In Nordic countries 30-day mortality rate is half that estimated with EuroSCORE II in high-risk adult patients given aprotinin and undergoing mainly complex cardiac procedures

Objectives. To describe current on- (isolated coronary arterty bypass grafting, iCABG) and off-label (non-iCABG) use of aprotinin and associated safety endpoints in adult patients undergoing high-risk cardiac surgery in Nordic countries. Design. Data come from 10 cardiac surgery centres in Finland, Norway and Sweden participating in the European Nordic aprotinin patient registry (NAPaR). Results. 486 patients were given aprotinin between 2016 and 2020. 59 patients (12.1%) underwent iCABG and 427 (87.9%) non-iCABG, including surgery for aortic dissection (16.7%) and endocarditis (36.0%). 89.9% were administered a full aprotinin dosage and 37.0% were re-sternotomies. Dual antiplatelet treatment affected 72.9% of iCABG and 7.0% of non-iCABG patients. 0.6% of patients had anaphylactic reactions associated with aprotinin. 6.4% (95 CI% 4.2%-8.6%) of patients were reoperated for bleeding. Rate of postoperative thromboembolic events, day 1 rise in creatinine >44μmol/L and new dialysis for any reason was 4.7% (95%CI 2.8%-6.6%), 16.7% (95%CI 13.4%-20.0%) and 14.0% (95%CI 10.9%-17.1%), respectively. In-hospital mortality and 30-day mortality was 4.9% (95%CI 2.8%-6.9%) and 6.3% (95%CI 3.7%-7.8%) in all patients versus mean EuroSCORE II 11.4% (95%CI 8.4%-14.0%, p < .01). 30-day mortality in patients undergoing surgery for aortic dissection and endocarditis was 6.2% (95%CI 0.9%-11.4%) and 6.3% (95%CI 2.7%-9.9%) versus mean EuroSCORE II 13.2% (95%CI 6.1%-21.0%, p = .11) and 14.5% (95%CI 12.1%-16.8%, p = .01), respectively. Conclusions. NAPaR data from Nordic countries suggest a favourable safety profile of aprotinin in adult cardiac surgery.

Infective Endocarditis Requiring Mitral Valve Replacement During Second Trimester of Pregnancy

Infective endocarditis requiring mitral valve replacement during pregnancy is a rare event. We present a case of infective endocarditis of the mitral valve during second trimester and report maternal and perinatal outcomes. Prompt identification and interdisciplinary treatment is crucial; maternal and fetal follow-up including serial fetal neurosonography is recommended.

Fresh Frozen Plasma Versus Solvent Detergent Plasma for Cardiopulmonary Bypass Priming in Neonates and Infants Undergoing Cardiac Surgery: A Retrospective Cohort Study

OBJECTIVE

Compared with fresh frozen plasma (FFP), Omniplasma has been attributed to an increased coagulation potential and an increased fibrinolytic potential. This study aimed to compare Omniplasma and FFP used for cardiopulmonary bypass (CPB) priming regarding the incidence of postoperative thrombotic or hemorrhagic complications and outcomes in pediatric patients undergoing cardiac surgery.

DESIGN

A retrospective observational cohort study SETTING: This single-center study was performed at the University Medical Center Groningen.

PARTICIPANT

All pediatric patients up to 10 kg undergoing cardiac surgery with CPB.

INTERVENTIONS

Procedures in which FFP was used for CPB priming were compared with those in which Omniplasma was used.

MEASUREMENTS AND MAIN RESULTS

The primary outcome parameter was a composite endpoint consisting of the following: (1) pediatric intensive care unit (PICU) mortality, (2) thromboembolic complications, and (3) hemorrhagic complications during PICU stay. The authors included 143 procedures in the analyses, 90 (63%) in the FFP group and 53 (37%) in the Omniplasma group. The occurrence of the combined primary endpoint (FFP 20% v Omniplasma 11%, p = 0.18) and its components did not differ between the used CPB priming agent). Omniplasma for CPB priming was associated with decreased unfractionated heparin administration per kg bodyweight (585 IU v 510 IU, p = 0.03), higher preoperative and postoperative activated clotting times (ACT) discrepancy (90% v 94%, p = 0.03), a lower postoperative ACT value (125 v 118 seconds, p = 0.01), and less red blood cell transfusion per kilogram bodyweight (78 v 55 mL, p = 0.02). However, none of the variables differed statistically significantly in the multivariate logistic regression analyses.

CONCLUSIONS

The authors did not find an association between the plasma used for CPB priming and thromboembolic and hemorrhagic complications and death in neonates and infants undergoing cardiac surgery. Omniplasma seems to be safe to use in this population.

Perfusion quality odds (PEQUOD) trial: validation of the multifactorial dynamic perfusion index as a predictor of cardiac surgery-associated acute kidney injury

OBJECTIVES

The multifactorial dynamic perfusion index was recently introduced as a predictor of cardiac surgery-associated acute kidney injury. The multifactorial dynamic perfusion index was developed based on retrospective data retrieved from the patient files. The present study aims to prospectively validate this index in an external series of patients, through an on-line measure of its various components.

METHODS

inclusion criteria were: adult patients undergoing cardiac surgery with cardiopulmonary bypass. Data collection included preoperative factors, and cardiopulmonary bypass-related factors. These were collected on-line using a dedicated monitor. Factors composing the multifactorial dynamic perfusion index are the nadir hematocrit, the nadir oxygen delivery, the time of exposure to a low oxygen delivery, the nadir mean arterial pressure, cardiopulmonary bypass duration, the use of red blood cell transfusions, and the peak arterial lactates.

RESULTS

200 hundred adult patients were investigated The multifactorial dynamic perfusion index had a good (c-statistics 0.81) discrimination for cardiac surgery-associated acute kidney injury (any stage) and an excellent (c-statistics 0.93) discrimination for severe patterns (stage 2-3). Calibration was modest for cardiac surgery-associated acute kidney injury (any stage) and good for stage 2-3. The use of vasoconstrictors was an additional factor associated with cardiac surgery-associated acute kidney injury.

CONCLUSIONS

The multifactorial dynamic perfusion index is validated for discrimination of cardiac surgery-associated acute kidney injury risk. It incorporates modifiable risk factors, and may help in reducing the occurrence of cardiac surgery-associated acute kidney injury.

Effect of geography on the use of ultrafiltration during cardiac surgery with cardiopulmonary bypass

BACKGROUND

Ultrafiltration (UF) is a common practice during cardiopulmonary bypass (CPB) where it is used as a blood management strategy to reduce red blood cell (RBC) transfusion, minimize adverse effects of hemodilution, and reduce proinflammatory mediators. However, its clinical utilization has been shown to vary throughout the continents.

PURPOSE

The purpose of this investigation was to assess the distribution of UF use across the United States.

DATA COLLECTION

Data on UF use during cardiac surgery was obtained from a national (United States) perfusion database for adult cardiac procedures performed from January 2016 through December 2018.

STUDY SAMPLE

Four geographical regions were established: Northeast (NE), South (SO), Midwest (MW) and West (WE). The primary endpoint was the use of UF with secondary endpoints UF volume, CPB and anesthesia asanguineous volumes, intraoperative allogeneic RBC transfusion, nadir hematocrit and urine output (UO). 92,859 adult cardiac cases from 191 hospitals were reviewed.

RESULTS

The NE and the WE had similar usages of UF (59.9% and 59.7% respectively), which were higher than the MW and the SO (38.6% and 34.9%, p < .001). When UF was utilized, the median [IQR] volume removed was highest in the NE (1900 [1200-2800]mL), and similar in all other regions (WE 1500 [850-2400 mL, MW 1500 [900-2300]mL and SO 1500 [950-2200]mL, p < .001. Median total UO was lowest in the NE 400 [210,650]mL vs all other regions (p < .001), and remained so when indexed by patient weight and operative time (NE-0.8 [0.5, 1.3]mL/kg/hour, MW-1.1 [0.7, 1.8] mL/kg/hour, SO-1.3 [0.8, 2.0]mL/kg/hour, WE-1.1 [0.7, 1.3]mL/kg/hour, p < .001. Intraoperative RBC transfusion rate was highest in the SO (21.3%) and WE (20.5%), while similar rates seen in the NE (16.2%) and MW (17.6%), p < .001.

CONCLUSIONS

Across the United States there is geographic variation on the use of UF. Further research is warranted to investigate why these practice variations exist and to better understand and determine their reasons for use.

Noteworthy in Cardiothoracic Surgery 2023

Noteworthy in Cardiothoracic Surgery 2023 summarizes a few of the most high-impact trials and provocative trends in cardiothoracic surgery and transplantation this past year. Transplantation using organs procured from donation after circulatory death (DCD) continues to increase, and the American Society of Transplant Surgeons released recommendations on best practices in 2023. We review a summary of data on the impact of DCD on heart and lung transplantation. There has been increased interest in extracorporeal life support (ECLS), particularly after the COVID-19 pandemic, and we review the results of the highly discussed ECLS-SHOCK trial, which randomized patients in cardiogenic shock with planned revascularization to ECLS vs usual care. With improving survival outcomes in complex aortic surgery, there is a need for higher-quality evidence to guide which cooling and cerebral perfusion strategies may optimize cognitive outcomes in these patients. We review the short-term outcomes of the GOT ICE trial (Cognitive Effects of Body Temperature During Hypothermic Circulatory Arrest), a multicenter, randomized controlled trial of three different nadir temperatures, evaluating outcomes in cognition and associated changes in functional magnetic resonance imaging. Finally, both the Society of Thoracic Surgeons (STS) and the American College of Cardiology, American Heart Association, American College of Chest Physicians and Heart Rhythm Society (ACC/AHA/ACCP/HRS) updated atrial fibrillation guidelines in 2023, and we review surgically relevant updates to the guidelines and the evidence behind them.

