Aggressive Blood Pressure Control in Intracerebral Hemorrhage (the Abc-Ich Study)—A Pilot Study

Abstract

Spontaneous intracerebral hemorrhage (ICH) accounts for one fifth of all strokes and is associated with an extremely high rate of morbidity and mortality. Affecting greater than 1 million people a year, ICH will leave the majority of its’ patients significantly disabled or dead. An initially high systolic blood pressure upon presentation is associated with hematoma expansion, peri-hema- toma expansion, and increased mortality. The relationship between blood pressure, the degree of blood pressure control and hematoma expansion has yet to be defined, but the literature has ob- served a relationship between tightly controlled blood pressures and decreased hematoma expansion. There have been many proposed mechanisms to explain this effect. Larger initial hematomas may lend greater hydrostatic forces and this could result in greater total hematoma volume, and greater surrounding edema. Recent literature has suggested that blood pressure reductions in acute ICH may be tolerated because of reduced metabolism, and preserved autoreguation in the peri-hematoma region. The volume of the hematoma is a critical determinant of mortality and functional outcome after intracerebral hemorrhage, and early hematoma growth is an important cause of neurologic deterioration. An increase in volume of more than thirty-three percent is detectable on repeated computed tomography (CT) in thirty-eight percent of patients initially scanned within the first three hours of onset of symptoms; in two thirds of these cases this change is noticeable on CT within the first hour. This supports the hypothesis that early aggressive blood pressure optimization would decrease hematoma size and edema. This is further supported by the fact that patients with high blood pressure and acute intracerebral hemorrhage have worse outcomes than their counterparts. We hypothesize that prompt and aggressive, early blood pressure reduction in emergency department patients with acute spontaneous intracerebral hemorrhage will result in a reduction of early hematoma growth. The study institution is a large urban emergency department and tertiary care stoke center, with over 55,000 emergency department visits per year. This prospective cohort study compared the results and outcomes observed within the enrolled prospective study population, to the results and outcomes of a matched historical cohort population (future patients with intracranial hemorrhage that did not receive the ABC-ICH protocol). Methods and Material: A nicardipine infusion was administered to optimize blood pressure in all patients presenting with intracerebral hemorrhage with a target mean arterial pressure (MAP) of 80 - 110. Hematoma volume (primary outcome measure) was measured on cat scans at time of presentation and at twenty-four hours. The hematoma volume in the enrolled prospective study population was compared to those of a matched cohort (patients with intracranial hemorrhage that did not receive the ABC-ICH protocol following the conclusion of the study). Results: One hundred total patients were enrolled into the study. Fifty patients were enrolled prospectively in the study and matched to a similar group of fifty cohort patients. The difference in the mean change of hematoma volume at twenty-four hours was 7.29 ml (control) and 2.84 ml (study). The result was an absolute decrease in hematoma size of 4.45 ml in the group treated aggressively with nicardapine for blood pressure reduction within one hour of their initial presentation. Conclusions: These results support the previous research suggesting that aggressive blood pressure control in intracerebral hemorrhage reduces hematoma growth, however the clinical benefit of such a reduction will have to be evaluated in ongoing research.