Testing Vascular Depression hypothesis: Neuropsychiatric Outcomes after Heart Surgery (NOAHS) Study
Abstract
Depression after coronary artery bypass graft (CABG) surgery is common (up to 40%) and increases risk of cardiac morbidity and mortality in the first year by more than two fold. However, current scarcity of data on etiopathogenesis of post-CABG depression hampers development of prevention or treatment strategies of post-CABG depression. “Vascular Depression” hypothesis posits that cerebrovascular disease predisposes, precipitates, or perpetuates late-onset depression and implicates etiopathogenesis and treatment strategies that are different from idiopathic, early-onset depression. Conspicuous similarities in demographics, longitudinal course, and presence of vascular risk factors exist between post-CABG depression and vascular depression. The NIMH-sponsored Neuropsychiatric Outcomes after Heart Surgery (NOAHS) study utilizes Transcranial Doppler ultrasound (TCD) to detect and quantify the location and severity of Intracranial Atherosclerosis (ICA), as well as to assess for other putative pre-CABG risk factors (e.g. pre-CABG depression, neuroticism, low social and support) for post-CABG depression in CABG surgery patients at the time of cardiac catheterization. The NOAHS study tests the Vascular Depression Hypothesis by follow the subjects over the subsequent 12 months to assess for incidence, symptomatology and course of post-CABG depression. Confirming these predictions will support the hypothesis that post-CABG depression is a form of Vascular Depression, thus laying the foundation for risk stratification with a mobile, bedside tool and development of etiologically-based prevention strategies to reduce morbidity and mortality associated with post-CABG depression.