Impact of Iron Deficiency Anemia in Patients with Pulmonary Arterial Hypertension

Abstract

The impact of iron deficiency anemia on hospital length of stay and in hospitalization mortality has not been investigated in patients whose main reason for admission is pulmonary arterial hypertension. We sought to compare the outcomes in hospitalization in patients with pulmonary arterial hypertension (PAH) with a diagnosis of iron deficiency anemia (IDA) versus those without from a large sample database. The National Inpatient Sample (NIS) was used to identify all patients hospitalized 18 years of age and older in 2016 with a primary or secondary diagnosis of PAH by ICD-10 code I270. Within each hospitalization, the diagnosis of IDA was further identified using ICD-10 code D50.xx. We then examined the relative risk profile, and outcomes of interests including length of stay (LOS), total charges, number of diagnoses, Elixhauser[EC1] mortality, readmission score and in hospital mortality of each group. Categorical variables were analyzed with logistic regression models while continuous variables were assessed using two sample t-tests. All analyses were conducted using SAS v 9.4 and accounted for the NIS sampling design and updated hospital trend weights. A total of 10,300 patients with a primary or secondary diagnosis of PAH were identified, and of those, 8.45% had a diagnosis of IDA[EC2] . The cohort with IDA had a majority of women (80% vs 68%, p=<0.0001[EC3]), and were more likely to be black (24.5% vs 18.4%, p<0.0001). The number of hospital diagnoses in the IDA group was higher as well (17.0 vs 19.24, p=<0.0001). The IDA cohort were more likely to obese (28.74% vs 23.12%, p = 0.0061), have heart failure (52.30% vs 46.24%, p=0.0350), and have high risk features such as a pericardial effusion (6.32% vs 2.97%, p=0.0015). The IDA cohort were also more likely to be readmitted (mean readmission scores 35.19, p<0.0001), but there was no significant difference in length of stay, in hospital mortality, or hospital charges. Patients with primary pulmonary hypertension and IDA are more likely to be female and non-Caucasian, obese, have heart failure, or pericardial effusion, higher number of co-morbidities, and are more likely to be readmitted that those without IDA.