Impact of Pulmonary Hypertension on in-hospital outcomes amongst Sickle Cell Disease hospitalizations

Introduction: Pulmonary hypertension (PH) is a common and severe complication of Sickle Cell Disease (SCD), and an independent risk factor for mortality. While there is a clear association between SCD and PH, the predictors of PH in SCD and the impact of PH on in-hospital outcomes of SCD hospitalizations remains unknown. In our study, we sought to assess the in-hospital prevalence, predictors, and the impact of PH in SCD hospitalizations.

Methods:

We used the 2016 and 2017 National Inpatient Sample (NIS) to identify all adult hospitalizations with a primary discharge diagnosis of SCD. The sample was then stratified based on the presence or absence of PH. We used the Pearson chi-square test and weighted Student’s t-test to analyze categorical and continuous variables, respectively. Multivariate logistic regression analysis was performed to calculate the adjusted odds ratio for various clinical outcomes. SAS was used for the analysis, and the p-value was defined as <0.05.

Results:

We identified n=191,080 weighted hospitalizations for SCD, of which, 5.54% (n=10590) had concomitant PH. Female gender and comorbidities including hypertension, obesity, illicit drug use, hepatic cirrhosis, renal failure, prior venous-thromboembolism, valvular, and congenital heart disease were identified as significant predictors of PH in SCD. PH was associated with increased in-hospital mortality (1.04% vs 0.22%, AOR=2.14, 95% CI 1.15-3.98, p=0.0158). PH in SCD hospitalizations also increased the odds of - acute kidney injury (AKI), need for dialysis, acute respiratory failure (ARF), and need for mechanical ventilation for > 96 hours. The adjusted odds ratio for venous thromboembolism, shock-state, and the need for cardiac catheterization (both right and bilateral) were also higher in patients with PH. Overall hospitalization cost and length of stay increased (7.06±0.16 vs 1.82±0.02 days) in patients with SCD and PH (see table 1).

Conclusion:

In sickle cell disease hospitalizations, PH is independently associated with increased in-hospital morbidity and mortality, with an increased need for in-hospital catheterizations thereby, prolonging the length of stay and overall health care costs. Identifying and treating PH in the SCD population would improve in-hospital outcomes.