Persistent depression may increase risk of cognitive decline in older patients with CAD

Persistent depression symptoms may be associated with significantly greater declines in cognitive performance in older patients with coronary artery disease who underwent cardiac catheterization, according to a study published in the March issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Relatively high rates of depression have been observed among older patients with coronary artery disease, including those undergoing coronary interventions, but it remains unknown whether depressive symptoms exacerbate their risk for long-term cognitive decline, the authors write in their study background.

Elizabeth A. Freiheit, M.A., of the University of Calgary, Alberta, Canada, and colleagues examined the association between depression symptoms and longer-term (less than or equal to 30 months after the procedure) changes in some areas of cognitive performance among older patients undergoing coronary catheterization who subsequently received coronary artery bypass graft (CABG) procedures, percutaneous coronary intervention (PCI) or medical therapy (MT) after catheterization. They also examined whether any associations were influenced by the presence of the apolipoprotein E (APOE) ε4 allele (believed to be a genetic risk factor for Alzheimer disease). The study included 350 patients, 60 years or older, who underwent nonemergency catheterization without prior revascularization.

"In longitudinal models adjusted for age, sex, educational level and baseline cognitive performance, those with persistent symptoms exhibited significantly greater decline at 30 months (relative to baseline) in attention/executive function, learning/memory, verbal fluency and global cognition compared with those with no or baseline-only depressive symptoms," the authors comment.

The investigators also note that persistent symptoms within the first year also were a significant risk factor for subsequent decline (from 12 to 30 months) across all four cognitive measures. For global cognition, and to a lesser extent verbal fluency, they suggest that the magnitude of the decline was greater for patients with the APOE ε4 allele.

"Consequently, a one-time assessment of depressive symptoms may be inadequate for detecting those at risk of longer-term adverse cognitive and functional outcomes," the authors conclude. "These findings illustrate the need for longer-term monitoring of depressive symptom severity and change by clinicians and other caregivers."