White matter hyperintensity progression is associated with incident probable dementia or mild cognitive impairment.

Background: White matter hyperintensity (WMH) on brain MRI is associated with developing dementia or mild cognitive impairment (MCI), but WMH progression over time has not been fully investigated as an independent risk factor.

Methods: We performed a post hoc analysis of the Systolic Blood Pressure Intervention Trial - Memory and Cognition in Decreased Hypertension (SPRINT MIND) trial. The primary outcome was incident probable dementia or MCI (dementia/MCI) before the follow-up MRI at 48 months from enrolment. The primary predictor was WMH progression, defined as the Z score difference between the follow-up and baseline WMH volumes. The secondary predictor was a binary WMH progression threshold (≥1.4 mL vs <1.4 mL).

Results: Among the 433 included patients, 33 (7.6%) developed dementia/MCI. There were 156 (36.0%) patients who met the WMH progression threshold of ≥1.4 mL, in whom the rate of dementia/MCI was 12.8% (20/156) vs 4.7% (13/277) of patients with <1.4 mL WMH progression (p=0.002). In multivariable logistic regression, the Z score of WMH progression was associated with dementia/MCI (OR 1.51, 95% CI 1.12 to 2.04, p=0.007) as was the WMH progression threshold of ≥1.4 mL (OR 2.89, 95% CI 1.23 to 6.81, p=0.015).

Conclusions: In this post hoc analysis of SPRINT MIND, WMH progression over 48 months was associated with the development of probable dementia or MCI.