Increased mortality, postoperative morbidity, and cost after red blood cell transfusion in patients having cardiac surgery

Associations between preoperative anaemia and hospital costs following major abdominal surgery: cohort study

Background

Determining the cost-effectiveness and sustainability of patient blood management programmes relies on quantifying the economic burden of preoperative anaemia. This retrospective cohort study aimed to evaluate the hospital costs attributable to preoperative anaemia in patients undergoing major abdominal surgery.

Methods

Patients who underwent major abdominal surgery between 2010 and 2018 were included. The association between preoperative patient haemoglobin (Hb) concentration and hospital costs was evaluated by curve estimation based on the least-square method. The in-hospital cost of index admission was calculated using an activity-based costing methodology. Multivariable regression analysis and propensity score matching were used to estimate the effects of Hb concentration on variables related directly to hospital costs.

Results

A total of 1286 patients were included. The median overall cost was US $18 476 (i.q.r.13 784–27 880), and 568 patients (44.2 per cent) had a Hb level below 13.0 g/dl. Patients with a preoperative Hb level below 9.0 g/dl had total hospital costs that were 50.6 (95 per cent c.i. 14.1 to 98.9) per cent higher than those for patients with a preoperative Hb level of 9.0–13.0 g/dl (P < 0.001), 72.5 (30.6 to 128.0) per cent higher than costs for patients with a Hb concentration of 13.1–15.0 g/dl (P < 0.001), and 62.4 (21.8 to 116.7) per cent higher than those for patients with a Hb level greater than 15.0 g/dl (P < 0.001). Multivariable general linear modelling showed that packed red blood cell (PRBC) transfusions were a principal cost driver in patients with a Hb concentration below 9.0 g/dl.

Conclusion

Patients with the lowest Hb concentration incurred the highest hospital costs, which were strongly associated with increased PRBC transfusions. Costs and possible complications may be decreased by treating preoperative anaemia, particularly more severe anaemia.

Sex-Specific Associations Between Preoperative Anemia and Postoperative Clinical Outcomes in Patients Undergoing Cardiac Surgery

BACKGROUND

Preoperative anemia is common in cardiac surgery, yet there were limited data describing the role of sex in the associations between anemia and clinical outcomes. Understanding these relationships may guide preoperative optimization efforts.

METHODS

This is an observational cohort study of adults undergoing isolated coronary artery bypass grafting or single- or double-valve surgery from 2008 to 2018 at a large tertiary medical center. Multivariable regression assessed the associations between preoperative hemoglobin concentrations and a primary outcome of postoperative acute kidney injury (AKI) and secondary outcomes of perioperative red blood cell (RBC) transfusion, reoperation, vascular complications (ie, stroke, pulmonary embolism, and myocardial infarction), and hospital length of stay (LOS). Each outcome was a single regression model, using interaction terms to assess sex-specific associations between hemoglobin and outcome.

RESULTS

A total of 4117 patients were included (57% men). Linear splines with sex-specific knots (13 g/dL in women and 14 g/dL in men) provided the best overall fit for preoperative hemoglobin and outcome relationships. In women, each 1 g/dL decrease in hemoglobin <13 g/dL was associated with increased odds of AKI (odds ratio = 1.49; 95% confidence interval [CI], [1.23-1.81]; P < .001), and there was no significant association between hemoglobin per 1 g/dL >13 g/dL and AKI (0.90 [0.56-1.45]; P = .67). The association between hemoglobin and AKI in men did not meet statistical significance (1.10 [0.99-1.22]; P = .076, per 1 g/dL decrease <14 g/dL; 1.00 [0.79-1.26]; P = .98 for hemoglobin per 1 g/dL >14 g/dL). In women, lower preoperative hemoglobin (per 1 g/dL decrease <13 g/dL) was associated with increased odds of RBC transfusion (2.90 [2.33-3.60]; P < .001), reoperation (1.27 [1.11-1.45]; P < .001) and a longer hospital LOS (multiplicative increase in geometric mean 1.05 [1.03-1.07]; P < .001). In men, preoperative hemoglobin (per 1 g/dL decrease <14 g/dL) was associated with increased odds of perioperative RBCs (2.56 [2.27-2.88]; P < .001) and longer hospital LOS (multiplicative increase in geometric mean 1.02 [1.01-1.04] days; P < .001) but not reoperation (0.94 [0.85-1.04]; P = .256). Preoperative hemoglobin per 1 g/dL >13 g/dL in women and 14 g/dL in men were associated with lower odds of RBCs transfusion (0.57 [0.47-0.69]; P < .001 and 0.74 [0.60-0.91]; P = .005, respectively).

