Depression and failure of cholesterol lowering after acute myocardial infarction.

OBJECTIVE: Depression after acute myocardial infarction (MI) is independently associated with cardiac mortality, but the mechanism explaining this association remains unclear. To our knowledge, there has been no prior study exploring the impact of post-MI depression on lipid lowering, a key secondary prevention measure in post-MI patients. In this prospective observational cohort pilot study, we hypothesized that patients with early post-MI depression would have inferior cholesterol reduction 6 months post-MI compared to nondepressed patients.
METHOD: Patients admitted to a cardiac intensive care unit or a cardiac step-down unit between October 2003 and July 2005 were enrolled in the study within 72 hours of MI. Two weeks post-MI, subjects were assessed for depression using the module for current major depressive disorder (MDD) from the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) and the Beck Depression Inventory-II (BDI-II). Information regarding cholesterol levels was collected 6 months after MI.
RESULTS: Initial and 6-month cholesterol levels were available for 70 subjects who had 2-week post-MI depression assessments. Post-MI depression, measured both using an interview for MDD and the BDI-II, was associated with inferior cholesterol reduction, with depressed subjects improving their cholesterol levels by approximately 8 mg/dL compared to a cholesterol reduction of 37 mg/dL in nondepressed subjects. Furthermore, depression diagnosed by formal MDD interview (beta=-.301; P<.001) and the BDI-II (beta=-.269; P=.001) continued to be associated with significantly smaller reductions in cholesterol levels on linear regression analyses that accounted for demographic and medical variables.
CONCLUSIONS: In this exploratory pilot study, early post-MI depression was independently associated with impaired lipid lowering 6 months after MI.