Contemporary Clinical Use of Aspirin: Mechanisms of Action, Current Concepts, Unresolved Questions, and Future Perspectives

The ability of aspirin to inhibit platelet aggregation has positioned this agent within the most frequently used drugs worldwide. The aim of this article is to review the contemporary clinical use of aspirin and also to discuss unresolved issues not yet translated into clinical practice. Results from several clinical trials have led to strong guideline recommendations for aspirin use in the acute management and secondary prevention of cardiovascular disease. On the contrary, guidelines regarding aspirin use as primary prevention of cardiovascular disease are almost conservative, supported by recent trials reporting that the bleeding risk outweighs the potential benefits in most patients. In pregnancy, aspirin has proved efficient in preventing preeclampsia and small-for-gestational-age births in women at high risk, and is hence widely recommended in clinical guidelines. Despite the vast amount of clinical data on aspirin, several unresolved questions remain. Randomized trials have reported that aspirin reduces the risk of recurrent venous thromboembolism, but the clinical relevance remains limited, because direct oral anticoagulants are more effective. Laboratory studies suggest that a twice-daily dosing regimen or evening intake may lead to more efficient platelet inhibition, and the potential clinical benefit of such strategies is currently being explored in ongoing clinical trials. Enteric-coated formulations of aspirin are frequently used, but it remains unclear if they are safer and as efficient as plain aspirin. In the future, aspirin use after percutaneous coronary interventions might not be mandatory in patients who also need anticoagulant therapy, as several trials support shorter aspirin duration strategies. On the other hand, new treatment indications for aspirin will likely arise, as there is growing evidence that aspirin may reduce the risk of colorectal cancer and other types of cancer.