Aspirin in the prevention of cardiovascular events in patients with diabetes

Diabetes imparts a substantial increased risk for cardiovascular disease-related mortality and morbidity. Because of this, current medical guidelines recommend prophylactic treatment with once-daily, low-dose aspirin (acetylsalicylic acid) for primary and secondary prevention of cardiovascular (CV) events in high-risk patients. However, only modest reductions in CV events and mortality have been observed with once-daily aspirin treatment in patients with diabetes, including patients with a previous CV event, perhaps because of disparity between aspirin pharmacokinetics and diabetes-related platelet abnormalities. Once-daily aspirin irreversibly inactivates platelets for only a short duration (acetylsalicylic acid half-life, approximately 15-20 minutes), after which time newly generated, active platelets enter the circulation and weaken aspirin's effect. Platelets from patients with diabetes are more reactive and are turned over more rapidly than platelets from normal individuals; the short inhibitory window provided by once-daily aspirin may therefore be insufficient to provide 24-h protection against CV events. Alternative conventional aspirin regimens (e.g. higher daily dose, twice-daily dosing, combination with clopidogrel) and newer formulations (e.g. 24-h, extended-release) have been proposed to overcome the apparent limited efficacy of conventional aspirin in patients with diabetes; however, tolerability concerns and limited clinical efficacy data need to be taken into account when considering the use of such regimens.