Protective effects of vitamin C on endothelium damage and platelet activation during myocardial infarction in patients with sustained generation of circulating microparticles

During myocardial infarction (MI), high levels of circulating procoagulant rnicroparticles (MP) shed from endothelial cells and platelets diffuse prothrombotic and proinflammatory potentials crucial for the coronary prognosis. In addition to conventional treatments, we evaluated whether vitamin C treatment could modify circulating levels of procoagulant MP. Upon admission, 61 patients with MI were prospectively randomized for immediate additional vitamin C treatment. Circulating NIP were quantified by functional prothrombinase assay before and after 5 days of vitamin C administration (1g day(-1)). The cellular origin of NIP was also assessed. In vitamin C-treated patients, the reduction in plate let-derived NIP was 10% higher (P=0.01). In patients with diabetes mellitus, dyslipidemia or more than two cardiovascular risk factors, vitamin C decreased endothelial and platelet-derived MP levels by similar to70% and 13%, respectively. This early effect on circulating platelet and endothelial-derived MP, testifies to the importance of oxidative stress during MI. Vitamin C could prove beneficial for the outcome of patients at higher thrombotic risk.