600mg Is Probably Your Best Clopidogrel Loading Dose

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”