An interventional study of Non-invasive convective head cooling and Standard of Care (SOC) in Stroke, Acute Ischemic Stroke and Brain Ischemia, sponsored by Auckland City Hospital. Not yet recruiting at 1 site in New Zealand. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-13.
Sponsored by Auckland City Hospital · Not applicable, Interventional, and Supportive care
COOLHEAD-2b is a multicentre, phase 2, prospective, randomised, controlled, open-label, blinded-endpoint trial evaluating the safety and efficacy of non-invasive convective head cooling as an adjunct to endovascular thrombectomy (EVT) in patients with acute anterior circulation ischaemic stroke. Head cooling is initiated as early as possible, including during inter-hospital transfer, and continued until one hour after reperfusion. The primary efficacy endpoint is final infarct volume at 24 hours.
Despite advances in reperfusion therapy, a substantial proportion of patients undergoing EVT for acute ischaemic stroke experience poor functional outcomes, particularly those with delayed reperfusion due to interhospital transfer. Therapeutic hypothermia is a potent neuroprotective intervention in preclinical stroke models but has not been successfully translated into clinical practice due to delayed initiation and systemic complications.
Convective head cooling is a non-invasive, portable method capable of selectively reducing brain temperature while minimizing systemic hypothermia. Phase 1 and feasibility studies (COOLHEAD-1 and COOLHEAD-2a) demonstrated that this approach is safe, well-tolerated, and feasible in patients undergoing EVT.
COOLHEAD-2b will test whether convective head cooling reduces infarct volume and improves clinical outcomes when applied early and continued throughout the EVT workflow, including interhospital transfer. Participants will be randomised 1:1 to head cooling plus standard care or standard care alone. Outcome assessors and imaging core laboratory staff will be blinded to treatment allocation.
All outcome measures are derived from prospectively collected clinical, imaging, and procedural data. Imaging outcomes are assessed by a blinded core laboratory using standardized methods. Functional outcome assessments are performed by trained assessors blinded to treatment allocation. Safety outcomes are actively monitored throughout the peri-procedural and post-procedural periods.
2,612 studies on the registry are indexed under Ischemic Stroke; 971 are open to participants now.
This study's planned enrollment of 182 is above the median of 120 across 1,776 interventional studies indexed under Ischemic Stroke.
Browse Ischemic Stroke studies →Auckland City Hospital is the lead sponsor of 6 studies on the registry; 2 are open to participants now.
Compared within Ischemic Stroke, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Stroke. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive non-invasive convective head cooling in addition to standard clinical care for acute anterior circulation ischaemic stroke undergoing endovascular thrombectomy. Head cooling is initiated as early as possible following randomisation and continued throughout interhospital transfer (if applicable), endovascular thrombectomy, and for one hour after reperfusion.
Device: Non-invasive convective head cooling
Participants receive standard clinical care for acute anterior circulation ischaemic stroke undergoing endovascular thrombectomy, without head cooling.
Other: Standard of Care (SOC)
Non-invasive convective head cooling delivered using a cooling cap system that circulates chilled fluid around the scalp and neck. Cooling is commenced in the emergency department following randomisation, with a target coolant temperature of -5 °C (adjustable for comfort). Cooling is continued during interhospital transfer (if applicable), during the endovascular thrombectomy procedure, and for one hour following reperfusion. Systemic rewarming measures may be used to maintain core body temperature above 35 °C if required.
Guideline-based management of acute ischaemic stroke, including endovascular thrombectomy, with supportive medical care as determined by the treating clinical team. No head cooling device is applied.
Final Infarct Volume
Final infarct volume (mL), defined as the manually segmented volume of infarcted brain tissue on 24-hour follow-up CT or MRI brain imaging. Segmentation will be performed by a blinded imaging core laboratory using de-identified imaging files.
Time frame: 24 hours after endovascular thrombectomy
Infarct growth
Infarct growth, defined as the difference between the final infarct volume on 24-hour follow-up imaging and the baseline infarct core volume estimated using automated CT perfusion software (relative cerebral blood flow \<30%).
