Introduction: Covert brain infarction (CBI) and worsening white matter grade (WMG) on serial MRI are associated with increased risk for ischemic stroke and dementia.
Hypothesis: We sought to evaluate the association of various measures of blood pressure and heart rate with these MRI findings.
Methods: In the Cardiovascular Health Study, a longitudinal cohort study of cardiovascular disease in older adults, we used relative risk regression to assess the risk of incident CBI and worsening WMG associated with mean, variability, and trend in systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) measured at four or more annual clinic visits between two brain MRIs. We included participants who underwent both brain MRIs and had no change in antihypertensive medication status, no CBI on the initial MRI, and no stroke before the follow-up MRI.
Results: Among 897 eligible participants, incident CBI occurred in 15% and worsening WMG in 27%. Mean SBP mean was strongly associated with increased risk for incident CBI (RR per 10 mmHg 1.29; 95% CI, 1.13-1.47), and DBP mean was strongly associated with increased risk for worsening WMG (RR per 10 mmHg 1.43; 95% CI, 1.23-1.67). DBP variability may be associated with incident CBI (RR per 10 mmHg 1.71; 95% CI, 1.10-2.65), The HR measures were not associated with these MRI findings.
Conclusions: Elevated mean levels of blood pressure contribute to covert cerebrovascular diseases. Control of mean blood pressure levels, even in older adults, remains a high priority for prevention of vascular brain injury.