Aortic Unclamping Research Articles

Can heartbeat recovery be improved with terminal non-cardioplegic warm blood perfusion prior to aortic unclamping in single-clamp technique coronary artery bypass surgery? A randomized controlled trial

BackgroundThe objective of this study is to investigate whether the use of antegrade perfusion with terminal non-cardioplegic warm blood (TNWB) before aortic unclamping in single-clamp technique coronary artery bypass has a positive impact on intraoperative heartbeat recovery.MethodsBetween December 2022 and May 2023, 40 consecutive patients undergoing coronary artery bypass using single-clamp technique were randomized into one of two groups: the TNWB group received an antegrade perfusion with TNWB before removing the aortic cross-clamp (n = 20), while the control group did not receive (n = 20). The time intervals between coronary perfusion and the onset of the first heartbeats and sinus rhythms, occurrences of spontaneous sinus rhythm, intraoperative defibrillation requirements, as well as postoperative CK-MB and troponin T levels were recorded and subjected to analysis.ResultsIn the TNWB group, the median onset of the first heartbeats after the initiation of coronary perfusion was 34 s (4-100), while in the control group, it was 90 s (15–340) (p < 0.001). The median onset of the sinus rhythms was 100 s (28–290) in the TNWB group and was 132 s (45–350) in the control group (p = 0.023). The occurrence of intraoperative arrhythmias was 15% in the TNWB group compared to 50% in the control group (p = 0.018), and the incidence for internal defibrillation was 5% in the TNWB group and was 30% in the control group (p = 0.037). The TNWB group showed the median CK-MB levels at 6 h postoperative was 14.10 ng/mL (9.78–19.26), compared to 18.31 ng/mL (13.98–23.80) in the control group (p = 0.045).ConclusionsDuring single clamp coronary artery bypass, administration TNWB into the aortic root before aortic unclamping has the potential to enhance heartbeat recovery, as evidenced by the shortened time to the initial heartbeat and the establishment of sinus beats following coronary perfusion.Trial registrationTrial registration number (Study ID): TCTR20231002003.

Cardioprotective Efficacy of Sevoflurane in Patients With Rheumatic Heart Disease Undergoing Heart Valve Surgery Under Cardiopulmonary Bypass.

In this study, we investigated whether cardioprotective properties of sevoflurane were expressed in patients with rheumatic heart disease undergoing heart valve surgery under cardiopulmonary bypass (CPB). Fifty patients with rheumatic heart disease undergoing heart valve surgery under CPB were randomly assigned to receive total anesthesia with sevoflurane or propofol during surgery. Except for this, anesthetic and surgical management was the same in all patients. The primary outcomes were postoperative high-sensitive cardiac troponin T (hs-cTnT) and creatine kinase-myocardial band (CK-MB) release. The secondary outcomes were hemodynamic events and short-term clinical outcomes (within 30 days after surgery). The plasma concentrations of hs-cTnT at 24-hour and CK-MB from 6-hour to 48-hour in the sevoflurane group were lower than those in the control group (the propofol group). After aortic unclamping, heartbeat recovery was faster and the rate of sinus rhythm was higher in the sevoflurane group than in the control group. Moreover, a lower proportion of pacemaker use and the need for intraoperative and postoperative inotropes were also found in the sevoflurane group. Nevertheless, there were no differences between the two groups regarding short-term clinical outcomes (durations of mechanical ventilation, intensive care unit stay, hospital stay, morbidity, and mortality rates). Sevoflurane administered during the entire anesthetic procedure had a myocardial protective effect with less evidence of myocardial damage in the first 48-hour postoperatively but short-term clinical outcomes were not significantly different when compared with the control group in patients with rheumatic heart disease undergoing heart valve surgery under CPB.

Myocardial protection in cardiac surgery: a comprehensive review of current therapies and future cardioprotective strategies.

Cardiac surgery with cardiopulmonary bypass results in global myocardial ischemia-reperfusion injury, leading to significant postoperative morbidity and mortality. Although cardioplegia is the cornerstone of intraoperative cardioprotection, a number of additional strategies have been identified. The concept of preconditioning and postconditioning, despite its limited direct clinical application, provided an essential contribution to the understanding of myocardial injury and organ protection. Therefore, physicians can use different tools to limit perioperative myocardial injury. These include the choice of anesthetic agents, remote ischemic preconditioning, tight glycemic control, optimization of respiratory parameters during the aortic unclamping phase to limit reperfusion injury, appropriate choice of monitoring to optimize hemodynamic parameters and limit perioperative use of catecholamines, and early reintroduction of cardioprotective agents in the postoperative period. Appropriate management before, during, and after cardiopulmonary bypass will help to decrease myocardial damage. This review aimed to highlight the current advancements in cardioprotection and their potential applications during cardiac surgery.

Efficacy of electroacupuncture on myocardial protection and postoperative rehabilitation in patients undergoing cardiac surgery with cardiopulmonary bypass: a systematic review and Meta-analysis.

