Release of cardiac troponin I in antegrade crystalloid versus cold blood cardioplegia

Objective: The purpose of this study was to assess the efficacy of myocardi al protection, comparing antegrade crystalloid cardioplegia with cold blood cardioplegia, in patients with preserved left ventricular function who wer e undergoing elective first coronary artery bypass grafting, Release of car diac troponin I was used as a marker for the effectiveness of myocardial pr otection, Methods: A consecutive series of 62 patients were randomly assign ed to receive crystalloid or blood cardioplegia, Cardiac troponin I concent rations were determined in venous blood samples before the operation, immed iately after unclamping, at 6, 9, 12, and 24 hours, and daily thereafter fo r 5 days, Results: Rising levels of troponin I were found in all patients. The time course and peak release were similar in the crystalloid cardiopleg ia and the blood cardioplegia groups. No patients in either group had elect rocardiographic evidence of perioperative myocardial infarction, Cardiac tr oponin I was able to detect small areas of myocardial damage, not revealed by electrocardiography or creatine kinase MB release, Aprotinin administrat ion was associated with lower cardiac troponin I release in both groups, Ca rdiac troponin I was lower in patients whose conditions did not require ele ctrical defibrillation after aortic unclanlping, irrespective of cardiopleg ia type. The presence of a main stem lesion was associated with higher card iac troponin I release only in the crystalloid cardioplegia group. Conclusi ons: Antegrade cold blood cardioplegia is equally effective as antegrade cr ystalloid cardioplegia in a randomized group of patients with preserved lef t ventricular function who were undergoing elective first coronary artery b ypass grafting, Aprotinin administration resulted in lower cardiac troponin I release, whereas electrical defibrillation was related to a higher relea se irrespective of cardioplegia type, The presence of a main stem lesion re sulted in higher cardiac troponin I release in the crystalloid cardioplegia group.