title: Late Post-Conditioning with Sevoflurane after Cardiac Surgery--Are Surrogate Markers Associated with Clinical Outcome?
abstract: BACKGROUND
  In a recent randomized controlled trial our group has demonstrated in 102 patients that late post-conditioning with sevoflurane performed in the intensive care unit after surgery involving extracorporeal circulation reduced damage to cardiomyocytes exposed to ischemia reperfusion injury. On the first post-operative day the sevoflurane patients presented with lower troponin T values when compared with those undergoing propofol sedation. In order to assess possible clinical relevant long-term implications in patients enrolled in this study, we performed the current retrospective analysis focusing on cardiac and non-cardiac events during the first 6 months after surgery.
  
  
  METHODS
  All patients who had successfully completed the late post-conditioning trial were included into this follow-up. Our primary and secondary endpoints were the proportion of patients experiencing cardiac and non-cardiac events, respectively. Additionally, we were interested in assessing therapeutic interventions such as initiation or change of drug therapy, interventional treatment or surgery.
  
  
  RESULTS
  Of 102 patients analyzed in the primary study 94 could be included in this follow-up. In the sevoflurane group (with 41 patients) 16 (39%) experienced one or several cardiac events within 6 months after cardiac surgery, in the propofol group (with 53 patients) 19 (36%, p=0.75). Four patients (9%) with sevoflurane vs. 7 (13%) with propofol sedation had non-cardiac events (p=0.61). While a similar percentage of patients suffered from cardiac and/or non-cardiac events, only 12 patients in the sevoflurane group compared to 20 propofol patients needed a therapeutic intervention (OR: 0.24, 95% CI: 0.04-1.43, p=0.12). A similar result was found for hospital admissions: 2 patients in the sevoflurane group had to be re-admitted to the hospital compared to 8 in the propofol group (OR 0.23, 95% CI: 0.04-1.29, p=0.10).
  
  
  CONCLUSIONS
  Sevoflurane does not seem to provide protection with regard to the occurrence of cardiac and non-cardiac events in the 6-month period following cardiac surgery with the use of extracorporeal circulation. However, there was a clear trend towards fewer interventions (less need for treatment, fewer hospital admissions) associated with sevoflurane post-conditioning in patients experiencing any event. Such results might encourage launching large multicenter post-conditioning trials with clinical outcome defined as primary endpoint.
authors.affiliation: Institute of Anesthesiology, University Hospital Zurich, Raemistrasse 100, Zurich, 8091, Switzerland.
authors.forename: John M
authors.initials: JM
authors.lastname: Bonvini
authors.affiliation: Institute of Anesthesiology, University Hospital Zurich, Raemistrasse 100, Zurich, 8091, Switzerland; Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland; Department of Anesthesiology, University of Illinois College of Medicine at Chicago, 1740 West Taylor Street, Suite 3200 West, Chicago, IL, 60612, United States of America.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Beck-Schimmer
authors.affiliation: Institute of Anesthesiology, University Hospital Zurich, Raemistrasse 100, Zurich, 8091, Switzerland.
authors.forename: Sonja J
authors.initials: SJ
authors.lastname: Kuhn
authors.affiliation: Antropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland.
authors.forename: Sereina M
authors.initials: SM
authors.lastname: Graber
authors.affiliation: Department of Anesthesia & Intensive Care Medicine, Cantonal Hospital of Muensterlingen, Campus 1, Muensterlingen, 8596, Switzerland.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Neff
authors.affiliation: Institute of Anesthesiology, University Hospital Zurich, Raemistrasse 100, Zurich, 8091, Switzerland; Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Schläpfer
mesh_terms: D000368:Aged; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000627:therapeutic use*; D006348:Cardiac Surgical Procedures; D005260:Female; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000517:prevention & control / Q000601:surgery; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage / Q000627:therapeutic use*; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D012189:Retrospective Studies; D000077149:Sevoflurane; D016896:Treatment Outcome
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D010975:Platelet Aggregation Inhibitors; D000077149:Sevoflurane