Association
between depression and increased risk of sudden
cardiac arrest
Some
studies have suggested that major depression is
associated with an increased risk of coronary
heart disease-related mortality. Altered
imbalance between sympathetic and
parasympathetic tone found in depressed subjects
could be the cause of increased risk of sudden
cardiac death in this population. Thus the
association between the presence and severity of
depression and a higher risk of sudden cardiac
death was investigated.
To explore this issue, the researchers used data
from a population-based, case-control study of
risk factors for incident out-of-hospital
cardiac arrest among more than 400 000 subjects
enrolled in a health maintenance organization.
There were 2228 patients aged 40 to 79 years who
experienced cardiac arrest between 1st January
1980 and 31st December 1994, and 4164 controls.
Comorbid conditions were identified and clinical
characteristics were collected from patient
records. A subject was classified as having
clinical depression if a physician diagnosed
depression or if he was being treated with
antidepressant medication within the year before
the cardiac event. Severe depression was defined
by referral to a mental health clinic or
hospitalization for depression.
The risk of out-of-hospital cardiac arrest for
patients with depression was nearly 2-fold
higher than among subjects without depression
and remained elevated after adjustment for
parameters (smoking, heavy alcohol consumption,
diabetes, hypertension, prior myocardial
infarction and prior congestive heart failure).
The association was found for men and for women,
in both younger and older patients, and in
subjects with or without prior
physician-diagnosed heart disease. Compared with
patients without depression, the risk of cardiac
arrest increased in depressed patients with the
severity of depression.
In this large sample, the presence and severity
of clinical depression was clearly associated
with a higher risk of cardiac arrest due to
heart disease, independently of major coronary
heart disease risk factors. Empana
JP, Jouven X, Lemaitre RN, Sotoodehnia N, Rea T,
Raghunathan TE, Simon G, Siscovick DS. Clinical
depression and risk of out-of-hospital cardiac
arrest. Arch Intern Med 2006,
166:195-200.