Diagnostic work-up of anemia and associated health outcomes in people with heart failure.

Background: Anemia is common in patients with heart failure (HF). Although iron testing is recommended, it is uncertain that solely emphasizing iron testing could result in lesser attention to other causes, like bleeding or cancer. This study aimed to evaluate the diagnostic work-up of incident anemia in patients with HF in routine care and associated health outcomes.

Methods: Observational study of 8932 non-anemic adults with HF in Stockholm, Sweden, was quantified for incidence of anemia, diagnostic work-up (recognition, laboratory/invasive testing) and treatment across severity of anemia and setting of care. Time-varying Cox regression explored associations between developing anemia and rate of major adverse cardiovascular events (MACE), HF hospitalization, cancer, and death.

Results: During median 2.7 years, 34% of patients developed incident anemia, and 13% developed severe anemia. Within 6 months from incident anemia, ferritin and transferrin saturation were tested in 44% overall and 65% of severe cases. Testing of liver enzymes, creatinine, and C-reactive protein was, however, done in > 90% of cases. Colonoscopy, esophagogastroduodenoscopy, urinalysis, and cystoscopy were performed in 2-10% of cases. Few patients were recognized with an ICD code diagnosis of anemia (16%). Treatments were infrequent: oral iron (10%), intravenous iron (16%), blood transfusions (6%), and erythropoietin-stimulating agents (< 1%). More anemia cases received treatment in cardiology care (43%) versus primary care (29%). New-onset anemia was associated with risk of MACE (adjusted HR 2.13, 95% CI 1.85-2.44), HF hospitalization (4.85, 4.30-5.48), cancer (3.41, 3.09-3.77), and death (2.04, 1.82-2.29).

Conclusions: One in three patients with HF experienced anemia, which was associated with adverse health outcomes. Testing for iron stores and invasive work-up was suboptimal. A large proportion of anemia events remained under-recognized and untreated, a pattern of care that warrants correction.