Intermittent antegrade warm cardioplegia reduces oxidative stress and improves metabolism of the ischemic-reperfused human myocardium.

The aim of this study was to compare the effect of intermittent antegrade warm blood cardioplegia and intermittent antegrade cold blood cardioplegia on myocardial metabolism and free radical generation of the ischemic-reperfused human myocardium. Thirty patients undergoing mitral valve procedures were randomly allocated to two groups: group 1 (15 patients) received warm blood cardioplegia and group 2 (15 patients), cold blood cardioplegia. Myocardial metabolism was assessed before aortic clamping, 1 minute after crossclamp removal, and after 20 minutes of reperfusion, by collecting blood simultaneously from the radial artery and coronary sinus. All samples were analyzed for lactate, creatine kinase, reduced and oxidized glutathione, ascorbic acid, fluorescent products of lipid peroxidation, and leukocyte activation (elastase). In all patients, early reperfusion was associated with significant coronary sinus lactate release. In group 2, but not in group 1, significant coronary sinus release of reduced and oxidized glutathione, fluorescent products of lipid peroxidation, and creatine kinase was also found; moreover, arterial-coronary sinus difference of ascorbic acid content was increased only in group 2, suggesting a transmyocardial consumption of this antioxidant vitamin. After 20 minutes of reperfusion, coronary sinus lactate release was no longer present in group 1, whereas significant production was still evident in group 2. In this group, significant coronary sinus release of fluorescent products of lipoperoxidation and reduced and oxidized glutathione was also observed at this time. No significant release of elastase from the coronary sinus was noted in the two groups throughout the study. The left ventricular stroke work index measured at the end of the study indicated a better functional recovery in group 1 than in group 2. In conclusion, intermittent antegrade warm blood cardioplegia protects the myocardium from ischemia-reperfusion injury better than intermittent antegrade cold blood cardioplegia; this phenomenon may be partly due to the decreased tissue oxidant burden mediated by intermittent warm blood cardioplegia.

Blood cardioplegia reduces oxidant burden in the ischemic and reperfused human myocardium.

In 20 patients receiving cold crystalloid cardioplegia (n = 10) or cold blood cardioplegia (n = 10) during elective coronary artery bypass grafting, the atrial myocardium was tested for glutathione-related antioxidant defenses and lipid peroxidation. In both groups, ischemia and reperfusion induced a significant increase in lipid peroxidation values (p < 0.05) that was associated with a depression of nonprotein thiol compound levels (p < 0.05). Compared with the cold crystalloid cardioplegia-treated patients, the cold blood cardioplegia-treated patients showed a lower lipid peroxidation (p < 0.05) and higher values of nonprotein thiol compounds (p < 0.05). Moreover, a significant ischemia and reperfusion-dependent activation of glutathione transferase was observed only in the cold crystalloid cardioplegia-treated patients. Selenium-dependent glutathione peroxidase and glutathione reductase activities did not change after release of the aortic cross-clamp and did not differ between the two groups. The highest postoperative plasma level of the myocardial-specific isoenzyme of creatine kinase was significantly more elevated in the cold crystalloid cardioplegia patients. Overall, these tissue biochemical features indicate a lower oxidant burden in the myocardium of cold blood cardioplegia-treated patients, a finding suggesting superior protection for the ischemic and reperfused human myocardium also through antioxidant-type mechanisms, apparently medicated by the antioxidant capacity of erythrocytes and specific plasma molecules.

Intermittent antegrade warm blood cardioplegia.

Intermittent antegrade warm blood cardioplegia has been used routinely at our institution over the last 3 years. We report here a comparison between the first 250 consecutive patients undergoing elective coronary artery bypass grafting in which intermittent antegrade warm blood cardioplegia was used (group A) and the last 250 consecutive patients who received intermittent antegrade cold blood cardioplegia, during bypass grafting (group B). There were no differences in sex, age, number of grafts, and functional status between the two groups; left ventricular ejection fraction was lower in group A. The overall mortality rate in group A was 0.8% versus 3.6% in group B (p < 0.05). There was no in-hospital mortality among high-risk patients (ejection fraction < or = 0.35) in group A (0/53) versus two deaths in group B (2/28) (p < 0.05). No patient in group A needed circulatory assistance; 4 patients in group B received intraaortic balloon pumping. Only 1 patient in group A required inotropic support versus 20 patients in group B (p < 0.0005), and 5 patients in group A received lidocaine hydrochloride for ventricular arrhythmias versus 18 in group B (p < 0.01). The rates of myocardial infarction and stroke were not different between the two groups. The peak concentration of the myocardial-specific isoenzyme of creatine kinase were higher in group B in absolute value (51 +/- 30 IU/L) than in Group A (38 +/- 38 IU/L) (p < 0.0005) and in percent of total creatine kinase (8.2% +/- 4.1% versus 6.2% +/- 2.9%, respectively).

Intermittent antegrade cardioplegia: warm blood vs cold crystalloid. A clinical study.

Intermittent antegrade warm blood cardioplegia (IAWBC) is a not usual technique of myocardial protection. We propose a delivery protocol that standardizes the length of ischemic intervals, duration of each cardioplegic dose and K+ amount. Cardioplegia is represented by blood, taken from the oxygenator and injected directly into the aortic root, and K+, added by means of a syringe pump. We reviewed the first 300 patients who underwent elective or urgent coronary artery by-pass procedures (group A) and compared them with the last 300 patients operated on with intermittent antegrade cold crystalloid cardioplegia (group B). The overall mortality in group A was lower than in group B (0.7 vs 3.0, p < 0.05); there was no in-hospital death in patients with poor left ventricle (LVEF < 35%) in group A (0/64 vs 3/39, p < 0.025). Reduction of mortality was due to a drastic fall of morbidity. In group A no patients needed circulatory assistance (13 in group B, p < 0.0005) or intraaortic balloon pumping (9 in group B, p < 0.005) in operating room or in intensive care unit (ICU); only 1 patient had inotropic drug (29 in group B, p < 0.0005) and only 6 needed lignocaine infusion (27 in group B, p < 0.0005). Incidence of postoperative myocardial infarction was lower in group A (4 vs 9 in group B) as well cerebrovascular accidents (4 vs 10 in group B), but difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)