Effect of antidepressants and their relative affinity for the serotonin transporter on the risk of myocardial infarction

Background-Antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), attenuate platelet activation by depleting serotonin storage and may decrease risk of myocardial infarction (MI). These drugs differ in their affinity for the platelet serotonin transporter and therefore may vary in their effects on MI protection. Methods and Results-A case-control study of first MI in patients aged 40 through 75 years was conducted among 36 hospitals in a 5-county area during a 3-year period. Case subjects were patients hospitalized with a first MI, and control subjects were randomly selected from the same geographic area. Detailed information regarding medication use and other clinical and demographic data were obtained by telephone interview. Among the 1080 cases and 4256 controls who participated, there were 223 users of antidepressants with high serotonin transporter affinity, all of which were SSRIs (paroxetine, fluoxetine, and sertraline). After adjustment with multivariable logistic regression for age, gender, race, education, physical activity, quantity of cigarettes smoked per day, body mass index, aspirin use, family history of MI, and history of diabetes, hypertension, or hypercholesterolemia, the odds ratio for MI among current users of antidepressants with high serotonin transporter affinity compared with nonusers was 0.59 (95% CI 0.39 to 0.91; P=0.02). Increasing serotonin transporter affinity was associated with reduced odds of MI among users of all SSRIs (P for trend <0.01) but not tricyclic (P=0.77) or atypical (P=0.70) antidepressants. There was no association detected between non-SSRI antidepressant use and MI. Conclusions-Increasing serotonin transporter affinity correlates with greater MI protection with SSRI but not other antidepressant exposure.