The Evolution of Antiplatelet Therapy After Percutaneous Coronary Interventions: A 40-Year Journey

Antiplatelet therapy has a critical role to play in the successful management of patients undergoing percutaneous coronary intervention (PCI). Over the past 40 years, a multitude of participants worldwide have been enrolled in trials evaluating the impact of antiplatelet agents on clinical outcomes. The use of aspirin in unstable angina in the Canadian Aspirin trial was key to establishing the benefit of aspirin in acute coronary syndrome. The Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) trial demonstrated that the P2Y12 inhibitor clopidogrel, when added to aspirin, reduced major cardiovascular events. While the use of antiplatelet agents in coronary artery disease antedates the introduction of PCI and remains the cornerstone of secondary prevention of atherosclerotic cardiovascular disease, strategies aiming to optimise their best use are still constantly evolving. In this review, the major randomised trials shaping current clinical practice for the use of aspirin and P2Y12 inhibitors in patients undergoing PCI are summarised, with a focus on aspirin-free strategies and on the role of P2Y12 inhibitor treatment before PCI, two major topics of ongoing investigation that are critical to patient care but that are not addressed in current practice guidelines. Multiple questions remain regarding the use of antiplatelet agents after PCI, including the personalisation of dosing, intensity, pharmacologic formulation, and duration of antiplatelet therapy based on individual patient characteristics and the optimal treatment of patients at high bleeding risk.