Patients with heart disease are at increased risk of depression and should be screened routinely, and referred and treated as necessary for the condition, a new science advisory from the American Heart Association states.
Depression has been shown in numerous studies to have profound adverse effects on prognosis and quality of life in heart disease patients. Findings from more than 60 prospective studies, several major review articles, and more than 100 additional narrative reviews of the literature have demonstrated links between depression and cardiovascular morbidity and mortality, according to the advisory, which was published online last month by the Prevention Committee of the American Heart Association Cardiovascular Nursing Council, Clinical Cardiology Council, Epidemiology and Prevention Council, and Interdisciplinary Council on Quality of Care and Outcome Research.
It has been shown that depression is about three times more common in acute myocardial infarction patients than it is in the general community, and in-hospital assessments indicate that up to 20% of patients with myocardial infarction meet the criteria for major depression. An even greater proportion exhibits depressive symptoms, Judith H.K. Lichtman, Ph.D., cochair of the committee, and her colleagues wrote (Circulation 2008 Sept. 29 [doi:10.1161/circulationaha.108.190769]).
Furthermore, the 12-month prevalence of major depression in patients with cardiac disease was 9.3%, compared with 4.8% in those with no comorbid medical illness, in nearly 40,000 participants in a recent National Health Interview Survey.
“There is general consensus that depression remains associated with at least a doubling in risk of cardiac events over the subsequent 1–2 years after an MI,” the authors wrote. Both biological factors—such as human platelet antigen dysfunction, impaired vascular function, and reduced heart rate variability—and behavioral and/or social mechanisms—such as diet, exercise, medication adherence, tobacco use, social isolation, and chronic life stress—have been suggested as possible links between depression and heart disease.
“Although the specific behavioral and biological processes remain unclear, the alteration of these processes is associated with depressive symptoms, consistently in a direction that increases cardiovascular risk,” wrote the committee, adding that depression is associated with decreased compliance with medications; reduced chances of successful modification of other cardiac risk factors and participation in cardiac rehabilitation; higher health care utilization and cost; and greatly reduced quality of life.
“Thus, whether depression impacts cardiac outcomes directly or indirectly, the need to screen and treat depression is imperative,” they wrote.
The committee advised the following:
▸ Routine screening for depression in heart disease patients in a variety of settings, including the doctor's office, hospital, clinic, and cardiac rehabilitation center. At a minimum, administration of the Patient Health Questionnaire (PHQ-2), a two-item assessment of depression that addresses loss of interest or pleasure in normal activities, and feelings of depression and hopelessness, is advised.
▸ Administration of PHQ-9, an expanded version of the PHQ-2, to those who answer “yes” to one or both of the PHQ-2 items. The PHQ-9 assesses additional symptoms of depression, such as altered sleep patterns, fatigue, changes in appetite, and feelings of failure. In addition to yielding a provisional depression diagnosis, it provides a severity score that can be useful for guiding treatment and for patient monitoring. The tool has been shown to have “reasonable” sensitivity and specificity for those with heart disease, according to the advisory.
▸ Follow-up assessment during a subsequent visit in patients with mild symptoms.
▸ A review of the responses with those patients who had high depression scores.
▸ Referral for more comprehensive evaluation by a qualified professional in those with a PHQ-9 score of 10 or higher (out of a possible 27).
▸ Evaluation for other mental disorders, such as anxiety, in those who meet criteria for a more comprehensive evaluation.
▸ Careful monitoring for adherence to medical care, drug efficacy, and safety (with respect to both cardiovascular disease and mental health).
▸ Coordination of care among health care providers.
“Cardiologists should take depression into account in the management of [heart disease], regardless of whether they treat the depression or refer the patient to a health care provider who is qualified in the assessment and treatment of depression, which often may be the patient's primary care provider,” the committee wrote.
Depression can occur before and continue after an acute cardiac event and should not be ignored based on the premise that it is a “normal” reaction to a stressful life event, the authors wrote.
They explained that although there is no direct evidence that depression screening improves outcomes in heart disease patients, there is plenty of evidence that the presence of depression is linked with increased morbidity and mortality, poorer risk factor modifications, lower rates of rehabilitation, and reduced quality of life.