Heart failure readmissions in patients with iron deficiency anemia: A national readmission database analysis

Abstract Background: Heart Failure is a long-standing enervative that contributes to significant morbidity and mortality worldwide. Burden of HF and its complications is increasing over time, which creates a substantial burden on health care, both in terms of resources and economically. Iron deficiency anemia (IDA) is one of the key risk factors that plays a crucial role in HF disease progression and outcomes. There is a paucity of data regarding the impact of IDA on clinical and economic consequences, including readmissions among HF patients, and our study aims to bridge that gap. Methods: We performed a retrospective analysis on the National Readmission Database (2016-17), which tracks hospitalizations and discharges among US hospitals and provides survey-weighted national estimates of outcomes. We identified adults ≥18 years, with principal diagnosis of HF with IDA using respective ICD-10 codes who were admitted non electively and discharged by the end of November to allow for a complete 30-day follow-up period. The primary outcome was 30-day readmission rate. Secondary outcomes included in-hospital mortality, length of stay (LOS), and 2017 inflation-adjusted total hospitalization charges in USD. Results: A total of 59, 204 index hospitalizations with a mean age of 72±15 years, predominantly females (n=32, 817; 55%) were identified for HF patients with IDA in the 2016-17 NRD database. Among those, the 30-day readmission rate was 20. 25% (95% CI 19. 71-20. 8) (n=11, 990). Mortality rate among index hospitalizations was 2. 64% (95% CI 2. 42 – 2. 87), which rose to 6. 46% (95% CI 5. 75-7. 18) during readmission hospitalization. Mean LOS was similar among index (6. 54 days 95% CI 6. 41-6. 67) and readmission (6. 38 days 95% CI 6. 19-6. 58) hospitalizations in HF with IDA patients. However, readmission hospitalization in HF with IDA patients had a higher mean hospital cost during readmission (62, 899 95% CI: 58, 434 – 67, 365) compared to index hospitalization (57, 435 95% CI: 54, 975 – 59, 894). In our multivariate adjusted analysis, diabetes mellitus (DM) (OR 1. 13), peripheral vascular disease (PVD) (OR 1. 15), CKD (OR 1. 23), HIV infection (OR 1. 79), atrial fibrillation (AF) (OR 1. 15), and chronic pulmonary disease (CPD) (OR 1. 23) were significantly (p0. 05) associated with higher 30-day readmission rates. Younger age (OR 0. 99; 95% CI 0. 99-0. 99, p0. 001) and higher income quartiles (Q) i. e. , 51st-75th Q and 76th-100th Q were significantly associated with lower readmission rate (OR 0. 91 and 0. 87; p0. 05) compared to 0-25th Q. We noted that day of admission (weekday vs weekend), hospital bed size (small, medium and large), teaching status of hospital, non-home discharge status, alcohol abuse, and LOS did not have any significant impact on 30-day readmissions. Conclusion: Our study highlights that HF patients with IDA have a high mortality rate during index admission, which increases threefold on subsequent readmission. Although LOS was similar among index and readmission hospitalizations, readmission stay had a higher cost associated with it. Higher income quartile and younger age translated to a lower risk of readmission, but there was no effect of non-home discharge status, hospital bed size, or teaching status on the readmission rate. Comorbidities such as DM, CKD, AF, HIV, PVD, and CPD significantly increased the risk of readmissions among HF patients with IDA. Further research is warranted to mitigate the higher 30-day readmissions in the aforementioned patients and reduce the healthcare burden.