The Papworth Bleeding Risk Score: a stratification scheme for identifying cardiac surgery patients at risk of excessive early postoperative bleeding

Does heparin rebound lead to postoperative blood loss in patients undergoing cardiac surgery with cardiopulmonary bypass?

BACKGROUND

Heparin rebound is a common observed phenomenon after cardiac surgery with CPB and is associated with increased postoperative blood loss. However, the administration of extra protamine may lead to increased blood loss as well. Therefore, we want to investigate the relation between heparin rebound and postoperative blood loss and the necessity to provide extra protamine to reverse heparin rebound.

METHODS

We searched PubMed, Cochrane, EMBASE, Google Scholar and Web of Science to review the question: "Does heparin rebound lead to postoperative blood loss in patients undergoing cardiac surgery with cardiopulmonary bypass." Combination of search words were framed within four major categories: heparin rebound, blood loss, cardiac surgery and cardiopulmonary bypass. All studies that met our question were included. Quality assessment was performed using the Cochrane risk of bias (RoB2) tool for randomized controlled trials and the risk of bias in non-randomized studies of intervention (ROBINS-I) for non-randomised trials.

RESULTS

4 randomized and 17 non-randomized studies were included. The mean incidence of heparin rebound was 40%. The postoperative heparin levels, due to heparin rebound, were often below or equal to 0.2 IU/mL. We could not demonstrate an association between heparin rebound and postoperative blood loss or transfusion requirements. However the quality of evidence was poor due to a broad variety of definitions of heparin rebound, measured by various coagulation tests and studies with small sample sizes.

CONCLUSION

The influence of heparin rebound on postoperative bleeding seems to be negligible, but might get significant in conjunction with incomplete heparin reversal or other coagulopathies. For that reason, it might be useful to get a picture of the entire coagulation spectrum after cardiac surgery, as can be done by the use of a viscoelastic test in conjunction with an aggregometry test.

Risk of Transfusion in Isolated Coronary Artery Bypass Graft: Models Developed From The Society of Thoracic Surgeons Database

BACKGROUND

Perioperative blood transfusion is associated with adverse outcomes and higher costs after coronary artery bypass graft (CABG) surgery. We developed risk assessments for patients' probability of perioperative transfusion and the expected transfusion volume to improve clinical management and resource use.

METHODS

Among 1,266,545 consecutive (2008-2016) isolated CABG operations in The Society of Thoracic Surgeons Adult Cardiac Surgery Database, 657,821 (51.9%) received perioperative transfusions of red blood cells (RBC), fresh frozen plasma (FFP), cryoprecipitate, and/or platelets. We developed "full" models to predict perioperative transfusion of any blood product, and of RBC, FFP, or platelets. Using least absolute shrinkage and selection operator model selection, we built a rapid risk score based on 5 variables (age, body surface area, sex, preoperative hematocrit, and use of intra-aortic balloon pump).

RESULTS

C statistics for the full model were 0.785, 0.815, 0.707, and 0.699 for any blood product, RBC, FFP, and platelets, respectively. C statistics for rapid risk assessments were 0.752, 0.785, 0.670, and 0.661 for any blood product, RBC, FFP, and platelets, respectively. The observed vs expected risk plots showed strong calibration for full models and risk assessment tools; absolute differences between observed and expected risks of transfusion were <10.8% in each percentile of expected risk. Risk assessment-predicted probabilities of transfusion were strongly and nonlinearly associated (P < .0001) with total units transfused.

CONCLUSIONS

These robust and well-calibrated risk assessment tools for perioperative transfusion in CABG can inform surgeons regarding patients' risks and the number of RBC, FFP, and platelets units they can expect to need. This can aid in optimizing outcomes and increasing efficient use of blood products.

Impact of intraoperative blood products, fluid administration, and persistent hypothermia on bleeding leading to reexploration after cardiac surgery

OBJECTIVE

Risk factors for severe postoperative bleeding after cardiac surgery remain multiple and incompletely elucidated. We evaluated the impact of intraoperative blood product transfusions, intravenous fluid administration, and persistently low core body temperature (CBT) at intensive care unit arrival on risk of perioperative bleeding leading to reexploration.

METHODS

We retrospectively queried our tertiary care center's Society of Thoracic Surgeons Institutional Database for all index, on-pump, adult cardiac surgery patients between July 2016 and September 2022. Intraoperative fluid (crystalloid and colloid) and blood product administrations, as well as perioperative CBT data, were harvested from electronic medical records. Linear and nonlinear mixed models, treating surgeon as a random effect to account for inter-surgeon practice differences, were used to assess the association between above factors and reexploration for bleeding.

RESULTS

Of 4037 patients, 151 (3.7%) underwent reexploration for bleeding. Reexplored patients experienced remarkably greater postoperative morbidity (23% vs 6%, P < .001) and 30-day mortality (14% vs 2%, P < .001). In linear models, progressively increasing IV crystalloid administration (adjusted odds ratio, 1.11, 95% confidence interval, 1.03-1.19) and decreasing CBT on intensive care unit arrival (adjusted odds ratio, 1.20; 95% confidence interval, 1.05-1.37) were associated with greater risk of bleeding leading to reexploration. Nonlinear analysis revealed increasing risk after ∼6 L of crystalloid administration and a U-shaped relationship between CBT and reexploration risk. Intraoperative blood product transfusion of any kind was not associated with reexploration.

CONCLUSIONS

We found evidence of both dilution- and hypothermia-related effects associated with perioperative bleeding leading to reexploration in cardiac surgery. Interventions targeting modification of such risk factors may decrease the rate this complication.

Investigation of von Willebrand factor multimer abnormalities before and after aortic valve replacement using the Hydragel-5 assay

BACKGROUND

Severe aortic stenosis (sAS) is associated with acquired von Willebrand syndrome (AVWS) by loss of high-molecular-weight multimers (HMWM) of von Willebrand factor (VWF), potentially resulting in perioperative bleeding. Analysis of VWF multimers remains challenging. Recently, the new, rapid Hydragel 5 assay has been developed, using electrophoretic protein separation for dividing VWF-multimers into low (LMWM), intermediate (IMWM), and HMWM, the hemostatically active part of VWF. Here, we evaluated its impact on predicting blood loss in presence of AVWS after surgical aortic valve replacement (SAVR).

METHODS

We prospectively examined 52 patients (age: 68 ± 7 years; 54 % male) admitted to SAVR. They were divided in two groups (A: normal VWF, n = 28; B: abnormal VWF, n = 24, defined as VWF-activity/antigen (VWF:Ac/Ag)-ratio < 0.7 and/or HMWM loss). Blood samples and echocardiographic data were collected before, seven days and three months after SAVR. Blood loss and transfusions were recorded.

RESULTS

Baseline characteristics and clinical data were similar in both groups. HMWM loss was present in 38.5 % of all patients. HMWM, the VWF:Ac/Ag- and HMWM/(IMWM+LMWM)-ratios were significantly decreased preoperatively in group B but normalized after SAVR. Bleeding, re-thoracotomy and transfusion rates were comparable. HMWM loss was inversely correlated with the peak aortic gradient (Pmax) and positively with the aortic valve area (AVA), while HMWM/(IMWM+LMWM)-ratio negatively correlated with the mean aortic gradient (Pmean).

CONCLUSION

HMWM and HMWM/(IMWM+LMWM)-ratio inversely correlate with severity of AS and normalize after SAVR. The Hydragel-5 assay's might be valuable for routine diagnostics to assess bleeding risk and postoperative normalization of AS and VWF abnormalities in SAVR patients.

To be or not to be on: aspirin and coronary artery bypass graft surgery

Aspirin's role in secondary prevention for patients with known coronary artery disease (CAD) is well established, validated by numerous landmark trials over the past several decades. However, its perioperative use in coronary artery bypass graft (CABG) surgery remains contentious due to the delicate balance between the risks of thrombosis and bleeding. While continuation of aspirin in patients undergoing CABG following acute coronary syndrome is widely supported due to the high risk of re-infarction, the evidence is less definitive for elective CABG procedures. The literature indicates a significant benefit of aspirin in reducing cardiovascular events in CAD patients, yet its impact on perioperative outcomes in CABG surgery is less clear. Some studies suggest increased bleeding risks without substantial improvement in cardiac outcomes. Specific to elective CABG, evidence is mixed, with some data indicating no significant difference in thrombotic or bleeding complications whether aspirin is continued or withheld preoperatively. Advancements in pharmacological therapies and perioperative care have evolved significantly since the initial aspirin trials, raising questions about the contemporary relevance of earlier findings. Individualized patient assessments and the development of risk stratification tools are needed to optimize perioperative aspirin use in CABG surgery. Further research is essential to establish clearer guidelines and improve patient outcomes. The objective of this review is to critically evaluate the existing evidence into the optimal management of perioperative aspirin in elective CABG patients.

