Published Jul 21, 2015

Callaghan, NSW, Australia - Acute Coronary Syndrome (ACS) and Coronary Heart Disease (CHD) are important contributors to the increased morbidity and mortality rates worldwide. Currently, pharmacotherapy is the main treatment modality for patients with a history of ACS or CHD. However, even with dual antiplatelet therapy (aspirin plus P2Y12 antagonist, such as Clopidogrel), patients with ACS or CHD are still at substantially high risk of blood clot development. This is partly due to the failure to deactivate the role of platelet via thrombin receptors’ pathway, which can lead to the aggregation of platelets and subsequent thrombosis. Researchers from the University of Newcastle, Australia have performed and published a study aimed to examine if the different types of newly invented Thrombin-receptor Antagonists (TRAs) are able to lower the risk of recurrent blood clot development without increasing the risk of bleeding unacceptably. As described in the article, “Efficacy and Safety of Thrombin-Receptor Antagonist (Atopaxar and Vorapaxar) in Patients with Acute Coronary Syndrome (ACS) or Coronary Artery Disease (CAD) – A Meta-Analysis of Randomised Controlled Trails,“ published in Value in Health Regional Issues Volume 6 focusing on Asia, this study systematically reviewed and synthesized the evidences from published clinical trials investigating the efficacy and safety of those new TRAs and also indirectly compared the treatment effect between different kinds of TRAs. Based on the pooling evidence from seven clinical trials,  the study found TRA treatment to be more effective than the placebo alone while accompanying with higher risk of bleeding. The indirect comparison between the two TRAs suggested that atopaxar might be more favorable than vorapaxar in the occurrence of major cardiovascular events and incidence of bleeding. The lead author, Dr Lan Gao, PhD, currently a research fellow at Deakin University said, “Since the FDA has approved vorapaxar as a treatment for patients with a history of heart attack, it is important to examine whether the benefits outweigh the risks based on the trial data.  Moreover, indirect comparison between the two TRAs can also fill the gap in the knowledge as there is no head-to-head study comparing the two TRAs.