How low can you go? Blood pressure targeting in patients with intracerebral hemorrhage
The Article: Cerebral ischemia and deterioration with lower blood pressure target in intracerebral hemorrhage by Andrew B. Buletko, MD, et al. Neurology, 2018.
The Takeaway: Lower systemic blood pressures in patients with acute intracerebral hemorrhage (ICH) were associated with worse ischemia on MRI and neurological deterioration, characterized by a worsening of NIHSS score during their hospital stay.
Methods: 286 patients with acute intracerebral hemorrhage were included in the study. The study enrollment period straddled the date the institution changed their ICH blood pressure target from <160 mmHg to <140 mmHg. Primary outcomes were acute ischemia on MRI within 2 weeks of presentation, and acute neurological deterioration (NIHSS score change of >4 during hospital stay). There were no significant differences in characteristics of the study groups: they were largely older (>65), with risk factors we associated with stroke- hypertension, history of smoking, hyperlipidemia, and diabetes.
Results: In terms of primary outcomes, the group with a lower SBP target (<140 mmHg) did significantly worse. There was more ischemia seen on DWI-weighted MRI (32% vs 16%, p=0.047), and more neurological deterioration (19% vs 5%, p=0.022). The group with lower SBP also spent 1 day longer in the ICU and in the hospital. Univariate analysis comparing groups that showed MRI-confirmed ischemia vs. no ischemia elucidated similar results. The ischemic group had significantly lower SBP over their first 24 hours of admission (132 +/- 7.5 vs. 141 +/- 11.6, p<0.001) and were more likely to have neurological deterioration (43% vs. 2%, p<0.001).
Thoughts: This institution changed their blood pressure targets in response to the INTERACT-2 trial, which showed blood pressures <140 mmHg did not have a reduced risk of death or disability, but did have significantly better modified Rankin scores, suggesting better functional outcomes. However, critics of the trial have pointed out some significant outcomes that were just statistically so.
This study was small, retrospective, and a single center. However, it was able to compare similar study populations before and after the intervention of a protocol change. This intervention showed worse ischemia and clinical deterioration in patients with lower SBP.
Buletko, Andrew B., et al. “Cerebral Ischemia and Deterioration with Lower Blood Pressure Target in Intracerebral Hemorrhage.” Neurology, vol. 91, no. 11, 2018, doi:10.1212/wnl.0000000000006156.
Hill, Michael D., and Keith W. Muir. “Interact-2.” Stroke, vol. 44, no. 10, 2013, pp. 2951–2952., doi:10.1161/strokeaha.113.002790.