Original Investigation
Inhaled Xenon Attenuates Myocardial Damage in Comatose Survivors of Out-of-Hospital Cardiac Arrest: The Xe-Hypotheca Trial

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Abstract

Background

The authors previously reported that inhaled xenon combined with hypothermia attenuates brain white matter injury in comatose survivors of out-of-hospital cardiac arrest (OHCA).

Objectives

A pre-defined secondary objective was to assess the effect of inhaled xenon on myocardial ischemic damage in the same study population.

Methods

A total of 110 comatose patients who had experienced OHCA from a cardiac cause were randomized to receive either inhaled xenon (40% end-tidal concentration) combined with hypothermia (33°C) for 24 h (n = 55; xenon group) or hypothermia treatment alone (n = 55; control group). Troponin-T levels were measured at hospital admission, and at 24 h, 48 h, and 72 h post-cardiac arrest. All available cases were analyzed for troponin-T release.

Results

Troponin-T measurements were available from 54 xenon patients and 54 control patients. The baseline characteristics did not differ significantly between the groups. After adjustments for age, sex, study site, primary coronary percutaneous intervention (PCI), and norepinephrine dose, the mean ± SD post-arrival incremental change of the ln-transformed troponin-T at 72 h was 0.79 ± 1.54 in the xenon group and 1.56 ± 1.38 in the control group (adjusted mean difference −0.66; 95% confidence interval: −1.16 to −0.16; p = 0.01). The effect of xenon on the change in the troponin-T values did not differ in patients with or without PCI or in those with a diagnosis of ST-segment elevation myocardial infarction (group by PCI or ST-segment elevation myocardial infarction interaction effect; p = 0.86 and p = 0.71, respectively).

Conclusions

Among comatose survivors of OHCA, in comparison with hypothermia alone, inhaled xenon combined with hypothermia suggested a less severe myocardial injury as demonstrated by the significantly reduced release of troponin-T.

Key Words

cardioprotection
hypothermia
out-of-hospital cardiac arrest
xenon

Abbreviations and Acronyms

CI
confidence interval
HR
hazard ratio
ICU
intensive care unit
NSTEMI
non–ST-segment elevation myocardial infarction
OHCA
out-of-hospital cardiac arrest
PCI
percutaneous coronary intervention
STEMI
ST-segment elevation myocardial infarction

Cited by (0)

The study was funded by the Academy of Finland and by clinical research funding from the Hospital District of Southwest Finland. The study was academic, that is, the funding organizations did not have any role in design and conduct of the study, collection, management, analysis, and interpretation of the data and preparation, review, or approval of the manuscript. Dr. R. Laitio is a paid governmental consultant official for the National Supervisory Authority for Welfare and Health. Dr. Maze is a founder, board director, and equity shareholder of NeuroproteXeon, a company that intends to commercialize the use of xenon for ongoing acute neurological injury, including its administration to successfully resuscitated patients after out-of-hospital cardiac arrest. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

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