CONCLUSIONS

Preoperative anemia was associated with inferior clinical outcomes after cardiac surgery. The associations between hemoglobin and outcomes were distinct for women and men, with different spline knot points identified (13 and 14 g/dL, respectively). Clinicians should consider data-driven approaches to determine preoperative hemoglobin values associated with increasing risk for adverse perioperative outcomes across sexes.

Machine learning models to predict red blood cell transfusion in patients undergoing mitral valve surgery

Background

Red blood cell (RBC) transfusion therapy has been widely used in surgery, and has yielded excellent treatment outcomes. However, in some instances, the demand for RBC transfusion is assessed by doctors based on their experience. In this study, we use machine learning models to predict the need for RBC transfusion during mitral valve surgery to guide the surgeon's assessment of the patient's need for intraoperative blood transfusion.

Methods

We retrospectively reviewed 698 cases of isolated mitral valve surgery with and without combined tricuspid valve operation. Seventy percent of the database was used as the training set and the remainder as the testing set for 13 machine learning algorithms to build a model to predict the need for intraoperative RBC transfusion. According to the characteristic value of model mining, we analyzed the risk-related factors to determine the main effects of variables influencing the outcome.

Results

A total of 166 patients of the cases considered had undergone intraoperative RBC transfusion (24.52%). Of the 13 machine learning algorithms, CatBoost delivered the best performance, with an AUC of 0.888 (95% CI: 0.845-0.909) in testing set. Further analysis using the CatBoost model revealed that hematocrit (<37.81%), age (>64 y), body weight (<59.92 kg), body mass index (BMI) (<22.56 kg/m²), hemoglobin (<122.6 g/L), type of surgery (median thoracotomy surgery), height (<160.61 cm), platelet (>194.12×10⁹/L), RBC (<4.08×10¹²/L), and gender (female) were the main risk-related factors for RBC transfusion. A total of 204 patients were tested, 177 of whom were predicted accurately (86.8%).

Conclusions

Machine learning models can be used to accurately predict the outcomes of RBC transfusion, and should be used to guide surgeons in clinical practice.

ABO blood group is related to bleeding in cardiac surgery

BACKGROUND

Increased bleeding and blood product transfusions during cardiac surgery are associated with poor outcomes. The patient's ABO blood group is related to hemostatic balance, although it is unclear whether this influences bleeding during cardiac surgery. This study aimed to evaluate whether ABO blood group is related to bleeding during cardiac surgery.

METHODS

This retrospective study evaluated data from 17,058 cardiac surgical procedures that were performed in four Danish cardiosurgical centers. Data regarding chest tube drainage and transfusion volumes were retrieved from a clinical database and combined with information regarding ABO group. The primary outcome was chest tube drainage volume and the secondary outcomes were transfused volumes of various blood products.

RESULTS

Blood group O had the largest chest tube drainage volume (mean: 745 mL, 95% CI: 720-771 mL) and blood group AB had the smallest volume (mean: 664 mL, 95% CI: 598-731 mL). The inter-group difference in the mean drainage volume was 81 mL (95% CI: 8-154 mL, P < .05). Patients with blood group A or blood group B had mean drainage volumes that were between the volumes for groups AB and O. Relative to group O, group AB received smaller mean volumes of all blood products. The most pronounced difference was in platelet concentrates, with mean values of 170 mL for group O (95% CI: 157-184 mL) and 63 mL for group AB (95% CI: 34-92 mL).

CONCLUSION

The patient's ABO group appears to be related to volumes of chest tube drainage and transfused blood products during cardiac surgery.

