Effect of Intensive Blood Pressure Control on Incident Stroke Risk in Patients With Mild Cognitive Impairment

Background: Patients with mild cognitive impairment may be at higher risk of incident stroke, but the effect of intensive blood pressure (BP) control on that risk has not been explored.

Methods: We performed a post hoc analysis of SPRINT (Systolic Blood Pressure Intervention Trial) and included patients with a baseline Montreal Cognitive Assessment score of 19 to 25 and without a prior history of stroke. The primary outcome was incident stroke (ischemic and hemorrhagic) during follow-up. We report the unadjusted cumulative risk of our primary outcome by SPRINT randomization arm (intensive versus standard BP control) and also fit Cox models to the primary outcome and adjusted for patient age at randomization, race/ethnicity, sex, baseline BP, atrial fibrillation, diabetes, and smoking.

Results: We included 5091 patients (mean age 68.2, 44% female, 56.7% non-Hispanic White, and 50.2% randomized to intensive BP control), of which 95/5091 (1.9%) had an incident stroke during a mean of 3.8±0.9 years of follow-up. The risk of incident stroke in patients randomized to standard BP control was 57/2536 (2.3%) and to intensive BP control was 38/2555 (1.5%; P=0.045). In the adjusted Cox model, the hazard ratio for incident stroke events with intensive BP control was 0.65 (95% CI, 0.43-0.98; P=0.040).

Conclusions: Although the SPRINT trial failed to show a reduction in stroke with intensive BP control for all subjects, those with a Montreal Cognitive Assessment score consistent with mild cognitive impairment at baseline had an association between intensive BP control and lower risk of incident stroke. Future trials of primary prevention of stroke may benefit from enrichment using baseline vascular biomarkers of elevated risk, such as mild cognitive impairment.