Intermittent Antegrade Cold Blood Cardioplegia Research Articles

WARM VERSUS COLD INTERMITTENT BLOOD CARDIOPLEGIA FOR MYOCARDIAL PROTECTION DURING ON-PUMP CORONARY ARTERY BYPASS GRAFTING

Background: Obtaining an optimal surgical result depends on performing a technically proficient operation while protecting the heart from potential damage. Cardioplegia is an essential component in myocardial protection during aortic cross-clamping and cardiopulmonary bypass. The development of cardioplegia solutions is one of the major advances in cardiac surgery that allowed surgeons to extend the period of ischemic arrest to well over 3 hours to perform complex surgical procedures without adversely affecting myocardial functio).Aim of the work: We sought to compare between two specific modalities of myocardial protection using either intermittent ante-grade cold blood cardioplegia or warm blood cardioplegia.Patients and Methods: This prospective study included 200 successive adult patients who have undergone elective on-pump coronary artery bypass grafting (CABG) operations. Randomization was done immediately before the beginning of the operation so that group allocation was blinded to the patient. Participants were recruited between 14 January 2017 and 10 July 2019 at Mahalla Cardiac Center. All patients were thoroughly evaluated preoperatively, intraoperatively, and postoperatively.Results: There was no statistically significant difference between the two groups as regards bypass and cross clamp times. However, there was a statistically significant difference between the two groups as regards spontaneous defibrillation. There were no significant differences in both groups regarding the needed either inotropic support, or an IABP to achieve weaning. The total period of mechanical ventilation was statistically shorter in the warm group compared to the cold group.Conclusion: We found that there was no difference in the clinical effect of warm or cold blood cardioplegia despite the relative increase in postoperative serum cTnI in the warm cardioplegia group. Both strategies appear to allow a comparable and satisfactory method for myocardial protection during the period of cardiac arrest.

Neonatal quadricuspid truncal valve repair with left coronary artery unroofing

Neonatal quadricuspid truncal valve repair with left coronary artery unroofing

Abstract 19149: Pulmonary Oxidative Stress, Reperfusion Injury and Lung Tissue Damage During Cardiac Surgery: The Outcome of an Experimental Trial in a Porcine Model

Background and Objective: The incidence of pulmonary complications following cardiac surgery remains high and is associated with increased in-hospital mortality and costs. Established surgical practice predominantly regards diverting the pulmonary circulation and deflating the lungs from mechanical ventilator (to facilitate surgical exposure) as a safe approach during the period of cardiopulmonary bypass (CPB) and cardioplegic arrest (CA). In this experimental trial we investigate for the first time the incidence of pulmonary dysfunction, ischemia, oxidative stress, and lung tissue damage associated with cardiac surgery in a porcine experimental model and CPB and CA. Methods: Landrace white female pigs (~60kg) were randomised to either median sternotomy alone (Control; n=6) or with CPB (80 minutes) and CA with intermittent antegrade cold blood cardioplegia delivered at 20 minutes intervals (CPB+CA; n=7). Standardised anaesthetic, surgical and perfusion protocols were used in accordance with Home Office Guidance. During CPB the lungs were left deflated as per routine surgical practice. Serial blood samples and lung biopsies were collected at baseline, prior weaning CPB (ischemia), and 1 hour following CPB weaning (recovery). Functional, inflammatory, oxidative, histo-pathological, micro-vascular permeability and apoptosis variables were compared. Results: In the CPB+CA group there was marked functional deterioration (respiratory index and alveolar-arterial oxygenation gradients; both p<0.05), significant pulmonary ischemia (reduced ATP/ADP and ATP/AMP ratios; both p<0.05), evidence of lung apoptosis (caspase-3 activity), increased pulmonary micro-vascular leakage (p<0.05) and pulmonary tight junctions fragmentation (immunohistochemistry). None of these findings was observed in the Control group. Conclusions: The established practice of cardiac surgery does not protect the lungs during CPB and CA and it is associated with pulmonary dysfunction, ischaemia, apoptosis, and marked lung tissue damage. Novel interventions of lung protection during cardiac surgery are required to minimise these detrimental effects.

Aortic Valve Replacement for Aortic Stenosis During Orthotopic Cardiac Transplant

Although concomitant coronary bypass, and mitral and tricuspid valve surgery have been used to expand the donor pool for cardiac transplantation, aortic valve disease is considered an absolute contraindication for use of an offered organ. A case is presented with the successful use of an organ requiring concomitant aortic valve replacement for calcific aortic stenosis on a congenitally bicuspid valve. Eighteen-month follow-up documented excellent allograft function with a normally functioning mechanical aortic prosthesis. Aortic valve disease in offered organs can be successfully treated with aortic valve replacement at the time of transplantation and should not preclude the use of the organ in the setting of a recipient who is a candidate for a marginal allograft.

