Antidepressant use, serotonin transporter affinity, and reinfarction among patients receiving clopidogrel: a population-based study

Purpose — Conflicting evidence exists regarding the association between antidepressant use and reinfarction among high-risk cardiovascular patients. Recent evidence suggests that clinical benefit associated with antidepressants may be related to serotonergic activity, suggesting that some antidepressants may offer greater advantages than others.

Methods — The researchers conducted a population-based nested case-control study among patients aged 66 years or older who commenced clopidogrel between April 1, 2002 and December 31, 2009, following hospital discharge for acute myocardial infarction (AMI). Cases were those who were readmitted for AMI, underwent percutaneous coronary intervention (PCI), or died within 90 days of discharge. Three controls were matched to each case on age, PCI, and the date of hospital discharge. The researchers categorized exposure to antidepressants as current or no use within 120 days before the index date, and the serotonergic activity of antidepressants was further categorized as low, medium, and high according to their affinity for the serotonin transporter

Results — Among 24 090 patients who received clopidogrel following AMI, the researchers identified 2494 cases. Of these, 2444 (98%) were successfully matched to 7045 controls. After extensive multivariable adjustment, antidepressant use was not associated with lower risk of the composite outcome (adjusted odds ratio [OR] 1.11 and 95% confidence interval [CI] 0.98-1.27). The absence of association was consistent across the different antidepressant groups categorized by serotonin transporter affinity.

Conclusion — In high-risk cardiovascular patients with a history of AMI and treated with clopidogrel, antidepressant use is associated with no additional reduction in risk of reinfarction irrespective of serotonin transporter affinity.