As stated above, the lowest effective dose of aspirin for long-term antiplatelet prophylaxis ranges between 50 and 100 mg/day, consistent with the saturability of platelet COX-1 inactivation at low doses (17), which was based on indirect comparisons of randomized controlled trials employing different aspirin dosing regimens (23), as well as on head-to-head randomized comparisons of different aspirin doses in patients with acute coronary syndromes and stable CVD (15, 24). This evidence concerns the gene PTGS1 and acute coronary syndrome.