Blood cardioplegia reduces intraoperative ventricular fibrillation and transfusion requirements compared to crystalloid cardioplegia in canine mitral valve repair

OBJECTIVE

Cardioplegic solutions are indispensable for open-heart surgeries, including mitral valve repair (MVR), a potentially curative treatment for myxomatous mitral valve disease in dogs. However, procedural methodologies are not fully established, and complications are yet to be comprehensively understood. Cardioplegic solutions contain various substances to protect the myocardium under temporal cardiac arrest. Nevertheless, ventricular fibrillation (VF) occurs as a common complication after releasing the crossclamp. Based on these backgrounds, the search for optimal cardioplegic solutions in dogs undergoing MVR is an urgent issue. This study aims to evaluate the occurrence of VF in dogs treated with blood cardioplegia (BCP) versus crystalloid cardioplegia (CCP) during MVR.

ANIMALS

A total of 251 client-owned dogs who underwent MVR from November 2015 to November 2017 were included.

METHODS

We retrospectively assessed the relationship between VF and type of cardioplegia (CCP or BCP) based on surgical records, including VF incidence, transfusion use, crossclamp time, and echocardiographic measurements.

RESULTS

Logistic regression analysis showed that the CCP group was associated with the occurrence of VF (OR, 2.378; CI, 1.133-4.992; P = .022). In addition, the CCP group was associated with transfusion use (OR, 2.586; CI, 1.232-5.428, P = .022). There was no difference between the groups for the pre- and postoperative echocardiographic measurements.

CLINICAL RELEVANCE

The BCP group had a lower incidence of VF and less transfusion use than the CCP group. This finding indicates that BCP may be a superior cardioplegic technique for MVR in dogs.

Investigating Potential Correlations between Calcium Metabolism Biomarkers and Periprocedural Clinical Events in Major Cardiovascular Surgeries: An Exploratory Study

Background: There is emerging but conflicting evidence regarding the association between calcium biomarkers, more specifically ionized calcium and the prognosis of intensive care unit (ICU) postoperative cardiac patients. Methods: Our study investigated the relationship between ionized calcium, vitamin D, and periprocedural clinical events such as cardiac, neurologic and renal complications, major bleeding, vasoactive-inotropic score (VIS), and length of ICU and hospitalization. Results: Our study included 83 consecutive subjects undergoing elective major cardiac surgery requiring cardiopulmonary bypass. The mean age of the participants was 64.9 ± 8.5 years. The majority of procedures comprised isolated CABG (N = 26, 31.3%), aortic valve procedures (N = 26, 31.3%), and mitral valve procedures (N = 12, 14.5%). A difference in calcium levels across all time points (p < 0.001) was observed, with preoperative calcium being directly associated with intraoperative VIS (r = 0.26, p = 0.016). On day 1, calcium levels were inversely associated with the duration of mechanical ventilation (r = -0.30, p = 0.007) and the length of hospital stay (r = -0.22, p = 0.049). At discharge, calcium was inversely associated with length of hospital stay (r = -0.22, p = 0.044). All calcium levels tended to be lower in those who died during the 1-year follow-up (p = 0.054). Preoperative vitamin D levels were significantly higher in those who experienced AKI during hospitalization (median 17.5, IQR 14.5-17.7, versus median 15.3, IQR 15.6-20.5, p = 0.048) Conclusion: Fluctuations in calcium levels and vitamin D may be associated with the clinical course of patients undergoing cardiac surgery. In our study, hypocalcemic patients exhibited a greater severity of illness, as evidenced by elevated VIS scores, and experienced prolonged mechanical ventilation time and hospital stays. Additional larger-scale studies are required to gain a deeper understanding of their impact on cardiac performance and the process of weaning from cardiopulmonary bypass, as well as to distinguish between causal and associative relationships.

Is ultrafiltration volume a predictor of postoperative acute kidney injury in patients undergoing cardiopulmonary bypass?

INTRODUCTION

Intraoperative ultrafiltration (UF) is a procedure used during cardiopulmonary bypass (CPB) to reduce haemodilution and prevent excessive blood transfusion. However, the effect of UF volume on acute kidney injury (AKI) is not well established, and the results are conflicting. Additionally, there are no set indications for applying UF during CPB.

METHODS

This retrospective study analysed 641 patients who underwent coronary artery bypass graft (CABG) surgery with CPB. Perioperative parameters were extracted from the patients' records, and the UF volume was recorded. Acute Kidney Injury Network classification was used to define AKI. Univariable and multivariable logistic regression models were used to predict AKI while controlling for confounding factors.

RESULTS

The study enrolled patients with a mean age of 58.8 ± 11.1 years, 39.2% of whom were female. AKI occurred in 22.5% of patients, with 16.1% (103) experiencing stage I and 6.4% (41) experiencing stage II. The results showed a significant association between UF volume and the risk of developing AKI, with higher UF volumes associated with a higher risk of AKI. In the multivariable analysis, the other predictors of AKI included age, lowest mean arterial pressure (MAP), and red blood cell (RBC) transfusion during CPB.

CONCLUSION

The predictors of postoperative AKI in coronary CABG patients were the volume of UF, age, MAP, and blood transfusion during CPB.

Sudden pump stop may cause air release in oxygenators, 'The Hammer Effect ': An in vitro evaluation

BACKGROUND

Oxygenators, as used in cardiopulmonary bypass (CPB) circuits, are components with good air removal properties. However, under some conditions the semipermeable characteristics of hollow fibers allow air to accidentally enter the blood side of the CPB circuit. This may occur when a fluid in motion is stopped suddenly by which the rapid change in momentum may cause a relative negative pressure drop, the so-called hammer effect. The hammer effect is not yet described in literature related to CPB. The aim of this in vitro study was to reproduce the hammer effect.

METHODS

The in vitro setup consisted of a CPB circuit with a fully occluded roller pump and one of four test oxygenators. The hammer test was performed by a sudden pump stop. The pressure wave was measured and after the test the residual air present in the oxygenator was forced into the arterial line and measured with a bubble detector.

RESULTS

We showed that a sudden pump stop could lead to the hammer effect, represented as a relative negative pressure drop in the arterial line. This hammer effect resulted in air release through the semipermeable fibers as we showed in two of the four tested brands of oxygenators.

CONCLUSIONS

We conclude that the hammer effect may occur before connection of the CPB system to the patient, and this may result in air release into the arterial blood side of the oxygenator. The hammer effect can be caused by clamping of the tubing in combination with a centrifugal pump, or by suddenly stopping the roller pump. With this study we would like to raise awareness of the hammer effect.

Antithrombin supplementation attenuates heparin resistance in plasma spiked with Gla-domainless factor Xa S195A in vitro

BACKGROUND

Andexanet alfa is a Gla-domainless mutant (S195A) factor Xa (GDXa) approved for acute reversal of oral factor Xa inhibitors. Cardiac surgery patients exposed to andexanet before cardiopulmonary bypass often exhibit severe heparin resistance. There is a paucity of data on the effectiveness and optimal dosage of antithrombin use in this setting. The objective of this study was to evaluate the in vitro effect of increased heparin with antithrombin levels on attenuating heparin resistance induced by GDXa.

METHODS

Heparinised normal pooled plasma and cardiopulmonary bypass plasma were spiked with GDXa 4 μM. Tissue factor-activated thrombin generation was used to assess heparin reversal effects of GDXa and restoration of anticoagulation with additional heparin with and without antithrombin. Serum thrombin-antithrombin complex, antithrombin activity, and tissue factor pathway inhibitor were also measured in tissue factor-activated, recalcified cardiopulmonary bypass plasma spiked with GDXa.

RESULTS

In normal pooled plasma, GDXa-induced heparin reversal was mitigated by maintaining a high heparin concentration (12 U ml-1) and supplementing antithrombin (1.5-4.5 μM) based on peak and velocity of thrombin generation. Heparin reversal by GDXa was also demonstrated in cardiopulmonary bypass plasma, but supplementing both heparin (8 U ml-1) and antithrombin (3 μM) attenuated GDXa-induced changes in peak and velocity of thrombin generation by 72.5% and 72.2%, respectively. High heparin and antithrombin levels attenuated thrombin-antithrombin complex formation in tissue factor-activated, GDXa-spiked cardiopulmonary bypass plasma by 85.7%, but tissue factor pathway inhibitor remained depleted compared with control cardiopulmonary bypass plasma.

CONCLUSIONS

Simultaneous supplementation of heparin and antithrombin mitigate GDXa-induced heparin resistance by compensating for the loss of tissue factor pathway inhibitor.

Prevalence and clinical implications of heightened plastic chemical exposure in pediatric patients undergoing cardiopulmonary bypass

BACKGROUND

Phthalate chemicals are used to manufacture plastic medical products, including many components of cardiopulmonary bypass (CPB) circuits. We aimed to quantify iatrogenic phthalate exposure in pediatric patients undergoing cardiac surgery and examine the link between phthalate exposure and postoperative outcomes.

STUDY DESIGN AND METHODS

The study included pediatric patients undergoing (n=122) unique cardiac surgeries at Children's National Hospital. For each patient, a single plasma sample was collected preoperatively and two additional samples were collected postoperatively upon return from the operating room and the morning after surgery. Concentrations of di(2-ethylhexyl) phthalate (DEHP) and its metabolites were quantified using ultra high-pressure liquid chromatography coupled to mass spectrometry.