Time frame: Baseline imaging to 24 hours after endovascular thrombectomy
Penumbral salvage index
Penumbral salvage index, defined as the proportion of baseline hypoperfused or penumbral brain tissue not progressing to infarction, calculated using baseline CT perfusion imaging and final infarct volume on 24-hour follow-up imaging.
Time frame: Baseline imaging to 24 hours after endovascular thrombectomy
Early neurological improvement
Early neurological improvement, defined as the percentage change in the National Institutes of Health Stroke Scale (NIHSS), a neurological deficit scale ranging from 0 to 42 where higher scores indicate worse neurological impairment, from baseline to 24 hours
Time frame: Baseline to 24 hours after endovascular thrombectomy
Modified Rankin Scale (mRS) score
Degree of disability or dependence in daily activities measured using the modified Rankin Scale (mRS), an ordinal scale ranging from 0 (no symptoms) to 6 (death), where higher scores indicate greater disability. Assessment is performed by a trained, blinded study team member using the Rankin Focused Assessment.
Time frame: 90 days after endovascular thrombectomy
Proportion of Participants with Functional Independence
Proportion of participants achieving functional independence, defined as a modified Rankin Scale (mRS) score of 0 to 2, where lower scores indicate less disability.
Time frame: 90 days after endovascular thrombectomy
Proportion of Participants with Excellent Functional Outcome
Proportion of participants achieving an excellent functional outcome defined as a modified Rankin Scale (mRS) score of 0 to 1, where lower scores indicate minimal or no disability.
Time frame: 90 Days post endovascular thrombectomy
Days Alive and Out of Hospital (DAOH-90)
Number of days participants are alive and not admitted to hospital during the first 90 days after endovascular thrombectomy.
Time frame: First 90 days after endovascular thrombectomy
All cause mortality
Death from any cause.
Time frame: 90 days after endovascular thrombectomy
Number of Participants with Symptomatic Intracranial Haemorrhage
Symptomatic intracranial haemorrhage defined according to the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) criteria as a parenchymal haemorrhage type 2 associated with neurological deterioration (increase in NIHSS score ≥4 points) or death.
Time frame: Within 36 hours after endovascular thrombectomy
Number of Participants with New Arrhythmia and Haemodynamic Compromise
Occurrence of a new cardiac arrhythmia associated with haemodynamic instability requiring clinical intervention.
Time frame: During the head cooling intervention period, from initiation of cooling to one hour after reperfusion.
Number of Participants with Uncontrolled Hypertension During Head Cooling
Blood pressure \>185/110 mmHg or an absolute increase in systolic blood pressure ≥30 mmHg from baseline on two consecutive measurements despite standard pharmacological treatment.
Time frame: During the head cooling intervention period, from initiation of cooling to one hour after reperfusion.
Number of Participants with Cold-Related Shivering
Clinically significant shivering attributed to head cooling that persists despite systemic warming measures.
Time frame: During the head cooling intervention period, from initiation of cooling to one hour after reperfusion.
Number of Participants with Pneumonia
Pneumonia diagnosed according to Centers for Disease Control and Prevention criteria.
Time frame: Within 7 days after stroke or hospital discharge, whichever occurs first
Number of Participants with Local Pressure or Cold-Related Skin Injury
Any local skin injury attributed to pressure or cold exposure from the head cooling device.
Time frame: From initiation of head cooling through hospital discharge, up to a maximum of 7 days
Number of Participants with Angiographic Vasospasm Requiring Treatment
Angiographic vasospasm occurring during endovascular thrombectomy requiring administration of intra-arterial vasodilators.
Time frame: During endovascular thrombectomy procedure
Intra-Procedural Complications
Composite outcome including target vessel dissection, vessel perforation, intracranial haemorrhage, or access site haematoma occurring during or immediately following the EVT procedure.
Time frame: During endovascular thrombectomy procedure
Plan to share: No — Individual participant data (IPD) will not be shared outside the study team. This trial involves detailed clinical, imaging, and procedural data collected within a relatively small and geographically defined population, which increases the risk of participant re-identification despite de-identification. In addition, no consent for broader data sharing beyond the study investigators was obtained from participants or their representatives. Access to the final dataset will therefore be restricted to the study investigators for the purposes of scientific analysis and publication.
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Auckland City Hospital