Depression Increases Long-Term Risk of Death After Coronary Heart Disease Diagnosis

Following a diagnosis of coronary heart disease, depression doubles the long-term risk of death in the first decade, according to a study presented at the American College of Cardiology’s 66th Annual Scientific Session in Washington, DC.

The study focused on patients diagnosed with a heart attack, stable angina, or unstable angina, conditions that all fall under the umbrella of coronary heart disease.

Scientist have known the association between heart disease and depression, with depression increasing the likelihood of heart disease and vice versa. Prior studies have examined depression within the first few months of a coronary heart disease diagnosis, but the new study is the first to provide more information on the effects of depression over the long-term.

“The majority of studies evaluating depression following a heart disease event have occurred within 30 days of the event,” said lead author Heidi May, PhD, MSPH. “We sought to determine if the risk of all-cause mortality associated with depression varies with time between the diagnosis of heart disease and follow-up depression diagnosis.”

For the study, investigators analyzed health records for approximately 25,000 Intermountain Healthcare patients who were tracked for an average of nearly 10 years following a coronary heart disease diagnosis.

Approximately 15% of patients received a follow-up diagnosis of depression, a substantially large figure than the estimated rate of 7.5% to 10% in the general population.

The results of the study showed that of the 3646 individuals with a follow-up diagnosis of depression, half died during the study period compared with 38% of 20,491 individuals without a depression diagnosis.

The findings suggest that individuals with depression are twice as likely to die compared with individuals without depression.

“I though depression would be significant, but not the most significant predictor,” May said.

The findings were adjusted for risk factors such as gender, age, heart attack or chest pain, medications, and follow-up complications. The study found that depression was the strongest predictor of death in the patient group, and were consistent regardless of gender, age, timing of depression onset, history of depression, or whether the patient had a heart attack.

The investigators suggest that clinicians seek ways to better identify depression in patients with coronary heart disease—–whether it be through patient questionnaires designed to screen for depression or by actively watching for signs of depression during follow up exams.

“It can be devastating to be diagnosed with coronary artery disease,” May said. “Clinicians need to pay attention to the things their patients are expressing, in terms of both physical symptoms as well as emotional and nonverbal factors.”

Depression has been linked to behaviors that can have a negative impact on cardiovascular health, such as poor diet, an increase in smoking or alcohol, reduced compliance with medical treatment, and a reduction in physical activity.

“Our study shows that it doesn’t matter if depression emerges in the short term or a few years down the road—–it’s a risk factor that continually needs to be assessed,” May said. “I think the take-home message is that patients with coronary heart disease need to be continuously screened for depression, and if found to be depressed, they need to receive adequate treatment and continued follow-up.

Patients diagnosed with coronary heart disease who have depression are approximately twice as likely to die compared with those who are not diagnosed with depression.

“There is a lot more research that needs to be done with depression and heart disease. Moving forward, we would like to further assess treatment affects, severity of symptoms, and other comorbidities that may put a patient at an increased risk of death,” the authors said.

Coronary heart disease is the most common form of heart disease and accounts for approximately 37,000 deaths in the United States per year.