Retrograde versus antegrade crystalloid cardioplegia in coronary surgery: value of troponin-I measurement.
BACKGROUND
The optimal route for delivery of cardioplegia is still in debate in patients with ischemic heart disease. Cardiac troponin-I is a new marker with the potential for detection of minor differences in myocardial ischemia.


METHODS
In a prospective randomized trial 58 patients undergoing elective coronary artery bypass grafting for two- or three-vessel coronary artery disease were divided into groups with antegrade (group A, n = 29) and retrograde (group R, n = 29) application of crystalloid cardioplegia (St. Thomas II). Patients with major risk factors were excluded. In addition to routine electrocardiogram monitoring, cardiac troponin-I and creatine kinase-MB activity were measured in all patients preoperatively at 2, 5, 8, 24, and 48 hours after aortic cross-clamp release, and at hospital discharge.


RESULTS
In both groups, there were no differences regarding operative parameters. A significantly higher cardiac troponin-I concentration was observed in the antegrade group at 24 hours after cross-clamp (8.2 +/- 8.5 microg/L vs 3.2 +/- 3.1 microg/L; p = 0.02). Patients with subtotal stenosis or occlusion of one or more main coronary arteries showed significantly lower cardiac troponin-I levels after retrograde application.


CONCLUSIONS
Lower concentrations of the cardiac troponin-I marker after retrograde application of cardioplegia indicate advantages of myocardial protection in ischemic heart disease.
Franke
U
U
Department of Thoracic and Cardiovascular Surgery, Medical School, Hannover, Germany. ulrich.franke@med.uni-jena.de
Wahlers
T
T
Cohnert
T U
TU
Koenig
J
J
Rath
N F
NF
Wirsing
M
M
Haverich
A
A
D000368:Aged; D001026:Coronary Artery Bypass; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods*; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019210:Troponin I / Q000097:blood*
D007527:Isoenzymes; D019210:Troponin I; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form