Abstract WP30: Therapeutic Hypothermia With Thin Liquid Convection is Safe and Feasible in Acute Stroke Patients: The Helping Stroke Patients With ThermoSuit Cooling (SISCO) Pilot Study

Abstract

Introduction: Animal studies have shown that therapeutic hypothermia of 32-34°C (TH) leads to a drop in infarct size after cerebral artery occlusion. Data suggests that early, rapid TH must be achieved to maximize neuroprotection from ischemic injury. There have been two RCTs of TH in stroke patients, both of which cooled slowly and failed to show the benefit of TH. Objective: The present study assessed the safety and feasibility of the ThermoSuit System (TSS) to induce rapid TH in acute ischemic stroke patients enrolled in the SISCO pivotal phase I trial. The TSS circulates cold water directly over the patient’s skin to achieve TH and has previously demonstrated significantly faster cooling than other methods. Methods: Eligible stroke patients were enrolled with an NIHSS > 5, less than 8 hours from LKW, or who met the extended window thrombectomy criteria. Patients were sedated and intubated according to protocols. Cooling was initiated by circulating ice-cold water (0-8°C) through the TSS. The patients were cooled until the core temperature reached 34-33°C, and the suit was removed. Temperature was maintained at 32°C to 34°C for 24 hours following the cooling induction using a conventional cooling blanket. Criteria for study success were defined as 1) at least 50% of the patients achieving 32-34°C within 1 hour; 2) NIHSS and mRS scores at 90 days post-stroke were not statistically worse than historical controls; 3) no significant increase in adverse event rates in cooled subjects vs. historical controls. RESULTS 14 subjects were enrolled, and 13 were cooled. 2 patients were excluded due to treatment delays and 1 due to missing outcome data, leaving 10 patients available for complete analysis. The average NIHSS on admission was 18, and the average patient age was 65. 7 patients had an LVO in the anterior circulation and 3 had posterior circulation strokes. All study success criteria were met. The median cooling time to 34°C was 40 minutes. The rates of unacceptable outcomes at 90 days (mRS >3) were 45% in 1314 published historical controls but only 10% in cooled subjects. Conclusion: The TSS is a safe and effective tool for rapid TH in ischemic stroke patients. Further studies are warranted to assess whether this cooling method is neuroprotective for these patients.