Different impacts of blood pressure variability on the progression of cerebral microbleeds and white matter lesions.

BACKGROUND AND PURPOSE Cerebral microbleeds (CMB) and white matter lesions (WML) are cerebral small vessel diseases. Hypertension is considered the most important risk factor. Its mechanism is not yet clarified. Our study assessed the association of blood pressure variability (BPV) with CMB and WML progression. METHODS Patients with a history of ischemic stroke within 1 to 6 months were consecutively recruited and followed-up for 12 to 18 months. Blood pressure was measured monthly and controlled to a target level. BPV was quantified by the maximum, standard deviation, coefficient of variation, successive variation, standard deviation independent of mean, and successive variation independent of mean. Magnetic resonance imaging was performed at baseline and the end of the study. CMB and WML were rated using Microbleed Anatomic Rating Scale and Age-Related White Matter Changes scales, respectively. Multiple logistic analyses assessed BPV associations with CMB and WML development. RESULTS Of 720 patients recruited, 500 and 584 had follow-up results for CMB and WML, respectively; 13.2% and 48.1% showed CMB and WML progression, respectively, over a median of 14 months. Patients with CMB had a higher mean, maximum, standard deviation, coefficient of variation, successive variation, standard deviation independent of the mean, and successive variation independent of the mean in either systolic blood pressure or diastolic blood pressure (P<0.05). Systolic blood pressure variability was an independent risk factor for deep and infratentorial CMB progression, whereas diastolic blood pressure variability was independently associated with CMB development in deep regions. WML progression was not significantly associated with BPV between visits. CONCLUSIONS BPV independently predicts CMB progression in deep and infratentorial regions. CLINICAL TRIAL REGISTRATION INFORMATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00202020.