Race/ethnicity and response to blood pressure lowering treatment after intracerebral hemorrhage

Background: It is unknown if race/ethnicity modifies the response to blood pressure (BP) lowering treatment after intracerebral hemorrhage (ICH). We aimed to examine the race/ethnicity differences in the response to BP lowering treatment after ICH. Methods: This is a post hoc analysis of the Antihypertensive Treatment of Acute Cerebral Hemorrhage II (ATACH-2) trial. The primary outcome is good outcome, defined as 90-day modified Rankin Scale 0–3. The primary predictor is race/ethnicity for which we included non-Hispanic categories of White, Black, Asian, and the category of Hispanic. We fit adjusted logistic regression models with the predictor of race/ethnicity and models with the interaction term of treatment*race/ethnicity. Results: We included a total of 953 patients in our analysis (White = 213, Black = 112, Asian = 554, and Hispanic = 74). In the models with the interaction between race/ethnicity and treatment, we found that White patients assigned to the intensive treatment arm had lower predicted probability of good outcome than those assigned to the standard treatment arm (Model 1: 56.2% vs. 68.1%, p = .027; Model 2: 53.4% vs. 68.3%, p = .009). When divided into White and non-White groups, intensive treatment was associated with higher odds of serious adverse events in White group but not in the non-White group. In addition, there was an association between intensive treatment and higher risk of hematoma expansion in White patients and lower risk of hematoma expansion in non-White patients. Conclusions: In the ATACH-2, there was an interaction between race/ethnicity and response to BP lowering treatment after ICH, with White patients having an association between intensive blood pressure reduction and worse outcome.