Debate heats up following contrasting trial results on brain cooling during stroke thrombectomy

 I guess you better hold off on having a stroke until this is solved. 

All my previous research posts on this suggested no useful intervention. Obviously no protocols were ever written on hypothermia so everyone is still shooting in the dark. The result being that survivors are still screwed with no consequences to the doctors who haven't written up protocols on this. Don't you just love incompetence?

They still are measuring the wrong endpoint! IT'S 100% RECOVERY!

• hypothermia (44 posts to February 2011)

Debate heats up following contrasting trial results on brain cooling during stroke thrombectomy

Two randomised trials presented this week at the European Stroke Organisation Conference (ESOC; 6–8 May 2026, Maastricht, Netherlands) have generated new evidence on the potential benefits of delivering intra-arterial cooling during mechanical thrombectomy procedures in large vessel occlusion (LVO) acute ischaemic stroke patients, with one producing clinical data favouring this approach and the other demonstrating safety but suggesting more neutral efficacy findings.

“The divergent results of the CHILL-ART and FOCUS trials present a classic dilemma: weighing conflicting data from similar protocols before publication,” said World Stroke Organization (WSO) vice president Gustavo Saposnik (University of Toronto, Toronto, Canada), speaking with NeuroNews in light of these first-time presentations. “While CHILL-ART suggests a robust functional benefit, FOCUS tempers this optimism, showing no functional gain despite a safety signal in reduced intracranial haemorrhage [ICH].

“This inconsistency highlights the uncertainty inherent to neurovascular research, echoing the turbulent history of [mechanical thrombectomy] prior to the 2015 pivotal trials. We must await full publication to parse technical or population differences. Currently, selective intra-arterial hypothermia remains a promise, not a proven standard. These results are hypothesis-generating; more definitive, large-scale data are required before routine integration into thrombectomy workflows.”

Positive efficacy data

CHILL-ART—the first of these multicentre randomised controlled trials (RCTs) to be shared during a late-breaking session at ESOC 2026—demonstrated that delivering targeted brain cooling during thrombectomy significantly improves recovery outcomes, as a meaningful increase in 90-day functional independence was observed in patients receiving adjunctive intra-arterial selective hypothermia versus those receiving standard thrombectomy alone.

The CHILL-ART RCT enrolled 262 anterior-circulation LVO patients across 26 comprehensive stroke centres in China. Participants aged 18–85 years and treated within 24 hours of stroke onset were randomly assigned to receive either thrombectomy plus intra-arterial infusion of cold saline in the hypothermia group, or thrombectomy with room-temperature saline in the control group.

The trial’s primary endpoint of functional independence (modified Rankin scale [mRS] score 0–2)(That's NOT 100% RECOVERY, IS IT? So failure!) at 90 days was achieved in 54.7% of patients in the hypothermia group compared to 39.8% in the control group, with an adjusted risk ratio of 1.36 (95% confidence interval [CI], 1.05–1.76; p=0.018). Investigators reported at ESOC 2026 that this equated to a number needed to treat (NNT) of seven. And, “importantly”, in the researchers’ view, safety outcomes were comparable between the hypothermia and control groups, with no significant increase in symptomatic ICH (7% vs 9%, respectively) nor 90-day mortality (13.3% vs 18%, respectively).

Subsequent sensitivity analyses also replicated these findings, indicating the robustness of the trial’s results, and outcomes were shown to be consistent across all study subgroups as well.

“Even when we successfully remove the clot, many patients do not regain independence because of ongoing brain injury after blood flow is restored,” said CHILL-ART principal investigator Zhi-Xin Huang (Southern Medical University, Guangzhou, China), who presented these data alongside Raul Nogueira (University of Pittsburgh Medical Center, Pittsburgh, USA). “Our findings show that targeted cooling delivered directly into the brain at the moment of reperfusion can meaningfully improve recovery without adding risk.”

According to the investigators, the intervention evaluated in this trial uses standard thrombectomy equipment and refrigerated saline, making it readily scalable in routine clinical practice without requiring specialised devices or additional training.

The researchers also note that, more broadly, CHILL-ART addresses a “critical unmet need” in stroke care: improving outcomes after technically successful clot removal.

By combining reperfusion with targeted neuroprotection, the study introduces a “promising new paradigm” in acute stroke treatment, and its findings may inform future clinical guidelines and support broader adoption of intra-arterial hypothermia as an accessible, cost-effective strategy to reduce disability after stroke, the investigators further posit.