RESULTS

Patients were subdivided into three groups, according to surgical procedure: (1) cardiac surgery not requiring CPB support, (2) cardiac surgery requiring CPB with a crystalloid prime, and (3) cardiac surgery requiring CPB with red blood cells (RBCs) to prime the circuit. Phthalate metabolites were detected in all patients, and postoperative phthalate levels were highest in patients undergoing CPB with an RBC-based prime. Age-matched (<1 year) CPB patients with elevated phthalate exposure were more likely to experience postoperative complications. RBC washing was an effective strategy to reduce phthalate levels in CPB prime.

DISCUSSION

Pediatric cardiac surgery patients are exposed to phthalate chemicals from plastic medical products, and the degree of exposure increases in the context of CPB with an RBC-based prime. Additional studies are warranted to measure the direct effect of phthalates on patient health outcomes and investigate mitigation strategies to reduce exposure.

Surgical Correction of a Sinus Venosus Atrial Septal Defect with Partial Anomalous Pulmonary Venous Connections Using Cardiac Computed Tomography Imaging and a 3D-Printed Model

Sinus venosus atrial septal defects (SVASDs), concurrent with partial anomalous pulmonary venous connections (PAPVCs), are a rare congenital heart disease in dogs. Surgical correction is essential when clinical signs or significant hemodynamic changes are present. We aimed to report on the successful surgical correction of an SVASD with PAPVCs, using a computed tomography (CT)-based customized 3D cardiac model. A 10-month-old male poodle was referred for corrective surgery for an ASD. Echocardiography confirmed a hemodynamically significant left-to-right shunting flow through an interatrial septal defect and severe right-sided heart volume overload. For a comprehensive diagnosis, a CT scan was performed, which confirmed an SVASD with PAPVCs. A customized 3D cardiac model was used for preoperative decision-making and surgical rehearsal. The defect was repaired using an autologous pericardial patch under a cardiopulmonary bypass (CPB). Temporary pacing was applied for sinus bradycardia and third-degree atrioventricular block. The patient recovered from the anesthesia without further complications. The pacemaker was removed during hospitalization and the patient was discharged without complications 2 weeks post-surgery. At the three-month follow-up, there was no shunting flow in the interatrial septum and the right-sided volume overload had been resolved. The cardiac medications were discontinued, and there were no complications. This report indicates the validity of surgical correction under CPB for an SVASD with PAPVCs, and the advantages of utilizing a CT-based 3D cardiac model for preoperative planning to increase the surgical success rate.

Improved owner quality of life following surgical repair of canine myxomatous mitral valve disease

OBJECTIVE

To determine quality-of-life changes in owners of dogs undergoing mitral valve repair for myxomatous mitral valve disease, up to 12 months postoperatively.

SAMPLE

Owners of 26 dogs undergoing mitral valve repair at a single UK veterinary referral hospital.

METHODS

Dogs underwent mitral valve repair under cardiopulmonary bypass as previously described. Owner quality of life was assessed by self-completion of a previously validated questionnaire preoperatively and at 1, 3, 6, and 12 months postoperatively.

RESULTS

There was a statistically significant improvement in quality-of-life scores from preoperatively up to 3 months postoperatively and a statistically significant improvement in individual question scores up to 6 months postoperatively.

CLINICAL RELEVANCE

Results suggested that owner quality of life is significantly improved following surgical repair of their pet's myxomatous mitral valve disease, and this improvement continues beyond the immediate postoperative period. These results may be useful when counseling owners of surgical candidates and is another useful outcome measure.

Acute severe pulmonary hypertension during weaning from cardiopulmonary bypass for aortic valve replacement surgery: A case report

Pulmonary arterial pressure (PAH) usually increases after cardiopulmonary bypass (CPB), but this normally does not affect weaning off CPB. Here we report a case of severe PAH in a patient with normal left atrial pressure. Prolonging CPB by 45 min did not lead to lower PAH. Given that lung injury can stimulate secretion of vasoconstrictors that trigger PAH, we decided to gradually increase blood flow into the lungs in an effort to restore the balance between pulmonary vasoconstrictors and vasodilators. Pulmonary artery pressure gradually decreased, allowing the patient to be weaned off CPB, after which she recovered uneventfully. Our experience suggests an approach for managing acute, severe PAH after CPB without the need for mechanical circulatory support.

Mortality and morbidity after combined heart and liver transplantation in the failing Fontan: An updated dual center retrospective study

INTRODUCTION

As the adult Fontan population with Fontan associated liver disease continues to increase, more patients are being referred for transplantation, including combined heart and liver transplantation.

METHODS

We report updated mortality and morbidity outcomes after combined heart and liver transplant in a retrospective cohort series of 40 patients (age 14 to 49 years) with Fontan circulation across two centers from 2006-2022.

RESULTS

The 30-day, 1-year, 5-year and 10-year survival rate was 90%, 80%, 73% and 73% respectively. Sixty percent of patients met a composite comorbidity of needing either post-transplant mechanical circulatory support, renal replacement therapy or tracheostomy. Cardiopulmonary bypass time > 283 min (4.7 h) and meeting the composite comorbidity were associated with mortality by Kaplan Meier analysis.

CONCLUSION

Further study to mitigate early mortality and the above comorbidities as well as the high risk of bleeding and vasoplegia in this patient population is warranted.

A novel method to facilitate human leukocyte antigen incompatible heart transplantation

BACKGROUND

Anti-human leukocyte antigen (HLA)-antibody production represents a major barrier to heart transplantation, limiting recipient compatibility with potential donors and increasing the risk of complications with poor waiting-list outcomes. Currently there is no consensus to when desensitization should take place, and through what mechanism, meaning that sensitized patients must wait for a compatible donor for many months, if not years. We aimed to determine if intraoperative immunoadsorption could provide a potential desensitization methodology.

METHODS

Anti-HLA antibody-containing whole blood was added to a Cardiopulmonary bypass (CPB) circuit set up to mimic a 20 kg patient undergoing heart transplantation. Plasma was separated and diverted to a standalone, secondary immunoadsorption system, with antibody-depleted plasma returned to the CPB circuit. Samples for anti-HLA antibody definition were taken at baseline, when combined with the CPB prime (on bypass), and then every 20 min for the duration of treatment (total 180 min).

RESULTS

A reduction in individual allele median fluorescence intensity (MFI) to below clinically relevant levels (<1000 MFI), and in the majority of cases below the lower positive detection limit (<500 MFI), even in alleles with a baseline MFI >4000 was demonstrated. Reduction occurred in all cases within 120 min, demonstrating efficacy in a time period usual for heart transplantation. Flowcytometric crossmatching of suitable pseudo-donor lymphocytes demonstrated a change from T cell and B cell positive channel shifts to negative, demonstrating a reduction in binding capacity.

CONCLUSIONS

Intraoperative immunoadsorption in an ex vivo setting demonstrates clinically relevant reductions in anti-HLA antibodies within the normal timeframe for heart transplantation. This method represents a potential desensitization technique that could enable sensitized children to accept a donor organ earlier, even in the presence of donor-specific anti-HLA antibodies.

A novel versatile concept of cardioplegia delivery in cardiac surgery: The ReverseTWO cardioplegia circuit system

Nowadays, the necessity of having a cardioplegia circuit capable of being adapted in order to administer different types of cardioplegia is strategically fundamental, both for the perfusionist and for the cardiac surgeon. This allows to avoid cutting tubes, guarantees sterility and, most of all, limits the number of cardioplegia circuits for the different strategies of cardiac arrest. The novel "ReverseTWO cardioplegia circuit system" is the development of the precedent "Reverse system" where mainly the 4:1 and crystalloid cardioplegia were used, It has the advantage of allowing immediate change of cardioplegia set-up versus four types of cardioplegia technique, when the strategy is unexpectedly changed before the beginning of cardiopulmonary bypass (CPB), is safe and enables the perfusionist to use one single custom pack of cardioplegia. Two pediatric roller pumps are usually used in our centre for cardioplegia administration; they have a standardized calibration (the leading with ¼ inch and the follower with 1/8 inch) and the circuit consequently has two different tube diameters for the two different pumps. The presence in the circuit of two different shunts coupled with two different coloured clamps allows the immediate set-up for different cardioplegia administration techniques utilizing a colour-coding mechanism The aim of this manuscript is to present the new ReverseTWO Circuit. This novel system allows to administer four different cardioplegic solutions (4:1, 1:4, crystalloid, ematic) based on multiple tubes, which can be selectively clamped, identified through a color-coding method. The specificity of this circuit is the great versatility, which leads to numerous advantages, such as reduced risk of perfusion accident and reduced costs related not only to the purchase of different cardioplegia kits but also to the storage. https://youtu.be/ovJBE4ok2Ds.

Time course changes in insulin sensitivity during cardiac surgery: A retrospective study on intraoperative glycemic management using an artificial pancreas

INTRODUCTION

Glycemic control is essential for improving the prognosis of cardiac surgery, although precise recommendations have not yet been established. Under a constant blood glucose level, the insulin infusion rate correlates with insulin resistance during glycemic control using an artificial pancreas (AP). We conducted this retrospective study to elucidate changes in intraoperative insulin sensitivity as a first step to creating glycemic control guidelines.

METHODS

Fifty-five cardiac surgery patients at our hospital who underwent intraoperative glycemic control using an AP were enrolled. Twenty-three patients undergoing surgical procedures requiring cardiac arrest under hypothermic cardiopulmonary bypass (CPB) with minimum rectal temperatures lower than 32°C, 13 patients undergoing surgical procedures requiring cardiac arrest under hypothermic CPB with minimum rectal temperatures of 32°C, eight patients undergoing on-pump beating coronary artery bypass grafting and 11 patients undergoing off-pump coronary artery bypass were assigned to groups A, B, C and D, respectively. We analyzed the time course of changes in the data derived from glycemic control using the AP.

