Myocardial protection during surgery for infective endocarditis: retrospective, single center, risk-adjusted study.

Commentary: Warm versus cold cardioplegia: The devil is in the details

This study analyzes the efficacy in myocardial protection of two types of cardioplegia solutions, namely, blood and crystalloid cardioplegia, both given intermittently in patients undergoing coronary artery bypass grafting (CABG). Adult patients undergoing primary isolated coronary artery bypass grafting between January 1998 and January 2011 with cardiopulmonary bypass, using either blood or crystalloid cardioplegia, were identified in our database. Propensity score matching was performed to create comparable patient groups. Multivariate logistic regression analysis was performed to identify independent risk factors for perioperative myocardial damage. The primary endpoint of the study was the maximum creatine kinase-MB (CK-MB) value within 5 days postoperatively with a cut-off point of 100 U/L. Early mortality and perioperative low cardiac output syndrome in both groups were compared. The study included 7138 CABG patients: 3369 patients using crystalloid cardioplegia and 3769 using blood cardioplegia. After propensity score matching, 2585 patients per study group remained for the analysis. Wilcoxon signed-rank test revealed significantly higher CK-MB levels in patients operated with the use of blood cardioplegia. Multivariate regression analysis identified blood cardioplegia as an independent risk factor for elevated CK-MB levels. However, it was associated with lower aspartate aminotransferase (AST) levels. The type of cardioplegia had no influence on early mortality, postoperative low cardiac output syndrome or intensive care unit stay. Blood cardioplegia was identified as an independent risk factor for elevated levels of CK-MB after CABG, but was associated with lower AST levels. The authors conclude that the type of cardioplegia had no significant influence on clinical outcome.

Objective. To analyze and compare the results of various types of cardioplegia in aortic valve replacement. Material and methods. PubMed, Embase, Cohrane CENTRAL, E-library and Medline databases were reviewed. We used the following keywords: «aortic valve replacement», «cardioplegia», «cold blood cardioplegia», «warm blood cardioplegia», «crystalloid cardioplegia», «blood cardioplegia». Finally, we found 53 articles published between 1998 and 2021. Results. When comparing cold blood cardioplegia and crystalloid cardioplegia in patients with reduced left ventricular ejection fraction <30%, we found higher survival and lower serum markers of myocardial damage after cold blood cardioplegia. Compared to warm blood cardioplegia, crystalloid cardioplegia reduced the incidence of inotropic support (p<0.05) within 24 hours after surgery. Spontaneous rhythm recovery was more common in the same group (p<0.05). When comparing warm and cold blood cardioplegia, we found shorter postoperative ICU-stay after warm cardioplegia. Spontaneous rhythm recovery was more common after warm blood cardioplegia (p<0.05), and lower incidence of postoperative atrial fibrillation was observed (p<0.05). We found higher left ventricular ejection fraction after warm blood cardioplegia (p<0.05). When comparing cold blood cardioplegia and Del Nido cardioplegia, we found higher incidence of inotropic support after blood cardioplegia (p<0.05). Incidence of kidney damage was higher after blood cardioplegia (p<0.05). Conclusion. Warm blood may be preferable in aortic valve replacement if it is applied in accordance with recommendations and characteristics of each patient.

Purpose: The purpose of this study was to evaluate the effect of different cardioplegic solutions on endothelial integrity and oxidative stress in cardiovascular surgery.Methods: In this randomized prospective study, after ethics approval and informed consent, 60 surgical patients were included. Patients undergoing coronary bypass surgery were randomized into two groups as warm blood cardioplegia (n = 30) and cold crystalloid cardioplegia (n = 30) following the cross-clamping. Measurements were performed at three time points: before induction of anesthesia (T1), at admission to intensive care unit (ICU) (T2) and at the 24th postoperative hour (T3). Besides biochemical routine hemodynamic monitoring, patients were assessed for the sialic acid (SA), ischemic-modified albumin (IMA), advanced oxide protein products (AOPPs), total thiol (SH), and free hemoglobin (fHb) level.Results: Neither crystalloid nor blood cardioplegia led to significant changes in the AOPPs, T-SH, and SA level (p >0.05). Crystalloid cardioplegia, however, increased IMA level compared to both baseline (p <0.01) and blood cardioplegia group (p <0.05). fHb levels were transiently increased in both groups at the second-time point (p <0.001). fHb level was lower in the crystalloid group compared to that in the other group (p <0.05) at T2.Conclusion: Cardioplegia type creates similar effects on glycocalyx integrity. However, myocardial protection could be provided with warm blood cardioplegia.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether blood cardioplegia is clinically superior to crystalloid cardioplegia for myocardial protection. Altogether 501 papers were identified. We selected 22 papers that represented the best evidence to answer the question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. This is a difficult topic to review, as the techniques studied in the many trials performed vary widely. Factors which may vary include warm or cold blood cardioplegia, antegrade and retrograde administration, systemic hypothermia or normothermia, topical heart cooling, high and low potassium solutions, 'hot shots', warm induction, volume of cardioplegia, patient factors and bypass times. However, three papers stand out. The meta-analysis of 34 randomised trials by Prof Fremes (2006) found a significantly lower incidence of low output syndrome (LOS) and CK-MB release with blood cardioplegia. He found no differences in myocardial infarction or mortality. This meta-analysis was confounded, however, by the fact that he was unable to extract data on LOS and CK-MB from the two largest trials which contributed over half the patients in his paper and are significantly larger than all other studies. The first paper by Ovrum (2006) randomised 1440 patients to antegrade cold blood or crystalloid and found no clinical differences, and the second paper by Martin (1994) of 1001 patients compared warm blood to cold crystalloid but the study had to be stopped due to a high incidence of neurological events in the warm blood group. We reviewed a further 18 randomised trials reporting over 50 patients. Of these, 10 reported some statistically significant clinical outcomes in favour of blood cardioplegia and five reported statistically significant differences in enzyme release in favour of blood cardioplegia. A recent survey of UK practice found that 56% of surgeons use cold blood cardioplegia, 14% use warm blood cardioplegia, 14% use crystalloid cardioplegia, 21% use retrograde infusion and 16% do not use any cardioplegia. The papers presented in our review support most of these practices!

