Incident cerebral microbleeds and hypertension defined by the 2017 ACC/AHA Guidelines

The cut-off for hypertension was lowered to blood pressure (BP) over 130/80 mmHg in the 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline. Whether the new definition of hypertension remains a potent risk factor of cerebral microbleeds (CMBs) is uncertain. We aimed to analyze the relationship between the new definition of hypertension and incident CMBs in a 7-year longitudinal community study.

This study is a sub-study of the Shanghai Aging Study (SAS). A total of 317 participants without stroke or dementia were included at baseline (2009-2011), and were invited to repeated clinical examinations and cerebral magnetic resonance imaging (MRI) at follow-up (2016-2018). CMBs at baseline and follow-up were evaluated on T2*-weighted gradient recalled echo (GRE) and susceptibility-weighted angiography (SWAN) sequence of MRI. We classified baseline BP into four categories: normal BP, elevated systolic BP, stage 1 hypertension and stage 2 hypertension according to the ACC/AHA guideline. We assessed the associations between BP categories and incident CMBs by generalized linear models.

A total of 159 participants (median age, 67 years) completed follow-up examinations with a mean interval of 6.9 years. Both stage 1 and stage 2 hypertension at baseline were significantly related with a higher risk of incident CMBs (IRR 2.77, 95% CI, 1.11-6.91, P=0.028; IRR 3.04, 95% CI, 1.29-7.16, P=0.011, respectively), indicating dose-response effects across BP categories. Participants with ≥5 incident CMBs or incident CMBs in the deep locations all had baseline stage 1 and 2 hypertension.

Participants with baseline stage 1 and stage 2 hypertension had a significantly higher risk of incident CMBs in this 7-year longitudinal community cohort.