Cardiovascular Outcome of Heart Failure Patients with Iron Deficiency Anemia Who Received Iron Infusion Vs Red Blood Cell Transfusion: Analysis from a Nationwide Trinetx Database

Background: Heart Failure (HF) is a significant global health burden, and Iron deficiency anemia (IDA) can worsen outcomes in HF. About 30-50% of HF patients are reported to have IDA, commonly due to nutritional deficiencies, gastrointestinal loss, impaired absorption, and chronic inflammatory cytokines present in HF. HF guidelines recommend IV iron to reduce HF hospitalization. This study aims to evaluate the cardiovascular outcome of HF patients with IDA treated with iron infusion vs RBC transfusion.

Methods: A nationwide retrospective cohort study was conducted using the TriNetX platform, analyzing adult HF patients with IDA from 2015 to 2023. The intervention cohort 1 received iron infusions without packed RBCs, while the control cohort 2 received packed RBCs without iron infusions. Cardiovascular and cerebrovascular outcomes, ICU admissions, and mortality were assessed from 1-month post-intervention. Cohorts were matched 1:1 using Propensity Score Matching (PSM) based on demographics, cardiovascular risk factors, chronic medical conditions, and nutritional status to minimize confounding variables in comparing the two treatment modalities.

Results: After propensity score matching, a total of 20,862 study participants were included in each study cohort. The mean age of cohort 1(patients who received iron infusion with no blood transfusion) and cohort 2(those who received RBC transfusion with no iron infusion were 69.2 +/- 15.0 and 69.3 +/-14.5 respectively. Majority of the patients were White (68%) and female (55%) in both cohorts. Patients in cohort 1 were 20 % less likely to have unstable angina, PCI/coronary angioplasty and acute myocardial ischemia compared with cohort 2 (OR 0.80; 95% CI 0.74 – 0.86). Myocardial infarctions were less likely to occur in patients in cohort 1 (OR 0.71; 95% CI 0.66 – 0.76) compared with patients in cohort 2. Additionally, Patients in Cohort 1 also demonstrated a significantly lower odd of composite cerebrovascular disease (stroke, TIA, carotid intervention/angioplasty) (OR 0.45; 95% CI 0.46 – 0.54) compared to those in cohort 2. The analysis further revealed a significant association with ICU admission (aOR 0.011; 95% CI 0.07 – 0.19) and mortality (aOR 0.99; 95% CI 0.287 – 0.312).

Conclusion: HF patients with IDA receiving iron infusion without RBC transfusion exhibited significantly lower risks of composite adverse cardiovascular and cerebrovascular outcomes compared to those receiving RBC transfusion without iron infusion. This supports IV iron's benefit in HF, reducing ICU hospitalization, mortality and adverse composite outcomes.