Brain volumes and risk of cardiovascular events and mortality. The SMART-MR study

Abstract

Brain atrophy is a strong predictor for cognitive decline and dementia, and these are, in turn, associated with increased mortality in the general population. Patients with cardiovascular disease have more brain atrophy and a higher morbidity and mortality. We investigated if brain volumes on magnetic resonance imaging were associated with the risk of cardiovascular events and mortality in patients with manifest arterial disease (n = 1215; mean age 58 years). Automated brain segmentation was used to quantify intracranial volume, and volumes of total brain, sulcal cerebrospinal fluid, and ventricles. After a median follow-up of 8.3 years, 184 patients died, 49 patients had an ischemic stroke, and 100 patients had an ischemic cardiac complication. Smaller relative brain volumes increased the risk of all-cause death (hazard ratio [HR] per standard deviation decrease in total brain volume: 1.58, 95% confidence interval [95% CI]: 1.33–1.88), vascular death (HR 1.69, 95% CI: 1.35–2.13), and ischemic stroke (HR 1.96, 95% CI: 1.43–2.69), independent of cardiovascular risk factors. These results suggest that brain volumes are an important determinant of poor outcome in patients with high cardiovascular risk.