BACKGROUND AND OBJECTIVE Studies in animal models and humans implicate cell adhesion molecules in atherogenesis but their role in mediating the risk of myocardial infarction is unclear. The ECTIM (étude cas-temoin de l'infarctus myocarde) extension study was established to determine whether a previously implicated polymorphism of the P-selectin gene was associated with myocardial infarction risk in men and women in Belfast and Glasgow.

PATIENTS AND STUDY SETTING 696 cases with a recent myocardial infarction and 561 age matched controls (both male and female) were recruited into a case–control study in MONICA project areas of Belfast and Glasgow.

RESULTS There was no significant association between conventional risk factors (such as hypercholesterolaemia, increased body mass index, or raised blood pressure) and either the rare or the common Pro⁷¹⁵ allele of the P-selectin gene in controls. Overall, comparing Pro⁷¹⁵/Pro⁷¹⁵ and Pro⁷¹⁵/Thr⁷¹⁵ with Thr⁷¹⁵/Thr⁷¹⁵, with adjustment for centre, age, and sex, the odds ratio was 0.78 (95% confidence interval 0.60 to 1.00) (p = 0.054), indicating a “protective” effect of the less common Pro⁷¹⁵ allele. There was no significant heterogeneity in odds ratios between men and women either in this sample or when combined with the original ECTIM subjects.

CONCLUSIONS In a large population based study in two regions of the UK, we have been able to corroborate the earlier ECTIM findings of a lower frequency of the Thr/Pro⁷¹⁵ polymorphism in subjects with myocardial infarction. An apparently “protective effect” of similar magnitude also seems to apply to women.