Socio-economic assessment of patient blood management practical implementation in surgical treatment of coronary heart disease (I20-I25)

Aim    To evaluate possible social and economic benefits of correcting preoperative iron deficiency /iron deficiency anemia as a comorbidity in a model population in the process of transition from the routine practice to the optimized preparation of patients to elective surgery (as exemplified by several circulatory diseases: I20 - I25, class IX ICD 10).Material and methods    By building imitation models depending on the patient blood management (PBM) practice, changes in years of life lost/saved adjusted for disability were evaluated, including in monetary terms, in relation to the annual number of operations performed for ischemic heart disease (IHD) (I20 - I25) in the age group of 17 years and older, as well as a potential effect of PBM on the applied health economics.Results    With implementation of the PBM systemic measures in cardiac surgery, the potentially prevented annual social and economic damage will amount to more than 38 thousand years of life saved and more than 20.2 billion rubles in monetary terms. Furthermore, it will be possible to exclude 9435 hemotransfusion from the cardiosurgical practice, which will annually save more than 2.3 thousand liters of blood with a total cost of 77.7 million rubles in favor of clinical situations that have no alternative.Conclusion    The implementation of PBM in cardiac surgery, the discipline with the highest levels of preoperative iron deficiency/anemia and the use of blood components, will not only improve the clinical outcomes and cost-effectiveness of surgical interventions, but will also prevent social and economic damage to the country.

Restrictive Transfusion Strategy after Cardiac Surgery

BACKGROUND

Recent guidelines on transfusion in cardiac surgery suggest that hemoglobin might not be the only criterion to trigger transfusion. Central venous oxygen saturation (Svo2), which is related to the balance between tissue oxygen delivery and consumption, may help the decision process of transfusion. We designed a randomized study to test whether central Svo2-guided transfusion could reduce transfusion incidence after cardiac surgery.

METHODS

This single center, single-blinded, randomized controlled trial was conducted on adult patients after cardiac surgery in the intensive care unit (ICU) of a tertiary university hospital. Patients were screened preoperatively and were assigned randomly to two study groups (control or Svo2) if they developed anemia (hemoglobin less than 9 g/dl), without active bleeding, during their ICU stay. Patients were transfused at each anemia episode during their ICU stay except the Svo2 patients who were transfused only if the pretransfusion central Svo2 was less than or equal to 65%. The primary outcome was the proportion of patients transfused in the ICU. The main secondary endpoints were (1) number of erythrocyte units transfused in the ICU and at study discharge, and (2) the proportion of patients transfused at study discharge.

RESULTS

Among 484 screened patients, 100 were randomized, with 50 in each group. All control patients were transfused in the ICU with a total of 94 transfused erythrocyte units. In the Svo2 group, 34 (68%) patients were transfused (odds ratio, 0.031 [95% CI, 0 to 0.153]; P < 0.001 vs. controls), with a total of 65 erythrocyte units. At study discharge, eight patients of the Svo2 group remained nontransfused and the cumulative count of erythrocyte units was 96 in the Svo2 group and 126 in the control group.

CONCLUSIONS

A restrictive transfusion strategy adjusted with central Svo2 may allow a significant reduction in the incidence of transfusion.

EDITOR’S PERSPECTIVE

Early postoperative bleeding after isolated coronary bypasses: Changes over a period of 20 years - An observational study

OBJECTIVES

The objectives were to analyze the evolution of the postoperative bleeding after coronary artery bypass grafting and to determine which factors impacted on this evolution.

METHODS

This is a single-center retrospective study including 4590 patients undergoing coronary bypass surgery between 1995 and 2017. The study period was divided into 3 same-sized periods. We analyzed the evolution of the bleeding according to: the chest volume bleeding over the first 24hours, the severity and the rate of transfusion during the hospital stay. Intrahospital outcomes were compared between "minor" and "major" bleedings. The risk factors of major bleeding were analyzed by multiple logistic regression.

