Total cerebral small vessel disease score and all-cause mortality in older adults of Amerindian ancestry: The Atahualpa Project

Abstract

Introduction Cerebral small vessel disease (SVD) predicts all-cause mortality in Eastern Asian and Caucasian populations. However, little is known about SVD impact in individuals of different races/ethnic groups. In this study, we sought to estimate the mortality risk according to the total SVD (tSVD) score in older adults of Amerindian ancestry. Methods Participants aged >= 60 years from the prospective population-based Atahualpa Project cohort underwent brain MRI between June 2012 and June 2017. The tSVD score was calculated based on the presence of moderate-to-severe white matter hyperintensities, enlarged perivascular spaces, one or more lacune, and one or more cerebral microbleed. We ascertained all-cause mortality during post-MRI follow-up. Poisson regression and Cox-proportional hazards models adjusted for demographics and cardiovascular risk were obtained to estimate mortality risk according to the tSVD score. Results Analysis included 375 participants with available brain MRI and clinical data (mean age 69.0 +/- 8.3 years, 56.3% women). The tSVD score was 0 point in 216 individuals (57.6%), 1 point in 71 (18.9%), 2 points in 53 (14.1%), and 3-4 points in 35 (9.3%). Increasing tSVD score was associated with advancing age, hypertension, low level of education, and physical inactivity. Using tSVD score of 0 as reference, a multivariate Poisson regression model showed an increased mortality for individuals with a tSVD score 3-4 points (IRR: 2.27; 95% CI: 1.20-4.28). Likewise, in the Cox-proportional model adjusted for demographics and cardiovascular risk, participants with a tSVD score 3-4 maintained a greater than two-fold mortality risk when compared to those with tSVD score of 0 points (HR: 2.32; 95% CI: 1.23-4.39). Conclusions High-burden SVD as determined by the tSVD score predicts mortality in community-dwelling older adults of Amerindian ancestry. Incidental diagnosis of covert SVD should prompt aggressive control of cardiovascular health.