The purpose of this study is to evaluate the platelet antiaggregant effect that a chronic treatment with ASA (150 mg) produces,comparing this effect between two formulations of ASA: normal and the one of sustained release, in patients with stable coronary disease.

A large clinical trials have established the efficacy of the antiaggregant products in patients with ischemic cardiopathy, stroke and intermittent claudication.

Without doubt, the acetylsalicylic acid (ASA) is the most used antiaggregant product, nevertheless, and spite of being centenarian, it last some questions pending regarding the most appropriate dose, mechanism of action implicated, the association with other drugs, and the pharmaceutical form in order to improve the efficacy and the safety of the ASA.

Some previous studies indicate that the slow release form of ASA has a different behaviour in the platelet effect in comparison with plain formulation.

The aim of this study is to demonstrate the best antiaggregant and safety profile of a low dose of a slow release formulation of ASA.

Inclusion Criteria:

• Previous episodes of myocardial infarction
• Previous episodes of instable angina pectoris
• Previous coronary revascularization
• Significant arterial coronary disease

Exclusion Criteria:

• Patients with other pathologies that requires treatment with other antiaggregants
• Patients in treatment with low molecular weight heparin or oral anticoagulant
• Patients with antecedents of hypersensibility to ASA