By Todd Neale, Senior Staff Writer, MedPage Today
Published: Feb 6, 2014
Action Points
- Note that two studies suggest a causal relationship between depression and cardiovascular events — with one post hoc analysis of a randomized trial demonstrating a lower rate of CVD events among those randomized to a depression intervention.
- Be aware that the high rate of events reported in the study by Stewart et al. may be due to the inclusion of mild troponin elevation in their definition of a “hard” CVD event.
Two new studies provided support for depression as a treatable cause of coronary heart disease.
The first, which relied on repeat measures of depressive symptoms over 2 decades of follow-up, demonstrated dose-response relationships between depression and both coronary death and nonfatal myocardial infarction, but not stroke, Eric Brunner, PhD, of University College London, and colleagues reported online in the European Journal of Preventive Cardiology.
The second, a post-hoc analysis of a randomized trial, showed that anintervention to treat depression in older adults reduced the risk of hard cardiovascular events, but only in those who did not have pre-existing cardiovascular disease at baseline, Jesse Stewart, PhD, of Indiana University-Purdue University Indianapolis, and colleagues reported in the January issue of Psychosomatic Medicine.
The findings of the studies bolster the ideas that depression is a causal factor in cardiovascular disease and that treating it can help prevent cardiovascular events, Redford Williams, MD, of Duke University, told MedPage Today.
The lack of an effect for the depression intervention for patients with pre-existing heart disease does not, however, indicate that treating depression in those with established disease does not work, said Williams, who was not involved in either study.
Although previous trials in patients with pre-existing heart disease have not generally shown a benefit for depression treatment, Williams pointed to other preliminary studies that have shown that cognitive behavioral stress management delivered in group settings to patients with coronary heart disease does reduce both morbidity and mortality.
But more work needs to be done, he said: “A large clinical trial for primary prevention would settle once and for all that treatment of depression is effective in reducing the increased coronary heart disease risk associated with depression.”
Whitehall II Cohort Study
To help resolve some issues with prior observational studies — which have generally supported an association between depression and coronary heart disease and stroke — Brunner and colleagues examined data from the Whitehall II cohort study, an investigation of cardiovascular disease in English civil servants who were an average of 44 years old at baseline.
The analysis included 10,036 patients who were followed for 24 years. During that time, the participants underwent up to six assessments of depressive symptoms with the 30-item General Health Questionnaire (GHQ-30) and one assessment with the Epidemiologic Studies Depression Scale (CES-D).
Overall, 23% of the participants screened positive for depressive symptoms at some point during follow-up with the GHQ-30 and 15% screened positive with the one-time CES-D.
The outcomes of interest were stroke or coronary death and nonfatal MI.
After adjustment for age, sex, and ethnicity, screening positive on the GHQ-30 was associated with incident stroke, but only during shorter, 5-year observation periods. That, combined with another analysis showing that the risk of depressive symptoms was greater following a stroke, “is consistent with the proposition of reverse causality, such that vascular causes of depressive symptoms were responsible for the association,” the authors wrote.
The relationship differed for coronary heart disease, however. The risk of incident disease was greater when the number of positive screens on the GHQ-30 during follow-up went up (P=0.04). That dose-response relationship “provides evidence supporting a causal relationship between depression and coronary heart disease, in contrast to the findings in relation to stroke.”
IMPACT Randomized Trial
To assess the effect of treating depression on the occurrence of cardiovascular events, Stewart and colleagues performed a post-hoc analysis of the IMPACT trial, which showed that a collaborative intervention involving antidepressants and psychotherapy improved depression outcomes relative to usual care in primary care patients 60 and older who had major depression or dysthymia.
The current analysis included 235 patients who were randomized at two primary care clinics in Indianapolis and were then followed for 8 years for MI or stroke; 29% of the patients had cardiovascular disease at baseline.
During the extended follow-up, half of the patients (51%) had a cardiovascular event, and the effect of the depression intervention differed based on cardiovascular disease status at baseline.
For those with heart disease, the intervention did not lower the rate of cardiovascular events (86% versus 81%; HR 1.19, 95% CI 0.70-2.03).
Among those free of heart disease at baseline, however, the intervention cut the rate of events nearly in half (28% versus 47%; HR 0.52, 95% CI 0.31-0.86). That means that about six patients would need to be treated with the intervention to prevent one cardiovascular event over a 5-year period.
“Although our results raise the possibility that the IMPACT intervention could be used as a primary prevention strategy for coronary artery disease and cerebrovascular disease,” the authors wrote, “there is now a need to conduct a well-powered randomized controlled trial designed to definitively test our hypothesis that treating depression earlier in the natural history of cardiovascular disease reduces the risk of cardiovascular disease events.”
They acknowledged that the study was limited by the post-hoc design, the small number of patients with heart disease at baseline, and the use of patients from only two of the original trial sites.
The study by Brunner and colleagues was supported by the British Medical Research Council, the British Heart Foundation, the British Health and Safety Executive, the British Department of Health, the British Stroke Association, the U.S. National Heart, Lung and Blood Institute, and the U.S. National Institute on Aging. The authors also reported support from a professorial fellowship from the Economic and Social Research Council, a National Institute for Health Research Program grant, and the National Institute for Health Research (NIHR) Biomedical Research Center based at Guy’s and St. Thomas’ NHS Foundation Trust and King’s College London.
Brunner and colleagues reported that they had no conflicts of interest.
The study by Stewart and colleagues was supported by the National Institute on Aging.
Stewart and colleagues reported that they had no conflicts of interest.
From the American Heart Association:
Additional source: Psychosomatic Medicine
Source reference:Stewart J, et al “Effect of collaborative care for depression on risk of cardiovascular events: data from the IMPACT randomized controlled trial” Psychosom Med2014; 76: 29-37.