Prasugrel ( Efient, Effient ), a new antiplatelet agent that provides higher levels of platelet inhibition than current standard therapies, could provide more consistent protection from ischemic events than standard treatment in patients who have had at least one coronary stent.
Narrowing or blockages in the arteries that supply blood to the heart can result in acute coronary syndromes, such as myocardial infarction, stroke, and unstable angina. Interventions such as balloon angioplasty and stents are used to treat the narrowing of these arteries. Although stent use has resulted in greater procedural success and lower rates of re-narrowing of the arteries than has balloon angioplasty alone, the use of coronary stents can result in blood clots which can block the stented artery, a condition known as stent thrombosis. Patients therefore need to take antiplatelets or anticoagulants after stent insertion to prevent blood clots from forming. Standard treatment is to use Clopidogrel ( Plavix ), one of a group of compounds known as thienopyridines that prevent platelet aggregation, together with Acetylsalicylic acid ( Aspirin ).
The TRITON-TIMI 38 trial assessed the effect of Prasugrel, a new thienopyridine, compared with Clopidogrel in patients with moderate to high risk acute coronary syndromes who were undergoing percutaneous coronary intervention. Stephen Wiviott, at Brigham and Womens Hospital and Harvard Medical School, Boston, colleagues from the TIMI Study Group, and their international collaborators did a subanalysis of the TRITON-TIMI 38 data to assess the rate, outcomes, and prevention of ischaemic events in 12,844 patients with different types of intracoronary stents who were treated with Prasugrel plus Acetylsalicylic acid or Clopidogrel plus Acetylsalicylic acid.
The investigators found that intensive antiplatelet therapy with Prasugel resulted in fewer ischaemic outcomes, including stent thrombosis, than with standard Clopidogrel, irrespective of the type of stent used.
In conclusion, these data highlight the importance of aggressive antiplatelet therapy to reduce ischaemic events in patients with acute coronary syndromes undergoing percutaneous coronary intervention. When balancing risks and benefits of strategies to prevent ischaemic events, consideration should be given to patient characteristics including risk of bleeding and ischaemic events as well as stent and procedural characteristics.
Source: Lancet, 2008