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Coronary Blood Flow Regulation During General Anesthesia

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ClinicalTrials.gov Identifier: NCT00866801
Recruitment Status : Completed
First Posted : March 23, 2009
Last Update Posted : October 14, 2015
Sponsor:
Collaborator:
Netherlands Heart Foundation
Information provided by (Responsible Party):
C.S.E. Bulte, VU University Medical Center

Brief Summary:

The central hypothesis in the present project is that general anesthesia may alter autonomic control such that perioperative coronary blood flow (CBF) is significantly disturbed.

These disturbances in coronary blood flow may contribute to the development of myocardial ischemia in the perioperative period. Furthermore, patients with an intrinsically altered autonomic sympathetic innervation, like diabetics, are even more prone to develop perioperative disturbances in coronary blood flow.

Here the researchers will investigate what the direct effects are of general and locoregional anesthesia on the CBF. Furthermore, the researchers aim to evaluate whether diabetic subjects show more disturbed CBF responses to anesthesia as compared to non-diabetics.


Condition or disease
Myocardial Ischemia Autonomic Neuropathy Healthy Diabetes

Detailed Description:

In response to intraoperative stress, increased autonomic sympathetic activity may alter myocardial oxygen demand. Under normal physiological circumstances, sympathetic stimulation increases myocardial blood flow via adrenergic coronary vasodilation. However, coronary vessels contain both α- and β-adrenoreceptors, and if the coronary circulation is impaired due to cardiovascular disease, unopposed adrenergic coronary vasoconstriction may contribute to ischemia. Anesthetics reduce both coronary blood flow (CBF) regulation and the sympathetic autonomic nervous activity. However, it is unclear whether anesthetic-related reductions in CBF are a result of inhibited autonomic sympathetic innervation. Data regarding alterations in myocardial blood flow in response to sympathetic stimulation during anesthesia provide conflicting results. Moffitt and Sethna showed in patients undergoing cardiac surgery that CBF decreased during sternotomy-induced sympathetic stimulation, whereas Kirno et al. showed an increase in coronary blood flow after sternotomy. To our best knowledge, coronary vascular responses to sympathetic stimulation in anesthetized healthy humans are lacking because of absence of reliable non-invasive measurement of myocardial blood flow. The introduction of non-invasive contrast-echocardiographic techniques that allow evaluation of regional myocardial blood flow enable evaluation of the relation between autonomic control and CBF during anesthesia.

Cardiac complications like myocardial ischemia remain one of the main causes of perioperative morbidity and mortality. Interestingly, the presence of cardiovascular autonomic neuropathy (CAN) strongly predicts abnormalities in myocardial perfusion and impaired coronary vasodilator responses to stress. This implies that symptoms of CAN, like resting tachycardia, orthostasis and alterations in heart rate variability may predict the degree of impairment of CBF regulation. Indeed, autonomic neuropathy as determined by heart rate variability predicted mortality in patients with coronary artery disease undergoing non-cardiac surgery, but the contribution of impaired coronary vasodilatory responses to these results has not been established. Clarification of the relation between autonomic control and CBF during anesthesia may not only contribute to our insight in pro-ischemic processes in the heart, but may lead to changes in preoperative assessment of patients at risk for perioperative ischemia, thereby reducing perioperative complications.

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Study Type : Observational
Actual Enrollment : 45 participants
Time Perspective: Prospective
Official Title: Cardiac Sympathetic Innervation and Coronary Blood Flow Regulation During General Anesthesia
Study Start Date : April 2009
Actual Primary Completion Date : February 2014
Actual Study Completion Date : October 2014

Group/Cohort
Healthy
Healthy subjects scheduled for general anesthesia
Healthy with thoracic epidural anelgesia
Healthy subjects scheduled for general anesthesia and thoracic epidural analgesia
Diabetes
Subjects with diabetes scheduled for general anesthesia
Diabetes with autonomic neuropathy
Subjects with diabetes and cardiovascular autonomic neuropathy scheduled for general anesthesia



Primary Outcome Measures :
  1. Coronary flow reserve [ Time Frame: Within the first 3 days postoperatively ]

Secondary Outcome Measures :
  1. Diabetic autonomic neuropathy [ Time Frame: Within the first 3 days postoperatively ]

Biospecimen Retention:   Samples Without DNA
Frozen plasma will be retained


Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
The study population consists patients scheduled for surgery and general anesthesia. Patients will be recruited from the preoperative screening clinic in the four, aforementioned, groups of patients.
Criteria

Inclusion Criteria:

  • male
  • age between 18-75 years
  • scheduled for non-cardiac intermediate or high risk surgery
  • for patient group 2: indication for thoracic epidural anesthesia

Exclusion Criteria:

  • neurosurgery
  • known/documented cardiac disease
  • (untreated) hypertension
  • abnormal ECG or echocardiogram
  • peripheral vascular disease
  • renal disease requiring hemo- or peritoneal dialysis
  • inability to perform transthoracic echocardiography
  • medication interfering with presynaptic catecholamine uptake
  • for patient group 2: contra-indication for thoracic epidural anesthesia (bleeding diathesis, infection at the puncture site, patient refusal, severe stenotic valvular disease)
  • previous allergic reaction to echocardiographic contrast agents
  • contraindications for the use of echocardiographic contrast agents

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00866801


Locations
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Netherlands
VU University Medical Center
Amsterdam, Noord-Holland, Netherlands, 1007 MB
Sponsors and Collaborators
VU University Medical Center
Netherlands Heart Foundation
Investigators
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Principal Investigator: Carolien SE Bulte, MD VU University Medical Center
Principal Investigator: R. A. Bouwman, MD, PhD VU University Medical Center
Study Chair: C. Boer, PhD VU University Medical Center
Study Director: S. A. Loer, MD, PhD, MSC VU University Medical Center
Study Chair: O. Kamp, MD, PhD VU University Medical Center
Study Chair: M. Diamant, MD, PhD VU University Medical Center

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: C.S.E. Bulte, MD, VU University Medical Center
ClinicalTrials.gov Identifier: NCT00866801    
Other Study ID Numbers: ANES 2008-12
2008 T003
First Posted: March 23, 2009    Key Record Dates
Last Update Posted: October 14, 2015
Last Verified: October 2015
Keywords provided by C.S.E. Bulte, VU University Medical Center:
coronary blood flow
coronary flow reserve
cardiac sympathetic innervation
general anesthesia
thoracic epidural
autonomic dysfunction
autonomic neuropathy
Additional relevant MeSH terms:
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Myocardial Ischemia
Ischemia
Pathologic Processes
Heart Diseases
Cardiovascular Diseases
Vascular Diseases
Anesthetics
Central Nervous System Depressants
Physiological Effects of Drugs