Differential associations between specific depressive symptoms and cardiovascular prognosis in patients with stable coronary heart disease

Abstract

Objectives: The purpose of this research was to evaluate the relationship between cognitive and somatic depressive symptoms and cardiovascular prognosis.

Background: Depression in patients with stable coronary heart disease (CHD) is associated with poor cardiac prognosis. Whether certain depressive symptoms are more cardiotoxic than others is unknown.

Methods: In the Heart and Soul Study, 1,019 patients with stable CHD were assessed using the Patient Health Questionnaire to determine the presence of the 9 depressive symptoms included in the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition. The mean age of the patients was 67 years, and 82% were men. A comparison was made on a new cardiovascular event (myocardial infarction, stroke, transient ischemic attack, or congestive heart failure) or death (mean follow-up duration 6.1 +/- 2.0 years) on the basis of cognitive and somatic sum scores and for patients with or without each of those specific depressive symptoms. Demographic characteristics, cardiac risk factors, and cardiac medications were controlled for.

Results: After adjustment for demographic data and cardiac risk factors, each somatic symptom was associated with 14% greater risk for events (hazard ratio [HR]: 1.14; 95% confidence interval [CI]: 1.05 to 1.24; p = 0.002). Fatigue (HR: 1.34; 95% CI: 1.07 to 1.67; p = 0.01), appetite problems (HR: 1.46; 95% CI: 1.12 to 1.91; p = 0.005), and sleeping difficulties (HR: 1.26; 95% CI: 1.00 to 1.58; p = 0.05) were most strongly predictive of cardiovascular events. In contrast, cognitive symptoms (HR: 1.08; 95% CI: 0.99 to 1.17; p = 0.09) were not significantly associated with cardiovascular events.

Conclusions: In patients with stable CHD, somatic symptoms of depression were more strongly predictive of cardiovascular events than cognitive symptoms, although the CIs surrounding these estimates had substantial overlap. These findings are highly consistent with those of previous studies. Further research is needed to understand the pathophysiological processes by which somatic depressive symptoms contribute to prognosis in patients with CHD.

Figure 1. Age-adjusted annual rate of cardiovascular events (myocardial infarction, heart failure, stroke, transient ischemic attack or death) during an average of 6.1 years follow-up by number of somatic or cognitive depressive symptoms*

*Somatic sumscore = number of somatic symptoms with score of ≥2; Cognitive sumscore = number of cognitive symptoms with score of ≥2 (or ≥1 for suicidal ideation)

Figure 2. Association between specific depressive symptoms (entered as a dichotomous variable) and cardiovascular events*

* Hazard ratio with 95% CI, adjusted for age, gender, diabetes mellitus, history of MI, history of stroke, history of heart failure, left ventricular ejection fraction, body mass index, smoking, aspirin, beta blocker, statin, and renin-angiotensin system inhibitor.