Phase 2 SHIELD-MI Trial Shows Dexrazoxane Cuts Intramyocardial Hemorrhage After STEMI Reperfusion

The SHIELD-MI investigators randomized STEMI patients to peri-reperfusion dexrazoxane or control and used cardiac MRI to quantify intramyocardial hemorrhage, infarct size, and microvascular obstruction. The primary signal was a measurable decrease in hemorrhagic injury accompanied by smaller final infarct size and higher ejection fraction at follow-up imaging. No serious adverse events were attributed to the drug, which is already approved for cardioprotection in oncology.

Intramyocardial hemorrhage occurs in roughly 40 percent of reperfused STEMI cases and is now formally recognized in the Fifth Universal Definition of Myocardial Infarction as the most severe form of myocardial injury. Prior observational work linked hemorrhage to sixfold higher major adverse cardiovascular event rates through iron-mediated inflammation and microvascular destruction. Dexrazoxane’s iron-chelating mechanism therefore targets a pathway left unaddressed by current reperfusion strategies.

Context from earlier doxorubicin cardioprotection studies and recent CMR mechanistic papers suggests the observed preservation of myocardium could translate into lower heart-failure incidence, yet absolute risk reductions remain unreported. The trial was small, single-center, and phase 2, limiting generalizability.

A multicenter phase 3 trial powered for 12-month heart-failure hospitalization and mortality is required before any change in guidelines or practice.