# Therapeutic hypothermia with rapid thin liquid convection is safe and feasible in acute ischemic stroke patients: the SISCO pilot study

## TL;DR

A new cooling method called ThermoSuit® can safely and quickly lower body temperature in stroke patients, potentially improving recovery outcomes.

## Contribution

The study demonstrates the feasibility and safety of rapid non-invasive cooling in acute ischemic stroke patients using the ThermoSuit® System.

## Key findings

- Patients cooled to 32–34 °C within 40 minutes on average with minimal shivering.
- No increased harm was observed, and 90% of patients had acceptable neurological outcomes.
- The pneumonia rate was 23%, comparable to prior cooling studies in stroke patients.

## Abstract

Laboratory studies have shown that rapid therapeutic hypothermia (TH) of <34 °C can reduce stroke infarct volume by over 50%. The EuroHyp-1 and ICTUS 2/3 trials found no benefits in the slow cooling of ischemic stroke patients, while extensive shivering was observed. More powerful cooling methods are required to improve outcomes.

In a feasibility study approved to include up to 30 patients, the ThermoSuit® System (TSS) was used to cool sedated ischemic stroke patients to 32–34 °C. Patients were cooled after reperfusion, and TH was maintained for 24 h. Cooling speeds, adverse events, and neurological outcomes [including Modified Rankin Score (mRS) at 90 days] were documented.

The trial was terminated after enrolling 14 subjects from 3 sites after meeting the study feasibility criteria. Ten subjects qualified for outcomes analysis. All cooled patients reached the 34 °C target with a median time of 40 min. Patients cooled under this protocol showed no increased harm and trends for improved neurological outcomes compared to previously published studies. A pneumonia rate of 23% (3/13) was comparable to prior studies in which stroke patients were cooled. Brief shivering occurred in most patients but was limited to 5.4% of the time while in the hypothermic temperature range. Patients cooled per the SISCO protocol had a rate of acceptable outcomes (mRS ≤ 3) of 90%. In intention-to-treat analysis, 82% of patients had acceptable outcomes.

The TSS is a feasible tool to achieve TH in ischemic stroke patients. This non-invasive cooling technique allows swift cooling of patients to ≤34 °C with little shivering and no apparent safety issues. Further studies are warranted to prove this rapid cooling method is cytoprotective in stroke patients, as evidenced by improved odds of functional independence.