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

Emory University

Status: Completed

Conditions: Stroke

Treatments: Procedure: cross clamp and partial occluding clamp; Procedure: partial occluding clamp; Procedure: No aortic clamping; Procedure: single cross clamp

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT01502683

IRB00046608

1K23HL105892-01A1 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

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.

Full 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.

Enrollment: 193 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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193 participants in 4 patient groups

Off-pump No Clamp

Experimental group

Description:

Off-pump coronary artery bypass patients randomized to no clamp for proximal anastomoses.

Treatment:

Procedure: No aortic clamping

Off-pump Partial Occluding Clamp

Experimental group

Description:

Off-pump coronary artery bypass patients randomized to partial occluding clamp for proximal anastomoses.

Treatment:

Procedure: partial occluding clamp

On-pump Single Cross Clamp

Experimental group

Description:

On-pump coronary artery bypass patients randomized to single cross clamp for cardioplegic arrest and proximal anastomoses.

Treatment:

Procedure: single cross clamp

On-pump Double Clamp

Experimental group

Description:

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.

Treatment:

Procedure: cross clamp and partial occluding clamp