Different Responses to Blood Pressure Reduction in Lobar and Deep Intracerebral Hemorrhage

Intensive blood pressure (BP) reduction may benefit patients with acute intracerebral hemorrhage (ICH), but it is unknown if those benefits apply equally to patients with lobar and deep ICH. Our objective was to assess the impact of intensive BP reduction on hematoma expansion (HE), 90-day functional outcomes, and renal adverse events (RAEs) in patients with deep ICH compared with those with lobar ICH.

This was an exploratory, post hoc analysis of the Antihypertensive Treatment of Acute Cerebral Hemorrhage II (ATACH-2) randomized clinical trial, which investigated the efficacy of intensive BP reduction (110-139 mm Hg systolic BP) versus standard (140-179 mm Hg systolic BP) reduction 4.5 h after acute spontaneous ICH. Our end points of interest were HE (> 6 mL increase in hematoma volume between baseline and 24 h), 90-day functional outcome (modified Rankin Scale score 0-3 vs. 4-6), and RAEs.

Of 1000 ATACH-2 participants, only 875 participants (87.5%) with complete neuroimaging data were included (778 [89%] deep and 97 [11%] lobar, mean age of 62 years, 62% male). Multivariable logistic regressions results showed that intensive BP reduction decreased the risk of HE (odds ratio [OR] 0.60, 95% confidence interval [CI] 0.38-0.93; p = 0.024) and increased the risk of RAE (OR 2.42, 95% CI 1.29-4.72; p = 0.007) in deep ICH, whereas in lobar ICH results were nonsignificant for HE (OR 0.91, 95% CI 0.34-2.41; p = 0.9). Intensive BP reduction was not significantly associated with 90-day unfavorable functional outcome in either deep (OR 1.03, 95% CI 0.71-1.51; p = 0.9) or lobar (OR 0.97, 95% CI 0.31-2.95; p = 0.9) ICH.

In this exploratory analysis of the ATACH-2 study, intensive BP reduction was associated with reduced risk of HE and increased risk of RAE in deep but not lobar ICH. These results emphasize the need for a better understanding of the biological differences in ICH, which may have therapeutic implications.