Relationship of Inter-Individual Blood Pressure Variability and the Risk for Recurrent Stroke.

Background Evidence suggests that patients with higher blood pressure variability ( BPV ) have a higher risk for stroke, but any link between BPV and stroke recurrence is unknown among those who had a stroke or transient ischemic attack ( TIA ). Methods and Results Data for patients with a history of stroke or TIA at enrollment were extracted from the ASCOT (Anglo Scandinavian Cardiac Outcomes Trial) and the ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial). BPV was defined as the within-subject standard deviation or coefficient of variation of systolic blood pressure across visits from 12 weeks poststroke or TIA onward. BPV was significantly higher in patients with a history of stroke or TIA than those without. BPV was a predictor of recurrent stroke in the pooled analysis. In the ASCOT study, 252 patients (12.3%) had a recurrent stroke among 2046 with a history of stroke. Incidence of recurrent stroke was significantly higher in the highest BPV quartile (17.8%) compared with the lowest quartile (10.5%); by treatment arm, this reached significance for the amlodipine-arm only (high- BPV : 18.7% versus low- BPV : 12.9%; P=0.029). Of the 2173 patients from the ALLHAT with a history of stroke or TIA , patients with the highest quartile of BPV had a higher incidence of recurrent stroke (9.6%) compared with the lowest quartile BPV (5.5%); by treatment arm, this reached significance for the chlorthalidone-arm only (high- BPV : 12.1% versus low- BPV : 5.4%; P=0.007). Conclusions Visit-to-visit BPV is a predictor of recurrent stroke in patients with a history of stroke or TIA on antihypertensive treatment. Considering BPV following a stroke may be important to reduce the risk for a recurrent stroke.