To evaluate the efficacy of electroacupuncture (EA) intervention on myocardial protection and postoperative rehabilitation in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Eight databases, including PubMed, Embase, the Cochrane Library, Web of Science, Chinese BioMedical Literature Database, China National Knowledge Infrastructure Database, Wanfang Data, China Science and Technology Journal Database, and two clinical trial registries, were searched. All randomized controlled trials (RCTs) related to EA intervention in cardiac surgery with CPB were collected. Based on the inclusion and exclusion criteria, two researchers independently screened articles and extracted data. After the quality evaluation, RevMan 5.3 software was used for analysis. Fourteen RCTs involving 836 patients were included. Compared with the control treatment, EA significantly increased the incidence of cardiac automatic rebeat after aortic unclamping [relative risk (RR) = 1.15, 95% confidence interval (CI) (1.01, 1.31), P < 0.05; moderate]. Twenty-four hours after aortic unclamping, EA significantly increased the superoxide dismutase [standardized mean difference (SMD) = 0.96, 95% CI(0.32, 1.61), P < 0.05; low], and interleukin (IL)-2 [SMD = 1.33, 95% CI(0.19, 2.47), P < 0.05; very low] expression levels and decreased the malondialdehyde [SMD =－1.62, 95% CI(－2.15, －1.09), P < 0.05; moderate], tumour necrosis factor-α [SMD = －1.28, 95% CI(－2.37, －0.19), P < 0.05; moderate], and cardiac troponin I [SMD = －1.09, 95% CI(－1.85, －0.32), P < 0.05; low] expression levels as well as the inotrope scores [SMD = －0.77, 95% CI(－1.22, －0.31), P < 0.05; high]. There was no difference in IL-6 and IL-10 expression levels. The amount of intraoperative sedative [SMD = -0.31, 95% CI(－0.54, －0.09), P < 0.05; moderate] and opioid analgesic [SMD = -0.96, 95% CI(－1.53, －0.38), P < 0.05; low] medication was significantly lower in the EA group than in the control group. Moreover, the postoperative tracheal intubation time [SMD = －0.92, 95% CI(－1.40, －0.45), P < 0.05; low] and intensive care unit stay [SMD = －1.71, 95% CI(－3.06, －0.36), P < 0.05; low] were significantly shorter in the EA group than in the control group. There were no differences in the time to get out of bed for the first time, total days of antibiotic use after surgery, or postoperative hospital stay. No adverse reactions related to EA were reported in any of the included studies. In cardiac surgery with CPB, EA may be a safe and effective strategy to reduce myocardial ischaemia-reperfusion injury and speed up the recovery of patients after surgery. These findings must be interpreted with caution, as most of the evidence was of low or moderate quality. More RCTs with larger sample sizes and higher quality are needed to provide more convincing evidence.

A Multimodal Cardioprotection Strategy During Cardiac Surgery: The ProCCard Study

The ProCCard study tested whether combining several cardioprotective interventions would reduce the myocardial and other biological and clinical damage in patients undergoing cardiac surgery. Prospective, randomized, controlled trial. Multicenter tertiary care hospitals. 210 patients scheduled to undergo aortic valve surgery. A control group (standard of care) was compared to a treated group combining five perioperative cardioprotective techniques: anesthesia with sevoflurane, remote ischemic preconditioning, close intraoperative blood glucose control, moderate respiratory acidosis (pH 7.30) just before aortic unclamping (concept of the "pH paradox"), and gentle reperfusion just after aortic unclamping. The primary outcome was the postoperative 72-h area under the curve (AUC) for high-sensitivity cardiac troponin I (hsTnI). Secondary endpoints were biological markers and clinical events occurring during the 30 postoperative days and the prespecified subgroup analyses. The linear relationship between the 72-h AUC for hsTnI and aortic clamping time, significant in both groups (p < 0.0001), was not modified by the treatment (p = 0.57). The rate of adverse events at 30 days was identical. A non-significant reduction of the 72-h AUC for hsTnI (-24%, p = 0.15) was observed when sevoflurane was administered during cardiopulmonary bypass (46% of patients in the treated group). The incidence of postoperative renal failure was not reduced (p = 0.104). This multimodal cardioprotection has not demonstrated any biological or clinical benefit during cardiac surgery. The cardio- and reno-protective effects of sevoflurane and remote ischemic preconditioning therefore remain to be demonstrated in this context.

