Positive effect of intravenous iron-oxide administration on left ventricular remodelling in patients with acute ST-elevation myocardial infarction - a cardiovascular magnetic resonance (CMR) study

Abstract

Objectives: This study investigated the safety profile and potential "therapeutic" effect of intravenous ultrasmall superparamagnetic iron-oxide (USPIO)-based iron administration regarding infarct healing in patients with ST-elevation myocardial infarction (STEMI). USPIO-administration was recently shown to enable an improved characterization of myocardial infarct pathology in acute STEMI patients.

Materials and methods: Seventeen study patients (IRON, 54 ± 9 yrs, 88% male) and 22 matched controls (CONTROL, 57 ± 9 yrs, 77% male) both with primary reperfused STEMI underwent multi-parametric CMR studies in the first week and three months after acute MI. Only IRON patients received a single intravenous bolus of 510 mg elemental iron as ferumoxytol (Feraheme(TM)) within four days following acute MI.

Results: Three months later, all patients were alive and there were no adverse cardiac events. Significant improvement in left ventricular (LV) ejection fraction (IRON: 53 ± 10% to 59 ± 9%, p=0.002;

Control: 54 ± 6% to 57 ± 10%, p=0.005) as well as shrinkage of infarct size were seen in both groups at follow-up. There was a more pronounced decrease in infarct size in the IRON group (IRON: -10.3 ± 5.4% vs.

Control: -7.0 ± 8.4%, p=0.050) in addition to a significant decrease in both endocardial extent and prevalence of transmural infarctions in IRON but not in CONTROL patients. A significant decrease in LV end systolic volume was only seen in the IRON group (71 ± 25 mL to 59 ± 25 mL, p=0.002).

Conclusions: Intravenous iron administration in acute STEMI patients seems to be associated with an improved infarct healing and a beneficial global left ventricular remodelling. These findings together with the good safety profile make USPIO-based iron administration a promising future candidate as a "diagnostic" and "therapeutic" adjunctive solution in acute MI management.

Keywords: CMR; Ferumoxytol; LGE; Myocardial infarction; USPIO; Ventricular remodelling.