Effectiveness of Depression Treatment Following Coronary Artery Bypass Surgery

BACKGROUND:

Cardiovascular disease morbidity and mortality is an important health issue. Depression has emerged as a risk factor for increased morbidity and mortality in patients with coronary heart disease. CABG is a surgical procedure that is specifically directed to improvement in quality of life for patients with severe coronary artery disease, though its impact on mortality is questionable. Patients with depression after CABG are found to not demonstrate sufficient improvement in quality of life, resulting in a significantly higher level of healthcare costs.

DESIGN NARRATIVE:

In this randomized study, 300 patients who show elevated levels of depressive symptoms at 3 to 5 days following CABG and at 2 weeks after hospital discharge will be recruited. They will be randomized to receive either 1) their physician's "usual care" for depression, or 2) a stepped collaborative care program involving a telephone-based nurse care manager. The nurse care manager will contact patients at regular intervals to assess treatment preferences for depression (e.g., counseling, self-management workbook, pharmacotherapy, or specialty referral), promote adherence with care, and monitor the therapeutic response in concert with patient's primary care physicians and under the supervision of a study clinician. One hundred and fifty nondepressed post-CABG patients will be randomly selected to serve as a control cohort to facilitate comparisons with the depressed patients on various baseline and follow-up measures, and to better understand the benefits derived from depression treatment (total N=450). Blinded telephone assessments will be conducted at 2, 4, 8, and 12 months post CABG and then every 6 months until the last patient completes his/her 8-month assessment (range: 8-44 months follow-up). Intent-to-treat analyses will be used to test the primary hypothesis that the intervention will produce at least a clinically meaningful 0.5 effect size improvement in health related quality of life (HRQoL) at 8 months post CABG, as measured by the SF-36 Mental Component Summary score, compared to patients who receive their primary care physician's "usual care" for depression. The secondary hypotheses are that compared to "usual care" patients, intervention patients will 1) experience higher levels of functional status, and lower levels of depressive symptoms, risk for future cardiovascular events, and health services costs, and 2) report similar levels of HRQoL as nondepressed post-CABG patients. Providing evidence-based, stepped, collaborative care treatment for post-CABG depression may be an ideal method for organized health care delivery systems to improve outcomes. The focus on HRQoL and health services costs will facilitate comparisons of the benefits derived from the intervention to that of other established treatments of cardiovascular risk factors and care for other chronic conditions.

Inclusion criteria

• Recently underwent CABG (combined or redo procedure) at one of 8 Pittsburgh area study hospitals
• A PHQ score greater than 10 OR if nondepressed control, a PHQ score less than 5 at both 2 days post CABG to the date of discharge following CABG and when reassessed 2 weeks after hospital discharge
• Folstein Mini-Mental State Examination (MMSE) score greater than or equal to 24
• Able to be evaluated and treated for depression as an outpatient post CABG
• Has a household telephone

Exclusion criteria

• Presently in treatment with a mental health specialist
• Actively suicidal
• History of psychotic illness
• History of bipolar illness according to subject self-report and past medical history
• Current alcohol dependence or other substance abuse as evidenced by chart review and the CAGE questionnaire
• Organic mood syndromes, including those secondary to medical illness or drugs
• Presence of non-cardiovascular conditions that are likely to be fatal within 1 year
• Unstable medical condition as indicated by history, physical, and/or laboratory findings
• Previous enrollment in the study cohort
• Non-English speaking, illiterate, or possessing any other communication barrier
• If nondepressed control, current or previous diagnosis or treatment of depression