Interplay between platelets and coagulation: from protective haemostasis to pathological arterial thrombosis

Haemostasis refers to the physiological process aimed at repairing vessel injury and preventing bleeding. It involves four interlinked stages culminating in the formation of a platelet-fibrin haemostatic plug that is eventually dissolved once the vessel heals. In contrast, arterial thrombosis is a pathological condition resulting from atheroma exposure, triggering the formation of a platelet-rich thrombus that may obstruct blood flow, leading to the clinical manifestations of ischaemic cardiovascular disease. The following review will provide a comprehensive overview of the finely regulated endogenous antithrombotic mechanisms responsible for maintaining the haemostatic balance and preventing intravascular thrombosis. Thereafter, it will further detail the different stages and mechanisms governing the intricate interplay between the vessel, platelets, and the coagulation cascade in haemostasis, highlighting the most recent advances in platelet biology and function, to further elucidate the differential traits and players contributing to pathological arterial thrombus growth. The review will also delve into the impact of emerging cardiovascular risk factors on tilting the haemostatic balance towards a pro-thrombotic state, thereby increasing the patient's vulnerability to thrombotic events. Finally, it will underscore the importance of early screening for subclinical atherosclerosis through advanced imaging technologies capable of quantifying plaque burden and metabolic activity since they may set the stage for an increased thrombotic risk. Implementing proactive interventions to halt atherosclerosis progression or inducing its regression at early stages is crucial for preserving haemostasis and reducing the likelihood of ischaemic atherothrombotic disease.