Acute Blood Pressure Lowering and Risk of Ischemic Lesions on MRI After Intracerebral Hemorrhage

Abstract

Importance: Diffusion-weighted imaging (DWI) lesions have been demonstrated in patients with subacute intracerebral hemorrhage (ICH), suggesting ischemic injury, which may be related to blood pressure (BP) reduction.

Objective: To test the hypothesis that acute intensive BP lowering is associated with DWI lesions after ICH.

Design, setting, and participants: The Intracerebral Hemorrhage Acutely Decreasing Arterial Pressure Trial 2 (ICHADAPT-2) was a multicenter, randomized, open-label, blinded-end point trial. Between November 2012 and August 2022, patients with ICH presenting within 6 hours of onset were randomized to a systolic BP (SBP) target of less than 140 mm Hg or less than 180 mm Hg. The trial was conducted at 3 comprehensive stroke centers in Canada and Australia, including 1 telestroke referral hub and 1 community stroke hospital. A total of 162 patients with acute ICH were randomized. The primary analysis population was restricted to those undergoing DWI at 48 hours.

Intervention: Patients were randomly assigned to an acute SBP target of less than 140 mm Hg or less than 180 mm Hg.

Main outcome and measure: The primary end point was the incidence of acute DWI lesions on brain magnetic resonance imaging obtained 48 ± 12 hours after randomization.

Results: DWI was obtained in 79 (48% female) patients with a mean (SD) age of 71 (13) years and median baseline ICH volume of 11.2 (range, 0.5-122.2) mL. The median times from onset to randomization and DWI were 3.17 (range, 0.7-14.6) hours and 51.6 (range, 17.0-121.4) hours, respectively. Mean (SD) baseline SBP was 183 (22) mm Hg in the less than 140 mm Hg target group and 181 (28) mm Hg in the less than 180 mm Hg target group. Mean SBP was lower over the 48-hour period after randomization in the less than 140 mm Hg group (mean difference, 18.9 mm Hg [95% CI, 17.6-20.2]; P < .001). DWI lesions were detected in 13 of 42 patients (31%) in the less than 140 mm Hg group and 14 of 37 patients (38%) in the less than 180 mm Hg group (odds ratio, 0.74 [95% CI, 0.12-4.64]; P = .32). The median number of DWI lesions (1 [95% CI, 1-10] vs 1.5 [95% CI, 1-10]; P = .26) and total DWI lesion volume (0.1 [95% CI, 0.01-41.3] mL vs 0.3 [95% CI, 0.02-2.03] mL; P = .17) were not different in the less than 140 mm Hg and less than 180 mm Hg groups.

Conclusions and relevance: DWI lesion frequency and volume were unaffected by intensive antihypertensive therapy. These results support the safety of early BP reduction in acute ICH.

Figure 1.. Flowchart of Randomization, Blood Pressure (BP) Target Allocation, and Follow-Up

^aStudy sites were not required to maintain screening logs, thus the total number of patients assessed for study eligibility was not available. CT indicates computed tomography; DWI, diffusion-weighted imaging; GCS, Glasgow Coma Scale; ICH, intracerebral hemorrhage; mRS, modified Rankin Scale.

Figure 2.. Mean Systolic Blood Pressure (SBP) Over First 48 Hours After Randomization in Both Treatment Groups

Blood pressure was monitored at 15-minute intervals for the first hour after randomization (time 0), every 30 minutes from hours 1 to 24, and every 4 hours up to 48 hours. Mean SBP was lower over the 48-hour period after randomization in the less than 140 mm Hg target group (adjusted mean difference for period, 18.9 mm Hg [95% CI, 17.6-20.2]; P < .001). Error bars represent standard error of the mean at each time point.