Impact of introduction of a goal directed transfusion strategy in a patient blood management program: A single cardiac surgery centre experience

BACKGROUND

The aim of this retrospective and observational study was to analyse the impact of the introduction of a goal directed transfusion (GDT) strategy based on a viscoelastic test (ROTEM®) and specific procoagulant products in a patient blood management (PBM) Program on blood product use and perioperative bleeding in a single cardiac surgery centre.

STUDY DESIGN AND METHODS

Patient population underwent cardiac surgery from 2011 to 2021 was divided in two groups based on PBM protocol used (G#11-14, years 2011-2014, G#15-21, years 2015-2021) and compared for the following variables: intraoperative and postoperative transfusions of packed red blood cell and any procoagulant products, postoperative drain blood loss volume and rate of re-exploration surgery. The second program was defined after the introduction of a GDT protocol based on viscoelastic tests and specific procoagulant products.

RESULTS

After the introduction of a GDT protocol, about 80% less amongst patients were transfused with fresh frozen plasma and any procoagulant product (p < 0.001 for both phases). Moreover, similar results were obtained with PRBC transfusions (p < 0.001) and drain blood loss volume (p = 0.006) in the postoperative phase. The main factors affecting the use of any procoagulant and PBRC transfusion in the multivariate logistic regression analysis was Group (2 versus 1, OR 0.207, p < 0.001) and preoperative haemoglobin (OR 0.728, p < 0.001), respectively.

DISCUSSION

In our experience, a GDT strategy for the diagnosis and treatment of the coagulopathy in patients undergone cardiac surgery led to a significant reduction in bleeding and transfusion.

Strategies to prevent blood loss and reduce transfusion in emergency general surgery, WSES-AAST consensus paper

Emergency general surgeons often provide care to severely ill patients requiring surgical interventions and intensive support. One of the primary drivers of morbidity and mortality is perioperative bleeding. In general, when addressing life threatening haemorrhage, blood transfusion can become an essential part of overall resuscitation. However, under all circumstances, indications for blood transfusion must be accurately evaluated. When patients decline blood transfusions, regardless of the reason, surgeons should aim to provide optimal care and respect and accommodate each patient's values and target the best outcome possible given the patient's desires and his/her clinical condition. The aim of this position paper was to perform a review of the existing literature and to provide comprehensive recommendations on organizational, surgical, anaesthetic, and haemostatic strategies that can be used to provide optimal peri-operative blood management, reduce, or avoid blood transfusions and ultimately improve patient outcomes.

POBS-Card, a new score of severe bleeding after cardiac surgery: Construction and external validation

Objective

Bleeding after cardiac surgery leads to poor outcomes. The objective of the study was to build the PeriOperative Bleeding Score in Cardiac surgery (POBS-Card) to predict bleeding after cardiac surgery.

Methods

We conducted a retrospective cohort study in 2 academic hospitals (2016-2019). Inclusion criteria were adult patients after cardiac surgery under cardiopulmonary bypass. Exclusion criteria were heart transplantation, assistance, aortic dissection, and preoperative hemostasis diseases. Bleeding was defined by the universal definition for perioperative bleeding score ≥2. POBS-Card score was built using multivariate regression (derivation cohort, one center). The performance diagnosis was assessed using the area under the curve in a validation cohort (2 centers) and compared with other scores.

Results

In total, 1704 patients were included in the derivation cohort, 344 (20%) with bleeding. Preoperative factors were body mass index <25 kg/m2 (odds ratio [OR], 1.48 [1.14-1.93]), type of surgery (redo: OR, 1.76 [1.07-2.82]; combined: OR, 1.81 [1.19-2.74]; ascendant aorta: OR, 1.56 [1.02-2.38]), ongoing antiplatelet therapy (single: OR, 1.50 [1.09-2.05]; double: OR, 2.00 [1.15-3.37]), activated thromboplastin time ratio >1.2 (OR, 1.44 [1.03-1.99]), prothrombin ratio <60% (OR, 1.91 [1.21-2.97]), platelet count <150 g/L (OR, 1.74 [1.17-2.57]), and fibrinogen <3 g/L (OR, 1.33 [1.02-1.73]). In the validation cohort of 597 patients, the area under the curve was 0.645 [0.605-0.683] and was superior to other scores (WILL-BLEED, Papworth, TRUST, TRACK). A threshold >14 predicted bleeding with a sensitivity of 50% and a specificity of 73%.

Conclusions

POBS-Card score was superior to other scores in predicting severe bleeding after cardiac surgery. Performances remained modest, questioning the place of these scores in the perioperative strategy of bleeding-sparing.

Safety outcomes of anti-platelet therapy post coronary artery bypass graft surgery: A systematic review and network meta-analysis of randomized control trials

BACKGROUND

Antiplatelet therapy is used to decrease the risk of graft failure post coronary artery bypass graft surgery. We aimed to compare dual antiplatelet therapy (DAPT) with monotherapy along with a comparison of Aspirin, Ticagrelor, Aspirin+Ticagrelor (A+T) and Aspirin+Clopidogrel (A+C) to determine the major and minor bleeding risk, risk of postoperative myocardial infarction (MI), stroke, and all-cause mortality (ACM).

METHODS

Randomized Controlled Trials comparing the four groups were included. Odds ratio (OR) and Absolute Risk (AR) were employed to assess the mean and standard deviation (SD) with 95% confidence intervals (CI). The Bayesian random-effects model was used for statistical analysis. Risk difference and Cochran Q tests were used to calculate rank probability (RP) and heterogeneity, respectively.

RESULTS

We included 10 trials, consisting of 21 arms and 3926 patients. For the risk of major and minor bleed, A + T and Ticagrelor showed the lowest mean value of 0.040 (0.043) and 0.067 (0.073), respectively, and the highest RP of being the safest group. While a direct comparison between DAPT and monotherapy resulted in an OR of 0.57 [0.34, 0.95] for the risk of minor bleed. A + T was found to have the highest RP and the lowest mean value in terms of ACM, MI, and stroke.

CONCLUSION

No significant difference was found between monotherapy or dual-antiplatelet therapy for the major bleeding risk safety outcome, however DAPT was found to have a significantly higher rate of minor bleeding complications post-CABG. DAPT should be considered as the antiplatelet modality of choice post-CABG.

Development and validation of a postoperative bleeding complications prediction model in infective endocarditis

OBJECTIVES

Bleeding complications are one of the most serious postoperative complications after cardiac surgery and are associated with high mortality, especially in patients with infective endocarditis (IE). Our objectives were to identify the risk factors and develop a prediction model for postoperative bleeding complications in IE patients.

METHODS

The clinical data of IE patients treated from October 2013 to January 2022 were reviewed. Multivariate logistic regression analysis was used to evaluate independent risk factors for postoperative bleeding complications and develop a prediction model accordingly. The prediction model was verified in a temporal validation cohort. The performance of the model was evaluated in terms of its discrimination power, calibration, precision, and clinical utility.

RESULTS

A total of 423 consecutive patients with IE who underwent surgery were included in the final analysis, including 315 and 108 patients in the training cohort and validation cohort, respectively. Four variables were selected for developing a prediction model, including platelet counts, systolic blood pressure, heart failure and vegetations on the mitral and aortic valves. In the training cohort, the model exhibited excellent discrimination power (AUC = 0.883), calibration (Hosmer-Lemeshow test, P = 0.803), and precision (Brier score = 0.037). In addition, the model also demonstrated good discrimination power (AUC = 0.805), calibration (Hosmer-Lemeshow test, P = 0.413), and precision (Brier score = 0.067) in the validation cohort.

CONCLUSIONS

We developed and validated a promising risk model with good discrimination power, calibration, and precision for predicting postoperative bleeding complications in IE patients.

Organizational and budget impact model (OBIM) of SAME a new autotransfusion medical device

OBJECTIVES

This study aimed to assess the budget and organizational impact of progressively replacing the intraoperative cell salvage centrifugation-based systems currently installed in French hospitals with the SAME system, a new autotransfusion medical device.