RESULTS

The chest volume decreased particularly during the first years of the study period. Major bleedings decreased over the periods (7.3%, 4.9% and 3.8% respectively, P<0.0001), as did the rate of transfusion (26.4%, 23.5% and 19.6% respectively, P<0.0001). Major bleedings were correlated with hospital mortality (8.2% versus 1.1%, P<0.0001). The risk factors of major bleeding were the period 1 (1995 to 2003), a renal failure, a resternotomy, the EuroSCORE, the hematocrit prior to cardiopulmonary bypass and the duration of cardiopulmonary bypass.

CONCLUSIONS

Postoperative bleeding decreased mainly in the 1990s. Progressive changes in bleeding prevention and blood recovery, surgical techniques, haemoglobin threshold for transfusion decision and practitioners' experience have contributed to these results and must be continued to optimize the postoperative outcomes.

Postoperative Nadir Hemoglobin and Adverse Outcomes in Patients Undergoing On-Pump Cardiac Operation

BACKGROUND

Patients undergoing cardiac operation are susceptible to anemia. Low hemoglobin concentration is a risk factor for composite adverse events and death after cardiac operation. Here we investigated the association of postoperative nadir hemoglobin with adverse outcomes in patients undergoing on-pump cardiac operation.

METHODS

Adult patients in 2 medical centers were retrospectively analyzed. The primary outcome was postoperative composite adverse events. The secondary outcome was all-cause death in the hospital.

RESULTS

Of the 8206 patients analyzed, 1628 (19.8%) experienced composite adverse events after operation and 109 (1.3%) died. Patients receiving on-pump cardiac operation with nadir hemoglobin of 9.0 to 9.9 g/L showed a low incidence of composite adverse events (175 of 1423 [12.3%]) and death (5 of 1423 [0.4%]). Compared with nadir hemoglobin at 9.0 to 9.9 g/dL, the relative risk (RR) of composite adverse events increased stepwise as nadir hemoglobin fell below 9.0 g/dL: adjusted RR was 1.44 (95% confidence interval [CI], 1.14-1.83) for 8.5 to 8.9 g/dL, 1.56 (95% CI, 1.23-1.99) for 8.0 to 8.4 g/dL, 1.66 (95% CI, 1.31-2.11) for 7.5 to 7.9 g/dL, 2.22 (95% CI, 1.75-2.83) for 7.0 to 7.4 g/dL, and 4.00 (95% CI, 3.18-5.04) for less than 7 .0 g/dL. Furthermore, the risk of death was significantly higher when nadir hemoglobin was below 7.0 g/dL than when it was 9.0 to 9.9 g/dL (RR, 5.36; 95% CI, 2.20-16.12).

CONCLUSIONS

Compared with the risks when nadir hemoglobin is 9.0 to 9.9 g/dL, the risk of composite adverse events increases when postoperative nadir hemoglobin is below 9.0 g/dL, whereas risk of death increases when nadir hemoglobin is below 7.0 g/dL.

Evaluation of a novel Cardiac Peri-Operative Transfusion Trigger Scoring system in patients with coronary artery disease

BACKGROUND

A simple and accurate scoring system to guide perioperative blood transfusion in patients with coronary artery disease (CAD) undergoing cardiac surgery is lacking. The trigger point for blood transfusions for these patients may be different from existing transfusion guidelines. This study aimed to evaluate the safety and efficacy of a new scoring strategy for use in guiding transfusion decisions in patients with CAD.

METHODS

A multicenter randomized controlled trial was conducted at three third-level grade-A hospitals from January 2015 to May 2018. Data of 254 patients in a Cardiac Peri-Operative Transfusion Trigger Score (cPOTTS) group and 246 patients in a group receiving conventional evaluation of the need for transfusion (conventional group) were analysed. The requirements for transfusion and the per capita consumption of red blood cells (RBCs) were compared between groups.

RESULTS

Baseline characteristics of the two groups were comparable. Logistic regression analyses revealed no significant differences between the two groups in primary outcomes (1-year mortality and perioperative ischemic cardiac events), secondary outcomes (shock, infections, and renal impairment), ICU admission, and ICU stay duration. However, patients in the cPOTTS group had significantly shorter hospital stays, lower hospital costs, lower utilization rate and lower per capita consumption of transfused RBCs than controls. Stratified analyses revealed no significant differences between groups in associations between baseline characteristics and perioperative ischemic cardiac events, except for hemofiltration or dialysis and NYHA class in I.

