Intravenous ferric carboxymaltose for iron repletion following acute heart failure in patients with and without diabetes: a subgroup analysis of the randomized AFFIRM-AHF trial

Background: In AFFIRM-AHF, treatment of iron deficiency with intravenous ferric carboxymaltose (FCM) reduced the risk of heart failure (HF) hospitalization and improved quality of life (QoL) vs placebo in patients stabilized following an acute HF (AHF) episode, with no effect on cardiovascular (CV) death. Diabetes and iron deficiency frequently accompany AHF. This post hoc analysis explored the effects of diabetes on outcomes in AFFIRM-AHF patients.

Methods: Patients were stratified by diabetes yes/no at baseline. The effects of FCM vs placebo on primary (total HF hospitalizations and CV death) and secondary (total CV hospitalizations and CV death; CV death; total HF hospitalizations; time to first HF hospitalization or CV death; and days lost due to HF hospitalizations or CV death) endpoints at Week 52 and change vs baseline in disease-specific QoL (12-item Kansas City Cardiomyopathy Questionnaire [KCCQ-12]) at Week 24 were assessed by subgroup. For each endpoint, the interaction between diabetes status and treatment outcome was explored.

Results: Of 1108 AFFIRM-AHF patients, 475 (FCM: 231; placebo: 244) had diabetes and 633 (FCM: 327; placebo: 306) did not have diabetes. Patients with diabetes were more commonly male (61.5% vs 50.9%), with a higher frequency of ischemic HF etiology (57.9% vs 39.0%), prior HF history (77.7% vs 66.5%), and comorbidities (including previous myocardial infarction [49.3% vs 32.9%] and chronic kidney disease [51.4% vs 32.4%]) than those without diabetes. The annualized event rate/100 patient-years with FCM vs placebo for the primary endpoint was 66.9 vs 80.9 in patients with diabetes (rate ratio [RR]: 0.83, 95% CI 0.58-1.81) and 51.3 vs 66.9 in patients without diabetes (RR: 0.77, 95% CI 0.55-1.07), with no significant interaction between diabetes status and treatment effect (p_interaction = 0.76). Similar findings were observed for secondary outcomes. Change from baseline in KCCQ-12 overall summary score was numerically greater with FCM vs placebo at almost all time points in both subgroups, with no interaction between diabetes and treatment effect at Week 24.

Conclusions: The clinical and QoL benefits observed with intravenous FCM in patients with iron deficiency following stabilization from an AHF episode are independent of diabetes status. Trial registration Clinicaltrials.gov, NCT02937454 (registered 10.18.2016).