Insulin cardioplegia for elective coronary bypass surgery.
BACKGROUND
Improved methods of myocardial preservation are required to reduce the morbidity and mortality of coronary bypass surgery for high-risk subgroups. Metabolic stimulation with insulin, glucose solutions, or both has been proposed as a method to preserve the ischemic myocardium. We performed a prospective, double-blind, randomized trial to evaluate the effects of insulin and glucose as cardioplegic additives when used as part of a tepid continuous blood cardioplegic strategy.


METHODS
We randomized 56 male patients undergoing elective isolated coronary bypass surgery to 1 of 4 cardioplegic groups containing either 42 or 84 mmol/L glucose with or without 10 IU/L of insulin. Perioperative assessments of myocardial metabolism and left ventricular function were performed.


RESULTS
Insulin-enhanced cardioplegia was associated with beneficial effects on both myocardial metabolic and functional recovery after cardioplegic arrest. Insulin's effect was independent of the ambient glucose concentration.


CONCLUSIONS
Cardioplegic formulations containing a 42 mmol/L concentration of glucose and a 10 IU/L concentration of insulin provide significant benefit to patients undergoing isolated coronary bypass surgery. The clinical effect of these formulations will need to be assessed in high-risk subgroups of patients, such as those with unstable angina, recent myocardial infarction, or poor left ventricular function.
Rao
V
V
Toronto General Hospital and Sunnybrook Health Science Centre at The University of Toronto, Toronto, Ontario, Canada.
Borger
M A
MA
Weisel
R D
RD
Ivanov
J
J
Christakis
G T
GT
Cohen
G
G
Yau
T M
TM
D001026:Coronary Artery Bypass; D004311:Double-Blind Method; D017558:Elective Surgical Procedures; D005947:Glucose / Q000008:administration & dosage* / Q000378:metabolism; D006324:Heart Arrest, Induced; D006439:Hemodynamics; D006801:Humans; D007328:Insulin / Q000008:administration & dosage* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D011183:Postoperative Complications / Q000517:prevention & control*; D011446:Prospective Studies
D007328:Insulin; D005947:Glucose