Clinical trials in long-term antiplatelet therapies: focus on the role of aspirin

Purpose of review The purpose of this review is to summarize the existing evidence for use of long-term antiplatelet therapies for primary and secondary prevention of adverse cardiovascular events. Recent findings In the setting of primary prevention, several contemporary trials have shown a lack of net clinical benefit with use of aspirin across different patient groups, including those with diabetes mellitus, older age or high estimated cardiac risk. For secondary prevention, the addition of either ticagrelor or low-dose rivaroxaban to aspirin monotherapy significantly lowered recurrent vascular events, albeit with excess bleeding. Aspirin withdrawal did not result in excess thrombotic risk or less bleeding among patients undergoing percutaneous coronary intervention (PCI) treated with ticagrelor. Summary In the contemporary era, routine use of aspirin is not beneficial in the majority of patients free of cardiac disease. In contrast, for secondary prevention, aspirin monotherapy is not sufficient to lower recurrent vascular risk. Antiplatelet monotherapy with ticagrelor may emerge as an alternative to lower bleeding whereas maintaining ischemic efficacy in selected patients undergoing PCI.