Therapeutic hypothermia after recanalization in patients with acute ischemic stroke.

Abstract

BACKGROUND AND PURPOSE: Therapeutic hypothermia improves outcomes in experimental

stroke models, especially after ischemia-reperfusion injury. We investigated the

clinical and radiological effects of therapeutic hypothermia in acute ischemic

stroke patients after recanalization. METHODS: A prospective cohort study at 2

stroke centers was performed. We enrolled patients with acute ischemic stroke in

the anterior circulation with an initial National Institutes of Health Stroke

Scale>/=10 who had successful recanalization (>/=thrombolysis in cerebral

ischemia, 2b). Patients at center A underwent a mild hypothermia (34.5 degrees C)

protocol, which included mechanical ventilation, and 48-hour hypothermia and

48-hour rewarming. Patients at center B were treated according to the guidelines

without hypothermia. Cerebral edema, hemorrhagic transformation, good outcome

(3-month modified Rankin Scale, </=2), mortality, and safety profiles were

compared. Potential variables at baseline and during the therapy were analyzed to

evaluate for independent predictors of good outcome. RESULTS: The hypothermia

group (n=39) had less cerebral edema (P=0.001), hemorrhagic transformation

(P=0.016), and better outcome (P=0.017) compared with the normothermia group

(n=36). Mortality, hemicraniectomy rate, and medical complications were not

statistically different. After adjustment for potential confounders, therapeutic

hypothermia (odds ratio, 3.0; 95% confidence interval, 1.0-8.9; P=0.047) and

distal occlusion (odds ratio, 7.3; 95% confidence interval; 1.3-40.3; P=0.022)

were the independent predictors for good outcome. Absence of cerebral edema (odds

ratio, 5.4; 95% confidence interval, 1.6-18.2; P=0.006) and no medical

complications (odds ratio, 9.3; 95% confidence interval, 2.2-39.9; P=0.003) were

also independent predictors for good outcome during the therapy. CONCLUSIONS: In

patients with ischemic stroke, after successful recanalization, therapeutic

hypothermia may reduce risk of cerebral edema and hemorrhagic transformation, and

lead to improved clinical outcomes.