Unfulfilled potential for secondary prevention of cognitive decline in individuals with covert brain infarcts: A population‐based study

Abstract

AbstractBackgroundModifiable cardiometabolic risk factors account for about 25% of all dementia, including Alzheimer’s disease. Risk factor control is therefore pivotal, particularly in patients with high risk of dementia after stroke. However, 15‐20% of elderly individuals have brain infarcts on routine MRI that have not produced notable stroke symptoms (‘covert brain infarcts’ [CBI]), and in whom risk factors consequently may not be treated optimally.MethodWe included 5934 participants of the population‐based Rotterdam Study who underwent routine brain MRI and cognitive assessment between 2005‐2016 (mean age 65 years, 55% women). Clinical stroke symptoms were ascertained through interview and medical records review. In individuals with CBI, we determined the extent to which cardiometabolic risk factors (systolic blood pressure, LDL‐cholesterol, serum glucose) are managed according to AHA/ASA guidelines for secondary stroke prevention.ResultOf 507 patients with brain infarction on MRI, 395 (78%) had not had prior clinical stroke. Prevalence of CBI increased steeply with age, from 2% at age 45‐49 to 20% after age 85, and was associated with worse performance on a cognitive assessment battery (β[95%CI]=‐0.19[‐0.32;‐0.06]). 34% of participants >60 years with CBI had one or more untreated, modifiable cardiometabolic risk factors, compared to 9% of participants with prior clinical stroke, and optimal risk factor control was twice as likely after clinical stroke than with covert brain infarcts (28 vs. 13%). Among individuals with CBI, those with suboptimal cardiometabolic risk management did worse on cognitive testing, notably in the memory domain (global cognition– β[95%CI]=‐0.27[‐0.65;0.12]; memory– β=‐0.40[‐0.73;‐0.08]). Similar differences were seen when additionally examining lifestyle factors (obesity and smoking). Of participants with CBI, less than half (45%) were using antithrombotic medication, compared to 88% after clinical stroke. The percentage of undertreated individuals was similar when comparing the earlier (2005‐2010) with the later years of the study (2011‐2016).ConclusionIn one third of individuals with covert brain infarcts, cardiometabolic risk factor management does not align with secondary stroke prevention guidelines, potentially resulting in poorer cognitive function. These findings should prompt further study into the optimal secondary preventive strategies for this large group of elderly individuals with undiagnosed covert brain infarcts.