Objective:

To investigate the time point by which achieving intensive systolic blood pressure (BP) control to <140mmHg correlated with decreased risk for hematoma expansion (HE).

Background:

Prior studies have suggested that early, intensive BP reduction is associated with decreased risk for HE after intracerebral hemorrhage (ICH). However, the ideal definition of early control is not yet clear.

Design/Methods:

We performed an exploratory analysis of the Antihypertensive Treatment of Acute Cerebral Hemorrhage II trial. Patients with supratentorial hemorrhages and complete BP data were included. Kaplan Meier curves were used to visualize timing of BP control among patients who did vs. did not develop HE. HE was defined at >6mL of growth on imaging at 24 hours post randomization. Two sample melded β tests were applied to determine when survival curves significantly diverged. Unadjusted and adjusted logistic regression models were used to clarify the association between achieving systolic BP <140mmHg by various time points and HE.

Results:

We included 970 patients (mean age 62 years, 39% female). The median time from randomization to systolic BP <140mmgHg was 90 minutes (IQR 143 minutes). Baseline characteristics of patients who did vs. did not achieve BP control by 90 minutes did not differ (mean age 64 vs. 60 years; ever smoker 37 vs. 51%). Melded β tests confirmed that BP trajectories between patients who did vs. did not develop HE >6mL diverged significantly at 90 minutes from randomization (OR 1.46, 95% CI 1.03-2.06). In logistic regression models, achieving BP control by 90 minutes was associated with decreased odds of HE (unadjusted OR 0.7, 95% CI, 0.6-0.9; adjusted for ICH score components OR 0.6, 95% CI 0.4-0.9), whereas earlier time points were not.

Conclusions: