Among 24,137 patients identified with significant CAD, a new depression diagnosis was associated with a twofold higher risk of all-cause death after multivariable adjustment, the investigators reported in the European Heart Journal Quality of Care and Clinical Outcomes.
“It was stronger than any follow-up events, stronger than diabetes, stronger than smoking, sex, prior diagnosis of high blood pressure or depression, and even whether they had a heart attack,” lead author Dr Heidi T May (Intermountain Heart Institute, Murray, UT) told theheart.org | Medscape Cardiology. “I thought it would be a significant predictor, but I didn’t anticipate it would be the strongest.
“I would think most people would find that amazing.”
She said the results emphasize the need for continual depression screening among all CAD patients, but an accompanying editorial notes that recommendations by the American Heart Association (AHA) for routine screening in patients with heart disease have been met with some opposition, in large part because of a lack of studies showing a survival benefit with depression treatment.
“Given the uncertainty of whether treating major depression reduces the associated risk for mortality, it might be fruitful to consider whether depressive episodes can be prevented. To do this, we first have to identify the key risk factors for incident depression in patients with CAD,” Drs Robert M Carney and Kenneth Freedland (Washington University School of Medicine, St Louis, MO) write in the editorial.
The current study provides some clues in this regard. The investigators used ICD codes to identify 3646 patients (15%) who had a new depression diagnosis and found they were significantly younger than those without depression (64 vs 65 years), more often female (37% vs 24%), diabetic (40% vs 30%), previously diagnosed with depression (26% vs 5%), and less likely to present with MI (28% vs 36%).
Patients with a depression diagnosis were significantly more likely to die during follow-up (median 8.9 years) than those without depression (50% vs 38.2%, P<0.0001).
Depression at any time following CAD was a significant risk factor for all-cause mortality in univariate (hazard ratio [HR] 2.18, P<0.0001) and multivariate (HR 2.00, P<0.0001) analyses.
The association was also confirmed in subgroups and in a landmark analysis of a depression diagnosis occurring within 1 year of a CAD diagnosis (HR 1.63,P<0.0001), 1 to 3 years (HR 1.48, P=0.004), 3 to 5 years (HR 1.93, P<0.0001), and >5 years (HR 1.20, P<0.0001).
Interestingly, 27.1% of patients were diagnosed within 1 year of their baseline CAD diagnosis and 15% in years 3 to 5, but 36.6% were diagnosed after 5 years.