Myocardial protection with glucose-insulin potassium in patients with acute coronary syndromes requiring coronary artery bypass grafting: A case series

Emergent cardiac surgery in patients with acute coronary syndrome (ACS) is always a challenging task for surgeons, anesthesiologists and patients. As “time is muscle,” early revascularization by percutaneous coronary intervention (PCI) has been largely advocated to salvage myocardial ischemic cells. In cases judged not suitable for PCI, on-pump coronary artery bypass grafting (CABG) is indicated with cardioplegic arrest and eventually anesthetic preconditioning to enhance myocardial protection. In these high-risk emergent procedures, adjuvant interventions to cardioplegic arrest are aimed to maximize the chance of cardiac functional recovery. Although the infusion of glucose-insulin-potassium (GIK) has demonstrated interesting cardioprotective effects in animal models of myocardial ischemia and in patients undergoing elective cardiac surgery, this cardioprotective strategy has not yet been adopted largely and has been ignored so far in emergent myocardial revascularization procedures. In this case series, we describe the effects of GIK on left ventricular performance assessed by transesophageal echocardiography in four patients with ACS who required emergent CABG surgery. The GIK solution of 20 g glucose, 20 UI insulin and 10 mEq potassium chloride was infused twice over 30 min, first after anesthesia induction and later after aortic unclamping. The systolic performance was assessed after anesthesia induction and after each GIK infusion using the 3D left ventricular ejection fraction, as well as the global longitudinal and circumferential strain. The diastolic function was assessed based on mitral inflow patterns (E-and A-waves) as well as flow propagation velocity.

The Cardiac Power Index during Abdominal Open Aortic Surgery: Intraoperative Insights into the Cardiac Performance-A Retrospective Observational Analysis.

Background: The Cardiac Power Index (CPI) measures the rate of energy output generated by the heart and correlates this with in-hospital mortality due to cardiogenic shock. In open aortic surgery, both aortic clamping and unclamping expose the heart to abrupt variations of the left ventricle afterload, preload, and contractility, with possible hemodynamic impairment. We investigated how aortic-cross clamping (Ao-XC) and unclamping (Ao-UC) procedures affect the CPI during open aortic surgery. Methods: We retrospectively analyzed our surgical database of 67 patients submitted to open surgical aortic repair at Humanitas Research Hospital, Milan. Patients were monitored by an EV1000-FloTrac SystemTM (Edwards Lifescience, Irvine, CA, USA) beyond the standard intra-operative hemodynamic monitoring. The primary outcome was the variation of basal CPI after aortic clamping and unclamping. Secondary outcomes were variations of the cardiac index (CI), mean arterial pressure (MAP), heart rate, and lactate during aortic clamping and after unclamping. The CPI was computed as: (CI × MAP)/451. Results: The CPI changed significantly after aortic unclamping. CPI: basal = 0.39 ± 0.1 W/m2, after Ao-XC = 0.39 ± 0.1 W/m2, and after Ao-UC = 0.44 ± 0.2 W/m2, p < 0.05. The CI changed during both cross-clamping and unclamping (p < 0.0001), whilst the MAP and heart rate did not during any phase of the surgery. Five subjects (8.3%) needed inotropic support after cross-clamping. Their basal CPI was lower than the general population: 0.31 ± 0.11 W/m2 vs. 0.39 ± 0.1 W/m2. Conclusions: The CPI describes the adaptation of the cardiac function to the changes in preload, contractility, and afterload occurring during aortic cross-clamping and unclamping. It may be used to explore the cardiac performance in real-time and predict cardiac impairment in the intraoperative period in a minimally invasive way, similar to ventriculo-arterial coupling parameters.

Edaravone attenuates sustained pial arteriolar vasoconstriction independently of endothelial function after unclamping of the abdominal aorta in rabbits.

BackgroundCerebral blood flow (CBF) has direct effects on neuronal function and neurocognitive disorders. Oxidative stress from abdominal aortic surgery is important in the pathophysiology of CBF impairment. We investigated the effect of edaravone on the pial arteriolar diameter changes induced by abdominal aortic surgery and the involvement of the endothelium in the changes.MethodsThe closed cranial window technique was used in rabbits to measure changes in pial arteriolar diameter after the unclamping of abdominal aortic cross-clamping with an intravenous free radical scavenger, edaravone (control group [n = 6], edaravone 10 μg/kg/ min [n = 6], 100 μg/kg/min [n = 6]). Pial vasodilatory responses to topical application of acetylcholine (ACh) into the cranial window were investigated before abdominal aortic cross-clamping and after unclamping with intravenous administration of edaravone (control group [n = 6], edaravone 100 μg/kg/min [n = 6]).ResultsAortic unclamping-induced vasoconstriction was significantly attenuated by continuous infusion of edaravone at 100 μg/kg/min. Topical ACh after unclamping did not produce any changes in pial arteriolar responses in comparison to before aortic cross-clamping in the control or edaravone groups. The changes in the response to topical ACh after unclamping in the saline and edaravone groups did not differ significantly.ConclusionsFree radicals during abdominal aortic surgery might have contracted cerebral blood vessels independently of endothelial function in rabbits. Suppression of free radicals attenuated the sustained pial arteriolar vasoconstriction after aortic unclamping. Thus, the free radical scavenger might have some brain protective effect that maintains CBF independently of endothelial function.

