH-related rehospitalization. METHODS: This study utilized the Pharmetrics Plus claims database from 2011-2015 and included patients with ≥2 claims for Pulmonary Hypertension (ICD-9: 416.0/416.8) with a right-heart catheterization and a PAH-related hospitalization. Patients were followed from first PAH-related hospitalization to next all-cause and PAH-related rehospitalization or censor. Rehospitalization rate and time to rehospitalization were calculated. Patients were categorized into those initiating a prostacyclin (PCYI), continuing a prostacyclin (PCYC), or other treatment (ALT). Analysis included ANOVA for continuous variables with ALT as the reference, chi-square tests for categorical, and Cox proportional hazard (CPH) models for time to rehospitalization adjusting for age, gender, and Charlson Comorbidity (CCI) scores. RESULTS: Patients receiving a prostacyclin were younger (PCYI: 49.74 (SD=16.35), PCYC: 50.35 (SD=16.83), ALT: 54.61 (SD=15.44), p<0.01) and more frequently female (PCYI:64.55%, PCYC:73.91%, ALT:46.56%, p≤0.01). Assessing the proportion of patients who were rehospitalized all-cause, PCYI had the fewest (58.18%, PCYC:63.48%, ALT:71.97%, p≤0.01) with similar but non-significant results for PAH-related rehospitalizations (PCYI:40.91%, PCYC:53.48%, ALT:52.18%, p=0.06). The average time to all-cause rehospitalization (PCYI: 396.8 (SD=380.8), PCYC: 409.70 (SD=419.95), ALT: 219.47 (SD=309.09), p<0.01) and PAH-related rehospitalization (PCYI: 438.8(SD 393.7), PCYC: 442.6 (SD=439.0), ALT: 321.1 (SD=386.8), p<0.01) were longer with prostacyclins compared to ALT. After adjusting for covariates CPH models showed similar results for all-cause rehospitalization (PCYI: HR=0.53, p<0.01; PCYC: HR=0.62, p<0.01) but was only significant among PCYI group for PAH-related rehospitalization (PCYI: HR=0.64, p<0.01; PCYC: HR=0.89, p=0.2). CONCLUSIONS: This study highlights the real-world benefit of including a prostacyclin for treatment of PAH to reduce/delay hospital readmissions, regardless of whether the patient is continuing or initializing a new prostacyclin.