Penetrating ulcer of the aortic arch presenting with hemoptysis

CLINICAL SUMMARY A 58-year-old nonsmoker presented with a 6-month history of hemoptysis and a 1-month history of left-sided chest pain. He was known to have poorly controlled hypertension. Physical examination was unremarkable. Chest radiographic analysis showed a lesion in the left lung apex lying against the aortic arch. Contrast computed tomographic (CT) scanning demonstrated continuity between the lesion and the aortic lumen. Positron emission tomographic analysis confirmed high uptake in the lesion, and the patient was referred to us as having a case of lung cancer with extension into the aorta (Figure 1). However, multislice CT analysis with 3-dimensional reconstruction clarified the presence of a PAU in the arch leaking into the lung, with surrounding hematoma (Figure 2). The patient continued to experience pain, and we proceeded to surgical intervention. Hypothermic (24 C) cardiopulmonary bypass was established between the right atrium and the right subclavian artery. Myocardial protection was with intermittent antegrade cold blood cardioplegia. The ulcer was full of clot and penetrating into the lung. The clot was sent for culture. The base of the ulcer extended to the descending aorta, adhering to the left lung and the phrenic nerve. Dissection to free the descending aorta was impossible. The aortic wall was thickened, inflamed, and friable. The ulcer was excised, and the aortic defect was patched with Dacron. Because of the poor quality of aortic tissue, the bleeding from the suture line could not be controlled, and therefore the arch was replaced with a Dacron (Golscal, Sulzer Vascutek, UK) graft, leaving an elephant trunk in the descending aorta. An island of aorta containing the innominate and left common carotid arteries was reimplanted onto the arch. The patient was weaned off cardio-

Retrograde Hot-Shot Cardioplegia in Patients With Left Ventricular Hypertrophy Undergoing Aortic Valve Replacement

Intermittent antegrade cold-blood cardioplegia followed by terminal warm-blood cardioplegic reperfusion or hot-shot is reported to reduce myocardial injury in the setting of coronary surgery. The efficacy of this cardioplegic technique in patients with left ventricular hypertrophy secondary to aortic stenosis remains uncertain. Thirty-six patients with left ventricular hypertrophy undergoing aortic valve replacement were prospectively randomized to cold-blood cardioplegia either alone (cold-blood cardioplegia group) or with retrograde hot-shot (hot-shot group). Reperfusion injury was assessed by measuring myocardial levels of adenosine triphosphate and lactate in left and right ventricular biopsies taken 5 minutes after institution of cardiopulmonary bypass and 20 minutes after removal of cross-clamp using high-performance liquid chromatography and enzymatic techniques. Myocardial injury was assessed by serial release of troponin I up to 48 hours postoperatively. Overall clinical outcome was prospectively collected. Baseline and intraoperative characteristics were similar between groups. In the hot-shot group, there were no significant changes in the myocardial concentration of adenosine triphosphate and lactate in both left and right ventricular biopsies after reperfusion. In the cold-blood cardioplegia group, there was a trend to a fall in adenosine triphosphate levels in the left and right ventricular biopsies after reperfusion, but this reached statistical significance only in the right ventricle. Troponin I release was raised in both groups at 4 and 12 hours after surgery (p < 0.05), but did not reach levels of myocardial infarction. The terminal retrograde hot-shot reperfusion does not add any extra benefit to antegrade cold-blood cardioplegia in preventing myocardial injury in patients with left ventricular hypertrophy undergoing aortic valve replacement. Nevertheless, it appears to reduce ischemic stress in the right ventricle. There was no difference in clinical outcome between groups.

Myocardial protection with intermittent cold blood during aortic valve operation: antegrade versus retrograde delivery

Background Intermittent antegrade cold blood cardioplegia is superior to warm blood cardioplegia in patients who have aortic valve operation. This study compared the cardioprotective efficacy of intermittent antegrade and retrograde cold blood cardioplegia with emphasis on metabolic stress in the left and right ventricles. Methods Thirty-nine patients who had elective aortic valve replacement were prospectively randomly selected to receive intermittent antegrade or retrograde cold blood cardioplegia. Left and right ventricular biopsies were collected 5 minutes after institution of cardiopulmonary bypass and 20 minutes after cross-clamp removal and were used to determine metabolic changes. Metabolites (adenine nucleotides, amino acids, and lactate) were measured using high-powered liquid chromatography and enzymatic techniques. Serial measurement of troponin I release was also used as a marker of myocardial injury. Results Preoperative characteristics were similar between groups. There was no in-hospital mortality, and no differences were observed in postoperative complications. Preischemic concentration of taurine was significantly higher in left ventricular biopsies, whereas adenosine triphosphate tended to be lower in the left ventricle. At reperfusion adenosine triphosphate levels were significantly lower than preischemic levels in right but not left ventricles irrespective of the route of delivery. The alanine-glutamate ratio was significantly elevated in both ventricles. Myocardial injury as assessed by troponin I release was also significantly increased in both groups. Conclusions Retrograde and antegrade intermittent cold blood cardioplegic techniques are associated with suboptimal myocardial protection. Metabolic stress was more pronounced in the right than the left ventricle irrespective of the cardioplegic route of delivery used.