METHODS

An Organizational and Budget Impact Model (OBIM) was developed based on two methodological guidelines issued by the French Health Authority (Haute Autorité de Santé, HAS). The OBIM was also developed based on a pragmatic literature review, hospital data and hospital pharmacists' expertise.

RESULTS

Considering an average hospital cohort of 600 cardio-thoracic surgery patients, with 57% experiencing mild hemorrhages, 23% moderate hemorrhages, and 20% massive hemorrhages, and a SAME market share of 33% in Year 1, the implementation of SAME resulted in significant savings. With an average allogeneic transfusion of 4.19 packed red blood cells (RBC) and 0.62 platelet concentrate per patient based on National Hemovigilance Report of the ANSM (French National Agency for the Safety of Medicines and Health Products) and when using SAME system a reduction of 45% of RBC transfusion associated with a reduction of 60% and 90% of platelet use for moderate and massive hemorrhages respectively, the first year annual saving amounted to €44,601 and the cumulated saving over 5 years to €535,206.

DISCUSSION

This model structure was developed based on overall hospitals' needs and acknowledged guidelines, with inputs based on French literatures and hospital data, so findings were specifics to a context. Among the inputs, the number of annual SAME procedure is not based on device capability but rather on hospital capability with the number of operating rooms used for cardio-thoracic surgery equipped with the device.

CONCLUSIONS

The results of this OBIM demonstrated the economic and organizational benefits of SAME for hospitals. This benefit results mainly of a reduction in the use of allogeneic blood products (RBCs, platelets).

Using machine learning to predict bleeding after cardiac surgery

OBJECTIVES

The primary objective was to predict bleeding after cardiac surgery with machine learning using the data from the Australia New Zealand Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database, cardiopulmonary bypass perfusion database, intensive care unit database and laboratory results.

METHODS

We obtained surgical, perfusion, intensive care unit and laboratory data from a single Australian tertiary cardiac surgical hospital from February 2015 to March 2022 and included 2000 patients undergoing cardiac surgery. We trained our models to predict either the Papworth definition or Dyke et al.'s universal definition of perioperative bleeding. Our primary outcome was the performance of our machine learning algorithms using sensitivity, specificity, positive and negative predictive values, accuracy, area under receiver operating characteristics curve (AUROC) and area under precision-recall curve (AUPRC).

RESULTS

Of the 2000 patients undergoing cardiac surgery, 13.3% (226/2000) had bleeding using the Papworth definition and 17.2% (343/2000) had moderate to massive bleeding using Dyke et al.'s definition. The best-performing model based on AUPRC was the Ensemble Voting Classifier model for both Papworth (AUPRC 0.310, AUROC 0.738) and Dyke definitions of bleeding (AUPRC 0.452, AUROC 0.797).

CONCLUSIONS

Machine learning can incorporate routinely collected data from various datasets to predict bleeding after cardiac surgery.

Development of a Novel Prediction Model for Red Blood Cell Transfusion Risk in Cardiac Surgery

BACKGROUND

Cardiac surgery is a complex and invasive procedure that often requires blood transfusions to replace the blood lost during surgery. Blood products are a scarce and expensive resource. Therefore, it is essential to develop a standardized approach to determine the need for blood transfusions in cardiac surgery. The main objective of our study is to develop a simple prediction model for determining the risk of red blood cell transfusion in cardiac surgery.

METHODS

Retrospective cohorts of adult patients who underwent cardiac surgery between 2017 and 2019 were studied to identify hypothetical predictors of blood transfusion. Finally, a multivariable logistic regression model was developed to predict the risk of transfusion in cardiac surgery using the AUC and the Hosmer-Lemeshow goodness-of-fit test.

RESULTS

We included 1234 patients who underwent cardiac surgery. Of the entire cohort, 875 patients underwent a cardiac procedure 69.4% [CI 95% (66.8%; 72.0%)]; 119 patients 9.6% [CI 95% (8.1%; 11.4%)] underwent a combined procedure, and 258 patients 20.9% [CI 95% (18.7; 23.2)] underwent other cardiac procedures. The median perioperative hemoglobin was 13.0 mg/dL IQR (11.7; 14.2). The factors associated with the risk of transfusion were age > 60 years OR 1.37 CI 95% (1.02; 1.83); sex female OR 1.67 CI 95% (1.24; 2.24); BMI > 30 OR 1.46 (1.10; 1.93); perioperative hemoglobin < 14 OR 2.11 to 51.41 and combined surgery OR 3.97 CI 95% (2.19; 7.17). The final model shows an AUC of 80.9% for the transfusion risk prediction [IC 95% (78.5-83.3%)]; p < 0.001].

CONCLUSIONS

We have developed a model with good discriminatory ability, which is more parsimonious and efficient than other models.

Albumin Infusion and Blood Loss After Cardiac Surgery

BACKGROUND

In the recent ALBICS (ALBumin In Cardiac Surgery) trial, 4% albumin used for cardiopulmonary bypass priming and volume replacement increased perioperative bleeding compared with Ringer acetate. In the present exploratory study, albumin-related bleeding was further characterized.

METHODS

Ringer acetate and 4% albumin were compared in a randomized, double-blinded fashion in 1386 on-pump adult cardiac surgery patients. The study end points for bleeding were the Universal Definition of Perioperative Bleeding (UDPB) class and its components.

RESULTS

The UDPB bleeding grades were higher in the albumin group than the Ringer group: "insignificant" (albumin vs Ringer: 47.5% vs 62.9%), "mild" (12.7% vs 8.9%), "moderate" (28.7% vs 24.4%), "severe" (10.2% vs 3.2%), and "massive" (0.9% vs. 0.6%; P < .001). Patients in the albumin group received red blood cells (45.2% vs 31.5%; odds ratio [OR], 1.80; 95% CI, 1.44-2.24; P < .001), platelets (33.3% vs 21.8%; OR, 1.79; 95% CI, 1.41-2.28; P < .001), and fibrinogen (5.6% vs 2.6%; OR, 2.24; 95% CI, 1.27-3.95; P < .05), and underwent resternotomy (5.3% vs 1.9%; OR, 2.95; 95% CI, 1.55-5.60, P < .001) more often than patients in the Ringer group. The strongest predictors of bleeding were albumin group allocation (OR, 2.18; 95% CI, 1.74-2.74) and complex (OR, 2.61; 95% CI, 2.02-3.37) and urgent surgery (OR, 1.63; 95% CI, 1.26-2.13). In interaction analysis, the effect of albumin on the risk of bleeding was stronger in patients on preoperative acetylsalicylic acid.

CONCLUSIONS

Perioperative administration of albumin, compared with Ringer's acetate, resulted in increased blood loss and higher UDBP class. The magnitude of this effect was similar to the complexity and urgency of the surgery.

Cost Analysis of Aprotinin Reintroduction in French Cardiac Surgery Centres: A Real-World Data-Based Analysis

INTRODUCTION

The European Medicines Agency restored aprotinin (APR) use for preventing blood loss in patients undergoing isolated coronary artery bypass graft (iCABG) in 2016 but requested the collection of patient and surgery data in a registry (NAPaR). The aim of this analysis was to evaluate the impact of APR reintroduction in France on the main hospital costs (operating room, transfusion and intensive unit stay) compared to the current use of tranexamic acid (TXA), which was the only antifibrinolytic available before APR reinstatement.

METHODS

A multicenter before-after post-hoc analysis to compare APR and TXA was carried out in four French university hospitals. APR use followed the ARCOTHOVA (French Association of Cardiothoracic and Vascular Anesthetists) protocol, which had framed three main indications in 2018. Data from 236 APR patients were retrieved from the NAPaR (N = 874); 223 TXA patients were retrospectively retrieved from each center database and matched to APR patients upon indication classes. Budget impact was evaluated using both direct costs associated with antifibrinolytics and transfusion products (within the first 48 h) and other costs such as surgery duration and ICU stay.

RESULTS

The 459 collected patients were distributed as: 17% on-label; 83% off-label. Mean cost per patient until ICU discharge tended to be lower in the APR group versus the TXA group, which resulted in an estimated gross saving of €3136 per patient. These savings concerned operating room and transfusion costs but were mainly driven by reduced ICU stays. When extrapolated to the whole French NAPaR population, the total savings of the therapeutic switch was estimated at around €3 million.

CONCLUSION

The budget impact projected that using APR according to ARCOTHOVA protocol resulted in decreased requirement for transfusion and complications related to surgery. Both were associated with substantial cost savings from the hospital's perspective compared with exclusive use of TXA.

