This article originally appeared in the February 2006 Harvard Mental Health Letter and is provided courtesy of Harvard Health Publications.

Mind and mood after a heart attack

Could psychiatric treatment save the lives of heart patients?

A sad or broken heart can have more than one meaning. What research physicians call a cardiovascular event — including heart attacks, strokes, cardiac arrest, angina (severe chest pain), surgery involving the coronary arteries, and other cardiovascular problems — is also an event in consciousness, with emotional consequences. Heart disease can be depressing, anxiety-provoking, and traumatic. About 50% of patients hospitalized with coronary artery disease have some depressive symptoms, and up to 20% develop major depression. Depression may be even more common in survivors of strokes. In addition, a review of 25 studies found that 15% of patients developed post-traumatic stress disorder after a heart attack, sudden cardiac arrest, or cardiac surgery.

Depression and anxiety in heart disease patients raise the risk of deterioration and death. People hospitalized or undergoing surgery for heart conditions are 2–5 times more likely than average to die or suffer further cardiovascular events in the following year if they have symptoms of depression at the time of hospitalization. Depression has a similar effect on patients hospitalized for heart failure (inability of the heart to pump sufficient blood). In fact, recurrence of cardiovascular events is more closely linked to depression than to high cholesterol, smoking, high blood pressure, or diabetes.

The anxiety that often accompanies depression may predict the outcome of heart disease even better. In one three-year study, depression doubled the risk of recurrent cardiac events, but anxiety tripled the risk.

Specialists are becoming interested in Type D (“distressed”) personality with its habits of gloom, worry, pessimism, and lack of self-assurance that resemble chronic mild to moderate depression (dysthymia). Belgian researchers found that over a 10-year period, patients in a cardiac rehabilitation program were nearly three times as likely to die or have a second heart attack if they had this kind of personality.

Isolation
Another source of strain on an already compromised cardiovascular system is the absence of relatives and friends who provide solace, advice, and practical help. A study of heart attack survivors showed that men who lived alone had twice the average death rate in the first year. Another large study found that people were more likely to die in the nine years after a heart attack, regardless of their physical condition, if they did not talk to their doctors, rarely visited friends or family, and did not belong to a voluntary organization.

What matters, apparently, is not so much the size of a person’s social circle as a belief that help will be available when needed. People who say they lack friends in times of need are more likely to die or have a recurrent cardiovascular event, whether they are living alone or not. One study found that hospitalized female (although not male) patients with heart failure were more likely to avoid rehospitalization and death if they had someone to discuss their problems with and to help them make decisions. Help with everyday activities like shopping, cooking, and transportation was less important.

It’s hardly surprising that depression and anxiety can make a heart condition worse. Depressed people often don’t eat and sleep well, don’t exercise, drop out of rehabilitation programs, and neglect to take prescribed drugs.

Physiology
Mind and mood can also affect the cardiovascular system directly by creating a chronic state of emergency. In a normal emergency, blood vessels are constricted, the heart beats faster, appetite is suppressed, and sleep is delayed. Inflammatory substances in the blood increase, and the blood becomes stickier in case a wound needs clotting. When the crisis ends, feedback signals shut the response down.

But for a person who is seriously depressed or anxious or under chronic stress, the emergency is lasting. Stress hormone levels remain high. Blood vessels are less flexible than normal. Inflammatory substances can damage the lining of arteries. And the heart becomes less sensitive to signals telling it to slow down or speed up as the body’s demands change — a condition called low heart rate variability.

Cause and effect are difficult to disentangle in the relationship between depression and heart disease. One complication is overlapping symptoms — appetite loss, insomnia, and fatigue. And vicious cycles arise: Depression or traumatic stress damages the cardiovascular system, and the damage causes further distress and depression. Fear of dying alone strains the heart, and this strain heightens the fear.

Emotional stress and heart disease could also have common causes. One study found that heart attack patients hospitalized with depression were more likely to die in the next year even if the depressive symptoms improved. The neurotransmitters that regulate mood travel in pathways that can be blocked by strokes — blood clots or bleeding in the brain. Vascular dementia results from strokes that cut off blood supply in critical regions; some believe vascular depression is a parallel.

Cardiologists don’t always pay sufficient attention to depression and anxiety in patients. They might be persuaded to take more interest if it could be shown that antidepressant drugs or psychotherapy helps preserve health or prolong life in people with cardiovascular disease. Some of that evidence has begun to trickle in.

Antidepressant effects
The most popular antidepressant drugs today are the selective serotonin reuptake inhibitors (SSRIs). They have less serious physical side effects than other antidepressants and do not disturb heart rhythms. They may also increase heart rate variability and lower the clotting capacity of the blood. (A warning: This can raise the risk of abnormal bleeding.)

The potential of SSRIs for patients with heart disease has been explored in two studies with evocative acronyms: the Sertraline AntiDepressant Heart Attack Randomized Trial (SADHART) and the Enhancing Recovery in Coronary Heart Disease (ENRICHD) trial.

In SADHART, several hundred heart patients who were clinically depressed received either the SSRI sertraline (Zoloft) or a placebo for six months. Patients taking the drug suffered fewer cardiovascular events, including heart failure, heart attacks, and death. The difference was small, and could have been a chance effect — except in patients who had been depressed before the heart attack.

ENRICHD involved 2,500 patients who had recently had heart attacks and were depressed or socially isolated. Half of them got regular care; the other half received six months of individual and group cognitive behavioral therapy. For those who did not respond, an antidepressant was sometimes added. Following up after an average of three years, researchers found that patients who received antidepressants were 42% less likely to die or suffer another cardiovascular event.

This study was not designed as a controlled trial of antidepressants — patients did not receive a drug or placebo at random — so the results are not conclusive, but they are suggestive. As of late 2005, plans are being made for a large, fully controlled trial testing the effects of psychotherapy and antidepressants — a study with features of both SADHART and ENRICHD.

Psychotherapy
Clinical trials conducted as of 2005 have found that psychotherapy relieves depression and anxiety but does not lower the risk of cardiovascular events or death in heart patients. But psychotherapy is often being compared with cardiac rehabilitation programs that serve some of the same functions. These programs supply regular follow-up attention from health professionals who monitor patients, sustain their morale, and urge them to take better care of themselves. A review of 22 studies confirmed that depression doubles the risk of dying after a heart attack, but also found that this association was weaker in more recent research — which suggests that better rehabilitation may already be reducing the damage depression does to the heart.

Many questions remain. Which heart patients are most at risk for persistent depression that raises the risk of deterioration and death? How important are depression and other psychiatric disorders that exist before a heart attack, compared with psychiatric symptoms that occur during the event and shortly after? Do depressed patients get different and worse treatment after a cardiovascular event, and if so, why? How can they be persuaded to stay in cardiac rehabilitation programs?

Meanwhile, if one conclusion continues to emerge from the research, it’s that cardiologists should be better prepared to ask their patients about stress, low mood, and isolation, and patients should not hesitate to bring up these subjects themselves.