Trajectory of hematoma growth and functional recovery after intracerebral hemorrhage: a latent class analysis of blood pressure in acute stroke collaboration data

Introduction: Moderate blood pressure (BP) reduction reduces hematoma growth, but this has not been shown to translate into improved functional recovery after intracerebral hemorrhage (ICH). This study aimed to define patient profiles according to hematoma growth and functional recovery patterns, and explore the prognostic factors of the patterns. Methods: Analysis of the Blood Pressure in Acute Stroke Collaboration (BASC) dataset involved randomized controlled trials of early BP lowering in acute ICH. Latent class analysis was used to identify patient profiles by hematoma volume change from baseline to 24 h on outcome trajectories. Clinical outcomes include functional outcomes measured according to modified Rankin Scale (mRS) and serious adverse events at follow-up (usually 90 days). Generalized linear mixed models were used with adjustment of source trial as a random effect for clustering to identify the prognostic factors. Results: Among 6,221 participants from BASC, 2,450 patients (mean age 64.1 + 13.1 years, female 36.7%) were included. Baseline hematoma volumes (mL) were 6.8, 13.2, 27.1, and 59.2, respectively, for each class identified by patient profiles: no growth with favorable outcome (52.1%, median growth 0.2 [IQR −0.4 to 1.1] mL, median mRS 2 [IQR 1 to 2]), mild growth with disability (32.6%, 0.8 [−0.8 to 4.6] mL, mRS 4 [4 to 5]), moderate growth with death or disability (13.2%, 11.2 [4.9 to 27.0] mL, mRS 4 [3 to 6]), and large growth with death (2.1%, 35.2 [12.8 to 81.2] mL, mRS 6 [6 to 6]). Patients with moderate growth were younger and more likely to undergo neurosurgery than those in the mild or large growth groups. Baseline hematoma volume was the only significant factor associated with all the hematoma pattern groups. Conclusions: Patients with moderate growth were younger and more likely to receive neurosurgery than those in the mild or large growth groups. Baseline hematoma volume is the most important factor for hematoma growth and clinical outcome.