Practice Patterns of Antithrombotic Therapy during the Early Postoperative Course of Cardiac Surgery

BACKGROUND

The current practices regarding the management of antithrombotic therapy during the early postoperative course of cardiac surgery are not well described.

METHODS

An online survey with multiple-choice questions was sent to cardiac anesthesiologists and intensivists from France.

RESULTS

The response rate was 27% (n = 149), with 2/3 of the respondents having less than 10 years of experience. A total of 83% of the respondents reported using an institutional protocol for antithrombotic management. A total of 85% (n = 123) of the respondents regularly used low-molecular-weight heparin (LMWH) during the immediate postoperative course. For 23%, 38%, 9%, and 22% of the physicians, LMWH administration was initiated between the 4th and 6th hour, between the 6th and 12th hour, between the 12th and 24th hour, and on postoperative day 1, respectively. The main reasons for not using LMWH (n = 23) were a perceived increased risk of perioperative bleeding (22%), poor reversal compared with unfractionated heparin (74%), local habits and the refusal of surgeons (57%), and its overly complex management (35%). The modalities of LMWH use were widely varied among the physicians. Chest drains were mostly removed within 3 days of surgery with an unchanged dose of antithrombotic therapy. Regarding temporary epicardial pacing wire removal anticoagulation, 54%, 30%, and 17% of the respondents left the dose unchanged, suspended the anticoagulation, or lowered the anticoagulation dose, respectively.

CONCLUSION

LMWH was inconsistently used after cardiac surgery. Further research is warranted to provide high-quality evidence regarding the benefits and safety of LMWH use early after cardiac surgery.

Postoperative Outcomes in Elderly Patients Undergoing Cardiac Surgery With Preoperative Cognitive Impairment: A Systematic Review and Meta-Analysis

BACKGROUND

Older patients with preoperative cognitive impairment are at risk for increased postoperative complications after noncardiac surgery. This systematic review and meta-analysis aimed to determine the association between preoperative cognitive impairment and dementia and postoperative outcomes in older surgical patients after cardiac surgery.

METHODS

Eight electronic databases were searched from inception to January 4, 2022. Inclusion criteria were cardiac surgery patients ≥60 years of age; preoperative cognitive impairment; ≥1 postoperative complication reported; comparator group with no preoperative cognitive impairment; and written in English. Using a random-effects model, we calculated effect sizes as odds ratio (OR) and standardized mean differences (SMDs). Risk of random error was assessed by applying trial sequential analysis.

RESULTS

Sixteen studies (62,179 patients) were included. Preoperative cognitive impairment was associated with increased risk of delirium in older patients after cardiac surgery (70.0% vs 20.5%; OR, 8.35; 95% confidence interval [CI], 4.25-16.38; I2, 0%; P < .00001). Cognitive impairment was associated with increased hospital length of stay (LOS; SMD, 0.36; 95% CI, 0.20-0.51; I2, 22%; P < .00001) and intensive care unit (ICU) LOS (SMD, 0.39; 95% CI, 0.09-0.68; I2, 70%; P = .01). No significant association was seen for 30-day mortality (1.7% vs 1.1%; OR, 2.58; 95% CI, 0.64-10.44; I2, 55%; P = .18).

CONCLUSIONS

In older patients undergoing cardiac surgery, cognitive impairment was associated with an 8-fold increased risk of delirium, a 5% increase in absolute risk of major postoperative bleeding, and an increase in hospital and ICU LOS by approximately 0.4 days. Further research on the feasibility of implementing routine neurocognitive testing is warranted.

AntiPORT: adaptation of a transfusion prediction score to an Australian cardiac surgery population

Introduction: Risk scoring systems exist to predict perioperative blood transfusion risk in cardiac surgery, but none have been validated in the Australian or New Zealand population. The ACTA-PORT score was developed in the United Kingdom for this purpose. In this study, we validate and recalibrate the ACTA-PORT score in a large national database. Methods: We performed a retrospective validation study using data from the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Database between 1 September 2016 and 31 December 2018. The ACTA-PORT score was calculated using an equivalent of EuroSCORE I. Discrimination and calibration was assessed using area under the receiver operating characteristic (AUROC) curves, Brier scores, and calibration plots. ACTA-PORT was then recalibrated in a development set using logistic regression and the outcome of transfusion to develop new predicted transfusion rates, termed "AntiPORT", using AusSCORE "all procedures" as the regional equivalent of EuroSCORE I. The accuracy of these new predictions was assessed as for ACTA-PORT. Results: 30 388 patients were included in the study at 37 Australian centres. The rate of red blood cell transfusion was 33%. Discrimination of ACTA-PORT was good but calibration was poor, with overprediction of transfusion (AUROC curve, 0.76; 95% CI, 0.75-0.76; Brier score, 0.19). The recalibrated AntiPORT showed significantly improved calibration in both development and validation sets without compromising discrimination (AUROC curve, 0.76; 95% CI, 0.75-0.76; Brier score, 0.18). Conclusions: The AntiPORT is the first red cell transfusion risk scoring system for cardiac surgery patients to be validated using Australian data. It is accurate and simple to calculate. The demonstrated accuracy of AntiPORT may help facilitate benchmarking and future research in patient blood management, as well as providing a useful tool to help clinicians target these resource-saving strategies.

Operating Room Versus Intensive Care Unit Extubation Within 6 Hours After On-Pump Cardiac Surgery: Early Results and Hospital Costs

Time-directed extubation (fast-track) protocols may decrease length of stay and cost but data on operating room (OR) extubation is limited. The objective of this study was to compare the outcomes of extubation in the OR versus fast-track extubation within 6 hours of leaving the operating room. Patients undergoing nonemergent STS index cases (2011-2021) who were extubated within 6 hours were identified from a regional STS quality collaborative. Patients were stratified by extubation in the OR versus fast track. Propensity score matching (1:n) was performed to balance baseline differences. Of the 24,962 patients, 498 were extubated in the OR. After matching, 487 OR extubation cases and 899 fast track cases were well balanced. The rate of reintubation was higher for patients extubated in the OR [21/487 (4.3%) vs 16/899 (1.8%), P = 0.008] as was the incidence of reoperation for bleeding [12/487 (2.5%) vs 8/899 (0.9%), P = 0.03]. There was no significant difference in the rate of any reoperation [16/487 (3.3%) vs 15/899 (1.6%), P = 0.06] or operative mortality [4/487 (0.8%) vs 6/899 (0.6%), P = 0.7]. OR extubation was associated with shorter hospital length of stay (5.6 vs 6.2 days, P < 0.001) and lower total cost of admission ($29,602 vs $31,565 P < 0.001). OR extubation is associated with a higher postoperative risk of reintubation and reoperation due to bleeding, but lower resource utilization.Future research exploring predictors of extubation readiness may be required prior to widespread adoption of this practice.

Use and safety of aprotinin in routine clinical practice: A European postauthorisation safety study conducted in patients undergoing cardiac surgery

BACKGROUND

Aprotinin has been used to reduce blood loss and blood product transfusions in patients at high risk of major blood loss during cardiac surgery. Approval by the European Medicines Agency (EMA) for its current indication is limited to patients at high risk of major blood loss undergoing isolated coronary artery bypass graft surgery (iCABG).

OBJECTIVE

To report current real-world data on the use and certain endpoints related to the safety of aprotinin in adult patients.

DESIGN

The Nordic aprotinin patient registry (NAPaR) received data from 83 European centres in a noninterventional, postauthorisation safety study (PASS) performed at the request of the EMA.

SETTING

Cardiac surgical centres committed to enrolling patients in the NAPaR.

PATIENTS

Patients receiving aprotinin agreeing to participate.

INTERVENTION

The decision to administer aprotinin was made by the treating physicians.

MAIN OUTCOME MEASURES

Aprotinin safety endpoints were in-hospital death, thrombo-embolic events (TEEs), specifically stroke, renal impairment, re-exploration for bleeding/tamponade.