Argon Attenuates Multiorgan Failure in Relation with HMGB1 Inhibition.

Argon inhalation attenuates multiorgan failure (MOF) after experimental ischemic injury. We hypothesized that this protection could involve decreased High Mobility Group Box 1 (HMGB1) systemic release. We investigated this issue in an animal model of MOF induced by aortic cross-clamping. Anesthetized rabbits were submitted to supra-coeliac aortic cross-clamping for 30 min, followed by 300 min of reperfusion. They were randomly divided into three groups (n = 7/group). The Control group inhaled nitrogen (70%) and oxygen (30%). The Argon group was exposed to a mixture of argon (70%) and oxygen (30%). The last group inhaled nitrogen/oxygen (70/30%) with an administration of the HMGB1 inhibitor glycyrrhizin (4 mg/kg i.v.) 5 min before aortic unclamping. At the end of follow-up, cardiac output was significantly higher in Argon and Glycyrrhizin vs. Control (60 ± 4 and 49 ± 4 vs. 33 ± 8 mL/kg/min, respectively). Metabolic acidosis was attenuated in Argon and Glycyrrhizin vs. Control, along with reduced amount of norepinephrine to reverse arterial hypotension. This was associated with reduced interleukin-6 and HMGB1 plasma concentration in Argon and Glycyrrhizin vs. Control. End-organ damages were also attenuated in the liver and kidney in Argon and Glycyrrhizin vs. Control, respectively. Argon inhalation reduced HMGB1 blood level after experimental aortic cross-clamping and provided similar benefits to direct HMGB1 inhibition.

ECMO pour choc cardiogénique réfractaire post cardiotomie : expérience du service de chirurgie cardiaque du CHU de Grenoble Alpes

ObjectiveThe objective of our study is to detail our experience relating to ECMO implantations for post-cardiotomy refractory shock, by analyzing the pre-ECMO factors (history, type of surgery, LVEF), factors relating to ECMO (implantation time, duration) and post-ECMO factors (weaning, complications) in order to highlight those possibly associated with high mortality. MethodsThis is a univariate and multivariate retrospective study of ECMO data implemented between 2011 and 2019 at the Grenoble Alpes University Hospital Center following cardiac surgery. The time to implantation of ECMO was less than 3hours (intraoperative) between 3 and 24hours (early postoperative) and between 24 and 48hours after aortic unclamping (late postoperative). Preoperative or postoperative intra-aortic balloon counterpulsation (CPBIA) could be associated. Results114 veino-arterial ECMOs were implanted for refractory cardiogenic shock after 5702 cardiac surgeries (1.9%) with a survival rate of 30.7%. The mean age of the patients was 68.6+- 10.5 years. The implantation of ECMO was performed intraoperatively in 71 patients (62.2%), early postoperatively in 22 patients (19.2%) and late postoperatively in 21 patients (18.4%). The duration of assistance was less than 48hours in 27 patients (23.6%), between 48hours and one week in 58 patients (50.9%) and more than one week in 29 patients (25.5%). Univariate analysis revealed a statistically significant association between mortality rate and male sex (P=0.002), association absent with other preoperative characteristics, delay in implantation of ECMO, installation of CPBIA, post-operative characteristics and resuscitation suites. Multivariate analysis of the entire study population demonstrated that the use of ECMO for cardio-respiratory arrest was the only independent risk factor for mortality (OR=7.57 [1.41-40, 62]). After multivariate reanalysis excluding patients with ECMO placement for cardio respiratory arrest, age, preoperative renal failure, type of procedure and EuroSCORE II were risk factors for mortality. ConclusionIn this study, male gender, type of intervention, occurrence of cardiac arrest were significantly associated with the death rate. A study of greater power, multicentric, and with a larger sample, will have to be carried out to reach significance.

COMPARISON STUDY: INTERMITTENT ANTIGRADE WARM CARDIOPLEGIA VERSUS ANTIGRADE COLD INTERMITTENT BLOOD CARDIOPLEGIA FOR MYOCARDIAL PROTECTION DURING ELECTIVE ON PUMP CORONARY ARTERY BYPASS GRAFTING IN EARLY POST-OPERATIVE PERIOD

