Abstract TMP13: Individual Patient Data Meta-analysis of Hypothermia for Acute Ischaemic Stroke

Abstract

Background: It remains unclear whether inducing hypothermia is safe and effective for improving outcome after hyperacute ischaemic stroke. An individual patient data meta-analysis of completed trials was performed. Methods: Following electronic searches for trials comparing hypothermia to control, Chief Investigators were approached to share individual patient data (IPD). Odds ratios (OR, 95% confidence intervals, 95% CI) were analysed with ordinal logistic regression and binary logistic regression with adjustment for trial, cooling method (endovascular, surface or unknown) and age. Results: Data were obtained for 10 trials (320 participants): COAST-I, COAST-II, COOL AID pilot, COOL AID, COOLIST, HAIS-SE, ICTuS-L, ICTuS-2, MASCOT and MHAIS; IPD were not available for two studies. Trial designs varied and most had a small sample size, mean (SD) age 66 (11.5) years, female 42%, NIHSS 13.4 (5.3), time to treatment 4.5 (1.2) hours, thrombolysis 53%. In patients whose temperature was recorded (n=74), the lowest achieved temperature was in the hypothermia arm: 34.3 o C vs. 36.6 o C (p<0.001). Functional outcome (modified Rankin Scale) at day 90 did not differ between cooling vs. no cooling: n=297 OR 0.93 (95% CI 0.63-1.39, p=0.74). Serious adverse events (n=287) were increased in the cooling arm: 81.5% vs. 65.5% (p<0.001); pneumonia: 30.2% vs. 10.9% (p<0.001) and aspiration: 13.3% vs. 3.5% (p=0.004). There was no difference in death: 17.2% vs. 13.6% (p=0.21). Conclusion: Hypothermia lowered temperature by 2.3 C, did not alter functional outcome or mortality, but was associated with more SAEs. Larger trials are needed to assess hypothermia in hyperacute stroke.