Therapeutic Hypothermia in Patients with Malignant Ischemic Stroke and Hemicraniectomy—A Systematic Review and Meta-analysis

Abstract

Therapeutic hypothermia (TH) offers cerebral protection following ischemic stroke and may improve outcomes in conjunction with decompressive hemicraniectomy (DHC). We aimed to assess the effectiveness of TH in patients with malignant ischemic stroke and DHC. We performed a meta-analysis in patients with malignant ischemic stroke undergoing DHC comparing TH versus normothermia in studies published up to August 2019. Included studies had ≥10 adults with acute ischemic stroke. Primary outcome was functional independence, and secondary outcomes included complications. Effect size was pooled and described by relative risk (RR) ratios and 95% confidence intervals (CIs). Five studies (n= 269 patients; n= 130 TH, n= 139 controls) were included, 4 of which were prospective (n= 2 randomized controlled trials). Median achieved body temperature of TH was 33.6°C (range 33°C-35°C). Median modified Rankin Scale at the study completion was similar between TH and controls (RR 1.08, 95% CI 0.56-2.07, P= 0.8). Three studies reported individual patient modified Rankin Scale outcomes demonstrated a shift toward worse outcomes with TH (unadjusted common odds ratio 1.74; 95% CI 1.05-2.88, P= 0.01). Overall complications were similar between groups (RR 1.20, 95% CI 0.70-2.05, random effects P= 0.5). A suggestion of higher mortality was seen in TH (RR 1.50, 95% CI 0.97-2.32, P= 0.07). Clinical and functional outcomes were not overall different between patients undergoing systemic TH and controls following DHC despite the shift toward worse outcomes with TH observed in some studies.