Myocardial injury and CK-MB release during aortic valve surgery with selective coronary perfusion

Area of Science:

• Cardiology
• Cardiac Surgery
• Biochemistry

Background:

• Assessing myocardial injury markers is crucial after cardiac surgery.
• Creatine kinase MB isoenzyme (CK-MB) is a key indicator of myocardial damage.
• Understanding CK-MB kinetics post-aortic valve replacement informs myocardial protection strategies.

Purpose of the Study:

• To investigate the serum activity and kinetics of CK-MB in patients undergoing isolated aortic valve replacement.
• To compare CK-MB levels and kinetics with those observed in acute myocardial infarction (AMI).
• To evaluate the impact of myocardial protection methods, specifically selective coronary perfusion (CP), on CK-MB release.

Main Methods:

• Studied 25 patients undergoing isolated aortic valve replacement (Björk-Shiley prosthesis).
• Utilized hypothermia (30°C) and selective coronary perfusion (CP) for myocardial protection.
• Monitored serum CK-MB and total CK levels postoperatively, alongside electrocardiograms.

Main Results:

• CK-MB was detected in all patients post-surgery, with peak levels comparable to AMI.
• CK-MB kinetics differed from AMI, with peak CK-MB occurring 2 hours post-surgery.
• CK-MB release correlated with aortic cross-clamping (AC) duration, increasing significantly after 90 minutes.
• Longer CP duration was associated with higher postoperative CK-MB activity in subgroups with similar AC times.

Conclusions:

• Serum CK-MB levels post-aortic valve replacement are significant but exhibit distinct kinetics compared to AMI.
• The duration of aortic cross-clamping is a critical factor influencing myocardial enzyme release.
• Selective coronary perfusion appears to be beneficial for myocardial protection during aortic valve replacement.