Pharmacodynamic comparison of low-dose ticagrelor to low-dose prasugrel in patients with prior myocardial infarction: the ALTIC-2 study.

Given that patients with prior myocardial infarction and features of high ischemic and low bleeding risk may benefit by extending dual antiplatelet therapy beyond 1 year, we aimed of assessing platelet reactivity provided by ticagrelor 60 mg bid versus prasugrel 5 mg od in 20 such patients participating in a randomized, crossover study. The primary end point of platelet reactivity at the end of the two treatment periods (by VerifyNow, in PRU) was significantly lower for ticagrelor (31.9 PRU [95% CI 12.3-51.4]) compared with prasugrel (132.1 PRU [111.9-152.3]) with a least squares mean difference of -100.2 PRU (72.1-128.3, P < .001). This dedicated pharmacodynamic study showed that in post-myocardial infarction patients with high atherothrombotic risk and receiving P2Y12 receptor antagonist beyond 1 year, low-dose ticagrelor results in a significantly lower platelet reactivity compared to low-dose prasugrel.

De-Escalation of Treatment With Oral P2Y12 Receptor Inhibitors: Current Status and Perspectives.

In patients with an acute coronary syndrome undergoing percutaneous coronary intervention, novel P2Y12 receptor inhibitors, prasugrel and ticagrelor, are proposed as "first-line" antiplatelet agents in the absence of contraindications and up to a year from the index event. However, de-escalation of treatment to clopidogrel occurs with a variable frequency in real-life practice, most commonly due to an increased bleeding potential, more frequent side effects, and a higher cost for the novel agents. Pharmacodynamic studies provide most of the data on guidance for de-escalation. Despite positive messages from recent trials and registries, lack of definitive efficacy or safety results of such a strategy remains an obstacle to suggest de-escalation in a routine basis. Carefully designed studies are likely to improve our understanding of the impact of de-escalation and help to better define its position in current pharmacotherapy.

Cangrelor in Percutaneous Coronary Intervention: Current Status and Perspectives.

Cangrelor is an intravenously administered P2Y12 receptor antagonist with very fast, potent, and quickly reversible action. In the CHAMPION PHOENIX trial, cangrelor provided an improved anti-ischemic protection compared with clopidogrel, without increasing the risk of severe bleeding. Cangrelor is currently approved by drug regulating authorities for patients undergoing percutaneous coronary intervention (PCI) without prior treatment with a P2Y12 receptor antagonist and not receiving a glycoprotein IIb/IIIa inhibitor, while its use is endorsed with a class IIb recommendation by the European Society of Cardiology guidelines. Several subanalyses of CHAMPION PHOENIX trial have tried to elucidate the role of cangrelor in PCI, including its usefulness during a 2-hour landmark analysis, impact on intraprocedural stent thrombosis, and reduction in myocardial infarction (MI) rate. The influence of gender, geographic region, access site, and bivalirudin use on cangrelor's effects has also been reported. In patients with ST elevation MI and in clinical scenarios of disturbed absorption of oral antiplatelet agents or in need of an intravenous agent, cangrelor may surpass oral agents' drawbacks. Transitioning to an oral agent is mandatory following cangrelor infusion discontinuation, although ticagrelor may be administered earlier without any pharmacodynamic interaction. Nevertheless, the clinical role of cangrelor in conjunction with administration of prasugrel or ticagrelor remains unclear. Accruing real-life experience is expected to improve our understanding of cangrelor's role in everyday clinical practice.

Combination antiplatelet treatment in coronary artery disease patients: A necessary evil or an overzealous practice?

In seeking to improve care in coronary artery disease patients, further platelet inhibition has been occasionally applied beyond that provided by aspirin and a P2Y12 receptor antagonist. This review aims to offer insights about the rationale, the efficacy and safety of combination antiplatelet therapy, involving three or more agents. Overall, the use of glycoprotein (GP) IIb/IIIa inhibitors did not significantly modify the treatment effect of different antiplatelet strategies, including double vs standard clopidogrel, prasugrel vs clopidogrel, ticagrelor vs clopidogrel, cangrelor vs clopidogrel, and vorapaxar vs placebo. With the caveat that the use of GP IIb/IIIa inhibitor was not randomized, adding such an agent to aspirin and a P2Y12 receptor antagonist appears to carry a significantly increased bleeding potential. Moreover, adding vorapaxar to aspirin- and clopidogrel-treated patients is associated with more bleeding events, while the bleeding potential is further exacerbated in cases of quadruplicate antiplatelet treatment including aspirin, clopidogrel, vorapaxar, and a GP IIb/IIIa inhibitor. In ST-segment elevation, myocardial infarction patients' administration of an intravenous antiplatelet agent (GP IIb/IIIa inhibitor or cangrelor), in addition to aspirin and a P2Y12 receptor antagonist, efficiently bridges the pharmacodynamic gap of oral agents. Cilostazol on top of aspirin and clopidogrel appears to be safe, although of questionable clinical benefit. In conclusion, combination antiplatelet therapy should be reserved only for selected cases and following thoughtful consideration of the associated risk/benefit ratio.