Clinical trial NCT00700466: Intravenous Beta-blockade for Improvement of Autonomic Activity
Official title: Beta-adrenoceptor Blockade Prior to Induction of Anesthesia for Improvement of Depressed Autonomic Regulation
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Hypertension
Tachycardia
Heart Rate Variability
Keywords: Outcome assessment, patients;
autonomic nervous system;
perioperative care;
adrenergic beta antagonist
Autonomic regulation
Perioperative beta-blockade
outcome
Lead sponsor: University Hospital Schleswig-Holstein
Sponsor class: OTHER
First posted: 2008-06-18
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients scheduled for coronary artery bypass surgery

Brief summary: 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.


Eligibility criteria: Inclusion Criteria:

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

Exclusion Criteria:

* Emergency cases
* Myocardiac infraction within 4 weeks

Primary outcomes:
measure: Improvement of heart rate variability reflecting autonomic activity in the course of i.v. beta-blockade
timeFrame: Baseline, after i.v. beta-blockade, 6 months after discharge
Secondary outcomes:
measure: Hospital stay, one-year cardiac mortality and morbidity after discharge
timeFrame: Postoperatively until discharge, between discharge and 1 year after discharge
Other outcomes:
Locations:
city: Kiel
country: Germany
facility: University Hospital Schleswig-Holstein, Campus Kiel, Germany
state: Schleswig-Holstein
Study officials:
affiliation: Consultant in Anesthesiology, Dep. of Anesthesiology and Intenisve Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany
name: Robert Hanss, MD
role: PRINCIPAL_INVESTIGATOR
References: