Purpose

Methods

A historical pooled cohort study of all elderly non-HMO community dwelling Medicare beneficiaries represented in the 1998–1999 and 2000–2001 Medicare Current Beneficiary Survey to assess the incidence of AMI (ICD-9: 410 or 411). Antidepressant users were defined by at least one antidepressant drug mention in the year prior to the year of observation for AMI. Class users were defined as unique users of the corresponding class (SSRI, cyclic, other) according to 2005 U.S. Pharmacopeia therapeutic categories and individuals who switched drug classes at any time during the study were defined as combination users. Logistic regression models were used to compare odds of experiencing an AMI. Covariates included age, sex, race, poverty status, cardiovascular drug therapy, anticoagulant medication therapy, smoking history and current status, poverty status, and the DCG/HCC to adjust for severity, which includes 189 conditions, including depression and related disorders that are treated with antidepressants.

Results

Antidepressant users numbered 1,905 (584 SSRI users, 388 cyclic users, 111 other users, and 822 combination users). Nonantidepressant users numbered 8,892. The incidence of AMI was 2.1 % in the sample, 1.9 % in nonantidepressant users, 3 % in all antidepressant users, 3.4 % in all SSRI users, 2.1 % in cyclic users, 1.8 % in all other users, and 3.4 % in combination users. Logistic models revealed that antidepressant users (OR = 1.46, 95 % CI: 1.02–2.08) and SSRI users (OR = 1.86, 95 % CI: 1.07–3.22) were found to have significantly greater odds of AMI compared to nonantidepressant users.

Conclusion

Study findings conflict with previous studies, which have found SSRIs to be AMI protective. Study limitations include its restriction to the Medicare population and the 1-year maximum observation period.