Optimism, response to treatment of depression, and rehospitalization after coronary artery bypass graft surgery.

OBJECTIVE: Optimism has been associated with a lower risk of rehospitalization after coronary artery bypass graft (CABG) surgery, but little is known about how optimism affects treatment of depression in post-CABG patients.

METHODS: Using data from a collaborative care intervention trial for post-CABG depression, we conducted exploratory post hoc analyses of 284 depressed post-CABG patients (2-week posthospitalization score in the 9-item Patient Health Questionnaire ≥ 10) and 146 controls without depression who completed the Life Orientation Test - Revised (full scale and subscale) to assess dispositional optimism. We classified patients as optimists and pessimists based on the sample-specific Life Orientation Test - Revised distributions in each cohort (full sample, depressed, nondepressed). For 8 months, we assessed health-related quality of life (using the 36-item Short-Form Health Survey) and mood symptoms (using the Hamilton Rating Scale for Depression [HRS-D]) and adjudicated all-cause rehospitalization. We defined treatment response as a 50% or higher decline in HRS-D score from baseline.

RESULTS: Compared with pessimists, optimists had lower baseline mean HRS-D scores (8 versus 15, p = .001). Among depressed patients, optimists were more likely to respond to treatment at 8 months (58% versus 27%, odds ratio = 3.02, 95% confidence interval = 1.28-7.13, p = .01), a finding that was not sustained in the intervention group. The optimism subscale, but not the pessimism subscale, predicted treatment response. By 8 months, optimists were less likely to be rehospitalized (odds ratio = 0.54, 95% confidence interval = 0.32-0.93, p = .03).

CONCLUSIONS: Among depressed post-CABG patients, optimists responded to depression treatment at higher rates. Independent of depression, optimists were less likely to be rehospitalized by 8 months after CABG. Further research should explore the impact of optimism on these and other important long-term post-CABG outcomes.