RESULTS

Significant time course changes were observed in groups A and B, but not in groups C and D. Insulin resistance was induced after the start of hypothermic CPB in groups A and B, and the induced change was not resolved by the rewarming procedure, remaining sustained until the end of surgery.

CONCLUSIONS

Hypothermia is the predominant factor of the induced insulin resistance during cardiac surgery. Thus, careful glycemic management during hypothermic CPB is important. Prospective clinical studies are required to confirm the findings of this study.

Effect of Retrograde Autologous Priming on Coagulation Assessed by Rotation Thromboelastometry in Patients Undergoing Valvular Cardiac Surgery

OBJECTIVES

To investigate the effect of retrograde autologous priming (RAP) on coagulation function using rotation thromboelastometry (ROTEM) in patients undergoing valvular cardiac surgery.

DESIGN

A prospective, randomized, patient- and outcome assessor-blinded study.

SETTING

At a single-center university hospital.

PARTICIPANTS

Patients aged 20 years or older undergoing valvular cardiac surgery.

INTERVENTIONS

A total of 104 patients were allocated to the RAP or control group (1:1 ratio). In the RAP group, the prime was displaced into the collection bag before bypass initiation. ROTEM was performed at the induction of anesthesia, at the beginning of rewarming, and after the reversal of heparinization. Allogeneic plasma products and platelet concentrates were transfused according to ROTEM-based algorithms.

MEASUREMENTS AND MAIN RESULTS

An average volume of 635 ± 114 mL was removed using RAP (from the 1,600 mL initial prime volume). The hematocrit 10 minutes after cardiopulmonary bypass (CPB) was 24.7 ± 3.5% in the control group, and 26.1 ± 4.1% in the RAP group (p = 0.330). ROTEM, including EXTEM, INTEM, and FIBTEM, showed prolonged clotting time and decreased maximal clot firmness after CPB in both groups without intergroup differences. The number of patients who received intraoperative erythrocytes (27% v 25%, control versus RAP, p = 0.823), fresh frozen plasma (14% v 8%, control versus RAP, p = 0.339), cryoprecipitate (21% v 12%, control versus RAP, p = 0.185), or platelet concentrate transfusion (19% v 12%, control versus RAP, p = 0.277) did not differ between the groups.

CONCLUSIONS

Cardiopulmonary bypass induced impaired coagulation function on ROTEM. However, RAP did not improve coagulation function when compared with conventional priming in patients undergoing valvular cardiac surgery.

A review of using CO2-derived variables to detect tissue hypoperfusion during cardiopulmonary bypass

Complications after cardiac surgery with cardiopulmonary bypass (CPB) are associated with increased morbidity and mortality. Early detection and prompt reversion of tissue hypoperfusion during CPB are key factors to reduce organ dysfunction after cardiac surgery. CO2 (carbon dioxide)-derived variables which are easy to assess and routinely available to evaluate the adequacy of macro- and microcirculation may offer important information on the adequacy of the perfusion during CPB. However, since some practical issues remain unsolved in providing a reliable measurement of CO2 removal from the patient, CO2-derived variables are not widely monitoring during CPB. This review aims to demonstrate the basic principles of CO2-derived variables during CPB, the available techniques to assess CO2-derived variables on CPB and the clinically relevant applications.

Immunisation deferral practices surrounding congenital heart surgery

BACKGROUND

Perioperative immunisation administration surrounding congenital heart surgery is controversial. Delayed immunisation administration results in children being at risk of vaccine-preventable illnesses and is associated with failure to complete immunisation schedules. Among children with CHD, many of whom are medically fragile, vaccine-preventable illnesses can be devastating. Limited research shows perioperative immunisation may be safe and effective.

METHODS

We surveyed Pediatric Acute Care Cardiology Collaborative member centres and explored perioperative immunisation practices. We analysed responses using descriptive statistics.

RESULTS

Complete responses were submitted by 35/46 (76%) centres. Immunisations were deferred for any period prior to surgery by 23 (66%) centres and after surgery by 31 (89%) centres. Among those who deferred post-operative immunisation, 20 (65%) required deferral only for patients whose operations required cardiopulmonary bypass. Duration of deferral in the pre- and post-operative periods was variable. Many centres included exceptions to their policy for specific vaccine-preventable illnesses. Almost all (34, 97%) centres administer routine childhood immunisation to patients who remain admitted for prolonged periods.

CONCLUSIONS

Most centres defer routine childhood immunisation for some period before and after congenital heart surgery. Centre specific practices vary. Immunisation deferral confers risk to patients and may not be warranted in this population. Further research would be necessary to understand the immunologic impact of these practices.

External validation of the PC-ECMO score in postcardiotomy veno-arterial extracorporeal membrane oxygenation

Reliable stratification of the risk of early mortality after postcardiotomy veno-arterial extracorporeal membrane oxygenation (V-A-ECMO) remains elusive. In this study, we externally validated the PC-ECMO score, a specific risk scoring method for prediction of in-hospital mortality after postcardiotomy V-A-ECMO. Overall, 614 patients who required V-A-ECMO after adult cardiac surgery were gathered from an individual patient data meta-analysis of nine studies on this topic. The AUC of the logistic PC-ECMO score in predicting in-hospital mortality was 0.678 (95%CI 0.630-0.726; p < 0.0001). The AUC of the logistic PC-ECMO score in predicting on V-A-ECMO mortality was 0.652 (95%CI 0.609-0.695; p < 0.0001). The Brier score of the logistic PC-ECMO score for in-hospital mortality was 0.193, the slope 0.909, the calibration-in-the-large 0.074 and the expected/observed mortality ratio 0.979. 95%CIs of the calibration belt of fit relationship between observed and predicted in-hospital mortality were never above or below the bisector (p = 0.072). The present findings suggest that the PC-ECMO score may be a valuable tool in clinical research for stratification of the risk of patients requiring postcardiotomy V-A-ECMO.

Finding a common definition of heparin resistance in adult cardiac surgery: communication from the ISTH SSC subcommittee on perioperative and critical care thrombosis and hemostasis

Ensuring adequate anticoagulation for patients requiring cardiac surgery and cardiopulmonary bypass (CPB) is important due to the adverse consequences of inadequate anticoagulation with respect to bleeding and thrombosis. When target anticoagulation is not achieved with typical doses, the term heparin resistance is routinely used despite the lack of uniform diagnostic criteria. Prior reports and guidance documents that define heparin resistance in patients requiring CPB and guidance documents remain variable based on the lack of standardized criteria. As a result, we conducted a review of clinical trials and reports to evaluate the various heparin resistance definitions employed in this clinical setting and to identify potential standards for future clinical trials and clinical management. In addition, we also aimed to characterize the differences in the reported incidence of heparin resistance in the adult cardiac surgical literature based on the variability of both target-activated clotting (ACT) values and unfractionated heparin doses. Our findings suggest that the most extensively reported ACT target for CPB is 480 seconds or higher. Although most publications define heparin resistance as a failure to achieve this target after a weight-based dose of either 400 U/kg or 500 U/kg of heparin, a standardized definition would be useful to guide future clinical trials and help improve clinical management. We propose the inability to obtain an ACT target for CPB of 480 seconds or more after 500 U/kg as a standardized definition for heparin resistance in this setting.

Methylprednisolone Does Not Enhance Paraoxonase 1 Activity During Cardiopulmonary Bypass Surgery-A Randomized, Controlled Clinical Trial

OBJECTIVES

Cardiopulmonary bypass (CPB) is linked to systemic inflammatory responses and oxidative stress. Paraoxonase 1 (PON1) is an antioxidant enzyme with a cardioprotective role whose activity is decreased in systemic inflammation and in patients with acute myocardial and global ischemia. Glucocorticoids counteract the effect of oxidative stress by upregulating PON1 gene expression. The authors aimed to determine the effect of methylprednisolone on PON1 activity during cardiac surgery on CPB.

DESIGN

Prospective, randomized, controlled clinical trial.

SETTING

The University Medical Center Ljubljana, Slovenia.

PARTICIPANTS

Forty adult patients who underwent complex cardiac surgery on CPB between February 2016 and December 2017 were randomized into methylprednisolone and control groups (n = 20 each).

INTERVENTIONS

Patients in the methylprednisolone group received 1 g of methylprednisolone in the CPB priming solution, whereas patients in the control group were not given methylprednisolone during CPB.

MEASUREMENTS AND MAIN RESULTS

The effect of methylprednisolone from the CPB priming solution was compared with standard care during CPB on PON1 activity until postoperative day 5. Correlations of PON1 activity with lipid status, mediators of inflammation, and hemodynamics were analyzed also. No significant differences were found between study groups for PON1 activity, high-density lipoprotein, and low-density lipoprotein in any of the measurement intervals (p > 0.016). The methylprednisolone group had significantly lower tumor necrosis factor alpha (p < 0.001) and interleukin-6 (p < 0.001), as well as C-reactive protein and procalcitonin (p < 0.016) after surgery. No significant difference was found between groups for hemodynamic parameters. A positive correlation existed between PON1 and lipid status, whereas a negative correlation was found between PON1 activity and tumor necrosis factor alpha, interleukin-6, and CPB duration.

CONCLUSIONS

Methylprednisolone does not influence PON1 activity during cardiac surgery on CPB.

