Prediction of ischaemic and haemorrhagic stroke by self-measured blood pressure at home: The Ohasama study

Objective: To examine the predictive value of self-measured blood pressure values taken at home (home blood pressure) for risk of stroke and subtypes. Methods: We obtained home blood pressure measurements from 1702 people, aged ≥ 40 years, without a history of stroke, in the general population in Japan, and continued follow-up after a mean period of 10.6 years. The prognostic significance of blood pressure for stroke risk was examined using the Cox proportional hazards regression model, which was adjusted for possible confounding factors. Results: There was a linear relationship between home blood pressure and risk of stroke and subtypes. On average, each 10/5mmHg elevation in home systolic/ diastolic blood pressure respectively, was associated with an approximately 30/20% respectively, higher risk of total stroke. A similar relationship was observed for the risk of haemorrhagic stroke (intracerebral and subarachnoid haemorrhage), and the risk of ischaemic stroke [cerebral infarction and transient ischaemic attack (TIA)]. The risk of stroke and subtypes showed a significantly greater relation with home blood pressure values compared to conventional blood pressure values. Conclusions: This is the first study to demonstrate that home blood pressure is an independent predictor for haemorrhagic and ischaemic stroke, in the general population.