When is the best time to give clopido-grel bisulfate to patients needing diagnostic coronary angiography—immediately after unscheduled coronary stenting or before? Researchers from Hungary and Vienna say that starting treatment with clopidogrel (Plavix generic, Bristol-Myers Squibb/Sanofi-Aventis) before percutaneous coronary intervention (PCI) has several benefits.
The researchers compared 30-day outcomes in 2,679 patients with suspected coronary artery disease who received a loading dose of 300 mg of clopidogrel right after stenting and 1,481 who received the same dose six to 24 hours beforehand.
At 30 days, the patients who had received immediate treatment afterward were nearly twice as likely to have had an acute myocardial infarction (AMI), to have required repeated target vessel revascularizations, or to have died (4.74% vs. 2.77%). They were also significantly more likely to have stent thrombosis.
Pretreatment was associated with more major bleeding (1.35% vs. 0.41%); however, major bleeding was less frequent than AMI and the composite cardiac primary endpoint.
Research has shown that the risk of acute and subacute stent thrombosis is highest within the first post-implantation days. Indeed, in this study, most of the cardiac events occurred within the first few days.
The benefit of giving tablet clopidogrel more than six hours before the planned PCI might have been in preventing acute thrombotic occlusion during the first two to six hours after stent insertion. Within this time, the full dose of unfractionated heparin applied during PCI has mainly an anticoagulant effect, and only a moderate influence on platelet activity. They note, as well, that increased platelet reactivity has been documented in patients undergoing PCI.