Role of New Antiplatelet Drugs on Cardiovascular Disease: Update on Cangrelor

Meta-Analysis of the Role of Cangrelor for Patients Undergoing Percutaneous Coronary Intervention

Inhibition of the P2Y12 receptor by an oral P2Y12 inhibitor with loading doses along with Cyclooxygenase-1 inhibition by aspirin is considered a first-line treatment strategy in patients with the acute coronary syndrome and patients undergoing percutaneous coronary intervention (PCI). Limitations associated with oral P2Y12 receptor inhibitors include a requirement for in vivo conversion (thienopyridines), delayed onset of action, suboptimal inhibition, irreversible inhibition (thienopyridines), and delayed offset. In the acute setting, therapy with potent platelet inhibitors that have a fast onset and offset is desirable to attenuate thrombotic complications. Cangrelor, an intravenous agent, is an adenosine triphosphate analog, selectively and explicitly blocking P2Y12 receptor-mediated platelet activation. Cangrelor has been studied in a series of CHAMPION trials. A patient-level, meta-analysis of all 3 phase III trials (24,910 patients), demonstrated that cangrelor significantly reduced the rate of the composite outcome of death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis at 48 hours and 30 days compared with clopidogrel, with no significant increase in major bleeding. It is approved for clinical use in patients undergoing PCI to reduce the risk of myocardial infarction, repeat revascularization, and stent thrombosis in patients who have not been treated with a P2Y12 platelet inhibitor and are not being given a GPII_bIII_a inhibitor. In conclusion, patients unable to take oral medications undergoing emergent/urgent PCI and those who had recent PCI with drug eluting stent in need for urgent cardiac or noncardiac surgery are potential candidates for cangrelor.

Cangrelor: A New Route for P2Y12 Inhibition

Antiplatelet therapy with a P2Y12 inhibitor is a key component of treatment for patients with acute coronary syndromes undergoing percutaneous coronary intervention. Before the development of cangrelor (Kengreal, The Medicines Company, Parsippany, NJ), only oral P2Y12 inhibitors were available. Cangrelor is a reversible P2Y12 inhibitor that is administered as an intravenous infusion, and its quick onset and offset make it an appealing option for antiplatelet therapy, particularly for patients who are unable to take oral medications. Although cangrelor struggled to show benefit in early trials, the positive results of the CHAMPION PHOENIX trial led to its approval for use as an adjunct to percutaneous coronary intervention to reduce the risk of periprocedural myocardial infarction, repeat coronary revascularization, and stent thrombosis in patients who have not been treated with another P2Y12 inhibitor and are not being given a glycoprotein IIb/IIIa inhibitor. Cangrelor has also been evaluated as an option for bridging therapy in patients who must discontinue their oral P2Y12 inhibitor before coronary artery bypass grafting. This review of cangrelor will discuss its mechanism of action, its pharmacodynamics and pharmacokinetics, the clinical trial experience, and its potential place in therapy.

Antiplatelet Therapy in Acute Coronary Syndrome

Antiplatelet agents have for decades been used to improve outcomes in patients with acute coronary syndromes and have become increasingly valued, not only for their antithrombotic properties but also for their anti-inflammatory effects. The drug class continues to evolve as novel agents with increasingly efficacious antiplatelet actions are identified. This review will discuss antiplatelet agents, including aspirin, the P2Y₁₂ receptor antagonists and the glycoprotein IIb/IIIa inhibitors, that are currently used to treat patients with unstable angina and myocardial infarction, focusing on their pharmacological properties and the clinical evidence supporting their use.