Clinical Outcome Differences in Asia Versus Non-Asia Intracerebral Hemorrhage: IPD Analysis From BP-Lowering Clinical Trials.

BACKGROUND

Evidence of regional differences in clinical outcomes after intracerebral hemorrhage (ICH) is still scarce. We quantified differential outcomes and response to early intensive blood pressure lowering treatment by region in the Blood pressure in Acute Stroke Collaboration ICH data set.

METHODS

This was an observational analysis of pooled individual participant data from 16 completed randomized controlled trials of blood pressure-lowering treatment in acute ICH, based on the Blood pressure in Acute Stroke Collaboration data set. Generalized linear mixed models with inverse probability of treatment weighting (IPTW) were used to determine the association between regions (Asia [primarily East and South Asia] versus non-Asia) and clinical outcomes including neurological deterioration within 7 days, hematoma expansion at 24 hours (absolute ≥6 mL or relative ≥33%), and death or dependency (modified Rankin Scale scores, 3-6), major disability(modified Rankin Scale score, 3-5), death alone at 90 days.

RESULTS

Among 6221 patients (age, 63.3±13.0 years; female 36.4%), 3494 (56.2%) were from Asia. ICH participants from Asia had a significantly reduced risk of death or dependency (unadjusted odds ratio [OR], 0.44 [95% CI, 0.39-0.51]; IPTW-weighted OR, 0.67 [95% CI, 0.58-0.77]); and major disability (unadjusted OR, 0.49 [95% CI, 0.42-0.56]; IPTW-weighted OR, 0.67 [95% CI, 0.57-0.78]) at 90 days, neurological deterioration (unadjusted OR, 0.63 [95% CI, 0.52-0.77]; IPTW-weighted OR, 0.70 [95% CI, 0.56-0.89]) within 7 days, in comparison to those from non-Asia regions. However, there were no differences for hematoma expansion (P=0.97) at 24 hours or death (P=0.23) at 90 days using IPTW. Additionally, there were no significant interactions between blood pressure-lowering treatment and region (Asia versus non-Asia) for either outcome using IPTW.

CONCLUSIONS

Participants from East and South Asia had a favorable functional recovery and a lower risk of neurological deterioration compared with those from non-Asian regions after adjustment for confounders, with no differences in hematoma expansion at 24 hours after ICH. These findings suggest that future ICH studies on clinical outcomes should consider regional differences.