Abstract 83: Therapeutic Hypothermia in Patients With Acute Ischemic Stroke a Systematic Review of Prospective Controlled Studies

Background: Therapeutic hypothermia (TH) is a potent neuroprotectant in stroke models. We investigated its effects in published studies of ischemic stroke patients. Methods: This is a systematic review and meta-analysis of prospective randomized and non-randomized controlled studies published till July 2018. Full manuscripts reporting the type and outcomes of TH in acute ischemic stroke patients were included. We classified TH into systemic (body cooling) and selective (brain cooling). Two reviewers independently selected eligible studies and extracted the data. The main outcomes were neurological improvement (using the baseline to follow up NIHSS difference), complications, and mortality. Results: Of 2850 retrieved studies, 16 prospective controlled studies (813 patients) were included. Systemic TH was used in 13 studies (8 RCTs, 5 non-randomized parallel- controlled) while selective TH in 2 studies (1 RCT, 1 parallel- controlled), and one RCT used both types. Methods of cooling were highly variable and often multiple modalities were used. Median time from onset to TH start was 6 hours (IQR 7.5). Median target temperature was 33°C (range 32-35), which was reached within a median of 4 hours (IQR 3.7) in 9 systemic TH studies; while only one selective TH study reported the time to target temperature (17 minutes). Selective TH studies did not report enough outcomes to allow comparison with systemic TH. Outcomes are summarized in the forest plot and stratified by the study design (figure). Cardiac complications were higher in the TH vs controls (pooled relative risk “RR” 1.5, 95% CI 1.2 to 1.9, p 0.001). The pooled estimates suggest non-significant higher risks of pneumonia (RR 1.2, 95% CI 0.9 to 1.7, p 0.2) and death (RR 1.1, 95% CI 0.8 to 1.6, p 0.5) with TH. Eight studies reported baseline and follow-up NIHSS. The standardized mean difference was comparable (p = 0.413). Conclusions: TH was associated with complications without improving recovery or mortality rates.