People with clinical depression are at nearly twice the risk for cardiac arrest as those who are not depressed, independently of their other cardiovascular risk factors, said Dr. J.P. Empana of Hôpital Paul Brousse, Villejuif, France, and associates.
There may even be a dose effect in which the risk of cardiac arrest rises as the severity of depression increases, they said.
They assessed the relationship between physician-diagnosed depression and out-of-hospital cardiac arrest using data from a large U.S. HMO. The study compared the prevalence of depression among 2,228 patients aged 40–79 years who had incident cases of cardiac arrest with 4,164 controls.
Unlike previous studies of this issue, this investigation evaluated “a large population with a wide range of demographic and clinical characteristics,” Dr. Empana and associates said (Arch. Intern. Med. 2006;166:195–200).
However, the population studied was not racially diverse; 93% of the subjects were white.
The risk for cardiac arrest was almost twice as high for people with clinical depression than for those without depression, with an odds ratio of 1.88. After the data were adjusted to account for numerous cardiovascular risk factors, the odds ratio remained elevated, at 1.43.
This association between depression and cardiac arrest was seen across all demographic subgroups. Men and women were equally affected, as were elderly people and younger adults. The risk of cardiac arrest increased with increasing severity of depression, so that people who required hospitalization for their depression within the preceding year were at highest risk.
A previous case-control study suggested that the use of tricyclic antidepressants may raise the risk of sudden cardiac death. However, that suggestion seems to be refuted in this study. Excluding the subset of 277 patients who were taking antidepressants, 82% of whom were taking tricyclics, did not alter the results, they said.