Background: Defending the heart against potential damage during cross-clamping is the most important and vital step to ensuring a successful surgical outcome(1). The creation of cardioplegia solutions was one of the major advances in cardiac surgery that allowed surgeons to conduct complicated surgical procedures to avoid myocardial injury (14). Treating cardioplegia at a cool temperature would be a significant factor in lowering myocardial metabolism. However, the reduction in myocardial metabolism due to hypothermia, compared with that achieved by diastolic arrest, is usually very negligible. Since Normothermias enzymatic and cellular processes work better (7). Owing to the propensity of the heart to resume electrical operation during normothermia, however, this must be administered consistently or only with short interruptions (4). Terminal warm blood cardioplegia (hot shot) is normally done just before the elimination of the aortic cross-clamp since it has been demonstrated that myocardial metabolism is increasing (23). Methods: A prospective controlled randomised study (200 hundred patients aged 40 to 65 years of both sexes underwent elective CABG pump surgery) will be included. They will be divided into three groups of patients: Group I:includes 100 Patients who received intermittent cold blood cardioplegia. Group II:includes 100 Patients who received intermittent warm blood cardioplegia with controlled reperfusion for 3 minutes before aortic unclamping. Study made from January, 2019 to August, 2020, at National Heart Institute.All patients were thoroughly evaluated preoperatively, intraoperatively, and postoperatively. Results: We hypothesized that in our patient cohort, warm blood cardioplegia could be as successful as or even better than the conventional antegrade cold blood cardioplegia. Patients were randomised into two similar blocks, each of which consisted of 100 patients, each of whom obtained one of the two cardioplegic solutions. Our analysis did not indicate a statistically important difference in the post-operative release of myocardial biomarkers (Troponin I) &amp; CK in both classes. This finding did not significantly reflect the clinical outcome of our patient, which may indicate similar myocardial protection in primary low-risk CABG patients for both cold and warm blood cardioplegia. Conclusion: During the time of cardiac arrest, both methods tend to enable an equal and adequate approach for myocardial defence. To attain improved myocardial defence, warm blood cardioplegia needs a shorter administration interval. Therefore, the choice between one type of cardioplegia and the other remains at the discretion of the surgeon. The statistically minor variation found in the release of myocardial enzymes did not translate into distinct clinical results.

Prophylaxis postoperative atrial fibrillation (POAF) with exogenous phosphocreatine in cardiac surgery

IntroductionAmong all cardiovascular complications, new onset postoperative atrial fibrillation (POAF) is one of the most common complications, occurring in 30% to 50% of patients after cardiac surgery. (1) One of the possible mechanisms for the development of AF may be myocardial reperfusion after aortic unclamping (reperfusion arrhythmia). In this regard, the use of agents reducing the severity of reperfusion syndrome may reduce the frequency of POAF. One such remedy is exogenous phosphocreatineThe aim of our investigation evaluation efficacy of exogenous phosphocreatine for prevention of new-onset POAF in cardiac patients.MethodsAfter Institutional Ethics Committee approval, 56 patients posted for elective GABG surgery were randomly divided into two groups (n = 28 each). In study group (Pcr) patients received 2 g of exogenous phosphocreatine iv before aortic unclamping followed by continuous infusion at a dose of 1g per hour during 3 hours after aortic unclamping; In control group (C) patients received placebo The baseline and intraoperative characteristics of the patients were similar in both groups. Continuous ECG monitoring for arrhythmias was performed at 48 hours in all patients after CABG. The diagnostic hallmarks of AF on ECG included the loss of P-waves and the presence of irregular ventricular beats. The primary point was to determine the frequency of AF within 48 hours after surgery. Secondary points were frequency of cardioversion use the frequency (paroxysms of AF lasting 5-10 minutes with adverse effects),. Chi-square/Fisher's exact/Mid P exact test and Student's t-tests were applied for categorical and continuous data.ResultsIncidence of postoperative atrial fibrillation (POAF) in group Pcr was 26% vs. 37% in group C;(p = 0.47), a difference that was not signficant. The frequency of episodes of of ventricular tachyarrhythmias requiring cardioversion in group Pcr was significantly lesser than in the control group (n-5/17,8% and n-10/35%, respectively) In the group C 11 (38%) patients developed adverse effects, mostly hypotension, compared with only 4 patient (12,3%) in group Pcr (p = 0.04). The length of ainotropic support in early postoperative period was significantly lower in group Pcr compared with control group (175±37 vs 290±89 minutes).DiscussionProphylactic perioperative infusion exogenous phosphocreatine in patients undergoing CABG surgery reduces the incidence of cardioversion, adverse effects and the length postoperative of inotropic support Among all cardiovascular complications, new onset postoperative atrial fibrillation (POAF) is one of the most common complications, occurring in 30% to 50% of patients after cardiac surgery. (1) One of the possible mechanisms for the development of AF may be myocardial reperfusion after aortic unclamping (reperfusion arrhythmia). In this regard, the use of agents reducing the severity of reperfusion syndrome may reduce the frequency of POAF. One such remedy is exogenous phosphocreatine The aim of our investigation evaluation efficacy of exogenous phosphocreatine for prevention of new-onset POAF in cardiac patients. After Institutional Ethics Committee approval, 56 patients posted for elective GABG surgery were randomly divided into two groups (n = 28 each). In study group (Pcr) patients received 2 g of exogenous phosphocreatine iv before aortic unclamping followed by continuous infusion at a dose of 1g per hour during 3 hours after aortic unclamping; In control group (C) patients received placebo The baseline and intraoperative characteristics of the patients were similar in both groups. Continuous ECG monitoring for arrhythmias was performed at 48 hours in all patients after CABG. The diagnostic hallmarks of AF on ECG included the loss of P-waves and the presence of irregular ventricular beats. The primary point was to determine the frequency of AF within 48 hours after surgery. Secondary points were frequency of cardioversion use the frequency (paroxysms of AF lasting 5-10 minutes with adverse effects),. Chi-square/Fisher's exact/Mid P exact test and Student's t-tests were applied for categorical and continuous data. Incidence of postoperative atrial fibrillation (POAF) in group Pcr was 26% vs. 37% in group C;(p = 0.47), a difference that was not signficant. The frequency of episodes of of ventricular tachyarrhythmias requiring cardioversion in group Pcr was significantly lesser than in the control group (n-5/17,8% and n-10/35%, respectively) In the group C 11 (38%) patients developed adverse effects, mostly hypotension, compared with only 4 patient (12,3%) in group Pcr (p = 0.04). The length of ainotropic support in early postoperative period was significantly lower in group Pcr compared with control group (175±37 vs 290±89 minutes). Prophylactic perioperative infusion exogenous phosphocreatine in patients undergoing CABG surgery reduces the incidence of cardioversion, adverse effects and the length postoperative of inotropic support

