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Sustained Hypertensive SBP Trajectory Carries Highest Risk of Poor Outcome After ICH
In a pooled analysis of 11,269 patients with acute intracerebral hemorrhage, those who maintained a persistently elevated systolic blood pressure trajectory over the first 24 hours had the greatest odds of death or disability at 90 days, regardless of which blood pressure-lowering strategy was applied. Critically, both sustained hypertension and excessively rapid large reductions in SBP were associated with worse functional outcomes, suggesting that neither extreme of the blood pressure spectrum is beneficial.
What Was Studied
This study sought to define the optimal pattern of systolic blood pressure (SBP) control in the first 24 hours following acute intracerebral hemorrhage, and to determine how distinct SBP trajectories relate to functional recovery at 90 days. The primary outcome was poor functional recovery, defined as a modified Rankin Scale (mRS) score of 3–6 at 90 days after randomization — a threshold capturing moderate to severe disability and death.
How It Was Studied
This was a pooled individual patient-level data analysis drawing from all four INTERACT trials and the ATACH-II trial — five international, randomized, open-label, blinded endpoint-assessed controlled trials that each evaluated the effectiveness of early intensive SBP reduction in acute ICH. A total of 11,269 patients were included (INTERACT n = 10,269; ATACH-II n = 1,000), with a mean age of 62.4 years and 36.4% female. Latent class analysis was applied to serial SBP measurements taken across nine time points during the first 24 hours, generating distinct trajectory clusters. The low SBP trajectory group served as the reference comparator, and findings from the INTERACT dataset were validated in the ATACH-II cohort. Logistic regression models adjusted for baseline covariates and trial were used throughout.
What Was Observed
- Six distinct SBP trajectory clusters were identified across the 24-hour post-randomization window: low, moderate-to-low, moderate, high, high-to-moderate, and high-to-low. These phenotypes capture meaningfully different patterns of blood pressure behavior that go beyond what any single time-point measurement could convey.
- Higher trajectories were progressively associated with worse outcomes. Compared with the low SBP reference group, the odds of poor functional outcome (mRS 3–6 at 90 days) increased in a graded fashion across the higher trajectory clusters in INTERACT, with the severe hypertensive group showing the highest odds of death or disability. This gradient held regardless of which blood pressure-lowering treatment was used.
- Excessively large and rapid SBP reductions were also associated with diminished benefit. Reductions from above 200 mmHg to below 140 mmHg within the first hour were associated with reversal or attenuation of the favorable effects otherwise seen with moderate and rapid lowering, indicating that the speed and magnitude of early SBP change are both clinically relevant.
- Findings from INTERACT were validated in ATACH-II, supporting the reproducibility of the six-trajectory classification scheme across independent trial populations with partially differing treatment protocols and patient characteristics.
Why This Matters
These findings indicate that characterizing SBP as a dynamic trajectory over 24 hours — rather than relying on a single baseline or treatment-target measurement — provides meaningful prognostic information after acute ICH. The identification of a severe hypertensive trajectory as the highest-risk phenotype, independent of treatment assignment, suggests that failure to achieve adequate SBP control during this window is a key determinant of outcome. The results also challenge the assumption that more aggressive early BP lowering is uniformly beneficial, pointing instead toward the value of tailored, trajectory-aware management strategies.
How to Read This Result
This pooled analysis offers Class III evidence, meaning the trajectory-outcome associations are observational in nature despite originating from randomized trial data, and the absence of fully reported effect sizes in the abstract limits precise quantification of the observed risks.
Limitations
The study is classified as Class III evidence, reflecting inherent methodological constraints. The underlying trials used an open-label design, which introduces the possibility of performance bias. Pooling data from trials with distinct protocols, treatment targets, and patient populations may introduce heterogeneity that is difficult to fully account for. Most importantly, the trajectory clusters were derived through statistical modeling within the randomized trial dataset, so the associations between SBP trajectories and outcomes remain observational rather than reflecting causal relationships established by randomization. The precise optimal SBP target range also remains incompletely defined by this analysis.