Most STEMI is the result of an acute thrombotic event, so, more thrombotic inhibition is better, right? Italy, Hungary, Serbia and Belgium band together for ARMYDA-6 to test a randomized, prospective 600mg vs. 300mg clopidogrel loading dose prior to PCI in STEMI.
They didn't look at mortality and only followed 30-day outcomes - probably because they didn't have statistical power from only 201 patients to detect a difference - but their surrogate markers of infarct size, successful PCI, LVEF and 30-day "major cardiovascular events" all favored clopidogrel. Unfortunately, almost every nonsignificant difference between the two clinical groups favored the 600mg group - younger, less diabetes, fewer prior MIs, higher LVEF at baseline, faster loading and cath lab times, less multivessel disease, more TIMI flow >1 pre-PCI.
That being said, it's consistent with the prior ARMYDA-1 and CURRENT-OASIS studies, and even if this isn't a fabulous study, it's another but of evidence to consider.
"Outcome Comparison of 600- and 300-mg Loading Doses of Clopidogrel in Patients Undergoing Primary Percutaneous Coronary Intervention for ST-Segement Elevation Myocardial Infarction"