Major depression and first-time hospitalization with ischemic heart disease, cardiac procedures and mortality in the general population: A retrospective Danish population-based cohort study

Objective We investigated the association between unipolar depression and incident hospital admissions due to ischemic heart disease, invasive cardiac procedures and mortality independent of other medical illnesses. Methods A population-based cohort of 4.6 million persons aged 15 years or older and born in Denmark was followed up from 1995-2009. Incidence rate ratio (IRR) and mortality rate ratio (MRR) were estimated by survival analysis, stratified by or adjusted for gender, age, severe chronic somatic comorbidity and calendar time. Results Adjusted risks of cardiac hospital admissions and death were significantly increased by up to 15% and 68%, respectively, in persons with hospital admissions due to depression, and were most increased in 15-59 year old women (IRR: 1.64; MRR: 2.57) and men with depression (IRR: 1.39; MRR: 2.21), and during the first 180 days after being diagnosed with depression (women: IRR: 1.38; MRR: 2.35; men: IRR: 1.42; MRR: 2.67). One-year mortality after new ischemic heart disease was elevated by 34% in women and men. By contrast, overall rates of invasive cardiac procedures following cardiac hospitalizations were significantly decreased by 34% in persons with depression but were twofold increased in men recently diagnosed with depression. Conclusion Clinical depression leading to hospitalization was a risk factor for new cardiac complications independent of somatic comorbidity in the magnitude of other cardiac risk factors, particularly in individuals between 15-59 years of age and during the first weeks following psychiatric admission. Our findings support recent cardiovascular disease prevention guidelines on assessing depression among other psychosocial factors in patients at increased cardiovascular disease (CVD) risk.