Intermittent antegrade warm blood cardioplegia for CABG: extended interval of cardioplegia

Background. Intermittent delivery of warm cardioplegia provides a bloodless surgical field, but it is clinically important to evaluate the periods of normothermic ischemia. The aims of this study are to compare intermittent antegrade warm blood cardioplegia (IAWBC) with intermittent antegrade cold blood cardioplegia (IACBC) groups in terms of myocardial protection, and also to evaluate whether the length of ischemic time in the IAWBC group has an effect on myocardial dysfunction.Methods. This study is based on a retrospective review of patients who underwent elective coronary artery bypass surgery: 162 consecutive patients with IAWBC and 107 consecutive patients with IACBC.Results. The creatinine kinase peak was smaller in the IAWBC group compared with the IACBC group (p < 0.0001). The cardiac index after cardiopulmonary bypass was higher in the IAWBC group (p < 0.02), and the amount of inotropic support required to wean from cardiopulmonary bypass was less in the IAWBC group compared with the IACBC group (p < 0.0001).Conclusions. IAWBC with 30 minutes of ischemia provides to be clinically acceptable myocardial protection for coronary bypass surgery.

Intermittent antegrade warm blood cardioplegia in aortic valve replacement.

Intermittent antegrade warm blood cardioplegia (IAWBC) is a well established technique of myocardial protection for coronary artery surgery, with metabolic and experimental basis. To evaluate its effectiveness in aortic valve replacement (AVR), we compared 171 consecutive patients who underwent first AVR using IAWBC (group A) with the last 100 consecutive patients who underwent first AVR using intermittent antegrade cold blood cardioplegia (IACBC) (group B). The endpoints considered were myocardial protection related (recovery of spontaneous rhythm, need for mechanical support, incidence of low-output syndrome, perioperative Q wave myocardial infarct, CK-MB levels, ventricular arryhthmias and lidocaine infusion requirement, cardiac-related deaths, and deaths any cause) and temperature perfusion related (bleeding, awaking time, time to extubation, and cerebrovascular accidents). Mortality was similar in both groups, but no patient in group A died for cardiac-related cause (0 vs 4, p < 0.01). More patients in group A recovered a spontaneous rhythm (144 vs 47, p < 0.0001). Incidence of low-output syndrome was higher in group B (16 vs 3, p < 0.0005), as well as ventricular arryhthmias incidence and need for lidocaine infusion (respectively 15 vs 2, p < 0.0001, and 10 vs 1, p < 0.0005). Awaking time was shorter in warm patients (2.5 +/- 2.5 hours vs 4.4 +/- 3.7 hours, p < 0.0005), as the extubation time (9.4 +/- 7.7 hours vs 13.5 +/- 11.7 hours, p < 0.0005) and bleeding (803 +/- 714 mL/24 hours vs 1051 +/- 1375 mL/24 hours, p < 0.05). As a consequence, the intensive care unit and the postoperative hospital stays were shorter in group A (32 +/- 27 hours vs 48 +/- 20 hours, p < 0.0005, and 7.2 +/- 3.1 days vs 11.3 +/- 5.4 days, p < 0.0001, respectively). IAWBC provides lower cardiac-related mortality and morbidity in patients who undergo AVR in comparison with IACBC.

Randomized study of right ventricular function with intermittent warm or cold cardioplegia

Transient right ventricular dysfunction has been previously documented after bypass operations despite adequate myocardial protection with intermittent antegrade cold blood cardioplegia. Recently warm blood cardioplegia has been interrupted during construction of distal anastomoses to improve visualization. The effects of intermittent antegrade warm blood cardioplegia, and the resultant periods of right ventricular normothermic ischemia, on postoperative right ventricular function are unknown. To assess the effects of cardioplegia on right ventricular protection, 52 patients undergoing isolated bypass grafting were randomized to intermittent warm or cold blood cardioplegia. The two groups were similar with respect to age, sex, ventricular function, and right coronary stenoses. Cross-clamp times were similar (warm, 64 +/- 22 minutes; cold, 63 +/- 15 minutes; not significant). The cumulative time of cardioplegia interruption was longer in the cold group (42 +/- 8 minutes) than in the warm group (31 +/- 14 minutes; p < 0.002). A rapid-response thermodilution catheter was employed to assess postoperative right ventricular ejection fraction and end-diastolic and end-systolic volume indices. The right ventricular ejection fraction was greater in the warm group at 6 hours (warm, 0.46 +/- 0.06; cold, 0.37 +/- 0.08; p < 0.05) and 8 hours (warm, 0.43 +/- 0.08; cold, 0.37 +/- 0.08; p < 0.05) postoperatively. The right ventricular end-diastolic volume index was less in the warm group 8 hours postoperatively (warm, 83 +/- 11 mL/m2; cold, 94 +/- 16 mL/m2; p < 0.05). There were no differences in pulmonary arterial pressures or right ventricular stroke work index. Despite intermittent normothermic ischemia of half the cross-clamp time, patients receiving warm cardioplegia maintained right ventricular hemodynamics after bypass grafting.

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. (J T HORAC C ARDIOVASC S URG 1995;109:787-95)

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).