Off-Pump Coronary Artery Bypass Grafting Does Not Confer Superior Outcomes Among Frail Patients

Off-pump coronary revascularization (OPCAB) has been proposed to benefit patients who are at a greater surgical risk because it avoids the use of extracorporeal circulation. Although, historically, older patients were considered high-risk candidates, recent studies implicate frailty as a more comprehensive measure of perioperative fitness. Yet, the outcomes of OPCAB in frail patients have not been elucidated. Thus, using a national cohort of frail patients, we assessed the impact of OPCAB relative to on-pump coronary revascularization (ONCAB). Patients who underwent first-time elective coronary revascularization were tabulated from the 2010 to 2020 Nationwide Readmissions Database. Frailty was assessed using the previously-validated Johns Hopkins Adjusted Clinical Groups indicator. Multivariable models were used to consider the independent associations between OPCAB and the key outcomes. Of ∼26,529 frail patients, 6,322 (23.8%) underwent OPCAB. After risk adjustment and compared with ONCAB, OPCAB was linked with similar odds of in-hospital mortality but greater likelihood of postoperative cardiac arrest (adjusted odds ratio [AOR] 1.53, confidence interval [CI] 1.13 to 2.07) and myocardial infarction (AOR 1.44, CI 1.23 to 1.69). OPCAB was further associated with greater odds of postoperative infection (AOR 1.22, CI 1.02 to 1.47) but decreased need for blood transfusion (AOR 0.68, CI 0.60 to 0.77). In addition, OPCAB faced a +0.86-day increase in length of stay (CI 0.21 to 1.51) but similar costs (β $1,610, CI -$1,240 to 4,460) relative to ONCAB. Although OPCAB was associated with no difference in mortality compared with ONCAB, it was linked with greater likelihood of postoperative cardiac arrest and myocardial infarction. Our findings demonstrate that ONCAB remains associated with superior outcomes, even in the growing population of frail patients who underwent coronary revascularization.

Plasma hyperosmolality during cardiopulmonary bypass is a risk factor for postoperative acute kidney injury: Results from double blind randomised controlled trial

INTRODUCTION

The study objective was to investigate whether a Ringer's acetate based priming solution with addition of Mannitol and sodium concentrate increases the risk of cardiac surgery associated kidney injury (CSA-AKI).

METHODS

This is a double blind, prospective randomized controlled trial from a single tertiary teaching hospital in Sweden including patients aged ≥65 years (n = 195) admitted for routine cardiac surgery with cardiopulmonary bypass. Patients in the study group received Ringer's acetate 1000 mL + 400 mL Mannitol (60 g) + sodium chloride 40 mL (160 mmol) and heparin 2 mL (10 000 IU) 966 mOsmol (n = 98), while patients in the control group received Ringer's acetate 1400 mL + heparin 2 mL (10 000 IU), 388 mOsmol (n = 97) as pump prime. Acute kidney injury was analysed based on the Kidney Disease Improving Outcomes (KDIGO 1-3) definition.

RESULTS

The overall incidence of CSA-AKI (KDIGO stage 1) was 2.6% on day 1 in the ICU and 5.6% on day 3, postoperatively. The serum creatinine level did not show any postoperative intergroup differences, when compared to baseline preoperative values. Six patients in the Ringer and five patients in the Mannitol group developed CSA-AKI (KDIGO 1-3), all with glomerular filtration rates <60 mL/min/1.73 m2. These patients showed significantly higher plasma osmolality levels compared to preoperative values. Hyperosmolality together with patient age and the duration of the surgery were independent risk factors for postoperative acute kidney injury (KDIGO 1-3).

CONCLUSIONS

The use of a hyperosmolar prime solution did not increase the incidence of postoperative CSA-AKI in this study, while high plasma osmolality alone increased the associated risk by 30%. The data suggests further examination of plasma hyperosmolality as a relative risk factor of CSA-AKI.

Prophylactic corticosteroids for cardiopulmonary bypass in adult cardiac surgery

BACKGROUND

Cardiac surgery triggers a strong inflammatory reaction, which carries significant clinical consequences. Corticosteroids have been suggested as a potential perioperative strategy to reduce inflammation and help prevent postoperative complications. However, the safety and effectiveness of perioperative corticosteroid use in adult cardiac surgery is uncertain. This is an update of the 2011 review with 18 studies added.

OBJECTIVES

Primary objective: to estimate the effects of prophylactic corticosteroid use in adults undergoing cardiac surgery with cardiopulmonary bypass on the: - co-primary endpoints of mortality, myocardial complications, and pulmonary complications; and - secondary outcomes including atrial fibrillation, infection, organ injury, known complications of steroid therapy, prolonged mechanical ventilation, prolonged postoperative stay, and cost-effectiveness.

SECONDARY OBJECTIVE

to explore the role of characteristics of the study cohort and specific features of the intervention in determining the treatment effects via a series of prespecified subgroup analyses.

SEARCH METHODS

We used standard, extensive Cochrane search methods to identify randomised studies assessing the effect of corticosteroids in adult cardiac surgery. The latest searches were performed on 14 October 2022.

SELECTION CRITERIA

We included randomised controlled trials in adults (over 18 years, either with a diagnosis of coronary artery disease or cardiac valve disease, or who were candidates for cardiac surgery with the use of cardiopulmonary bypass), comparing corticosteroids with no treatments. There were no restrictions with respect to length of the follow-up period. All selected studies qualified for pooling of results for one or more endpoints.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were all-cause mortality, and cardiac and pulmonary complications. Secondary outcomes were infectious complications, gastrointestinal bleeding, occurrence of new post-surgery atrial fibrillation, re-thoracotomy for bleeding, neurological complications, renal failure, inotropic support, postoperative bleeding, mechanical ventilation time, length of stays in the intensive care unit (ICU) and hospital, patient quality of life, and cost-effectiveness. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

This updated review includes 72 randomised trials with 17,282 participants (all 72 trials with 16,962 participants were included in data synthesis). Four trials (6%) were considered at low risk of bias in all the domains. The median age of participants included in the studies was 62.9 years. Study populations consisted mainly (89%) of low-risk, first-time coronary artery bypass grafting (CABG) or valve surgery. The use of perioperative corticosteroids may result in little to no difference in all-cause mortality (risk with corticosteroids: 25 to 36 per 1000 versus 33 per 1000 with placebo or no treatment; risk ratio (RR) 0.90, 95% confidence interval (CI) 0.75 to 1.07; 25 studies, 14,940 participants; low-certainty evidence). Corticosteroids may increase the risk of myocardial complications (68 to 86 per 1000) compared with placebo or no treatment (66 per 1000; RR 1.16, 95% CI 1.04 to 1.31; 25 studies, 14,766 participants; low-certainty evidence), and may reduce the risk of pulmonary complications (risk with corticosteroids: 61 to 77 per 1000 versus 78 per 1000 with placebo/no treatment; RR 0.88, 0.78 to 0.99; 18 studies, 13,549 participants; low-certainty evidence). Analyses of secondary endpoints showed that corticosteroids may reduce the incidence of infectious complications (risk with corticosteroids: 94 to 113 per 1000 versus 123 per 1000 with placebo/no treatment; RR 0.84, 95% CI 0.76 to 0.92; 28 studies, 14,771 participants; low-certainty evidence). Corticosteroids may result in little to no difference in incidence of gastrointestinal bleeding (risk with corticosteroids: 9 to 17 per 1000 versus 10 per 1000 with placebo/no treatment; RR 1.21, 95% CI 0.87 to 1.67; 6 studies, 12,533 participants; low-certainty evidence) and renal failure (risk with corticosteroids: 23 to 35 per 1000 versus 34 per 1000 with placebo/no treatment; RR 0.84, 95% CI 0.69 to 1.02; 13 studies, 12,799; low-certainty evidence). Corticosteroids may reduce the length of hospital stay, but the evidence is very uncertain (-0.5 days, 0.97 to 0.04 fewer days of length of hospital stay compared with placebo/no treatment; 25 studies, 1841 participants; very low-certainty evidence). The results from the two largest trials included in the review possibly skew the overall findings from the meta-analysis.

AUTHORS' CONCLUSIONS

A systematic review of trials evaluating the organ protective effects of corticosteroids in cardiac surgery demonstrated little or no treatment effect on mortality, gastrointestinal bleeding, and renal failure. There were opposing treatment effects on cardiac and pulmonary complications, with evidence that corticosteroids may increase cardiac complications but reduce pulmonary complications; however, the level of certainty for these estimates was low. There were minor benefits from corticosteroid therapy for infectious complications, but the evidence on hospital length of stay was very uncertain. The inconsistent treatment effects across different outcomes and the limited data on high-risk groups reduced the applicability of the findings. Further research should explore the role of these drugs in specific, vulnerable cohorts.

Normalizing Anti-Thrombin III for heparin management during routine cardiopulmonary bypass for congenital cardiothoracic surgery: A single institution practice review

INTRODUCTION

Over the past decade, there has been an increase in the use of recombinant Anti-Thrombin III (AT-III) administration during neonatal and pediatric short- and long-term mechanical support for the replacement of acquired deficiencies. Recombinant AT-III (Thrombate) administration is an FDA licensed drug indicated primarily for patients with hereditary deficiency to treat and prevent thromboembolism and secondarily to prevent peri-operative and peri-partum thromboembolism. Herein we propose further use of Thrombate for primary AT-III deficiency of the newborn as well as for acquired dilution and consumption secondary to cardiopulmonary bypass (CPB).

