Stroke Study: Operative Strategies to Reduce Cerebral Embolic Events During Coronary Artery Bypass Surgery

This study is currently recruiting participants. (see Contacts and Locations)
Verified June 2014 by Emory University
Sponsor:
Collaborator:
Information provided by (Responsible Party):
Michael Halkos, Emory University
ClinicalTrials.gov Identifier:
NCT01502683
First received: December 28, 2011
Last updated: June 23, 2014
Last verified: June 2014
  Purpose

One of the most devastating complications of coronary artery bypass surgery (CABG) is postoperative stroke. While there are multiple causes of stroke after CABG, particles generated during handling of the aorta is believed to account for most neurologic effects. Handling of the aorta during CABG occurs several times during the operation. One strategy to reduce aortic handling is to avoid cardiopulmonary bypass altogether by using off-pump techniques (OPCAB). Another method is to avoid the use of aortic clamps and/or to use devices that do not require aortic clamping. This study will test the hypothesis that an off-pump (OPCAB) approach and devices to perform clampless surgery will result in the least amount of aortic handling and therefore the lowest incidence and frequency of neurologic adverse events.


Condition Intervention
Stroke
Procedure: No aortic clamping
Procedure: partial occluding clamp
Procedure: single cross clamp
Procedure: cross clamp and partial occluding clamp

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
Official Title: Operative Strategies to Reduce Cerebral Embolic Events During Coronary Artery Bypass Surgery

Resource links provided by NLM:


Further study details as provided by Emory University:

Primary Outcome Measures:
  • Cerebral embolic events measured via transcranial doppler ultrasound [ Time Frame: Intraoperative cerebral embolic events ] [ Designated as safety issue: No ]
    Cerebral embolic events measured via transcranial doppler ultrasound


Secondary Outcome Measures:
  • Neurocognitive dysfunction [ Time Frame: 30 days ] [ Designated as safety issue: No ]

Estimated Enrollment: 136
Study Start Date: December 2011
Estimated Study Completion Date: August 2015
Estimated Primary Completion Date: February 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Off-pump No Clamp
Off-pump coronary artery bypass patients randomized to no clamp for proximal anastomoses.
Procedure: No aortic clamping
No aortic clamp used in this group. The aortic clamp is a standard cardiac surgical instrument used during cardiac operations, not a specific device used for this study.
Experimental: Off-pump Partial Occluding Clamp
Off-pump coronary artery bypass patients randomized to partial occluding clamp for proximal anastomoses.
Procedure: partial occluding clamp
The partial-occluding clamp is a standardized instrument used during coronary artery bypass surgery, it is not a specific device for this study.
Experimental: On-pump Single Cross Clamp
On-pump coronary artery bypass patients randomized to single cross clamp for cardioplegic arrest and proximal anastomoses.
Procedure: single cross clamp
The proximal anastomoses performed under single clamp is an alternative method during coronary artery bypass surgery. The single clamp essentially means that whole operation is done using the cross clamp, which is a standard instrument during cardiac operations, not a specific device for this study.
Experimental: On-pump Double Clamp
On-pump coronary artery bypass patients randomized to cross-clamp for cardioplegic arrest and partial-occluding clamp for proximal anastomoses. This strategy involves the application of two clamps.
Procedure: cross clamp and partial occluding clamp
Both an aortic cross clamp and partial occluding clamp are used in this arm. Neither the cross clamp nor the partial clamp are specific devices for this study but are standard cardiac surgical instruments used during coronary artery bypass surgery and cardiac surgery.

Detailed Description:

One of the most devastating complications of coronary artery bypass surgery (CABG) is postoperative stroke. While the etiology of stroke after CABG is multifactorial, atheroemboli generated during aortic manipulation is believed to account for most cerebral embolic events. Manipulation of the aorta during CABG occurs during aortic cannulation, institution and maintenance of cardiopulmonary bypass, and during aortic clamping and unclamping with either a cross-clamp, partial-occluding clamp, or both. One operative strategy to minimize aortic manipulation is to avoid cardiopulmonary bypass altogether by using off-pump techniques (OPCAB). Another method is to avoid the use of aortic clamps and to construct proximal aortocoronary anastomoses with facilitating devices that do not require aortic clamping. The effect of these strategies on reducing cerebral embolic events and the underlying mechanism for this reduction are not well-defined.

This study will test the hypothesis that an off-pump (OPCAB) approach and facilitating devices to perform clampless proximal anastomoses will result in the least amount of aortic manipulation and therefore the lowest incidence and frequency of cerebral embolic events. The approach associated with the lowest incidence of TCD-detected cerebral embolic events will also result in the lowest incidence and severity of postoperative neurocognitive decline. Transcranial Doppler ultrasonography is an established method to detect cerebral embolic signals during cardiac surgery and will be utilized to detect cerebral embolic events during the operation. After an on- or off-pump strategy is selected, patients will be subsequently randomized to one of two clamping strategies. There will be 4 groups of patients: 1) OPCAB patients randomized to no clamping (facilitating device); 2) OPCAB patients randomized to partial clamping; 3) on-pump patients randomized to double clamping; and 4) on-pump patients randomized to a single clamp strategy.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • > 18 years
  • undergoing primary isolated coronary artery bypass surgery
  • ability to sign informed consent

Exclusion Criteria:

  • history of preoperative stroke
  • reoperative cardiac surgery
  • salvage or emergency CABG
  • known left ventricular or left atrial thrombus
  • concomitant valvular or aortic surgery
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01502683

Contacts
Contact: Renee Cook, BSN 404-686-3364 ncook@emory.edu

Locations
United States, Georgia
Emory University Hospital Midtown Recruiting
Atlanta, Georgia, United States, 30308
Contact: Renee Cook, BSN    404-686-3364    ncook@emory.edu   
Contact: Kim T Baio, MSN    404-686-2513 ext 3374    kbaio@emory.edu   
Principal Investigator: Michael E Halkos, MD         
Sponsors and Collaborators
Emory University
Investigators
Principal Investigator: Michael Halkos, MD Emory University
  More Information

No publications provided

Responsible Party: Michael Halkos, Assistant Professor of Surgery, Emory University
ClinicalTrials.gov Identifier: NCT01502683     History of Changes
Other Study ID Numbers: IRB00046608, 1K23HL105892-01A1
Study First Received: December 28, 2011
Last Updated: June 23, 2014
Health Authority: United States: Institutional Review Board
United States: Federal Government

Keywords provided by Emory University:
Stroke
neurocognitive dysfunction
cerebral embolic events

Additional relevant MeSH terms:
Stroke
Cerebral Infarction
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vascular Diseases
Cardiovascular Diseases
Brain Infarction
Brain Ischemia

ClinicalTrials.gov processed this record on July 24, 2014