Erythrocyte Promotion of Platelet Reactivity Decreases the Effectiveness of Aspirin as an Antithrombotic Therapeutic Modality

Abstract

To the Editor: Valles et al1 report persistent serotonin release from platelets prepared from patients with vascular disease who were taking aspirin (200 to 300 mg/d). These authors point to the potential clinical significance of their observation because serotonin stimulates vascular smooth muscle cell (VSMC) proliferation. Serotonin is also a vasoconstrictor and can induce or enhance platelet shape change (PSC) and aggregation.2 3 4 5 PSC is an early phase of platelet activation that is aspirin resistant and precedes aggregation.2 A link between serotonin and platelet activity was demonstrated in dyslipidemic patients in whom simvastatin (an effective lipid-lowering drug) reduced platelet hyperactivity and corrected the intraplatelet levels of serotonin.3 Furthermore, after PTCA, the addition of ticlopidine (a potent inhibitor of platelet activation) to aspirin and heparin normalized serotonin release from platelets.4 …