Patients with diabetes have a significantly diminished relative effectiveness of platelet inhibition with clopidogrel (Plavix) following myocardial infarction when compared with patients without diabetes.
Scientists led by Charlotte Andersson, MD, PhD, of Gentofte Hospital in Hellerup, Denmark, analyzed 58,851 patients who were hospitalized with incident heart attack, 12% of whom had diabetes, and 60% of whom were treated with clopidogrel. They found that nondiabetic clopidogrel users achieved a significant 23% reduction in cardiovascular mortality, whereas patients with diabetes only achieved a nonsignificant 7% reduction in risk.
In an editorial accompanying the September 5, 2012, article in the Journal of the American Medical Association, Deepak Bhatt, MD, MPH, noted that the reason diabetics do not benefit from clopidogrel as much as other patients is that compared with nondiabetics, diabetics with coronary artery disease have heightened platelet reactivity.
Despite its lower efficacy in preventing secondary heart attack, those patients with diabetes who took clopidogrel had lower crude incidence rates of all-cause mortality than those who were not taking the drug, and authors of the study maintain that clopidogrel may still be worthwhile for patients with diabetes.