Plasma exosomes characterization reveals a perioperative protein signature in older patients undergoing different types of on-pump cardiac surgery.

Although exosomes are extracellular nanovesicles mainly involved in cardioprotection, it is not known whether plasma exosomes of older patients undergoing different types of on-pump cardiac surgery protect cardiomyocytes from apoptosis. Since different exosomal proteins confer pro-survival effects, we have analyzed the protein cargo of exosomes circulating early after aortic unclamping. Plasma exosomes and serum cardiac troponin I levels were measured in older cardiac surgery patients (NYHA II-III) who underwent first-time on-pump coronary artery bypass graft (CABG; n = 15) or minimally invasive heart valve surgery (mitral valve repair, n = 15; aortic valve replacement, n = 15) at induction of anesthesia (T0, baseline), 3h (T1) and 72h (T2) after aortic unclamping. Anti-apoptotic role of exosomes was assessed in HL-1 cardiomyocytes exposed to hypoxia/re-oxygenation (H/R) by TUNEL assay. Protein exosomal cargo was characterized by mass spectrometry approach. Exosome levels increased at T1 (P < 0.01) in accord with troponin values in all groups. In CABG group, plasma exosomes further increased at T2 (P < 0.01) whereas troponin levels decreased. In vitro, all T1-exosomes prevented H/R-induced apoptosis. A total of 340 exosomal proteins were identified in all groups, yet 10% of those proteins were unique for each surgery type. In particular, 22 and 12 pro-survival proteins were detected in T1-exosomes of heart valve surgery and CABG patients, respectively. Our results suggest that endogenous intraoperative cardioprotection in older cardiac surgery patients is early mediated by distinct exosomal proteins regardless of surgery type.

Effectiveness of Bokeria—Boldyrev ACH Solution in Surgerical Treatment of Adult Patients with Obstructive Hypertrophic Cardiomyopathy

The study examined effectiveness of pharmaco-cold cardioplegia employing solutions of enhanced buffer capacity during surgery of obstructive hypertrophic cardiomyopathy in adult patients (N=51) operated during 2013-2018. In group 1 (N=28), the cardioplegia was performed with HTK (Custodiol) solution, whereas in group 2 (N=23), it was carried out with Bokeria-Boldyrev ACH solution. The mean, minimum, and maximum ages in group 1 were 46, 21, and 64 years, respectively; in group 2 - 42, 14, and 70 years, respectively. In both groups, the patients were subjected to myoectomy of exit pathway in the left ventricle according to Bokeria-Morrow operation and annuloplasty of tricuspid valve accompanied by reconstructive surgery (or replacement) of mitral valve. Atrial fibrillation (if any) was suppressed with cryoablation (-60°С) of the openings of the right and left pulmonary veins. The surgery was carried out in hypothermic mode at 28°C. The significant intergroup differences were observed in the asystole latent period after the onset of antegrade or retrograde injection of cardioplegic solution. In group 1, the asystole latent periods determined after antegrade or retrograde injection were 53±7 or 170±30 sec, respectively; in group 2 - 32±6 and 97±11 sec (p<0.0001), respectively. The mean times of aortic cross-clumping in groups 1 and 2 were 66±8 and 64±6 min, respectively; the electromechanical action of the heart restored after aortic unclamping in 35±7 and 30±6 sec, respectively. The biochemical and clinical data revealed no significant intergroup differences. Overall, novel Bokeria-Boldyrev ACH cardioplegic solution secured effective protection of the myocardium against intraoperative ischemia in adult patients with obstructive hypertrophic cardiomyopathy and significantly decreased the asystole latent period.

