RÉSUMÉ
<p><b>OBJECTIVE</b>Tobacco smoking results in increased platelet aggregability, which suggests that low-dose aspirin used in common clinical practice may not effectively inhibit platelet activity in smokers with coronary heart disease (CHD). This review was performed to assess the effect of aspirin on platelet aggregation in patients with CHD.</p><p><b>DATA SOURCES</b>We performed an electronic literature search of MEDLINE (starting from the beginning to March 15, 2009) using the term "smoking" or "tobacco" paired with the following: "platelet", "aspirin" or "coronary heart disease".</p><p><b>STUDY SELECTION</b>We looked for review articles regarding the effect of tobacco smoking on platelet activity and on the anti-platelet efficacy of aspirin in healthy people and patients with CHD. The search was limited in "core clinical journal". In total, 1321 relevant articles were retrieved, and 36 articles were ultimately cited.</p><p><b>RESULTS</b>Tobacco smoking results in increased platelet aggregability, which can be inhibited by low-dose aspirin in the healthy population. However, in patients with CHD, the increased platelet aggregability can not be effectively inhibited by the same low-dose of aspirin. A recent study indicated that clopidogrel or an increased dose of aspirin can effectively inhibit the increased platelet aggregability induced by tobacco smoking in patients with CHD.</p><p><b>CONCLUSIONS</b>It is important for patients with CHD to quit smoking. For the current smoker, it may be necessary to take larger doses of aspirin than normal or take an adenosine diphosphate receptor inhibitor along with aspirin to effectively inhibit the increased platelet activity.</p>