RESULTS

From 2016 to 2020, 5309 patients (male 71.5%; >75 years 18.9%) were treated with aprotinin; 1363 (25.7%) underwent iCABG and 3946 (74.3%) another procedure, including a surgical treatment for aortic dissection ( n  = 660, 16.7%); 54.5% of patients received the full-dose regimen. In-hospital mortality in iCABG patients was 1.3% (95% CI, 0.66 to 1.84%) vs. 8.3% (7.21 to 8.91%) in non-iCABG patients; incidence of TEEs and postoperative rise in creatinine level greater than 44 μmol l -1 2.3% (1.48 to 3.07%) and 2.7% (1.79 to 3.49%) vs. 7.2% (6.20 to 7.79%) and 15.5% (13.84 to 16.06%); patients undergoing re-exploration for bleeding 1.4% (0.71 to 1.93%) vs. 3.0% (2.39 to 3.44%). Twelve cases of hypersensitivity/anaphylactic reaction (0.2%) were reported as Adverse Drug Reactions.

CONCLUSION

The data in the NApaR indicated that in this patient population, at high risk of death or blood loss undergoing cardiac surgery, including complex cardiac surgeries other than iCABG, the incidence of adverse events is in line with data from current literature, where aprotinin was not used.

TRIAL REGISTRATION

EU PAS register number: EUPAS11384.

HEROES V-A-HEmoRrhagic cOmplications in veno-arterial Extracorporeal life Support-Development and internal validation of a multivariable prediction model in adult patients

BACKGROUND

Risk factors for bleeding complications during extracorporeal life support (ECLS) indicated for cardiac support remain poorly investigated. The aim is to develop and internally validate a prediction model to calculate the risk for bleeding complications in adult patients receiving veno-arterial (V-A) ECLS.

METHODS

Data of the Extracorporeal Life Support Organization registry of adult patients undergoing V-A ECLS between 2010 and 2020 were analyzed. The primary outcome was bleeding complications recorded during V-A ECLS. Multivariable logistic regression with backward stepwise elimination was used to develop the prediction model. Performance of the model was tested by discriminative ability and calibration with receiver operator characteristic, area under the curve, and visual inspection of the calibration plot. Internal validation was performed to detect overfitting of the model.

RESULTS

In total 28 767 adult patients were included, of which 29.0% developed bleeding complications. Sex, body mass index, surgical cannulation, pre-ECLS respiratory and hemodynamic variables, pre-ECLS support and interventions, and different type of diagnosis were included in the prediction model. This prediction model showed a predictive capability with an AUC of 0.66.

CONCLUSION

The model is based on the largest cohort of V-A ECLS patients and is the best available predictive model for bleeding events given the predictors that are available in V-A ECLS compared to current literature. The model can help in identifying patients at high risk for bleeding complications and will help in developing further research and decision-making in terms of anticoagulation management. External validation is warranted to extrapolate this model in the clinical setting.

Preoperative patient factors associated with blood product use in cardiac surgery, a retrospective cohort study

BACKGROUND

Cardiac surgery is associated with a high rate of blood use. The aim of this study is to identify preoperative patient factors associated with allogeneic Red Blood Cell (RBC) or non-Red Blood Cell (NRBC) use in cardiac surgery.

METHODS

All adult cardiac surgical procedures conducted at a single Western Australian institution were retrospectively analysed. Data was collected from the Australia and New Zealand Cardiac Surgery Database from 2015 to 2018. A number of preoperative factors were identified, relating to past medical history or preoperative cardiac status. Outcome 1 was defined as the use of one or more RBC products intra or post-operatively. Outcome 2 was defined as the use of one or more NRBC products intra or post-operatively. Multivariate logistical regression analysis was done to assess for the association between preoperative factors and allogeneic blood product use.

RESULTS

A total of 1595 patients were included in this study, of which 1488 underwent a Coronary Artery Bypass Graft, Valve or a combined procedure. Patients on dialysis preoperatively and those who had preoperative cardiogenic shock demonstrated the greatest risk of requiring RBC transfusion with an odds ratio of 5.643 (95% CI 1.305-24.40) and 3.257 (95% 1.801-5.882) respectively. Patients who had preoperative cardiogenic shock demonstrated the greatest risk of requiring NRBC transfusion with an odds ratio of 3.473 (95% CI 1.970-6.135). Patients who have had a previous cardiothoracic intervention are at increased risk of both RBC and NRBC transfusion, with adjusted odds ratios of 1.774 (95% CI 1.353-2.325) and 2.370 (95% CI 1.748-3.215) respectively.

CONCLUSION

A number of factors relating to past medical history or preoperative cardiac status are implicated with increased allogeneic blood product use in cardiac surgery. Identifying high-risk patients in a preoperative setting can enable us enrol them in a blood conservation program, therefore minimizing the risk of exposure to blood transfusion.

Fibrinogen and Bleeding in Adult Cardiac Surgery: A Review of the Literature

Background: Fibrinogen is a substrate for blood clots formation. In cardiac surgery, a number of different mechanisms lead to a decrease in fibrinogen levels and consequent impaired haemostasis. Patients undergoing cardiac surgery are therefore frequently exposed to blood loss and allogeneic blood transfusion, which are risk factors associated with morbidity and mortality. Thus, particular efforts in fibrinogen management should be made to decrease bleeding and the need for blood transfusion. Therefore, fibrinogen remains an active focus of investigations from basic science to clinical practice. This review aims to summarise the latest evidence regarding the role of fibrinogen and current practices in fibrinogen management in adult cardiac surgery. Methods: The PubMed database was systematically searched for literature investigating the role and disorders of fibrinogen in cardiac surgery and diagnostic and therapeutic procedures related to fibrinogen deficiency aimed at reducing blood loss and transfusion requirements. Clinical trials and reviews from the last 10 years were included. Results: In total, 146 articles were analysed. Conclusion: The early diagnosis and treatment of fibrinogen deficiency is crucial in maintaining haemostasis in bleeding patients. Further studies are needed to better understand the association between fibrinogen levels, bleeding, and fibrinogen supplementation and their impacts on patient outcomes in different clinical settings.

Association between time to therapeutic INR and length of stay following mechanical heart valve surgery

BACKGROUND

Warfarin is the only oral anticoagulant approved for use following mechanical valve surgery (MeVS). Patients may experience prolonged hospital length of stay (LOS) following MeVS awaiting an appropriate warfarin effect. We aimed to determine whether an association exists between time to achieve the first therapeutic international normalized ratio (INR) and LOS following MeVS.

MATERIALS AND METHODS

Retrospective single center cohort study. We included consecutive adult patients undergoing elective MeVS from 2013 to 2018. Landmark analyses and multivariable regression with time-updated INR were used to estimate the association between time to therapeutic INR (TTI) and LOS.

RESULTS

Among 384 patients (median age: 51 years, interquartile range [IQR]: 41-57; 58.3% male), the median TTI was 4 days (IQR: 2-5). Thirty seven percent of patients were discharged with a subtherapeutic INR, many on bridging anticoagulation or with an INR close to target. Those achieving therapeutic INR had an increased rate of hospital discharge (adjusted hazard ratio: 2.17; 95% confidence interval: 1.71-2.76; p < .0001). Attainment of a therapeutic INR anytime between postoperative Days 4 and 13 was significantly associated with a shorter LOS.

CONCLUSIONS

Prolonged time to achieve a therapeutic INR was independently associated with prolonged LOS. Future strategies aimed at improving attainment of therapeutic INR following MeVS may reduce hospital LOS.

Impact of Early, Low-Dose Factor VIIa on Subsequent Transfusions and Length of Stay in Cardiac Surgery

OBJECTIVE

Recombinant factor VII (rFVIIa) is used to treat cardiac surgical bleeding in an off-label manner. However, optimal dosing and timing of administration to provide efficacious yet safe outcomes remain unknown.

DESIGN

Retrospective, observational study.

SETTING

Tertiary care academic center.

PARTICIPANTS

Cardiac surgical patients (N = 214) who received low-dose rFVIIa for cardiac surgical bleeding.

INTERVENTIONS

Patients were allocated into one of three groups based on timing of rFVIIa administration during the course of bleeding resuscitation based on the number of hemostatic products given before rFVIIa administration: group one = ≤one products (n = 82); group two = two-to-four products (n = 73); and group three= ≥five products (n = 59).

MEASUREMENTS AND MAIN RESULTS

Patients who received low-dose rFVIIa later in the course of bleeding resuscitation (group three) had longer intensive care unit stays (p = 0.014) and increased incidence of postoperative renal failure when compared with group one (p = 0.039). Total transfusions were lowest in patients who received rFVIIa early in the course of resuscitation (group one) (median, two [interquartile range (IQR), 1-4.75]) and highest in group three (median, 11 [IQR, 8-14]; p < 0.001). Subsequent blood product transfusions after rFVIIa administration were highest in group two (p = 0.003); however, the median for all three groups was two products. There were no differences in thrombosis, reexplorations, or mortality in any of the groups.

