Post Stroke Cognitive Impairment and the Relationship with Ambulatory Blood Pressure Indices

Abstract Background Cognitive impairment is a common consequence of stroke, affecting approximately 40% of survivors, and is associated with adverse outcomes including increased disability and recurrent stroke. Hypertension is the most common risk factor for stroke and is a key target for secondary prevention of further stroke events and progression of background white matter change. Ambulatory blood pressure (ABP) assists in diagnosis and management of hypertension and is better at risk stratifying patients than clinic blood pressure. We examined the relationship between cognition and ABP profile at six months post stroke. Methods This was a prospective study of patients admitted with acute ischaemic or haemorrhagic stroke. Baseline clinical data included stroke type, aetiology, risk factors, demographic and socioeconomic data. Cognition was assessed at baseline and again at six months post stroke using the Montreal Cognitive Assessment (MoCA), with cognitive impairment defined as a score of <24 points. ABP was performed at 6-month follow up. Output variables including day and night mean BP, dipping, and ambulatory arterial stiffness index were correlated with MoCA scores. Statistical analysis was performed using Stata. Results Forty one patients (14 female) with mean age 61.8 years were enrolled. The majority (90%) had ischaemic strokes and 69% were functionally independent (modified Rankin score 0-2) at six months post stroke. Participants with MoCA <24 were older and had higher prevalence of hypertension and more severe white matter change on baseline brain imaging. On ABP, cognitive impairment was associated with nocturnal non-dipping of systolic (4.5% vs 10.7%) and diastolic (7.3% vs 14.2%) BP and higher AASI (0.58 vs 0.46, p= 0.02). Conclusion Cognitive impairment post stroke is associated with non-dipping BP and arterial stiffness, both of which are significant predictors of cardiovascular risk derived from ABP. Hypertension remains a key target for primary and secondary prevention of stroke and cognitive impairment.