Anxiety and depressive disorders are particularly common in patients with cardiovascular disease. One study showed that one week after myocardial infarction, an estimated 16 percent of patients met the criteria for a major depressive disorder. Other studies have found an association between coronary artery disease and hypertension and anxiety disorders. Davies and colleagues reviewed biologic explanations for the increased prevalence of depression and anxiety in patients with cardiovascular disease. They also studied the evidence for optimal pharmacologic and psychotherapeutic treatment of these psychiatric conditions in patients with cardiovascular disease.

Results of one study showed that mortality in depressed patients is 3.5 times greater than that in nondepressed patients following myocardial infarction; however, the association between psychiatric morbidity and cardiovascular disease goes beyond the psychologic impact of heart disease. Several studies report a prospective association between anxiety disorders and the later development of cardiovascular disease or sudden death. Depression also has been linked with the development of cardiovascular complications in patients with hypertension. Several biologic explanations have been proposed for the association between psychiatric and cardiovascular disease, including a serotonin-mediated effect on platelets and dysfunction of the autonomic nervous system. Psychologic symptoms may impair coping mechanisms and the ability to adhere to lifestyle changes and medication regimens. Finally, patients whose cardiovascular symptoms, such as dyspnea or chest pain, are attributed to anxiety or panic disorders may have a delay in diagnosis and increased morbidity because of treatment initiation when cardiovascular disease is advanced.

Certain drug treatments for psychiatric morbidity have been associated with a reduced incidence of myocardial infarction and an improved survival rate in patients who had unstable angina or myocardial infarction. A case-control study with 5,336 participants reported that the odds ratio for myocardial infarction (0.59) was significantly reduced in patients who were receiving fluoxetine, sertraline, or paroxetine. At least five double-blind comparative or placebo-controlled trials support the efficacy of selective serotonin reuptake inhibitors (SSRIs) in patients who have depression and ischemic heart disease or hypertension. The largest trial found significant improvement in depression scores in patients randomized to sertraline following hospital admission for myocardial infarction or unstable angina. Other studies found evidence supporting the use of fluoxetine and citalopram. In one study of 56 patients, nortriptyline was superior to fluoxetine and placebo in remission of depressive symptoms. Nortriptyline may be less likely to cause hypotension and other adverse cardiac effects commonly associated with tricyclic drugs.

Drug interactions are particularly important in patients with cardiovascular and psychiatric conditions. These patients are likely to be receiving several medications, many of which are metabolized by the cytochrome P450 enzymes CYP2D6 and CYP3A4. Paroxetine and fluoxetine are potent CYP2D6 inhibitors and can interfere with the metabolism of propranolol, metoprolol, flecainide, and encainide. Conversely, fluoxetine and nefazodone inhibit CYP3A4 and may interfere with simvastatin, amlodipine, nifedipine, diltiazem, and amiodarone.

Cognitive behavior therapy is effective for depression and anxiety disorders and has been successful in patients with chest pain but not in patients with cardiac disease. This therapy has not been proved to reduce cardiac events in patients with poor social supports.

The authors stress the need for physicians to recognize and effectively treat anxiety and depression in patients with cardiovascular disease. The accumulating evidence of effectiveness indicates that diagnosis and management of psychiatric morbidity should be incorporated into all clinical management of coronary heart disease and hypertension.