CONCLUSIONS

This study identified no differences in adverse outcomes based on timing of administration of low-dose rFVIIa for cardiac surgical bleeding defined by stage of resuscitation, but the benefits of early administration remain unclear.

Risk-Prediction Model for Transfusion of Erythrocyte Concentrate During Extracorporeal Circulation in Coronary Surgery

INTRODUCTION

Our objective was to identify preoperative risk factors and to develop and validate a risk-prediction model for the need for blood (erythrocyte concentrate [EC]) transfusion during extracorporeal circulation (ECC) in patients undergoing coronary artery bypass grafting (CABG).

METHODS

This is a retrospective observational study including 530 consecutive patients who underwent isolated on-pump CABG at our Centre over a full two-year period. The risk model was developed and validated by logistic regression and bootstrap analysis. Discrimination and calibration were assessed using the area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow (H-L) test, respectively.

RESULTS

EC transfusion during ECC was required in 91 patients (17.2%). Of these, the majority were transfused with one (54.9%) or two (41.8%) EC units. The final model covariates (reported as odds ratios; 95% confidence interval) were age (1.07; 1.02-1.13), glomerular filtration rate (0.98; 0.96-1.00), body surface area (0.95; 0.92-0.98), peripheral vascular disease (3.03; 1.01-9.05), cerebrovascular disease (4.58; 1.29-16.18), and hematocrit (0.55; 0.48-0.63). The risk model developed has an excellent discriminatory power (AUC: 0,963). The results of the H-L test showed that the model predicts accurately both on average and across the ranges of deciles of risk.

CONCLUSIONS

A risk-prediction model for EC transfusion during ECC was developed, which performed adequately in terms of discrimination, calibration, and stability over a wide spectrum of risk. It can be used as an instrument to provide accurate information about the need for EC transfusion during ECC, and as a valuable adjunct for local improvement of clinical practice. Key Findings: Risk factors with the greatest prediction for EC transfusion. Take-Home Message: The implementation of this model would be an important step in optimizing and improving the quality of surgery.

Association of Plasma Fibrinogen and Thromboelastography With Blood Loss in Complex Cardiac Surgery

Postoperative coagulopathic bleeding is common in cardiac surgery and is associated with increased morbidity and mortality. Ideally, real-time information on in-vivo coagulation should be available. However, up to now it is unclear which perioperative coagulation parameters can be used best to accurately identify patients at increased risk of bleeding. The present study analyzed the associations of perioperative fibrinogen concentrations and whole blood viscoelastic tests with postoperative bleeding in 89 patients undergoing combined cardiac surgery procedures. Postoperative bleeding was recorded until 24 hours after surgery. Regression analyses were performed to establish associations between blood loss and coagulation parameters after cardiopulmonary bypass including a prediction model with known confounding factors for bleeding. Coagulation tests show large changes over the perioperative course with the strongest coagulopathic deviations from baseline after cardiopulmonary bypass. After adjustment for multiple confounders, viscoelastic clot strength instead of fibrinogen concentration showed a similar performance for 24 hour blood loss and a better performance for 6 hour blood loss. This makes intraoperative viscoelastic testing a useful tool to strengthen early clinical decision-making with the potential to reduce perioperative blood transfusions.

A survey of patient blood management for patients undergoing cardiac surgery in nine European countries

STUDY OBJECTIVE

To describe and compare patient blood management (PBM) practices in cardiac surgery in nine European countries and identify the main risk factors for bleeding or transfusion according to the surveyed centres.

DESIGN

We set up an online survey to evaluate PBM practices in two clinical scenarios, risk factors for bleeding or transfusion, and previous experience with antifibrinolytics.

SETTING

This survey was completed by European anesthesiologists in 2019.

PATIENTS

No patients were included in the survey.

INTERVENTION

None.

MEASUREMENTS

We evaluated the degree of implementation of PBM practices in patients undergoing cardiac surgery.

MAIN RESULTS

Ninety-eight of 177 responses (38%) were complete with variable response rates by country. In a non-emergent situation, no respondents would transfuse red cells preoperatively in an anaemic patient, while cell salvage (89%) and antifibrinolytics (82%) would almost always be used. Optimization of Hemoglobin level (36%) and use of off-pump techniques (34%), minimally invasive surgery (25%) and relatively recently-developed CPB technologies such as mini-bypass (32%) and autologous priming (38%), varied greatly across countries. In an emergent clinical situation, topical haemostatic agents would frequently be used (61%). Tranexamic acid (72%) and aprotinin (20%) were the main antifibrinolytics used, with method of administration and dose varying markedly across countries. Five factors were considered to increase risk of bleeding or transfusion by at least 90% of respondents: pre-operative anaemia, prior cardiac surgery, clopidogrel 5 days or less before surgery, use of other P2Y12 inhibitors at any point, and thrombocytopenia <100.10⁹ platelets/mm³.

CONCLUSION

PBM guidelines are not universally implemented in European cardiac surgery centres or countries, resulting in discrepancies in techniques and products used for a given clinical situation.

Bleeding risk stratification in coronary artery surgery: the should-not-bleed score

BACKGROUND

An estimated 20% of allogeneic blood transfusions in the United States are associated with cardiac surgery. It is estimated that 11% of red cell resources were used for transfusion support of patients undergoing coronary artery bypass grafting (CABG) with a documented wide variability in transfusion rate (7.8 to 92.8%). To address the issue of unnecessary transfusions within the CABG population, we developed a model to predict which patients are at low risk of bleeding for whom transfusion treatment might be considered unnecessary. Herein we present our "SHOULD-NOT-BLEED-SCORE" application developed for the Windows® software platform which is based on our previous research.

METHODS

This study is aimed to develop a user-friendly application that stratifies patients with respect to bleeding risk. The statistical model we used in our previous research was focused on detection of CABG patients at low risk of bleeding. The rationale behind such an approach was to identify a CABG patient subgroup at low risk of bleeding. By identifying patients at low risk of bleeding we can define a subgroup of patients for whom transfusion treatment might be considered unnecessary. We developed a Windows platform application based on risk modelling which we previously calculated for 1426 patients undergoing elective CABG from January 2010 to January 2018.

RESULTS

The SHOULD-NOT-BLEED-SCORE risk score is developed for the Windows software platform. A mathematical model that is based on multivariate analysis was used for app development. The variables that entered the scoring system were: Age; Body Mass Index; Chronic Renal Failure; Preoperative Clopidogrel Exposure; Preoperative Red Blood Cells Count; Preoperative Fibrinogen Level; Preoperative Multiplate ASPI test area under the curve (AUC) units. The SHOULD-NOT-BLEED-SCORE identifies/predicts patients without a risk for excessive bleeding with strong discriminatory performance (Receiver Operating Curve (ROC) analysis AUC 72.3%, p < 0.001).

CONCLUSION

The SHOULD-NOT-BLEED risk scoring application may be useful in the preoperative risk screening process. The clinical and economic burden associated with unnecessary transfusions may be adequately addressed by a preoperative scoring system detecting patients at low risk of bleeding for whom transfusion treatment might be considered unnecessary.

Dynamic changes in platelets caused by shear stress in aortic valve stenosis

BACKGROUND AND OBJECTIVE:

Turbulent blood flow in patients with aortic valve stenosis (AS) results in morphological and functional changes in platelets and coagulation factors. The aim of this study is to determine how shear stress affects platelets and coagulation factors.

METHODS:

We retrospectively evaluated data from 78 patients who underwent AVR to treat AS between March 2008 and July 2017 at Kagoshima University Hospital.

RESULTS:

Platelet (PLT) count obviously decreased at three days after AVR, and increased above preoperative levels at the time of discharge. In contrast, platelet distribution width (PDW), mean platelet volume (MPV), and platelet large cell ratio (P-LCR) increased three days after AVR, then decreased to below preoperative levels. No differences were evident between groups with higher (HPPG > 100 mmHg) and lower (LPPG < 100 mmHg) peak pressure gradients (PPG) before AVR, whereas PLT count, PDW, MPV and P-LCR improved more in the HPPG group. Plateletcrit (PCT), which represents the total volume of platelets, increased after AVR due to decreased shear stress. High increasing rate of PCT was associated with lower PLT count, higher PDW and lower fibrinogen.

CONCLUSION:

Shear stress affects PLT count, PDW, and fibrinogen in patients with AS.

