Intravenous (IV) metoprolol is sparingly used in STEMI given concern about precipitation of cardiogenic shock (COMMIT/CCS-2 Trial)
A recent study (n=220) looked at usage of IV metoprolol versus controls in patients with STEMI and a killip class II or less prior to primary PCI
MRI was preformed 5-7 days after STEMI revealing reduced infarct size and increased left ventricular ejection fraction in the IV metoprolol group
IV beta-blockade appears cardioprotective in those with a low killip score and should be considered prior to primary PCI in certain subgroups
References
Ibanez B, Sanchez-Brunete V, Pizarro G, et al. Effect of early metoprolol on infarct size in ST-segment-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention: the Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction (METOCARD-CNIC) trial. Circulation. 2013 Oct 1; 128(14):1495-503.
