Oral antiplatelet therapy in acute coronary syndromes: update 2012

Abstract

Dual antiplatelet therapy (DAPT), usually consisting of clopidogrel and acetylsalicylic acid (ASA), has come into discussion in recent years due to an increasing number of major adverse cardiac events based on insufficient ADP-mediated platelet inhibition with clopidogrel, mainly explained by drug interactions or genetic variants slowing or hindering the bioactivation of the prodrug clopidgrel into an active metabolite. Accordingly, new antiplatelet agents like prasugrel and ticagrelor were investigated in large prospective randomized clinical trials in patients with different entities of acute coronary syndromes (ACS). Based on their beneficial results in comparison to clopidogrel, these agents have found their way into the recent international guidelines for treatment of patients with acute coronary syndromes. Both antiplatelet agents demonstrated superiority with respect to the primary composite endpoint (cardiovascular death/non-lethal myocardial infarction/stroke). Ticagrelor even exhibited a mortality benefit over the comparator, but both compounds also increased the risk of spontaneous major bleedings to a significant extent. However, the efficacy/safety ratio of prasugrel and ticagrelor compared to clopidogrel is better. This article widens the insight into the recent changes in antiplatelet therapy in ACS by discussing the clinically most important data derived from the TRITON-TIMI 38 trial and the PLATO trial, including also the retrospective and pre-defined subgroup analyses. This article also gives information about the recommended duration of DAPT and the situation when patients who need permanent anticoagulation (e.g. in case of non-valvular atrial fibrillation) deserve also DAPT after coronary stenting ('triple therapy').

Keywords: Acute coronary syndrome; antiplatelet therapy; prasugrel; ticagrelor; triple therapy.

Figure 1.

Main results of prasugrel in TRITON TIMI 38.

Figure 2.

Main results of prasugrel in PLATO.

Figure 3.

Differences of results between prasugrel and ticagrelor with respect to subgroup analyses in TRITON TIMI 38 und PLATO.^,,,