METHODOLOGY

All patients undergoing CPB obtain a preoperative AT-III level. Patients with identified deficiencies are normalized in the OR using recombinant AT-III as a patient load, in the CPB prime, or both. Patient baseline Heparin Dose Response (HDR) is assessed using the Heparin Management System (HMS) before being exposed to AT-III. If a patient load of AT-III is given, a second HDR is obtained and this AT-III Corrected HDR is used as the primary goal during CPB. Once CPB is initiated, an AT-III level is obtained with the first patient blood analysis. A subtherapeutic level results in an additional dose of AT-III. During the rewarm period, a final AT-III level is obtained and AT-III treated once again if subtherapeutic. A retrospective, matched analysis review of practice analyzing two groups, a Study Group (Repeat HDR, May 2022 onward) and Matched Group (Without Repeat HDR, July 2019 to April 2022), for age (D), weight (Kg) and operation was conducted. The focus of the study was to determine any change in heparin sensitivity identified post AT-III patient bolus load in the HDR (U/mL), Slope (U/mL/s), ACT (s), and total amount of heparin on CPB (U) and protamine (mg) used in each group.

RESULTS

No significance was seen in Baseline AT-III (%), post heparin load HDR (U/mL), first CPB ACT (s), first CPB HDR (U/mL), or total CPB heparin (u/Kg) between the two groups. Statistical significance was seen in Baseline ACT (s), Baseline HDR (U/mL), Baseline Slope (U/mL/s), Post Heparin Load ACT (s), first CPB AT-III (%), and Protamine (mg/Kg) (p < .05). No statistical significance was seen in the Study Intragroup between pre versus post AT-III patient load baseline sample in ACT (s), however significance was seen in HDR (U/mL) and Slope (U/mL/s) (p < .05).

CONCLUSION

Implementation of AT-III monitoring and therapy before and during CPB in conjunction with the HMS allows patients to maintain a steady state of anticoagulation with overall less need for excessive heparin replacement and potentially thrombin activation. The result is obtaining a steady state of anticoagulation, a reduced fluctuation in the heparin and ACT levels and a potential for lower co-morbidities associated with prolonged CPB times.

A novel approach to retrograde autologous priming for infant, pediatric and adult populations undergoing congenital heart surgery

INTRODUCTION

Retrograde Autologous Priming (RAP) of cardiopulmonary bypass (CPB) circuits is an effective way to reduce prime volume, commonly through the transfer of prime into separate reservoirs or circuit manipulation. We describe a simple and safe technique for RAP without the need for any circuit modifications or manipulations.

METHODS

For this technique, a separate roller pump for ultrafiltration (UF) is used. After adequate heparinization and arterial cannulation, the UF pump is initiated slowly, removing prime through the effluent of the UF, replacing with the patient's blood from the aortic cannula. Once the arterial line and UF circuit are autologous primed, the arterial head displaces reservoir crystalloid toward the UF circuit at a flow rate equal to the UF pump, displacing the crystalloid prime with blood from the UF circuit, autologous priming the boot and oxygenator with blood, crystalloid again being removed by the effluent. After venous cannulation, the venous line prime is replaced with autologous blood, the crystalloid removed by the effluent of the UF circuit via the arterial head. During RAP, if the patient becomes hypovolemic, either autologous volume is transfused back to the patient, or CPB is initiated, without the need for circuitry modifications.

RESULTS

The patient population in this sample consisted of 63 patients ranging between 6.1 kg and 115.6 kg. The smaller the patient, the less blood volume available for RAP and therefore the less prime volume able to be removed. Overall percent removal increases as our patients size increases compared to total circuit volume.

CONCLUSION

This RAP technique is a safe and effective way to achieve a standardized asanguinous prime for many regardless of patient or circuit size in the absence of contraindications such as low starting hematocrit, emergency surgery or physiologic instability. Most importantly, this potentially reduces the amount of hemodilution patients see from CPB initiation and therefore the lowest nadir hematocrit and consequently the amount of required homologous blood products needed during surgery.

Methodologic Quality and Pharmacotherapy Recommendations for Patient Blood Management Guidelines for Cardiac Surgery on Cardiopulmonary Bypass

Patient blood management (PBM) guidelines for patients undergoing cardiac surgery under cardiopulmonary bypass (CPB) have increased during the past decade, and pharmacotherapy plays an important role in PBM. In the face of the undefined consistency in the methodologic quality and pharmacotherapy recommendations across multiple guidelines, this study exclusively evaluated methodologies of the related guideline development process, and compiled medication recommendations of PBM for cardiac surgery patients. PBM guidelines for cardiac surgery under CPB were searched through some mainstream literature and guideline databases from database establishment to May 15, 2023. Nine guidelines meeting inclusion criteria were included in this study. The quality of the guidelines was evaluated using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool. "Stakeholder involvement" received the lowest mean score of 49.38% in the AGREE II scoring among the guidelines. PBM for cardiac surgery patients spans the perioperative phase. Drug therapy strategies of PBM for cardiac surgery patients involve anemia therapy, perioperative administration of antithrombotic drugs, intraoperative anticoagulation, and the use of hemostatic drugs. Unlike for adults, there is less evidence about the management of antithrombotic drugs and hemostatic drugs for pediatric cardiac surgery patients. Recombinant activated factor VII (rFVIIa) and desmopressin (DDAVP) are not recommended after pediatric cardiac surgery, whereas prothrombin complex concentrate could be considered in clinical trials. As for the controversies regarding the administration of rFVIIa and DDAVP after adult cardiac surgery by different societies, clinicians should exercise their clinical judgment based on individual patient features.

Early chest tube removal on the first postoperative day protocol of an enhanced recovery after cardiac surgery programme is safe

OBJECTIVES

The aim of this study was to assess the safety of early chest tube removal (CTR) protocol on the first postoperative day (POD1) of our enhanced recovery after surgery (ERAS) programme by comparing the risk of postoperative pneumothorax, pleural and pericardial effusion requiring intervention and hospital mortality.

METHODS

All consecutive patients undergoing elective coronary revascularization and/or valve surgery between 2015 and 2021 were assessed in terms of their perioperative management pathways: conventional standard of care (control group) versus standardized systematic perioperative ERAS programme including an early CTR on POD1 (ERAS group). A propensity score matching was applied. The primary end-point was a composite of postoperative pneumothorax, pleural and pericardial effusion requiring intervention and hospital mortality.

RESULTS

A total of 3153 patients were included. Propensity score analysis resulted in two groups well-matched pairs of 1026 patients. CTR on POD1 was significantly increased from 29.5% in the control group to 70.3% in the ERAS group (P < 0.001). The incidence of the primary end-point was 6.4% in the control group and 6.9% in the ERAS group (P = 0.658). Patients in the ERAS group, as compared with control group, had significant lower incidence of bronchopneumonia (9.0% vs 13.5%; P = 0.001) and higher incidence of mechanical ventilation ≤6 hours (84.6% vs 65.2%; P < 0.001), length of intensive care unit ≤1 day (61.2% vs 50.8%; P < 0.001) and hospital ≤6 days (67.3% vs.43.2%; P < 0.001).

CONCLUSIONS

CTR on POD1 protocol can be safely incorporated into a standardized systematic ERAS programme, enabling early mobilization, and contributing to the improvement of postoperative outcomes.

A Comprehensive Patient Blood Management Program During Cardiopulmonary Bypass in Patients Over 60 Years of Age

Purpose

There is currently no consensus on the most appropriate blood transfusion strategy for older adults undergoing cardiovascular surgery. We aimed to investigate the potential benefits of the patient blood management (PBM) program specifically for advanced age patients, and to evaluate the relationship of age and PBM in cardiovascular surgery.

Patients and Methods

We collected data from patients over 60 years old who underwent on-pump cardiovascular surgery. We compared transfusion and clinical outcomes between the pre-PBM and post-PBM groups using a propensity score matching method. Then, we conducted a subgroup analysis within the original cohort, specifically focusing on patients aged of 75 and above with multivariable adjusted models.

Results

Data of 9703 older adults were analyzed. Red blood cell (RBC) transfusion rates during cardiopulmonary bypass (CPB) (31.6% vs 13.1%, P<0.001), during the operation (50.8% vs 39.0%, P<0.001) and after the operation (5.6% vs 3.1%, P<0.001) were significantly reduced, and mortality and the risk of some adverse events were also reduced after the PBM. Subgroup analysis showed that there was no interaction between age and PBM, and advanced age (over age 75) did not modify the effect of PBM program in reducing RBC transfusion (Pinteraction=0.245), on mortality (Pinteration=0.829) and on certain complications.

Conclusion

The comprehensive PBM program could reduce RBC transfusion without adverse outcomes in older patients undergoing CPB. Even patients over age 75 may benefit from a more stringent transfusion indication. Comprehensive blood conservation measures should be applied to optimize the blood management for older patients.