Safe yet neutral outcomes

The FOCUS trial—also investigating selective intra-arterial cooling as an adjunct to thrombectomy for LVO acute ischaemic stroke, and also presented at ESOC 2026—found that, while the cooling technique did not improve functional recovery, it did significantly reduce the risk of any ICH. According to the study’s investigators, these findings therefore provide important insights into the potential role of targeted brain cooling in stroke treatment.

FOCUS was an RCT conducted across 12 hospitals in China that enrolled 258 patients with anterior-circulation LVO stroke who presented within 24 hours of symptom onset. Patients were randomly assigned to receive either selective intra-arterial cooling plus thrombectomy or standard thrombectomy treatment alone.

The trial’s results showed no significant difference in functional outcomes at 90 days between the two groups, with an adjusted common odds ratio of 1.16 (95% CI, 0.75–1.79; p=0.51). However, the cooling technique demonstrated notable safety benefits, reducing the incidence of any ICH at 24 hours compared to standard treatment (adjusted risk difference, -0.174; 95% CI, -0.288 to -0.059; p=0.003). Additionally, there was no difference in the occurrence of symptomatic ICH or mortality between groups.

The FOCUS investigators note that, while hypothermia has long been studied as a potential neuroprotective therapy for stroke based on its ability to reduce brain metabolism and limit secondary injury, its potential benefits require further study at this stage.

“These findings validate the feasibility of selective intra-arterial cooling as an adjunctive therapy during endovascular thrombectomy,” commented leading study author Shen Li (Capital Medical University, Beijing, China), who presented these data at ESOC 2026. “The marked decrease in any ICH indicates a potential protective effect on the blood-brain barrier and microvasculature, which may translate into clinical benefits. Although we did not observe a functional improvement in this trial, it paves the way for future studies with larger sample sizes or refined patient selection to fully unlock the neuroprotective potential of hypothermia.”

Brain Cooling Tech Leads New Inventions in Thoracic Surgery

Would any of this be useful in responding to a stroke? We'll never know. 

All my previous research posts on this suggested no useful intervention. Obviously no protocols were ever written on hypothermia so everyone is still shooting in the dark. The result being that survivors are still screwed with no consequences to the doctors who haven't written up protocols on this. Don't you just love incompetence?

• hypothermia (44 posts to February 2011)

 

 

Brain Cooling Tech Leads New Inventions in Thoracic Surgery

NEW ORLEANS -- Innovations in brain cooling and augmented reality were featured, among other projects, at this year's Society of Thoracic Surgeons meeting.
Following the keynote lecture on technological innovation and entrepreneurship by Mark Cohen, MD, of University of Michigan in Ann Arbor, four contestants lined up their pleas for investment in front of judges and audience members at the conference's "Shark Tank" session.
The informal winner was a balloon catheter with a cooling pump that is designed to prevent ischemic injury to the brain during cardiac arrest or stroke. The project won 45% of audience votes (with only 20 people having voted, however).
Brain Cooling
Presenter Robert Schultz, MD, a resident in cardiac surgery at Alberta Health Services in Calgary, said that cooling in aortic surgery decreases strokes by 97% and the question was how to make this available to all surgeons, not just cardiac surgeons.
The device from his start-up, Voyage Biomedical, makes it possible to initiate cooling outside the operating room, cool the head by 10 °C in 10 minutes, and leave the rest of the body warm (never below 32 °C) and the heart beating, Schultz told the audience.
Eventually, the goal is to get the brain cooling device on ambulances and in ICUs. So far, it has been tested in pigs and human cadavers.
A judge during the session, Steven Bolling, MD, of University of Michigan Hospital in Ann Arbor, expressed concern about the intellectual property protection on Schultz's cooling balloon pump when he could easily recreate the technology at his own institution.
Nevertheless, Voyage already has enough money offered by investors to get to first-in-human trials by 2023, Schultz said.

The Search for Methods to Monitor Brain Cooling

Would any of this be useful in responding to a stroke? We'll never know.

