Single-Dose Erythropoietin Doesn’t Reduce Myocardial Infarct Size

For patients with ST-elevation myocardial infarction (STEMI) undergoing reperfusion, an intravenous bolus of epoetin-α does not reduce infarct size, according to a study in the Journal of the American Medical Association.

The randomized controlled trial included 222 patients who underwent successful primary or rescue reperfusion with percutaneous coronary intervention after STEMI. After an initial dose-escalation phase, patients were randomly assigned to receive a single 60,000-U intravenous dose of epoetin-α or saline placebo within 4 hours after reperfusion. Infarct size was measured by use of cardiac magnetic resonance during the first week and again at 12 weeks after treatment.

Neither scan showed a significant difference in infarct size between groups: approximately 15 percent of left ventricular mass at 2–6 days after percutaneous coronary intervention and 10 percent at 12 weeks. Among patients aged 70 years or older, epoetin alfa was associated with a larger infarct size at the first assessment: 20 percent of left ventricular mass, compared with 12 percent in the placebo group. A composite of adverse events—death, myocardial infarction, stroke, or stent thrombosis—occurred in 4 percent of the epoetin-α group versus none of the placebo group.

Erythropoietin has shown cardioprotective effects in preclinical models of myocardial ischemia and ischemia reperfusion. However, this phase 2 clinical trial found no reduction in infarct size for STEMI patients receiving single-dose epoetin-α after successful reperfusion. The study also raises concerns about the safety of erythropoietin treatment after STEMI [Najjar SS, et al. Intravenous erythropoietin in patients with ST-segment elevation myocardial infarction. JAMA 2011; 305:1863–1872].

August 2011 (Vol. 3, Number 8)