Intravenous Beta-blockade for Improvement of Autonomic Activity

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. The investigators 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 Overview

• Status: Completed
• Conditions: Hypertension; Tachycardia; Heart Rate Variability
• Intervention / Treatment: Drug: i.v. beta-blocker infusion (metoprolol)

• Study Type: Observational
• Enrollment (Anticipated): 100

Contacts and Locations

Study Locations

• Germany
  • Schleswig-Holstein
    • Kiel, Schleswig-Holstein, Germany, 24105
      • University Hospital Schleswig-Holstein, Campus Kiel, Germany

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients scheduled for coronary artery bypass surgery

Description

Inclusion Criteria:

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

Exclusion Criteria:

• Emergency cases
• Myocardiac infraction within 4 weeks

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
1; Patients with hypertension and/or tachycardia prior to induction of anesthesia requiring i.v. beta-blockade for treatment of raised hemodynamic	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; Other Names: Metorpolol, Lopresor(R)
2; Patients with normal hemodynamic values prior to induction of anesthesia not requiring treatment

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Improvement of heart rate variability reflecting autonomic activity in the course of i.v. beta-blockade	Baseline, after i.v. beta-blockade, 6 months after discharge

Secondary Outcome Measures

Outcome Measure	Time Frame
Hospital stay, one-year cardiac mortality and morbidity after discharge	Postoperatively until discharge, between discharge and 1 year after discharge

Collaborators and Investigators

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

Study record dates

Study Major Dates

• Study Start: March 1, 2008
• Primary Completion (Actual): March 1, 2009
• Study Completion (Actual): November 1, 2009

Study Registration Dates

• First Submitted: June 13, 2008
• First Submitted That Met QC Criteria: June 17, 2008
• First Posted (Estimate): June 18, 2008

Study Record Updates

• Last Update Posted (Estimate): January 18, 2010
• Last Update Submitted That Met QC Criteria: January 15, 2010
• Last Verified: February 1, 2009

More Information

Terms related to this study

• Keywords: outcome; Outcome assessment, patients;; autonomic nervous system;; perioperative care;; adrenergic beta antagonist; Autonomic regulation; Perioperative beta-blockade
• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Arrhythmias, Cardiac; Cardiac Conduction System Disease; Tachycardia; Physiological Effects of Drugs; Adrenergic Antagonists; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Anti-Arrhythmia Agents; Antihypertensive Agents; Autonomic Agents; Peripheral Nervous System Agents; Sympatholytics; Adrenergic beta-1 Receptor Antagonists; Metoprolol; Adrenergic beta-Antagonists
• Other Study ID Numbers: Hanss_EA 162/07