Both the timing and dosage of clopidogrel (Plavix, Bristol-Myers Squibb/ Sanofi-Aventis) loading are important, according to a study of pretreatment in patients with ST-segment elevation myocardial infarction (STEMI). The results suggest pretreating patients with highdose clopidogrel drug as early as possible.
In this study from Canada and Israel, 217 patients received a generic clopidogrel loading dose before primary percutaneous coronary intervention (PCI), and 166 patients received it afterward. A similar number of patients received low doses (300 mg) and high doses (600 mg) before and after primary PCI.
Clopidogrel drug loading before primary PCI was associated with a lower incidence of recurrent acute coronary syndrome (ACS), stent thrombosis, congestive heart failure, or death at 30 days (21.7% vs. 33.7%). When the patients were further stratified into four groups according to the timing and dosage of cheap clopidogrel loading, the incidence of the primary outcome was 16% for those who received 600 mg before primary PCI and 27% for those receiving 300 mg before primary PCI, compared with rates of 28% with 600 mg and 39% with 300 mg after primary PCI. The benefits of pretreatment were greater in patients with infarction of the anterior wall when the interval from symptom onset to admission was three hours or less and the “door-to-balloon” time was more than 90 minutes. Patients taking chronic aspirin therapy and those receiving glycoprotein (GPIIb/IIIa) antagonists did not benefit less from clopidogrel pretreatment.
The researchers say that their findings might have an even greater effect as a new generation of more potent thienopyridines with more rapid onset of action becomes available.
Source: Am J Cardiol 2009;104:514-518