National trends and inpatient outcomes of pulmonary arterial hypertension related hospitalizations – Analysis of the National Inpatient Sample Database

Background: Pulmonary arterial hypertension (PAH) is associated with a significant burden of morbidity and mortality. We examined national trends in PAH-related hospitalizations, associated inpatient mortality (IM), length of stay (LOS) and hospitalization charges from 2007 to 2016, as well as predictors of IM and LOS in this population. Methods: We used the National Inpatient Sample to identify PAH admissions using International classification of diseases (ICD) codes 416.0 (ICD-9) and I27.0 (ICD-10). Records suggestive of secondary causes of pulmonary hypertension were excluded. 6162 (weighted) records with PAH as the primary diagnosis were analyzed. Results: Mean age was 38.7 years, with the majority being females (78.8%). Overall IM was 6.03%, mean LOS 7.6 ± 0.5 days and mean charges $84,100 ± 6200. PAH-related hospitalizations (per million) (27 in 2007 vs. 28 in 2016, p = 0.19) and associated IM (4.5% in 2007 vs. 6.8% in 2016, p = 0.748) as well as LOS (5.9 days in 2007 vs 6.7 days in 2016, p = 0.304) remained unchanged over the decade. Charges increased by 2.4-fold ($43,800 in 2007 to $103,300 in 2016, p = 0.002). While right heart failure, fluid/electrolyte disorders, cardiac arrhythmia and neurological disorders were associated with increased IM, Hispanic race was found to have a survival benefit. Fluid/electrolyte disorders and coagulopathy were associated with increased LOS. Conclusion: Despite significant advancements in PAH therapies over the duration of this study, the rate of PAH hospitalizations, and associated IM and LOS remain unchanged. The study identified the predictors of IM and prolonged LOS in PAH population which could be used for additional risk stratification of these patients.