Introduction
Iron deficiency (ID) is common in patients with heart failure and there are established treatment effects of correcting ID in patients with HFrEF and HFpEF. However, data for patients with ATTR amyloidosis is rare as patients are mostly excluded from large randomized trials. This study investigates the prevalence of ID in treatment naïve patients and the influence of treatment with TTR stabilizers.
Methods
We retrospectively analysed a cohort of consecutive patients presented at out institution from 2021 to 2024 with confirmed cardiac wtATTR-cardiomyopathy (wtATTR-CM). Markers of iron deficiency (Hb, TSAT, Ferritin) and baseline characteristics were recorded and patients with ID without anemia according to ESC recommendations (Ferritin<100µg/l, or Ferritin 100-300µg/l and TSAT< 20%, Hb>7.4 mmol/l in females and >8.1 mmol/l in males) were included. After initial evaluation all patients received guideline directed disease modifying therapy with TTR stabilizers and were re-evaluated after 12 months of therapy. Patients with events (either 3 months before or during treatment) that suggests significant changes in iron status (e.g. major surgery, severe infection, iron supplementation, blood loss or bone marrow supressing therapy) were excluded. Between group differences were calculated using Mann-Whitney-U test or Wilcoxon signed rank test if applicable. Descriptive risks for ID are expressed using odds-ratios.
Results
We identified 51 patients (19,6% female, mean age 78,1 ± 6,8 years) who fulfilled the inclusion and exclusion criteria. The second investigation was performed after a median of 370 days of TTR-stabilizer therapy. 54,9% of patients had atrial fibrillation and concomitant oral anticoagulation. Ventricular function was decreased and NT-pro-BNP markedly elevated (3193 ± 4423 pg/ml). 33 (64,7%) of patients were NAC stage 1 according to the latest 4 strata staging recommendation. ID was prevalent in 17,6% of patients. After 12 months of treatment the prevalence was 23,5% (Figure1, Wilcoxon signed rank test: non-significant small difference between baseline Mdn = 25 and 12 months Mdn = 24, Z = -1.1, p = .270, r = -0.2.) Over all timepoints ID was associated with elevated NAC stage (stage 1 vs. stage 2-4: OR of having ID 8.13; 95 % CI: 2.21 to 29.90, z statistic: 3.151;P = 0.0016)
Conclusion
ID without anaemia is common in patients with wtATTR-CM and associated with advanced disease stage and might reflect disease progression. Treatment with TTR stabilizers alone did not improve ID in this cohort so intravenous ID correction might be considered to improve symptoms in these patients.
Figure 1
