Aims Selective serotonin reuptake inhibitors (SSRIs) have been associated with serotonin depletion in platelets, potentially leading to abnormal aggregation and prolonged bleeding time. In view of the importance of serotonin in coronary thrombosis, and decreased platelet serotonin concentrations associated with SSRIs, the present study was performed to test the hypothesis of a decreased risk of acute myocardial infarction (AMI) associated with SSRIs.
Methods We conducted a population-based case-control analysis using the UK General Practice Research Database (GPRD). A total of 3319 patients aged 75 years or younger free of clinical conditions predisposing to ischaemic heart disease, with a first-time diagnosis of AMI between 1992 and 1997, and 13 139 controls without AMI matched to cases for age, sex, general practice attended, and calendar time were included. Conditional logistic regression was used to estimate relative risks.
Results Adjusted odds ratios (with 95% CI) for current use of SSRIs, non-SSRIs, or other antidepressants, compared to the group of nonusers of antidepressants were 0.9 (95% CI 0.5,1.8), 0.9 (95% CI 0.7,1.2), and 1.3 (95% CI 0.6,2.8), respectively. As compared with nonuse of SSRIs, current use (regardless of any other antidepressants used) resulted in an adjusted OR of 1.1 (95% CI 0.7,1.6).
Conclusions The current analysis provides evidence that SSRI exposure does not substantially decrease the risk of developing first-time AMI in patients free of factors predisposing to ischaemic heart disease. However, due to relatively small numbers of exposed subjects and the resulting wide confidence intervals, further studies may be needed to document a lack of effect of SSRIs in subjects without pre-existing diseases predisposing to AMI.