Exposure-Response Relationship of Tranexamic Acid in Cardiac Surgery

BACKGROUND

It is unclear whether high-dose regimens of tranexamic acid in cardiac surgery (total dose, 80 to 100 mg/kg) confer a clinical advantage over low-dose regimens (total dose, approximately 20 mg/kg), particularly as tranexamic acid-associated seizure may be dose-related. The authors' aim was to characterize the exposure-response relationship of this drug.

METHODS

Databases were searched for randomized controlled trials of intravenous tranexamic acid in adult patients undergoing cardiopulmonary bypass surgery. Observational studies were added for seizure assessment. Tranexamic acid concentrations were predicted in each arm of each study using a population pharmacokinetic model. The exposure-response relationship was evaluated by performing a model-based meta-analysis using nonlinear mixed-effect models.

RESULTS

Sixty-four randomized controlled trials and 18 observational studies (49,817 patients) were included. Seventy-three different regimens of tranexamic acid were identified, with the total dose administered ranging from 5.5 mg/kg to 20 g. The maximum effect of tranexamic acid for postoperative blood loss reduction was 40% (95% credible interval, 34 to 47%), and the EC50 was 5.6 mg/l (95% credible interval, 0.7 to 11 mg/l). Exposure values with low-dose regimens approached the 80% effective concentration, whereas with high-dose regimens, they exceeded the 90% effective concentration. The predicted cumulative blood loss up to 48 h postsurgery differed by 58 ml between the two regimens, and the absolute difference in erythrocyte transfusion rate was 2%. Compared to no tranexamic acid, low-dose and high-dose regimens increased the risk of seizure by 1.2-fold and 2-fold, respectively. However, the absolute risk increase was only clinically meaningful in the context of prolonged open-chamber surgery.

CONCLUSIONS

In cardiopulmonary bypass surgery, low-dose tranexamic acid seems to be an appropriate regimen for reducing bleeding outcomes. This meta-analysis has to be interpreted with caution because the results are observational and dependent on the lack of bias of the predicted tranexamic acid exposures and the quality of the included studies.

EDITOR’S PERSPECTIVE

Factors associated with excessive bleeding following elective on-pump coronary artery bypass grafting

INTRODUCTION

Excessive bleeding following cardiac surgery is associated with worse outcomes. We aimed to analyze preoperative and operative factors associated with excessive bleeding in coronary artery bypass patients to better understand which patients are under increased risk.

METHODS

The study was conducted as an observational study in a tertiary center for cardiac surgery by retrospective analysis of the hospital database. Patients were grouped according to chest tube output within the postoperative 24 h. Patients in the 4th percentile of chest tube output per kilogram were categorized as having excessive bleeding. Patients with excessive bleeding were compared with the other patients for preoperative and operative factors. Factors significant in univariate analysis were carried onto the multivariate analysis.

RESULTS

Patients with excessive bleeding were more likely to be males (91.4% vs. 78.7%, p = .002), have lower body mass index (BMI) (27.4 vs. 29.2, p < .001), and low platelets (6.9% vs. 1.5%, p = .006). Cardiopulmonary bypass (101.8 vs. 110.9 min, p = .022) time was longer in the excessive bleeding group. Patients with excessive bleeding were more likely to have more than three vessels revascularized. Male sex, lower BMI, low platelets, and longer cardiopulmonary bypass time were independently associated with increased bleeding.

CONCLUSION

Male sex, lower BMI, low platelet count, and longer cardiopulmonary bypass time are associated with extensive bleeding after elective coronary artery bypass surgery (CABG). Patients with higher bleeding risk should be identified preoperatively to account for adverse outcomes after CABG.

Von Willebrand factor in aortic or mitral valve stenosis and bleeding after heart valve surgery

OBJECTIVES

Low von Willebrand factor (VWF) increases the risk of bleeding. The objective was to assess the influence of VWF on bleeding after valvular surgery.

METHODS

We studied 82 consecutive patients in median age of 65.5 years with severe isolated aortic stenosis (AS, n = 62) or mitral stenosis (MS, n = 20), undergoing heart valve surgery in extracorporeal circulation. Preoperatively, we assessed VWF antigen (VWF:Ag) and activity (VWF:RCo), a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), and fibrinolysis inhibitors.

RESULTS

Compared with AS, MS patients were more frequently female (80 vs. 55%, p = 0.045) with atrial fibrillation (AF) (80 vs. 8%, p < 0.0001), with no difference in age or comorbidities. Median postoperative drainage was 420 ml for AS, and 425 ml for MS (p = 0.37). Patients with AS had lower VWF:RCo (125.8 [88.5-160.8] vs. 188.0 [140.3-207.3] IU/dl, p = 0.003) and VWF:Ag (135.8 [112.0-171.2] vs. 191.7 [147.3-236.4] IU/dl, p = 0.01) than MS patients. Mean VWF:RCo/Ag ratio was 0.88 ± 0.17, with no intergroup differences. ADAMTS13 levels and activity were similar in both groups. In AS, both VWF:RCo and VWF:Ag correlated inversely with maximal (r = -0.39, p = 0.0003 and r = -0.39, p = 0.0004, respectively) and mean (r = -0.40, p = 0.0004 and r = -0.39, p = 0.0006, respectively) transvalvular pressure gradients. There was no difference in perioperative bleeding between patients following mitral and aortic valve surgery, and bleeding was not associated with VWF:Ag or VWF:RCo.

CONCLUSIONS

In severe AS, VWF levels and activity correlate inversely with transvalvular pressure gradients, and are lower than in severe degenerative MS, but do not affect blood loss after valvular surgery in extracorporeal circulation.

Postoperative administration of tranexamic acid as approach to reduce blood loss after open-heart surgery

BACKGROUND: Tranexamic acid (TXA) reduces perioperative bleeding among patients undergoing heart surgery. It is uncertain whether its postoperative administration, after prior administration before cardiopulmonary bypass (CPB), has an additional benefit. OBJECTIVE: Our study aimed to evaluate whether the postoperative administration of TXA reduces the blood loss after heart surgery. METHODS: In a retrospective cohort study at the University Heart Center Dresden, patients who underwent on-pump open-heart surgery and received 1 g TXA before CPB were included. Patients with postoperative administration of 1 g TXA were compared to patients without. Primary endpoint was the postoperative blood loss within 24 hours. RESULTS: Among 2,179 patients undergoing heart surgery between 1 July 2013 and 31 October 2014, 92 (4.2%) received TXA postoperatively. After matching, 71 patients with postoperative administration of TXA were compared to 71 without (n = 142). Postoperative administration of TXA did not result in decreased blood loss (MD 146.7 mL; p = 0.064). There was no evidence of an increased risk for thromboembolic complications. CONCLUSIONS: The postoperative administration of TXA did not reduce blood loss. The use of TXA was shown to be safe in terms of thromboembolic events and hospital mortality. Unless there is no clear evidence, the postoperative administration of TXA should be restricted to patients with massive blood loss and signs of hyperfibrinolysis only.

Blood Loss Kinetics During the First 12 Hours After On-Pump Cardiac Surgical Procedures

BACKGROUND

Anemia and coagulation management and a restrictive transfusion strategy are key points of blood management in patients undergoing cardiac surgical procedures. However, little consideration has been given to the kinetics of postoperative bleeding. This prospective observational study investigated bleeding kinetics from chest tubes to assess whether it was possible to predict, within the early postoperative hours, major bleeding at 12 postoperative hours.

METHODS

Adult cardiac surgical patients who were admitted consecutively to the postoperative intensive care unit in a tertiary academic hospital from January to June 2016 were included. Blood volume was collected from the chest drains, and major bleeding was defined as bleeding exceeding the 90th percentile of the volume distribution at 12 postoperative hours. Receiver operating characteristics curve analysis was performed with hourly bleeding thresholds to determine the best predictor of major bleeding.

RESULTS

In 292 patients, bleeding at 12 postoperative hours ranged from 60 to 2190 mL (median, 350 mL), and 30 patients had major bleeding, with a threshold of 675 mL. Bleeding volume declined logarithmically, 54% [IQR, 45% to 63%] within the first 4 hours. Patients with major bleeding had a higher bleeding volume every hour (P < .004). A good predictive value was observed within the first 2 hours (2.73 mL/kg; receiver operating characteristics area under the curve, 0.87 ± 0.04 [IQR, 0.79 to 0.94]; P< .001).