Purpose: Prevention of myocardial injury is essential during cardiac surgery. Both crystalloid and blood cardioplegia are popular methods for myocardial protection. Most experimental studies have been in favor of blood cardioplegia. The objective of this study is to determine whether the use of warm blood cardioplegia (BCP) is superior to crystalloid cardioplegia (CCP) by means of myocardial injury markers and clinical outcome parameters. Materials and Methods: In a consecutive series of 293 patients, the first 150 received crystalloid cardioplegia, whereas the next 143 patients received blood cardioplegia. Postoperative myocardial injury was assessed by CTnI and CK-MB. Perioperative morbidity and mortality and clinical outcome parameters (need for inotropic support, ICU and hospital stay) were recorded. An unpaired student t-test was performed to analyse continuous postoperative variables relating to myocardial damage. The presence of possible confounders influencing the CTnI or CK-MB concentrations was tested using a student t-test for continuous variables, for categorical variables ANOVA was used. A final longitudinal model was created for CTnI and CK-MB. CTnI was analyzed by a mixed model with random intercept and slope. For all tests performed, statistical significance was 5%. Results: Both groups were well matched with respect to preoperative variables. No significant difference could be found in maximum postoperative levels of CTnI (8.8 ± 18.4 μg/l in BCP vs 9.6 ± 16.5 μg/l in CCP, p = 0.6455) or CK-MB (19.2 ± 31.0 μg/l in BCP vs 26.4 ± 41.5 μg/l in CCP, p = 0.1209). Nor was there any significant difference in other postoperative variables. Testing treatment effect over time proved only significant influence of the surgical intervention type on CTnI levels in time (p

Controversy exists as to whether warm or cold Calafiore blood cardioplegia (BCP) is better for cardiac preservation. Therefore, we compared hemodynamic performance, myocardial metabolism, and ultrastructural preservation in rat hearts after application of cold or warm BCP. The hearts of 24 male Wistar rats were excised and inserted into a blood perfused isolated heart apparatus, and after a stabilization period of 30 minutes, either cold (4°C) or warm (36°C) Calafiore BCP was administered during an aortic clamping time of 90 minutes (12 rats each). Hearts clamped without BCP and hearts immediately excised in anesthesia served as worst case and no damage controls, respectively (n=3 each). During reperfusion, functional hemodynamic parameters were recorded in BCP groups, and myocardial oxygen consumption and lactate production were calculated. After perfusion fixation, the hearts of three rats in each group were investigated for cellular edema and mitochondrial damage by morphometry using transmission electron microscopy. Cardiac function after BCP application during aortic clamping showed a slightly better recovery with warm than with cold Calafiore BCP as indicated by higher left ventricular developed pressure (warm 97% of baseline, cold 68% of baseline) after warm BCP. Other hemodynamic parameters and coronary flow were not different between warm and cold BCP. Myocardial oxygen consumption and lactate production were similar under warm and cold conditions. Electron microscopy showed typical signs of ischemia in the ischemia group without BCP. Mitochondrial ultrastructure was well preserved in both BCP groups, but cellular edema was more pronounced with cold than with warm BCP. The qualitative analysis was confirmed by the morphometric cellular edema index and the volume-to-surface ratio of the mitochondria. Only mild differences were observed between warm and cold BCP in rats with respect to cardiac function, metabolism, and tissue preservation after aortic clamping. However, a small tendency toward better postischemic recovery was observed with warm BCP.

