Official Title: “Beta-Adrenoceptor Blockade Prior to Induction of Anesthesia for Improvement of Depressed Autonomic Regulation”

Chronic beta-adrenoceptor blockade is known to improve outcome of high risk patients whereas amelioration of autonomic activity was demonstrated to be a major cause of outcome improvement. Therefore, perioperative beta-adrenoceptor blockade is recommended in patients with Revised Cardiac Risk Index score of three or greater. We hypothesise that preoperative intravenous beta-adrenoceptor blockade for treatment of hypertension and/or tachycardia improves autonomic activity reflected by increase of Total Power of Heart Rate Variability.

Material and Methods: After IRB approval 20 patients scheduled for elective cardiac surgery were included into the study. Routine medication was continued throughout the study as recommended by the guidelines. HRV (TP and Low to High Frequency ratio (LF/HF) reflecting sympathetic to parasympathetic balance) was analysed prior to induction of general anesthesia and beta-adrenoceptor blockade in all patients (Baseline). Patients were assigned by their baseline hemodynamics. Patients with hypertension (systolic blood pressure > 140mmHg or diastolic blood pressure > 90mmHg) or tachycardia (heart rate > 80bpm) were assigned to group BETA-BLOCK. In this group metoprolol-boli (2mg) were administered intravenously in stepwise manner until hemodynamic values decreased to normal. Total dosage was recorded. After normalisation of hemodynamics, second HRV analysis was performed (Intervention). Normotensive and normocardic patients were assigned to group CONTROL. No intervention was performed.

Statistics: Mann Whitney U test for comparison between groups and between events Baseline and Intervention within group BETA-BLOCK, p<0.05.

Study Type: Observational

Study Design: Cohort, Prospective

Study Primary Completion Date: August 2008

Intervention(s) in this Clinical Trial

• Drug: i.v. beta-blocker infusion (metoprolol)
  • A beta-blocker (metoprolol) will be infused for treatment of hypertension and/or tachycardia prior to induction of anesthesia aiming at decrease of blood pressure and heart rate to normal limits

Arms, Groups and Cohorts in this Clinical Trial

• : 1
  • Patients with hypertension and/or tachycardia prior to induction of anesthesia requiring i.v. beta-blockade for treatment of raised hemodynamic
• : 2
  • Patients with normal hemodynamic values prior to induction of anesthesia not requiring treatment

Primary Measures

• Improvement of heart rate variability reflecting autonomic activity in the course of i.v. beta-blockade
  • Time Frame: Prior and after i.v. beta-blockade
    Safety Issue?: No

Secondary Measures

• Hospital stay, one-year cardiac mortality and morbidity after discharge
  • Time Frame: Postoperatively until discharge, between discharge and 1 year after discharge
    Safety Issue?: No

Inclusion Criteria:

• Patients scheduled for coronary artery bypass surgery
• Ejection fraction > 30 %
• Informed consent

Exclusion Criteria:

• Emergency cases
• Myocardiac infraction within 4 weeks

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: N/A

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Sponsor: University of Schleswig-Holstein

Overall Clinical Trial Officials and Contacts

Robert Hanss, MD Principal Investigator Consultant in Anesthesiology, Dep. of Anesthesiology and Intenisve Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany  

Overall Contact: Robert Hanss, MD ++49 (0) 431 5972990 hanss@anaesthesie.uni-kiel.de

Information obtained from ClinicalTrials.gov on September 05, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00700466

Study ID Number: Hanss_EA 162/07

ClinicalTrials.gov Identifier: NCT00700466

Health Authority: Germany: Ethics Commission