CONCLUSIONS

The hourly rate of chest tube blood loss seems to be relevant to predict, within the first postoperative hours after cardiac surgical procedures, major bleeding at 12 postoperative hours. Early detection of blood loss may help to improve a patient's blood conservation strategy because it may prompt preemptive treatments.

Predictiveness of different preoperative risk assessments for postoperative bleeding after coronary artery bypass grafting surgery

Aim:

Postoperative bleeding is a significant cause of morbidity and mortality in patients undergoing cardiac surgery. Studies have been conducted, and guidelines have been published regarding patient blood management and aiming to prevent blood loss in the perioperative period. Various bleeding risk assessments were developed for preoperative period. We aimed to examine the correlations of scoring systems in the literature with the amount of postoperative bleeding in patients undergoing first time coronary artery bypass graft surgery, and to show the most suitable preoperative bleeding risk assessment for coronary artery bypass graft patients.

Methods:

The study included 550 consecutive patients who underwent coronary artery bypass graft operation. The inclusion criteria were considered as patients to be older than 18 years old and to undergo elective or emergent myocardial revascularization using cardiopulmonary bypass. All variables required for scoring systems were recorded. The initial results of the study were determined as the amount of chest tube drainage, the use of blood products, the change in hematocrit level, reoperation due to bleeding, duration of ventilation, duration of intensive care unit stay, and hospital stay. Mortality which occurred during first 30 days after operation was considered as operative mortality. Operative mortality was accepted as the primary endpoint. Secondary endpoints were massive bleeding and high amount of transfusion.

Results:

Data were obtained from a series of 550 consecutive patients treated with isolated coronary artery bypass graft. It was seen that PAPWORTH and WILL-BLEED risk assessments responded better for E-CABG grade 2 and 3 bleeding compared to other risk assessments. TRACK, TRUST, and ACTA-PORT scales were found to have low ability to distinguish patients with E-CABG bleeding grade 2 and 3.

Conclusion:

Predicting postoperative bleeding and transfusion rates with preoperative risk scores in patients undergoing coronary artery bypass graft surgery will provide valuable information to physicians for establishing a proper patient blood management protocol and this will decrease excessive transfusions, unnecessary reoperations as well as improve postoperative outcomes.

Predictive scores for major bleeding after coronary artery bypass surgery in low operative risk patients

BACKGROUND

Cardiac surgery is associated with perioperative bleeding and carries high risk of allogeneic blood transfusion. Recently new scores for prediction of severe bleeding have been developed. This study aims to compare the WILL-BLEED, CRUSADE, PAPWORTH, TRUST, TRACK and ACTION scores in predicting major bleeding after CABG in patients with low estimated operative risk.

METHODS

A multicenter observational study included 1391 patients who underwent isolated CABG from July 2015 to January 2018. We tested the hypothesis that the WILL-BLEED score, specifically designed for CABG, would perform at least as well as the CRUSADE, PAPWORTH, TRUST, TRACK and ACTION scores in predicting postoperative major bleeding in low operative risk patients. The primary endpoint was the performance of known bleeding risk scores after CABG. The secondary endpoint was the evaluation of in-hospital mortality.

RESULTS

Mean age was 68.2±9.4 years and median Euroscore II value was 1.69% (IQR 1.15-2.81%). Mean blood losses in the first 12 postoperative hours was 339.75 mL. Seventy-three (5.2%) subjects underwent administration of blood products. The rate of severe-massive bleeding according to UDPB grades 3-4 was 1.5%. WILL-BLEED, TRUST, TRACK and ACTION scores were significantly associated with severe postoperative bleeding. WILL-BLEED presented the best c-index (AUC: 0.658; 95% CI: 0.600,0.716). Reclassification analysis showed a worsening in sensitivity and significant negative reclassification of CRUSADE, PAPWORTH, TRACK and ACTION scores when compared with WILL-BEED. The combination of WILL-BLEED and TRUST scores improved the prediction ability (AUC: 0.673; 95% CI: 0.615-0.732). Overall in-hospital mortality was 1.65%. Early mortality in patients with severe versus no-severe bleeding was found to be 11.8% vs. 1.0% Severe bleeding (OR: 13.26; P value<0.001) was found to be significantly associated with early mortality.

CONCLUSIONS

Severe bleeding after CABG is a harmful event associated with adverse outcomes. WILL-BLEED Score has the better performance in predicting severe-massive bleeding after CABG. The TRUST Score, although suboptimal, represents a valuable alternative in this setting.

Strategies to minimize intraoperative blood loss during major surgery

Background

Reducing operative blood loss improves patient outcomes and reduces healthcare costs. The aim of this article was to review current surgical, anaesthetic and haemostatic intraoperative blood conservation strategies.

Methods

This narrative review was based on a literature search of relevant databases up to 31 July 2019 for publications relevant to reducing blood loss in the surgical patient.

Results

Interventions can begin early in the preoperative phase through identification of patients at high risk of bleeding. Directly acting anticoagulants can be stopped 48 h before most surgery in the presence of normal renal function. Aspirin can be continued for most procedures. Intraoperative cell salvage is recommended when anticipated blood loss is greater than 500 ml and this can be continued after surgery in certain situations. Tranexamic acid is safe, cheap and effective, and routine administration is recommended when anticipated blood loss is high. However, the optimal dose, timing and route of administration remain unclear. The use of topical agents, tourniquet and drains remains at the discretion of the surgeon. Anaesthetic techniques include correct patient positioning, avoidance of hypothermia and regional anaesthesia. Permissive hypotension may be beneficial in selected patients. Promising haemostatic strategies include use of pharmacological agents such as desmopressin, prothrombin complex concentrate and fibrinogen concentrate, and use of viscoelastic haemostatic assays.

Conclusion

Reducing perioperative blood loss requires a multimodal and multidisciplinary approach. Although high-quality evidence exists in certain areas, the overall evidence base for reducing intraoperative blood loss remains limited.

Absence of perioperative excessive bleeding in on-pump coronary artery bypass grafting cases performed by residents

OBJECTIVES

On-pump coronary artery bypass grafting (CABG) is associated with elevated bleeding risk. Our aim was to evaluate the role of surgical experience in postoperative blood loss.

METHODS

A propensity score-matched analysis was employed to compare on-pump CABG patients operated on by residents and specialists. End points included drainage volume and bleeding severity, as assessed by the Universal Definition of Perioperative Bleeding in cardiac surgery and E-CABG scale.

RESULTS

A total of 212 matched pairs (c-statistics 0.693) were selected from patients operated on by residents (n = 294) and specialists (n = 4394) between October 2012 and May 2018. Patients did not differ in bleeding risk. There were no statistically significant differences in postoperative 6-, 12- and 24-h drainages between subjects operated on by residents and specialists, and there was no between-group difference in rethoracotomy or transfusion rate. There were no differences in Universal Definition of Perioperative Bleeding or E-CABG grades. In June 2018, after a median follow-up of 2.8 years (range 0.1-5.7 years), the overall survival was 94%, with no differences between the patients operated on by residents (95%) and specialists (92%) (P = 0.27).

CONCLUSIONS

Patients undergoing on-pump CABG, when operated on by a resident, are not exposed to an elevated bleeding risk, as compared with patients operated on by experienced surgeons.

Optimizing Perioperative Blood and Coagulation Management During Cardiac Surgery

Bleeding and transfusion are common in cardiac surgery and associated with poorer outcome. Bleeding is frequently due to coagulopathy caused by the complex interaction between cardiopulmonary bypass, major surgical trauma, anticoagulation management, and perioperative factors. Patient blood management has emerged to improve outcome by the prediction, prevention, monitoring, and treatment of bleeding and transfusion. Each part of this chain has several individual modalities and when combined leads to result in a better outcome. This article reviews the hemostasis disturbances in cardiac surgery with cardiopulmonary bypass and gives an overview of the most important patient blood management strategies.

Consensus Report on Patient Blood Management in Cardiac Surgery by Turkish Society of Cardiovascular Surgery (TSCVS), Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care (SCTAIC)

Anemia, transfusion and bleeding independently increase the risk of complications and mortality in cardiac surgery. The main goals of patient blood management are to treat anemia, prevent bleeding, and optimize the use of blood products during the perioperative period. The benefit of this program has been confirmed in many studies and its utilization is strongly recommended by professional organizations. This consensus report has been prepared by the authors who are the task members appointed by the Turkish Society of Cardiovascular Surgery, Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care to raise the awareness of patient blood management. This report aims to summarize recommendations for all perioperative blood- conserving strategies in cardiac surgery.