Endothelial extracellular vesicles induce acute lung injury via follistatin-like protein 1

Cardiopulmonary bypass has been speculated to elicit systemic inflammation to initiate acute lung injury (ALI), including acute respiratory distress syndrome (ARDS), in patients after cardiac surgery. We previously found that post-operative patients showed an increase in endothelial cell-derived extracellular vesicles (eEVs) with components of coagulation and acute inflammatory responses. However, the mechanism underlying the onset of ALI owing to the release of eEVs after cardiopulmonary bypass, remains unclear. Plasma plasminogen-activated inhibitor-1 (PAI-1) and eEV levels were measured in patients with cardiopulmonary bypass. Endothelial cells and mice (C57BL/6, Toll-like receptor 4 knockout (TLR4-/-) and inducible nitric oxide synthase knockout (iNOS-/-)) were challenged with eEVs isolated from PAI-1-stimulated endothelial cells. Plasma PAI-1 and eEVs were remarkably enhanced after cardiopulmonary bypass. Plasma PAI-1 elevation was positively correlated with the increase in eEVs. The increase in plasma PAI-1 and eEV levels was associated with post-operative ARDS. The eEVs derived from PAI-1-stimulated endothelial cells could recognize TLR4 to stimulate a downstream signaling cascade identified as the Janus kinase 2/3 (JAK2/3)-signal transducer and activator of transcription 3 (STAT3)-interferon regulatory factor 1 (IRF-1) pathway, along with iNOS induction, and cytokine/chemokine production in vascular endothelial cells and C57BL/6 mice, ultimately contributing to ALI. ALI could be attenuated by JAK2/3 or STAT3 inhibitors (AG490 or S3I-201, respectively), and was relieved in TLR4-/- and iNOS-/- mice. eEVs activate the TLR4/JAK3/STAT3/IRF-1 signaling pathway to induce ALI/ARDS by delivering follistatin-like protein 1 (FSTL1), and FSTL1 knockdown in eEVs alleviates eEV-induced ALI/ARDS. Our data thus demonstrate that cardiopulmonary bypass may increase plasma PAI-1 levels to induce FSTL1-enriched eEVs, which target the TLR4-mediated JAK2/3/STAT3/IRF-1 signaling cascade and form a positive feedback loop, leading to ALI/ARDS after cardiac surgery. Our findings provide new insight into the molecular mechanisms and therapeutic targets for ALI/ARDS after cardiac surgery.

A comparison of single and double arterial cannulation for cardiopulmonary bypass for acute type A aortic surgery: A single center, retrospective observational study

Background: Acute type A aortic dissection (ATAAD) is a cardiovascular emergency and has high mortality and morbidity. We retrospectively compared the effects on outcomes of single arterial cannulation via axillary artery (AAC) with double arterial cannulation via axillary and femoral artery (DAC) in patients who underwent cardiopulmonary bypass (CPB) for ATAAD.Methods: Between January 2017 and May 2021, four hundred 29 patients who underwent aortic arch repair with circulatory arrest for ATAAD were divided into AAC group (n = 283) and DAC group (n = 146). The propensity score-matched (PSM) analysis were performed to compare the characteristics and outcomes of the groups.Results: After PSM (n = 137 in each), the DAC group had a longer duration of CPB (229 vs 244, p = 0.011), aortic cross-clamp time (121 vs 149, p < 0.001), durations of Intensive Care Unit (ICU) stay (7 vs 8, p = 0.014) and hospital stay (19 vs 25, p < 0.001) compared with AAC group. The incidences of dialysis (21% vs. 31%, p = 0.073), postoperative stroke (9% vs 15%, p = 0.143), ECMO support (2% vs 7%, p = 0.077), in-hospital mortality (7% vs 14%, p = 0.071) and follow-up mortality (10% vs 19%, p = 0.059) showed no significant difference between two groups. Multivariate logistic regression analysis showed postoperative ECMO (OR: 16.69, 95% CI: 1.78-156.29; p = 0.014) or stroke (OR: 11.34, 95% CI: 2.64-48.72; p < 0.001) were associated with in-hospital mortality. Univariate Cox regression results showed stroke history (OR: 4.61, 95% CI: 1.90-11.16; p = 0.001), aortic valvuloplasty (OR: 0.21, 95% CI: 0.07-0.59; p = 0.003), postoperative ALT day1 (OR: 1.00, 95% CI: 1.00-1.00; p = 0.008), ECMO (OR: 16.30, 95% CI: 4.78-55.61; p < 0.001), tracheotomy (OR: 3.78, 95% CI: 1.08-13.20; p = 0.037), postoperative stroke (OR: 4.61, 95% CI: 1.90-11.16; p < 0.001) and re-exploration for bleeding (OR: 3.52, 95% CI: 1.01-12.27; p = 0.048) were associated to follow-up mortality.Conclusions: For surgical treatment of ATAAD with CPB when compared to double axillary and femoral artery, single axillary cannulation was associated with shorter durations of CPB and ACC as well as ICU and hospital stays but no with significant difference in mortality.

Critical Illness-Related Corticosteroid Insufficiency (CIRCI) After Pediatric Cardiac Surgery

Although current studies do not support the routine use of corticosteroids after cardiopulmonary bypass in pediatric patients, there is incomplete understanding of the potential hemodynamic contribution of postoperative critical illness-related corticosteroid insufficiency in the intensive care unit. By reviewing the available studies and underlying pathophysiology of these phenomena in critically ill neonates, we can identify a subset of patients that may benefit from optimal diagnosis and treatment of receiving postoperative steroids. A suggested algorithm used at our institution is provided as a guideline for treatment of this high-risk population.

Prolonged Systemic Inflammatory Response Syndrome After Cardiac Surgery

OBJECTIVES

Cardiac surgery induces systemic inflammatory response syndrome (SIRS), leading to higher morbidity and mortality. There are no individualized predictors for worse outcomes or biomarkers for the multifactorial, excessive inflammatory response. The interest of this study was to evaluate whether a systematic use of the SIRS criteria could be used to predict postoperative outcomes beyond infection and sepsis, and if the development of an exaggerated inflammation response could be observed preoperatively.

DESIGN

The study was observational, with prospectively enrolled patients.

SETTING

This was a single institution study in a hospital setting combined with laboratory findings.

PARTICIPANTS

The study included a cohort of 261 volunteer patients.

INTERVENTIONS

Patients underwent cardiac surgery with cardiopulmonary bypass, and were followed up to 90 days. Biomarker profiling was run preoperatively.

MEASUREMENTS AND MAIN RESULTS

Altogether, 17 of 261 (6.4%) patients had prolonged SIRS, defined as fulfilling at least 2 criteria on 4 consecutive postoperative days. During hospitalization, postoperative atrial fibrillation (POAF) was found in 42.2% of patients, and stroke and transient ischemic attack in 3.8% of patients. Prolonged SIRS was a significant predictor of POAF (odds ratio [OR] 4.5, 95% CI 1.2-17.3), 90-day stroke (OR 4.5, 95% CI 1.1-18.0), and mortality (OR 10.7, 95% CI 1.7-68.8). Biomarker assays showed that preoperative nerve growth factor and interleukin 5 levels were associated with prolonged SIRS (OR 5.6, 95%, CI 1.4-23.2 and OR 0.7, 95%, CI 0.4-1.0, respectively).

CONCLUSIONS

Nerve growth factor and interleukin 5 can be used to predict prolonged systemic inflammatory response, which is associated with POAF, stroke, and mortality.

Case report: Blood pressure variation during cardiopulmonary bypass in a patient with multiple sclerosis

Introduction and importance

Multiple sclerosis is known to be associated with both sympathetic and parasympathetic cardiovascular autonomic dysregulation. Thus, patients with multiple sclerosis comorbidity represent a potentially challenging patient population in cardiac surgery, especially in on-pump operations. Despite this, very little is known about the hemodynamics during cardiopulmonary bypass and the optimal perfusion strategy for patients with multiple sclerosis undergoing cardiac operations.

Case presentation

In this report, the authors describe a patient with relapsing-remitting multiple sclerosis, who underwent successful triple valve operation for aortic and mitral stenosis and tricuspid valve insufficiency. Distinct blood pressure variations in form of temporary pressure dips were noted during total cardiopulmonary bypass time as well as during the reperfusion period.

Clinical discussion

Pressure variations were not attributable to surgical, pharmacological or perfusion-related manoeuvres. Thus, they most likely represent symptoms of cardiovascular autonomic dysregulation manifesting during cardiopulmonary bypass. In this patient, blood pressure variations terminated spontaneously and remained within an acceptable range without external correction.

Conclusions

When treating patients with multiple sclerosis comorbidity, the potential pressure variability due to cardiovascular autonomic dysregulation should be taken into consideration to avoid increased blood pressure volatility due to overcorrection or undercorrection during cardiopulmonary bypass.

Optimal timing of SARS-CoV-2 vaccination prior to cardiovascular surgery under cardiopulmonary bypass

BACKGROUND

mRNA vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became common. We investigated the optimal timing for inoculation against SARS-COV-2 in the candidates for cardiac surgery under cardiopulmonary bypass (CPB).

METHODS

In 100 patients with preoperative vaccination, who underwent CPB surgery between July 2021 and February 2022, the IgG against the receptor binding domain (RBD-IgG), with a threshold of >100 binding antibody unit (BAU)/mL for adequate immunity, was measured.

RESULTS

The vaccines, including 87 BNT162b2 (Pfizer/BioNTech) and 13 mRNA-1273 (Moderna), were inoculated at 98.8 ± 59.4 days before surgery. The median RBD-IgG titers before surgery, 1 day after surgery, and 1 month after surgery were 166.8, 100.0, and 84.0 BAU/mL, respectively. The standby interval (SBI) from the vaccination to the surgery showed a significantly negative correlations with the RBD-IgG titer before the surgery (p < 0.001). A cut-off SBI for RBD-IgG >100 BAU/mL before surgery was <81 days with a sensitivity of 76%, specificity of 62%, and area under ROC value of 0.73 (p = 0.03). The patients with SBI <81 days (n = 48) had significantly higher RBD-IgG (>100 BAU/mL) than those with SBI ⩾81 days (n = 52) at all perioperative periods.

CONCLUSIONS

Although 40% of the RBD-IgG titers reduce 1 day after CPB surgery, the patients who received the SARS-COV-2 vaccination within an 81-day window prior to the surgery maintained a desirable RBD-IgG level, even up to 1 month after surgery. It may be important to schedule the surgery no later than 81 days after the vaccination.

