Characteristics of Blood Pressure Profiles as Predictors of Long-Term Outcome After Acute Ischemic Stroke

Abstract

Background and Purpose— Most patients have elevated blood pressure (BP) in the early phase after an acute ischemic stroke. Mechanism and effects of this BP elevation are not well understood. The benefits of intervention by lowering the initial BP or waiting for spontaneous return to normal values remain debated. We studied the hypothesis that increased BP level and profile variability will adversely affect long-term outcome after stroke with and without thrombolytic treatment. Methods— We studied the 615 patients with acute ischemic hemispheric stroke in the first European Cooperative Acute Stroke Study (ECASS). BP was measured at 2-hour intervals during the first 20 hours after randomization, and then every 4 hours, up to 72 hours after admission. Studied features of individual 0- to 72-hour BP profiles were: baseline BP, maximum and minimum BP, mean level, and successive variation in the BP profile. The end point was good functional recovery (modified Rankin Scale [mRS] score of 0 to 1) at 90 days. Logistic regression was used to adjust for known prognostic factors, demographic, initial stroke severity, disease and medication histories, and computed tomography signs. Results— Higher systolic BP or diastolic BP at baseline were associated with favorable outcome assessed on modified mRS at 90 days (adjusted odds ratio [OR], 1.22; 95% CI, 1.01 to 1.49; and OR, 1.22; 95% CI, 1.01 to 1.49 per 10 mm Hg), lower within-patient 0- to 72-hour average systolic BP (SBP), or DBP implied favorable outcome (OR, 0.74; 95% CI, 0.61 to 0.90; and OR, 0.61; 95% CI, 0.41 to 0.90 per 10 mm Hg). Reduced variability of 0- to 72-hour DBP profile was an independent predictor of favorable outcome (OR, 0.58; 95% CI, 0.39 to 0.85 per 5 mm Hg). Conclusions— Higher baseline SBP or DBP was associated with favorable outcome after stroke. Other characteristics of first 72-hour BP profiles: lower mean level of SBP or DBP and reduced successive variability of DBP profile were independent predictors of favorable outcome at 90 days.