ORLANDO — Patients who were depressed after coronary artery bypass surgery were significantly more likely to have atherosclerotic disease progression within their grafted vessels during follow-up, in a post hoc analysis of data from over 1,300 patients.
This finding should prompt a prospective study to assess whether depression plays a causal role in atherosclerosis, Dr. Ambar Kulshreshtha said while presenting a poster at a conference on cardiovascular disease epidemiology and prevention sponsored by the American Heart Association.
The analysis used data collected in the Post Coronary Artery Bypass Graft trial designed to test whether treatment with an aggressive lipid-lowering regimen and low-dose warfarin could slow atherosclerosis progression within saphenous-vein bypass grafts. The study used patients who'd undergone coronary bypass surgery 1–11 years prior to enrollment. The primary findings of the trial were that aggressive lowering of LDL cholesterol significantly reduced the progression of atherosclerosis within grafted veins, but low-dose warfarin had no benefit (N. Engl. J. Med. 1997;336:153–63).
Almost 98% of enrolled patients—1,319—were evaluated for depression at the time they entered the study using the Centers for Epidemiologic Studies depression (CES-D) scale. Patients were considered depressed if their score was at least 16. According to the CES-D, a score of 16–27 represents mild depression, and a score greater than 27 indicates moderate to severe depression.
Upon evaluation, 127 of the postbypass patients scored 16 or greater on the CES-D, and the remaining 1,192 patients had scores of 15 or less.
All patients also had a baseline coronary angiogram when they entered the study, and a follow-up examination at an average of 4.2 years later.
In an analysis that adjusted for several baseline differences, patients who were diagnosed with depression at entry had a 40% increased risk of having substantial atherosclerosis progression in their saphenous vein grafts, versus patients who were not depressed at baseline, said Dr. Kulshreshtha, a cardiovascular research physician at Beth Israel Deaconess Medical Center in Boston.
This difference was statistically significant.
Among the potential confounders used for adjustment in the analysis were gender, race, years since bypass surgery, systolic blood pressure, kidney function, diabetes, body mass index, and physical activity.