Related Experiment Videos
A controlled trial of substrate-enhanced, warm reperfusion ("hot shot") versus simple reperfusion
R Edwards1, T Treasure, M Hossein-Nia
1Department of Cardiological Sciences, St. George's Hospital Medical School, London, England.
Insights
Modified reperfusion using glutamate and aspartate did not reduce myocardial injury in patients undergoing valve replacement. Biomarker levels and clinical outcomes were similar between groups, indicating no benefit from this modified reperfusion strategy.
Area of Science:
- Cardiology
- Cardiac Surgery
- Cardioprotection
Background:
- Modified reperfusion strategies are investigated to mitigate myocardial injury during cardiac surgery.
- Aortic cross-clamping can lead to myocardial ischemia, necessitating protective measures.
Purpose of the Study:
- To evaluate the efficacy of a modified reperfusate (normothermic, enhanced with glutamate and aspartate) in reducing myocardial injury.
- To compare perioperative cardiac enzyme release and clinical outcomes between modified and standard reperfusion.
Main Methods:
- A randomized controlled trial involving 40 patients undergoing valve replacement surgery.
- Patients received either standard reperfusion or a modified reperfusate for 5 minutes before aortic cross-clamp removal.
- Cardiac biomarkers (creatine kinase-MB, troponin-T) and clinical outcomes (myocardial infarction, inotropic support) were monitored postoperatively.
Main Results:
- No significant differences were observed in creatine kinase-MB activity, isoforms, or troponin-T levels between the modified and control groups.
- The incidence of postoperative myocardial infarction and the requirement for inotropic support were comparable in both groups.
- The modified reperfusion strategy did not demonstrate a protective effect on myocardial tissue.
Conclusions:
- The study failed to show any advantage of using the modified reperfusion strategy in patients undergoing valve replacement.
- This specific modified reperfusion protocol did not provide cardioprotection in the studied patient cohort.
Background:
Modified reperfusion after aortic cross-clamping is claimed to reduce myocardial injury, thus improving postoperative myocardial performance.
Methods:
We measured perioperative release of creatine kinase-MB and troponin-T in 40 patients undergoing valve replacement (combined with coronary grafts in 12 cases) to determine whether infusion of a modified reperfusate before cross-clamp removal reduced myocardial injury. Patients were randomly allocated to one of two groups with minimization for age, surgeon, operation, and ventricular function. The control group received unmodified reperfusion, while the study group received a normothermic reperfusate, enhanced with glutamate and aspartate, for 5 minutes before removal of the cross-clamp. Serial determinations of troponin-T, creatine kinase-MB isoforms, and total creatine kinase-MB activity were made up to 5 days postoperatively. Requirements for inotropic support and evidence of myocardial infarction were documented.
Results:
Creatine kinase-MB activity, creatine kinase-MB isoforms, and troponin-T were not significantly different between the two groups. There were no differences in the incidence of postoperative myocardial infarction or in inotrope requirement.
Conclusions:
Our study did not demonstrate any advantage in using modified reperfusion in this group of patients.