Could high blood pressure predict progression of brain microbleeds?

This study investigated whether high blood pressure determines the progression of small areas of bleeding (microbleeds) in the brain.

Brain microbleeds are small chronic brain hemorrhages (burst blood vessels). Brain microbleeds are associated with cognitive dysfunction (problems with mental ability such as memory or problem solving), balance disturbances, and increased risk of stroke and mortality.

Brain microbleeds are commonly found in patients with high blood pressure. High blood pressure is when the pressure inside blood vessels is too high, which can weaken blood vessels over time.

A way of measuring high blood pressure accurately is called ambulatory blood pressure. This involves measuring blood pressure at regular intervals over a 24-hour period. Individuals are able to use it at home and when they sleep.

This study investigated whether measuring ambulatory blood pressure predicts whether brain microbleeds will progress (grow) over 2 years.

The study included 193 individuals with high blood pressure. Patients were not being treated for high blood pressure at the start of the study but all began treatment after. Individuals underwent brain MRI for visualizing brain microbleeds and one round of 24-hour ambulatory blood pressure measurements. After two years, brain microbleed progression was determined.

The study found that high ambulatory blood pressure at the start of the study was associated with progression of brain microbleeds after 2 years in 6% of patients.

Patients that showed microbleed progression were significantly older, and also had a greater number of brain microbleeds at the start of the study. However, 3 patients suffered a stroke and none of these patients had progression of brain microbleeds. 

The investigators concluded that high ambulatory blood pressure levels are important predictors for progression of brain microbleeds. This means that controlling blood pressure may reduce the occurrence of brain microbleeds and complications such as cognitive dysfunction and stroke.

Some microbleeds present in patients at the start of the study disappeared at the 2-year follow up. This may have been due to treatment and controlled ambulatory blood pressure. Also this study had a relatively young population and short follow up period, and thus may partly account for the low rate (only 6%) of microbleed progression. 

If you or someone you know have high blood pressure, talk to a doctor about receiving an MRI scan or ambulatory blood pressure measurements to see if brain microbleeds should be of concern to you.