Cerebral microemboli during coronary artery bypass using different cardioplegia techniques

Area of Science:

• Cardiovascular Surgery
• Neurology
• Medical Engineering

Background:

• Transcranial Doppler echocardiography detects microemboli linked to adverse neuropsychological outcomes post-coronary artery bypass grafting (CABG).
• Neurologic outcome disparities after CABG are often attributed to variations in cardioplegia techniques.

Purpose of the Study:

• To investigate and compare the rate and number of microembolic events during CABG using three distinct cardioplegia techniques: cold antegrade, warm antegrade, and warm retrograde.
• To identify specific stages of the CABG procedure where microembolic event rates differ based on cardioplegia strategy.

Main Methods:

• Continuous monitoring for transcranial Doppler-detected microembolic events during CABG in patients receiving cold antegrade (n=20), warm antegrade (n=17), or warm retrograde (n=20) cardioplegia.
• Monitoring encompassed stages from aortic cannulation to chest closure, including bypass initiation, aortic clamping, and declamping.

Main Results:

• Total microembolic events per patient (22-2,072) were comparable across all cardioplegia groups.
• Microembolic event rates and totals at each procedural stage were generally similar between groups.
• Total embolic events peaked during aortic clamping, with the highest rate occurring at bypass initiation.
• Immediate embolic events were significantly higher in the warm retrograde group compared to both antegrade groups during aortic declamping.

Conclusions:

• While overall microembolic event burdens were similar, the warm retrograde cardioplegia technique demonstrated a higher incidence of immediate embolic events during aortic declamping.
• The findings suggest potential differences in embolic event profiles among cardioplegia techniques, warranting further investigation into their impact on neurologic outcomes.