Platelet aggregation pathways and blood coagulation cascade

The platelet aggregation pathways and blood coagulation cascade are the two primary components of hemostasis, the physiological process that prevents blood loss after vascular injury (StatPearls, 2023). Platelet aggregation is initiated by the adhesion of platelets to exposed subendothelial collagen and von Willebrand factor, followed by activation and the release of agonists like ADP and thromboxane A2 (NIH, 2017). This leads to the recruitment of additional platelets and the formation of a primary plug through the cross-linking of fibrinogen via the glycoprotein IIb/IIIa receptor (NIH, 2017). Concurrently, the coagulation cascade is activated through a series of zymogen-to-protease conversions, traditionally divided into the intrinsic and extrinsic pathways, which converge on the common pathway to generate thrombin (Wikipedia, 2024). Thrombin then converts soluble fibrinogen into insoluble fibrin, which stabilizes the platelet plug into a mature clot (NIH, 2017). Pathological activation of these pathways leads to thrombosis, a major cause of myocardial infarction, stroke, and venous thromboembolism, while deficiencies in these components result in bleeding disorders like hemophilia (ResearchGate, 2017). Therapeutic strategies involve the use of antiplatelet agents to inhibit platelet activation and anticoagulants to block specific factors within the coagulation cascade, thereby reducing the risk of thrombotic events (Walsh Medical Media, 2017).

Other names

HemostasisCoagulation systemThrombosis pathwaysBlood clotting cascade

Inhibition of platelet activation and aggregation (e.g., COX-1 inhibition, P2Y12 antagonism, GPIIb/IIIa inhibition) and inhibition of the coagulation cascade (e.g., Vitamin K antagonism, direct thrombin inhibition, Factor Xa inhibition).