Spontaneous Restoration of Sinus Rhythm during Heart Transplantation is Associated with a Reduced Incidence of Primary Graft Dysfunction and Early Mortality

Insults to the donor heart during heart transplantation (HT) include ischemia and reperfusion injury after release of the aortic cross-clamp in the recipient. Restoration of heart beat after aortic unclamping can be by spontaneous resumption of sinus rhythm, pacing for atrioventricular (AV) block, or direct-current (DC) cardioversion for ventricular fibrillation. We investigated the association between mode of heart beat restoration and primary graft dysfunction (PGD). HT recipients between 1997-2017 were grouped by mode of heart beat restoration after aortic unclamping into: spontaneous (S; 126 pts), pacing (P; 17 pts) or DC (58 pts) groups. Endpoints were 30-day mortality and PGD (defined by the ISHLT consensus statement). Baseline characteristics differing among the groups included proportion of women, pre-HT amiodarone and gender mismatch (Table). PGD was significantly higher for the P-group (71%) >DC-group (59%) >S-group (21%, p<0.001). Multivariable analysis consistently showed that restoration of sinus by DC, and pacing for AV block, were independently associated with significant ∼5-fold and ∼10-fold increased risk for PGD, respectively (Figure) compared to spontaneous sinus restoration. Consistently, 30-day mortality was significantly lower for S- (6%) than for DC- (17%) patients and highest for the P group (22%, p<0.001). Spontaneous restoration of sinus after aortic unclamping at HT is associated with a reduced risk for PGD and early mortality, whereas pacing for AV block and DC are associated with an increased risk.

Pulsatile Versus Nonpulsatile Flow During Cardiopulmonary Bypass: Extent of Hemolysis and Clinical Significance.

Pulsatile flow has been used during cardiopulmonary bypass (CPB) for decades and its use is increasing with advancing extracorporeal technology. Pulsatile flow generates higher circuit pressures and shear forces than nonpulsatile flow at comparable pump flow and patient mean arterial pressure. Very little is known about the effect this has on erythrocytes. We included 62 adult patients (32 in the pulsatile group and 30 in the nonpulsatile group) undergoing elective coronary artery bypass grafting in this prospective observational study. Blood samples were collected at routine sampling times throughout surgery and were analyzed for the presence of free heme and globin using mass spectroscopy. Patient characteristics, CPB, and aortic cross-clamp times, pump flow as well as patient mean arterial pressure were similar in both groups. Maximum circuit pressure in the pulsatile flow group was statistically significantly higher than that in the nonpulsatile flow group (257.12 vs. 190.64 mmHg, p < 0.0001). Both heme and globin levels were higher in the pulsatile flow group. This reached statistical significance with globin at 30 minutes of CPB and with heme after aortic unclamping. We conclude that pulsatile CPB using roller pumps results in a greater extent of hemolysis. The clinical significance, however, is not yet known.

Lower limit of adequate oxygen delivery for the maintenance of aerobic metabolism during cardiopulmonary bypass in neonates

BackgroundThe objective of cardiopulmonary bypass (CPB) is to maintain an adequate balance between oxygen delivery (Ḋo2) and consumption. The critical Ḋo2 is that at which consumption becomes supply dependent. This study aimed to identify the critical Ḋo2 in neonates, who have higher metabolic rates than adults. MethodsIn a retrospective cohort of neonates, Ḋo2 was calculated from CPB parameters recorded during aortic cross-clamping. High lactate concentration measured after aortic unclamping (lactOFF) was used to identify anaerobic metabolism. Data were analysed using mixed linear and proportional odds regression models. The relationship between Ḋo2 and temperature was analysed in a subgroup of patients with lactOFF <2.5 mM, thought to have had balanced oxygen delivery and consumption. The estimated regression coefficient was further used to adjust hypothetical Ḋo2 thresholds, and Ḋo2 excursions below the threshold were quantified as magnitude–durations. The lowest threshold that provided magnitude–durations and linked with an increase in lactOFF was used as the lowest suitable (critical) Ḋo2 at 37°C. ResultsOverall, 22 896 time points were analysed in 180 neonates. In 40 patients with lactOFF <2.5 mM, Ḋo2 varied by 22.87 (0.70) ml min−1 m−2 °C−1. When varying the Ḋo2 threshold between 340 and 380 ml min−1 m−2, excursions below the threshold were linked with incremental lactOFF. A 100 ml m−2 excursion below the 340 ml min−1 m−2Ḋo2 threshold increased the risk of a 1 mM increment in lactOFF by 22% (odds ratio: 1.22; 95% confidence interval: 1.02–1.45). ConclusionsIt was found that 340 ml min−1 m−2 is likely to represent the lowest suitable Ḋo2 required in neonates to maintain aerobic metabolism during normothermic CPB.

Cardiac Preconditioning Effect of Ketamine-Dexmedetomidine versus Fentanyl-Propofol during Arrested Heart Revascularization.

