New pooled cohort risk equations and presence of asymptomatic brain infarction

Background and purpose: The new pooled cohort risk (PCR) equations is sex- and race-specific estimates of the 10-year risk of atherosclerotic cardiovascular events among disease-free adults. Little is known about the association between the PCR model and presence of silent brain infarction (SBI).

Methods: We conducted a cross-sectional study of 1603 neurologically asymptomatic Korean people (mean age, 56.6±8.3; 838 men), who underwent brain MRI. We explored the association of PCR with SBI by race. SBI was divided into deep subcortical and hemispheric (hs-SBI).

Results: One-hundred seventy-five (10.9%) subjects had SBI. The PCR as white was independently related to the presence of SBI (odds ratio, 1.06; 95% confidence interval, 1.04-1.09), multiple (≥2) SBIs (1.09; 1.05-1.12), deep subcortical SBI (1.06; 1.04-1.09), and hs-SBI (1.07; 1.02-1.11). Compared with the lowest PCR category (<5%), dose-response relationships were observed between increasing category (5% to <7.5%, 7.5% to <10%, and ≥10%) and the presence of SBI, respectively (1.85, 0.91-3.74; 2.41, 1.13-5.14; and 3.76, 2.17-6.52), multiple SBIs (0.88, 0.10-8.02; 8.44, 2.29-31.11; and 8.47, 2.66-27.02), deep subcortical SBI (1.92, 0.92-4.02; 2.46, 1.11-4.45; and 3.77, 2.11-6.74), and hs-SBI (1.20, 0.12-11.81; 5.59, 1.08-28.96; and 5.96, 1.46-24.38). C-statistic of PCR category for SBI was 0.63 (0.60-0.65); multiple SBIs, 0.71 (0.69-0.73); deep subcortical SBI, 0.62 (0.60-0.65); and hs-SBI, 0.71 (0.68-0.73). Calibration as black showed similar pattern to findings from white model.

Conclusions: Discrimination was fairly compatible with each race model. The PCR might serve as a simple clinical tool for identifying people at high risk for the untoward consequences of SBI, particularly multiple SBIs and hs-SBI.