Abstract 180: The Relation of Timing and Degree of Blood Pressure Control with Hematoma Growth - Secondary Analysis of The Interact2 Trial

Abstract

Background: Acute blood pressure (BP) lowering therapy has shown clinical benefit in patients with acute intracerebral hemorrhage (ICH), but the effect of timing and degree of BP control on ICH growth has received less study. Methods: Among the INTERACT2 participants (N=2839) with acute ICH allocated either to intensive BP lowering therapy (IT, systolic target <140mmHg) or standard BP treatment (ST), CT brain imaging at baseline and 24 hours were centrally analysed in a subset of 491 (34%) in the IT and 473 (34%) in the ST groups. Results: Absolute mean ICH growth was lower in patients reaching BP target in <1h from randomization (1.7ml), as compared to those reaching target in 1-6h (4.2ml), and >6h (4.6ml, p=0.04). Hematoma growth was particularly high (14.4ml, 95%CI:10.0-18.8) in patients admitted with systolic BP>160mmHg who achieved <10mmHg systolic BP lowering over 24h, as compared to those achieving 10-20mmHg (3.7ml, 95%CI:0.3-7.1) or 20-30mmHg BP reduction (2.7ml, 95%CI:1.1-4.3); p<0.01). Patients maintaining target BP at 0-2 measurements over 24h had higher absolute volume increase (3.6ml; 95%CI:1.8-5.4) as compared to those who maintained target BP over 3-4 (1.6ml, 95%CI:-0.3-3.5), or 5-8 measurements (0.4ml, 95%CI:-1.7-2.4; p=0.01). Conclusion: These findings suggest that early and sustained BP control have favorable effects on hematoma growth. This reinforces the principle for patients with acute ICH to receive BP lowering therapy as early as possible and to achieve a lower level of systolic BP for the most favorable outcome.