Matters of the (Depressed) Heart: What’s the Risk?

Major depressive disorder (MDD) appears to be an independent risk factor for cardiovascular disease in older adults.¹ Although previous studies have been inconclusive, a multicenter Dutch study found a threefold increased risk of cardiovascular disease in older primary care patients with major depression. The researchers conducted a 2-year prospective cohort study that followed 143 primary care patients with major depression and 139 nondepressed patients who acted as controls. All patients were age 55 years or older, and women were more heavily represented in the study population, with 99 women in the depressed cohort and 90 in the control group.

MDD was defined according to DSM-IV criteria, and severity of depression was measured using the Montgomery Åsberg Depression Rating Scale. The primary endpoint was morbidity or mortality attributed to a cardiovascular event (eg, ischemic heart disease, transient ischemic attack, stroke, heart failure or other cardiovascular event).

The depressed and control groups were relatively comparable, except that patients with MDD were more likely than controls to live alone (50% vs 30%). Prevalence of diabetes also was greater among depressed patients compared with controls (12% vs 4%), but fasting glucose levels were similar, indicating that the diabetes was well controlled, according to the study authors. In addition, participants with MDD were less physically active and had a higher mean body mass index (28.2 vs 26.8 kg/m2) than controls.

The patients were followed for 24 months. Every 6 months, psychopathologic and cardiovascular measures were collected via telephone interviews, and data on lifestyle domains were collected via written questionnaires.

Of patients experiencing a cardiovascular event during the 2-year study period, 75% were among the group with MDD. In total, 36 (13%) of the study population experienced a cardiovascular event. Ischemic heart disease (myocardial infarction or angina pectoris) developed in 13 (9%) of the patients with MDD. A cerebrovascular event occurred in 3 (2%), and other cardiovascular diseases (ie, heart failure, conduction disorders, or vascular disease) developed in 11 (8%). In comparison, ischemic heart disease developed in 1 (< 1%) control, a cerebrovascular event occurred in 3 (2%) controls, and other cardiovascular diseases developed in 5 (4%).

MDD was associated with a hazard ratio of 2.83 for cardiovascular events that, when adjusted to factor in baseline data on cardiovascular medication (the only confounding variable), dropped to 2.46.

The authors concluded that major depressive disorder is a modifiable risk factor for cardiovascular disease in older primary care patients and is independent of other known cardiovascular risk factors. They suggested that further research should focus on whether treatment for depression results in a better cardiovascular outcomes in this patient population.

References:

1. van Marwijk HW, van der Kooy KG, Stehouwer CD, et al. Depression increases the onset of cardiovascular disease over and above other determinants in older primary care patients, a cohort study. BMC Cardiovasc Disord. 2015;12;15:40. http://www.biomedcentral.com/content/pdf/s12872-015-0036-y.pdf. Accessed May 28, 2015.