The Search for Methods to Monitor Brain Cooling

Until a little more than a decade ago, doctors had few options to treat newborns whose brains were deprived of oxygen or blood at birth, a condition known as perinatal hypoxic-ischemic encephalopathy, or HIE. If babies could be stabilized and kept breathing, physicians and nurses could offer only supportive care and had to watch and wait to see how much brain damage their patients would suffer. “This was a disease where we had no treatment that worked, and [around] 60 percent of these babies were either dying or had a disability,” says Rosemary Higgins, a program scientist at the National Institute of Child Health and Human Development.
In 2005, research findings reshaped the field. Higgins and other neonatologists reported the results of a couple of large clinical trials testing the effects of so-called cooling therapy on brain damage. Hundreds of babies suffering from HIE—the effects on the brain of oxygen deprivation during delivery, due to umbilical cord problems, the placenta coming away from the uterus too soon, or other complications—had their temperatures chilled from roughly 37 °C to about 33 °C for 72 hours, then slowly rewarmed (in one study it was whole-body cooling, in the other it was just the head). Although many babies still died of the brain damage or ended up with a severe disability, more fared better in the treatment groups than in the control groups (New Engl J Med, 353:1574-84; The Lancet, 365:663-70).
“Cooling was a landmark discovery for this disease,” Higgins says. Finally, doctors (and their patients) weren’t completely helpless. The intervention used in these studies reduced the number of newborns dying or enduring a severe disability to below 50 percent.
But to Higgins and other doctors, the improvements achieved with cooling were just the start. “It sounds wonderful that we’ve made significant improvement, but in my mind that’s really just a proof of concept that you can make a difference,” says Sandra Juul, the head of neonatology at the University of Washington School of Medicine and Seattle Children’s Hospital. “But 50 percent is not acceptable.”
Cooling sites of injury is an old concept, dating back to Hippocrates and Roman warriors, and practiced in modern times by any parent who’s applied an ice pack to a boo-boo. Reducing temperatures slows cellular responses to damage, including cell death and subsequent inflammatory reactions. What cooling doesn’t do, however, is heal damaged tissue.
Investigators are therefore trying to boost the effects of cooling therapy and to find those babies who will benefit from extra interventions. There are some promising leads. Juul, for instance, is heading a phase 3 clinical trial to examine the effects of giving HIE babies erythropoietin, a hormone required for brain and red blood cell development, together with cooling therapy. Others are looking into adding xenon to babies’ ventilators or administering antiseizure medications.
The challenge with any of these add-ons is that there is no good way to quickly assess how babies’ brains are responding to treatment. As it is, there’s no readily available technology that offers real-time reporting on progress in stopping brain damage. Doctors can use bedside assessments, such as whether the baby is conscious or has responsive pupils, and more high-tech exams, such as MRI. The former, however, isn’t a precise method of predicting brain damage, and the latter is logistically challenging because the baby needs to be moved to a radiology suite.
Two more-practical diagnostic approaches are serum biomarkers of brain damage and physiologic recordings, such as electroencephalogram (EEG). Lina Chalak of the University of Texas Southwestern Medical Center in Dallas has worked on both. Most recently, her team designed a real-time “heat map” of babies’ responses to cooling therapy that correlated with their developmental outcomes at 24 months of age.
Her team collected data from 10 newborns—eight of whom underwent cooling therapy, and another two who were normal and did not. For 60 hours they collected data from a method of EEG called amplitude-integrated EEG, which records trends in neural activity over time, and near-infrared spectroscopy (NIRS), which tracks blood flow and oxygenation. Combining the two metrics reveals so-called neurovascular coupling, Chalak says—essentially, how well neuronal behavioral and blood flow correspond. “You need neurons and blood vessels to communicate with each other.”
Using a newly developed computational analysis, Chalak’s group plotted this neurovascular coupling in real time on a color-coded heat map, reminiscent of the kind meteorologists use to display weather dynamics. Chalak’s map revealed the synchrony within the babies’ brains between their neural and vascular systems (Scientific Reports, 7:45958, 2017). Normal babies and babies with HIE who had better outcomes two years later showed higher neurovascular coupling (as indicated by big red islands in a sea of blue on the map). Babies without such patterning—showing instead a spattering of blue, yellow, orange, and red—tended to have poorer outcomes. “Neurons were firing, and blood vessels were not caring. There was no relationship,” Chalak says.
She adds that the study is a proof of concept, and much more validation is required before the technique could earn a place at the bedside. Further along in validation studies are protein biomarkers present in the blood, which could be used to assess brain damage and how the brain is responding to treatment. Among them: proteins that signal astrocyte damage, such as GFAP (glial fibrillary acidic protein) and inflammatory cytokines. Although such biomarkers aren’t collected continuously like EEG data, physicians could easily measure them from the blood draws that babies regularly endure throughout cooling therapy.
An ancillary goal of the erythropoietin trial is to assess the utility of these biomarkers in monitoring brain injury and tracking responses to the intervention. “I hope we’re not too far away from a blood test for brain injury,” says An Massaro, a neonatologist at the Main Hospital of the Children’s National Health System, who is participating in the study. Chalak is also taking part, and will be adding her heat maps to the suite of data she collects on the infants. Massaro says she anticipates the study will provide answers not just on biomarkers and physiologic predictors of brain damage, but on ways to save more babies from the devastation of HIE. “I think it’s going to be a very exciting time of clinical studies of brain therapeutics, but our big issue is identifying the right patients to put in these trials and the right patients to ultimately treat.”