Effect of Inhaled Xenon on Cardiac Function in Comatose Survivors of Out-of-Hospital Cardiac Arrest—A Substudy of the Xenon in Combination With Hypothermia After Cardiac Arrest Trial

Abstract

<p>OBJECTIVES: This explorative substudy aimed at determining the effect of<br>inhaled xenon on left ventricular function by echocardiography in comatose survivors<br>of out-of-hospital cardiac arrest.<br>DESIGN: A randomized two-group single-blinded phase 2 clinical drug trial.<br>SETTING: A multipurpose ICU in two university hospitals.<br>PATIENTS: Of the 110 randomized comatose survivors after out-of-hospital cardiac<br>arrest with a shockable rhythm in the xenon in combination with hypothermia<br>after cardiac arrest trial, 38 patients (24–76 yr old) with complete echocardiography<br>were included in this study.<br>INTERVENTIONS: Patients were randomized to receive either inhaled xenon<br>combined with hypothermia (33 C) for 24 hours or hypothermia treatment alone.<br>Echocardiography was performed at hospital admission and 24 4 hours after<br>hypothermia.<br>MEASUREMENTS AND MAIN RESULTS: Left ventricular ejection fraction,<br>myocardial longitudinal systolic strain, and diastolic function were analyzed<br>blinded to treatment. There were 17 xenon and 21 control patients in whom echocardiography<br>was completed. Clinical characteristics did not differ significantly<br>between the groups. At admission, ejection fraction was similar in xenon and control<br>patients (39% 10% vs 38% 11%; p = 0.711) but higher in xenon than<br>control patients after hypothermia (50% 10% vs 42% 10%; p = 0.014).<br>Global longitudinal systolic strain was similar in xenon and control patients at<br>admission (–9.0% 3.8% vs –8.1% 3.6%; p = 0.555) but better in xenon<br>than control patients after hypothermia (–14.4.0% 4.0% vs –10.5% 4.0%;<br>p = 0.006). In patients with coronary artery disease, longitudinal strain improved in<br>the nonischemic myocardial segments in xenon patients. There were no changes<br>in diastolic function between the groups.<br></p>