Direct effects of oxygenated crystalloid or blood cardioplegia on isolated myocyte contractile function

Postoperative conduction disturbances: A comparison of blood and crystalloid cardioplegia

We retrospectively analyzed early results of coronary artery bypass grafting (CABG) surgery using two different types of cardioplegia for myocardial protection: antegrade intermittent warm blood or cold crystalloid cardioplegia. From January 2015 to October 2016, 330 consecutive patients underwent isolated on-pump CABG. Cardiac arrest was obtained with use of warm blood cardioplegia (WBC group, n = 297) or cold crystalloid cardioplegia (CCC group, n = 33), according to the choice of the surgeon. Euroscore II and preoperative characteristics were similar in both groups, except for the creatinine clearance, slightly lower in WBC group (77.33 ± 27.86 mL/min versus 88.77 ± 51.02 mL/min) (P < 0.05). Complete revascularization was achieved in both groups. In-hospital mortality was 2.0% (n = 6) in WBC group, absent in CCC group. The required mean number of cardioplegia’s doses per patient was higher in WBC group (2.3 ± 0.8) versus CCC group (2.0 ± 0.7) (P = 0.045), despite a lower number of distal coronary artery anastomoses (2.7 ± 0.8 versus 3.2 ± 0.9) (P = 0.0001). Cardiopulmonary and aortic cross-clamp times were similar in both groups. The incidence of perioperative myocardial infarction (WBC group 3.4% versus CCC group 3.0%) and low cardiac output syndrome (4.4% versus 3.0%) were similar in both groups. As compared with WBC group, in CCC group CK-MB/CK ratio >10% was lower during each time points of evaluation, with a statistical significant difference at time 0 (4% ± 1.6% versus 5% ± 2.5%) (P = 0.021). In presence of complete revascularization, despite the value of CK-MB/CK ratio >10% was less in the CCC group, clinical results were not affected by both types of cardioplegia adopted to myocardial protection. As compared with cold crystalloid, warm blood cardioplegia requires a shorter interval of administration to achieve better myocardial protection.

Background: Blood cardioplegia attenuates cardiopulmonary bypass (CPB)-induced systemic inflammatory response in patients undergoing cardiac surgery, which may favorably influence the microvascular system in this cohort. The aim of this study was to investigate whether blood cardioplegia would offer advantages over crystalloid cardioplegia in the preservation of microcirculation in patients undergoing coronary artery bypass grafting (CABG) with CPB.Methods: In this prospective observational cohort study, 20 patients who received crystalloid (n = 10) or blood cardioplegia (n = 10) were analyzed. The microcirculatory measurements were obtained sublingually using incident dark-field imaging at five time points ranging from the induction of anesthesia (T0) to discontinuation of CPB (T5).Results: In the both crystalloid [crystalloid cardioplegia group (CCG)] and blood cardioplegia [blood cardioplegia group (BCG)] groups, perfused vessel density (PVD), total vessel density (TVD), and proportion of perfused vessels (PPV) were reduced after the beginning of CPB. The observed reduction in microcirculatory parameters during CPB was only restored in patients who received blood cardioplegia and increased to baseline levels as demonstrated by the percentage changes from T0 to T5 (%Δ)T0−T5 in all the functional microcirculatory parameters [%ΔTVDT0−T5(CCG): −10.86 ± 2.323 vs. %ΔTVDT0−T5(BCG): 0.0804 ± 1.107, p < 0.001; %ΔPVDT0−T5(CCG): −12.91 ± 2.884 vs. %ΔPVDT0−T5(BCG): 1.528 ± 1.144, p < 0.001; %ΔPPVT0−T5(CCG): −2.345 ± 1.049 vs. %ΔPPVT0−T5(BCG): 1.482 ± 0.576, p < 0.01].Conclusion: Blood cardioplegia ameliorates CPB-induced microcirculatory alterations better than crystalloid cardioplegia in patients undergoing CABG, which may reflect attenuation of the systemic inflammatory response. Future investigations are needed to identify the underlying mechanisms of the beneficial effects of blood cardioplegia on microcirculation.

A clinical trial of blood and crystalloid cardioplegia

Myocardial Protection With Different Cardioplegia in Adult Cardiac Surgery: A Network Meta-Analysis

Surgical Revascularization of Acute (1 Hour) Coronary Occlusion: Blood versus Crystalloid Cardioplegia

This study investigates the effects of high glucose content on patients undergoing cold crystalloid versus cold blood cardioplegia in terms of early clinical results, functional myocardial recovery and ischaemia-reperfusion injury in patients undergoing repair of acyanotic cardiac lesions. Patients were randomly assigned to receive either crystalloid (n = 31) or blood cardioplegia (n = 31). Early clinical results were assessed. Changes in left ventricular fractional shortening, arterial blood lactate levels, central venous saturation, cardiac Troponin I release and blood glucose concentration were measured during the first 24 h after ischaemia. There was no significant difference in clinical outcomes and postoperative complication rates between groups. The postoperative changes in left ventricular function, lactate levels, central venous saturation and Troponin I were not significantly different between groups. The use of crystalloid cardioplegia was associated with significant increases in serum glucose compared with blood cardioplegia. A high glucose content blood cardioplegia does not show any advantage compared with crystalloid cardioplegia in terms of clinical outcomes, functional recovery and the degree of ischaemic injury in infants and children undergoing repair of acyanotic heart lesions. High glucose concentration of the cardioplegic solution might potentiate ischaemia-reperfusion injury and diminish the beneficial effects of blood cardioplegia.