Blood pressure and risk of stroke in patients with cerebrovascular disease

Abstract
There is widespread clinical uncertainty about lowering blood pressure in patients with ischaemic cerebrovascular disease. This often manifests as comparatively high thresholds for starting treatment and modest targets in reducing blood pressure. Concern has arisen partly from reports of a J shaped association between blood pressure and recurrent stroke in these patients.1 This relation may, however, be because severe strokes are associated both with a fall in blood pressure2 and independently with a relatively high risk of stroke recurrence, rather than from any adverse effects of low blood pressure itself. If this were true, then people with a history of minor cerebrovascular disease would have direct and continuous relations between usual blood pressure and risk of stroke, as observed in people without cerebrovascular disease.3 Data from …