Background:Myocardial damage due to ischemia and reperfusion is still unavoidable during coronary surgery. Anesthetic agents have myocardial preconditioning effect. Ketamine has sympathomimetic effect, while dexmedetomidine has a sympatholytic effect in addition to anesthetic, analgesic, and anti-inflammatory properties of both the drugs. This study was carried out to compare ketamine–dexmedetomidine (KD) combination with fentanyl–propofol (FP) combination on the release of cardiac troponin T (cTnT) and outcome after coronary artery bypass graft.Patients and Methods:Ninety adult patients who underwent coronary artery bypass grafting (CABG) were assigned to receive either KD base anesthesia (KD group) or FP anesthesia (FP group). Trends of high-sensitive cTnT, CK-MB, and serum cortisol were followed in the first postoperative 24 h. Other outcomes were vital signs, weaning from cardiopulmonary bypass, tracheal extubation time, and echocardiographic findings.Results:There was a significant lower release of cTnT in KD group than FP group during its peak values at 6 h after aortic unclamping (92.01 ± 7.332 in KD versus 96.73 ± 12.532 ng.L−1 P = 0.032). significant lower levels of serum cortisol levels were noted KD group than in FP group at 6 and 12 h after aortic unclamping P < 0.001. As regard tracheal extubation time, patients assigned to KD group extubated earlier than whom in FP group 202.22 ± 28.674 versus 304.67 ± 40.598 min respectively P < 0.001.Conclusion:The use of KD during on-pump CABG confers better myocardial protective and anti-inflammatory effect than fentanyl propofol.

Mitral valve repair based on intraoperative objective parameters measurement: State of the art and perspective

Currently, mitral valve repair (MVr) success for primary mitral regurgitation relies mainly on surgeon's expertise and major heterogeneities are observe concerning MVr rate, technics, and results. MVr success is estimated by a morphological echocardiographic assessment after aortic unclamping. To date, coaptation forces have been poorly characterized. We developed a device allowing a precise morphologic and qualitative assessment of coaptation. A first prototype allowing three-dimensional mapping of coaptation forces was developed and a provisional patent was filed. A number of features informed the design of the new device, including force sensitivity, flexibility, and biocompatibility. Varying sensing technologies were screened (including piezo-electric, piezo-resistive, and resistive sensors), and a specific device to hold the sensor was designed and prototyped. The first generation of prototype was tested on a porcine ex vivo beating heart model. The device was inserted between the mitral leaflet through a left atrial incision between two running sutures. The sensor was positioned and connected to a custom-made acquisition system. The coaptation signal was recorded in normal valves and after creation of a posterior central prolapse. We were able to obtain precise surface mapping of mitral coaptation forces in this model. The coaptation signal was notably more intense in the normal valve compare to the prolapsed valve in otherwise similar hemodynamic conditions ( Fig. 1 ). A mapping of coaptation forces along the entire mitral valve surface can be achieved with the method and device we have developed. This technology may be useful to assist surgeons during MVr while providing real-time objective measurement in support of the conventional intraoperative morphological assessment. An extensive development roadmap has been developed and is being put in place to move our invention toward clinical trials.

Multimodal cardioprotective strategy in cardiac surgery (the ProCCard trial): Study protocol for a multicenter randomized controlled trial

BackgroundMyocardial damage in patients undergoing cardiac surgery increases both morbidity and mortality. Different protective strategies dealing with either preconditioning or postconditioning or assessing a single aspect of cardioprotection have shown conflicting results. We tested the hypothesis that a multimodal approach would improve cardioprotection and limit myocardial damage following cardiac surgery with cardiopulmonary bypass.MethodsThis study is a pragmatic multicenter (six French institutions), prospective, randomized, single-blinded, controlled trial. The randomization is stratified by centers. In the study, 210 patients scheduled for aortic valve surgery with or without coronary artery bypass grafting will be assigned to a control or a treatment group (105 patients in each group). In the control group, patients receive total intravenous anesthesia with propofol and liberal intraoperative blood glucose management (initiation of insulin infusion when blood glucose, measured every 60 min, is greater than 180 mg/dl), as a standard of care. The treatment group receives a bundle of care combining five techniques of cardioprotection: (1) remote ischemic preconditioning applied before aortic cross-clamping; (2) maintenance of anesthesia with sevoflurane; (3) tight intraoperative blood glucose management (initiation of insulin infusion when blood glucose, measured every 30 min, is greater than 140 mg/dl); (4) moderate respiratory acidosis (pH 7.30) at the end of cardiopulmonary bypass; and (5) a gentle reperfusion protocol following aortic unclamping. The primary outcome is myocardial damage measured by postoperative 72-h area under the curve of high-sensitivity cardiac troponin I.DiscussionThe ProCCard study will be the first multicenter randomized controlled trial aiming to assess the role of a bundle of care combining several cardioprotective strategies to reduce myocardial damage in patients undergoing cardiac surgery with cardiopulmonary bypass.Trial registrationClinicalTrials.gov, NCT03230136. Registered on July 26, 2017. Last updated on April 17, 2019.