Microcirculatory Alterations in Cardiac Surgery: A Comprehensive Guide

Microcirculation is essential for cellular life and its functions. It comprises a complex network of capillaries, arterioles, and venules, which distributes oxygenated blood across and within organs based on regional metabolic demands. Because previous research indicated that organ function is linked to microcirculatory function, it is crucial to maintain sufficient and effective microcirculatory function during major surgery. Impaired microcirculation can lead to inadequate tissue perfusion, potentially resulting in perioperative complications and an unfavorable outcome. Indeed, changes in microcirculation in cardiovascular disease and cardiac surgery have a direct correlation with prolonged stays in the postoperative intensive care unit and high mortality rates within 30 days. Additionally, cardiopulmonary bypass, a regularly employed method in cardiac surgery, has been proven to induce microcirculatory malfunction and, thus, lead to postoperative multiple organ dysfunction. As global hemodynamic parameters can remain stable or improve, whereas microcirculation is still compromised, tracking microcirculatory variables could lead to the development of targeted microcirculatory treatment within hemodynamic management. Therefore, it is necessary to enhance the use of microcirculatory monitoring in the medical domain to assist physicians in the therapeutic management of patients undergoing cardiac surgery. This potentially can lead to better hemodynamic management and outcomes. This review article concentrates on the use of handheld video microscopes for real-time microcirculatory assessment of cardiac surgery patients in the immediate and early postoperative period. Emphasis is placed on integrating microcirculatory monitoring with conventional hemodynamic monitoring in the therapeutic management of patients undergoing cardiac surgery.

Encouraging results of blood conservation in neonatal open-heart surgery

OBJECTIVE

To report early outcomes of blood conservation in neonatal open-heart surgery.

METHODS

Ninety-nine patients undergoing neonatal open-heart surgery during the implementation of a blood conservation program between May 2021 and February 2023 were reviewed. Patients either received traditional blood management (blood prime, n = 43) or received blood conservation strategies (clear prime, n = 56). Baseline characteristics and outcomes were compared between groups.

RESULTS

There was no difference in body weight (median, 3.2 kg vs 3.3 kg; P = .83), age at surgery (median, 5 days vs 5 days; P = .37), distribution of The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Categories categories or duration of cardiopulmonary bypass. Patients in the clear prime group had higher preoperative hematocrit (median, 41% vs 38%; P < .01), shorter postoperative mechanical ventilation time (median, 48 hours vs 92 hours; P = .02) and postoperative intensive care unit length of stay (median, 6 days vs 9 days; P < .01) than patients in the blood prime group. Fourteen patients (25%) in the clear prime group, including 1 Norwood patient, were discharged without any transfusion. Among patients within the clear prime group, hospitalizations without blood exposure were associated with higher preoperative hematocrit (median, 43% vs 40%; P = .02), shorter postoperative mechanical ventilation times (median, 22 hours vs 66 hours; P = .01) and shorter postoperative hospital stays (median, 10 days vs 15 days; P = .02).

CONCLUSIONS

Bloodless surgery is possible in a significant proportion of neonates undergoing open-heart surgery, including the Norwood operation, even in the early stages of experience. Early clinical results are favorable but long-term follow-up and continued efforts are warranted to prove safety and reproducibility.

Safety of bloodless open-heart surgery on cardiopulmonary bypass in selected children: A single center experience with minimal invasive extracorporeal circulation

INTRODUCTION

Bloodless cardiac surgery refers to open-heart surgery without blood or blood products. The cardiopulmonary bypass (CPB) circuits are primed with crystalloid solely, and there is no intraoperative blood transfusion.

METHODS

Our program considers bloodless congenital cardiac surgery with a minimal invasive extracorporeal circulation (MiECC) system for patients above 10 kg of weight. We performed a single-center retrospective cohort study of all consecutive patients undergoing bloodless cardiac surgery for congenital heart defects between January 2016 and December 2018.

RESULTS

A total of 164 patients were reviewed (86 male and 78 female) at a median age of 9.6 years (interquartile range (IQR), 4.5-15), a weight of 32 kg (IQR, 16-55), preoperative hemoglobin 13.7 g/dl (IQR, 12.6-14.9), and preoperative hematocrit of 40.4% (IQR, 37.2-44.3). Median CPB time was 81.5 min (IQR, 58-125), and median hematocrit coming off CPB was 26% (IQR, 23-29.7). The congenital heart surgery risk (STAT) category was distributed in STAT 1 for 70, STAT 2 for 80, STAT 3 for 9, and STAT 4 for 5 patients. Most patients (95%) were extubated in the operating room with a low complication rate during the hospital stay (14.6%). Only 6 (4%) patients needed a blood transfusion during the postoperative period, with a higher incidence of complications during the hospital course (p < 0.001).

CONCLUSIONS

Bloodless congenital heart surgery with MiECC system is safe in low-surgical-risk patients. Our patients had a low rate of complications and short hospital stays.

Congenital Absence of Pericardium: A Case Report and Technical Considerations in Cardiac Surgery

This case report describes a rare instance of left-sided congenital pericardial agenesis (CPA) encountered during coronary artery bypass grafting (CABG) in a 77-year-old male. In this unique case, the presence of an unusual strip of left pericardium containing the phrenic nerve posed significant surgical challenges. Special attention was required for the graft lay, ensuring adequate filling of the heart during assessment before closure, as well as emphasis on the need for generous graft length. Additionally, the evaluation of graft positioning prior to cardiopulmonary bypass was crucial. Despite these complexities, CABG was successfully performed with no complications to note. This case underscores the importance of adaptability in surgical technique to manage the unique challenges posed by CPA, leading to a positive outcome despite the atypical cardiac anatomy.

Incidentally discovered cold hemagglutinins within autologous blood bag and cardioplegia line in a patient with a recent history of COVID-19 undergoing coronary artery surgery

INTRODUCTION

Cold agglutinin disease (CAD) is a rare autoimmune disorder characterized by destruction (hemolysis) of erythrocytes. In CAD, autoantibodies that cause agglutination at temperature of optimum +3-+4 ℃ degree cause symptoms. It is known that CAD often occurs after viral infections. Also, it has been reported in case reports that COVID-19 disease can cause CAD.

CASE REPORT

46-year-old male patient with a history of diabetes mellitus and hypertension presented to outpatient clinic in our department to have CABG surgery. He recovered from COVID-19 disease 1.5 months ago. Cardiopulmonary bypass was initiated and the cross-clamp was placed and antegrade Delnido cardioplegia solution was started to be given at +4 ℃. It was observed that the cardioplegia line was agglutinated. On the other hand, it was seen that the autologous blood taken by the anesthesiologist was also agglutinated and formed air bubbles and became unusable. X-clamp was removed and the heart rhythm recovered. The patient was consulted to hematology during postoperative intensive care follow-ups. The cold agglutinin test performed at of +4 ℃ was reported as positive. In this case, we associated the CAD with covid-19 for three main reasons. First one, the patient's complaints about CAD started after COVID-19 disease. Secondly, in the national health archive, the patient's pre-COVID-19 blood tests were completely normal but it was seen that LDH increased and RBC-HCT incompatibility started after COVID-19. As the third, when we search the literature, we have seen the COVID-19 related CAD in many case reports published by hematologists.

CONCLUSION

With the rare cold agglutinin disease, it seems that we will encounter it more often after the COVID-19 pandemic. Except for deep hypothermia, the most important problem is seen during cardioplegia administration. Therefore, non-blood cardioplegia can be lifesaving.

A two-circuit strategy for intraoperative extracorporeal support during single lung transplantation in a patient bridged with venovenous extracorporeal membrane oxygenation

Venovenous extracorporeal membrane oxygenation is increasingly used as a bridging strategy in decompensating patients awaiting lung transplantation. Various approaches for continuing support intraoperatively have been previously described. A two-circuit strategy that uses the in situ venovenous extracorporeal membrane oxygenation circuit supplemented with peripheral cardiopulmonary bypass allows for diversion of native cardiac output away from the transplanted lung as well as seamless continuation of venovenous extracorporeal membrane oxygenation postoperatively.

Cardiopulmonary bypass management and acute kidney injury in cardiac surgery patients

BACKGROUND

Cardiopulmonary bypass (CPB) ensures tissue oxygenation during cardiac surgery. New technology allows continuous registration of CPB variables during the operation. The aim of the present investigation was to study the association between CPB management and the risk of postoperative acute kidney injury (AKI).

METHODS

This observational study based on prospectively registered data included 2661 coronary artery bypass grafting and/or valve patients operated during 2016-2020. Individual patient characteristics and postoperative outcomes collected from the SWEDEHEART registry were merged with CPB variables automatically registered every 20 s during CPB. Associations between CPB variables and AKI were analyzed with multivariable logistic regression models adjusted for patient characteristics.

RESULTS

In total, 387 patients (14.5%) developed postoperative AKI. After adjustments, longer time on CPB and aortic cross-clamp, periods of compromised blood flow during aortic cross-clamp time, and lower nadir hematocrit were associated with the risk of AKI, while mean blood flow, bladder temperature, central venous pressure, and mixed venous oxygen saturation were not. Patient characteristics independently associated with AKI were advanced age, higher body mass index, hypertension, diabetes mellitus, atrial fibrillation, lower left ventricular ejection fraction, estimated glomerular filtration rate <60 or >90 mL/min/m2 , and preoperative hemoglobin concentration below or above the normal sex-specific range.

CONCLUSIONS

To reduce the risk of AKI after cardiac surgery, aortic clamp time and CPB time should be kept short, and low hematocrit and periods of compromised blood flow during aortic cross-clamp time should be avoided if possible.