Researchers found that compared with hypothermia alone, hypothermia plus inhaled xenon was associated with less white matter damage in comatose survivors of out-of-hospital cardiac arrest.
However, there were no differences between the groups in neurological outcomes or mortality at 6 months, according to the findings, which were published in JAMA.
Timo Laitio, MD, PhD, and colleagues conducted a randomized, single blind trial in which 110 comatose patients (mean age, 61.5 years; age range, 24 to 76 years; 72.7% men) with out-of-hospital cardiac arrest between August 2009 and March 2015 were assigned inhaled xenon plus hypothermia to 33°C for 24 hours or hypothermia alone.
The primary endpoint was cerebral white matter damage, as assessed by fractional anisotropy from diffusion tensor MRI, which was to be performed 36 to 52 hours after cardiac arrest. Secondary endpoints included neurological outcome as assessed by the modified Rankin scale and mortality, both at 6 months.
All patients completed the study, and MRI data were available for 88.2% a median of 53 hours after cardiac arrest, Laitio, from the division of perioperative services, intensive care medicine and pain management, Turku University Hospital, Finland, and colleagues wrote.
After adjustment for age, sex and site, they found that the mean global fractional anisotropy value was 3.8% greater (95% CI, 1.1-6.4) in the xenon group than in the control group (adjusted mean difference, 0.016; 95% CI, 0.005-0.027).
At 6 months, 68.2% of patients were still alive, with mortality rates being 27.3% in the xenon group and 34.5% in the control group (adjusted HR = 0.49; 95% CI, 0.23-1.01), according to the researchers.
When they conducted an ordinal analysis of the modified Rankin scale at 6 months, they found the median value was 1 (interquartile range, 1-6) in the xenon group and 1 (interquartile range, 0-6) in the control group (median difference, 0; P = .68).
“These preliminary findings require further evaluation in an adequately powered clinical trial designed to assess clinical outcomes associated with inhaled xenon among survivors of out-of-hospital cardiac arrest,” Laitio and colleagues wrote. – by Erik Swain
Disclosure: Laitio reports receiving institutional funding from Neuroprotexeon Company. Please see the full study for a list of the other researchers’ relevant financial disclosures.