Four decades have passed since the first trial suggesting the efficacy of aspirin in the secondary prevention of myocardial infarction. Further trials, collectively summarized by the Antithrombotic Trialists' Collaboration, solidified the historical role of aspirin in secondary prevention. Although the benefit of aspirin in the immediate phase after a myocardial infarction remains incontrovertible, a number of emerging lines of evidence, discussed in this narrative review, raise some uncertainty as to the primacy of aspirin for the lifelong management of all patients with chronic coronary syndrome (CCS). For example, data challenging the previously unquestioned role of aspirin in CCS have come from recent trials where aspirin was discontinued in specific clinical scenarios, including early discontinuation of the aspirin component of dual antiplatelet therapy after percutaneous coronary intervention and the withholding of aspirin among patients with both CCS and atrial fibrillation who require anticoagulation. Recent primary prevention trials have also failed to consistently demonstrate net benefit for aspirin in patients treated to optimal contemporary cardiovascular risk factor targets, indicating that the efficacy of aspirin for secondary prevention of CCS may similarly have changed with the addition of more modern secondary prevention therapies. The totality of recent evidence supports further study of the universal need for lifelong aspirin in secondary prevention for all adults with CCS, particularly in stable older patients who are at highest risk for aspirin-induced bleeding.
Keywords: aspirin; myocardial ischemia; secondary prevention.