CONCLUSIONS

This novel scoring system offered a practical and straightforward guideline of perioperative blood transfusion in patients with CAD. Trial registration chiCTR1800016561(2017/7/19).

The Effect of Preoperative Hematocrit Levels on Early Outcomes After Coronary Artery Bypass Graft

Introduction

Coronary artery bypass graft (CABG) is the most potent of surgical procedures; in this procedure, the narrowing of the coronary artery due to atherosclerotic plaque is bypassed by forming an alternate route for blood flow to the heart. There are various risk factors associated with the procedure. The aim of this study was to observe if postoperative outcomes are affected by preoperative hematocrit (hct) levels in patients.

Methods 

This longitudinal study was conducted from April 2019 to December 2019. Eighty-two (82) participants who were to undergo CABG surgery were divided into two groups based on their preoperative hct levels. Group 1 had 42 participants with lower levels of hct (less than 35.5% for women and 38.3% for men), whereas group 2 consisted of 40 participants with normal hct levels (greater than 35.5% for women and 38.3% for men).

Results

The results showed that participants undergoing CABG with lower than normal hct levels had increased blood loss through drainage as compared to participants who had normal hct levels (680.1 ± 301 mL vs. 500.7 ± 412 mL; p-value: 0.02). Group 1 participants also had an increased need for blood and blood product transfusion as compared to group 2 (3.2 ± 1.8 units vs. 1.8 ± 0.9 units; p-value: <0.0001). Furthermore, the participants in group 1 had longer stays in the ICU relative to the other group (5.2 ± 3.1 days vs. 3.4 ± 2.5 days; p-value: 0.003).

Conclusion

Based on our findings, patients who undergo CABG surgery with lower than normal hct levels are at increased risk of certain complications, including excessive blood loss, need for transfusion, and increased duration of ICU stay. Therefore, preoperative hct levels should be routinely checked in patients undergoing CABG to prevent these complications.

Effects of implementing rotational thromboelastometry in cardiac surgery: A retrospective cohort study

Since 2013, rotational thromboelastometry has been available in our hospital to assess coagulopathy. The aim of the study was to retrospectively evaluate the effect of thromboelastometry testing in cardiac surgery patients. Altogether 177 patients from 2012 and 177 patients from 2014 were included. In 2014, the thromboelastometry testing was performed on 56 patients. The mean blood drainage volume decreased and the number of patients receiving platelets decreased between 2012 and 2014. In addition, the use of fresh frozen plasma units decreased, and the use of prothrombin complex concentrate increased in 2014. When studied separately, the patients with a thromboelastometry testing received platelets, fresh frozen plasma, fibrinogen and prothrombin complex concentrate more often, but smaller amounts of red blood cells. In conclusion, after implementing the thromboelastometry testing to the practice, the blood products were given more cautiously overall. The use of thromboelastometry testing was associated with increased possibility to receive coagulation product transfusions. However, it appears that thromboelastometry testing was mostly used to assist in management of major bleeding.

Association of In-Hospital Surgical Bleeding Events with Prolonged Hospital Length of Stay, Days Spent in Critical Care, Complications, and Mortality: A Retrospective Cohort Study Among Patients Undergoing Neoplasm-Directed Surgeries in English Hospitals

Purpose

To evaluate the association of in-hospital surgical bleeding events with the outcomes of hospital length of stay (LOS), days spent in critical care, complications, and mortality among patients undergoing neoplasm-directed surgeries in English hospitals.

Patients and Methods

This is a retrospective cohort study using English hospital discharge data (Hospital Episode Statistics [HES]) linked to electronic health records (Clinical Practice Research Datalink [CPRD]). HES includes information on patient demographics, admission and discharge dates, diagnoses and procedures, days spent in critical care, and discharge status. CPRD includes information on patient demographics, diagnoses and symptoms, drug exposures, vaccination history, and laboratory tests. Patients aged ≥18 years who underwent selected neoplasm-directed surgeries between 1-Jan-2010 and 29-February-2016: hysterectomy, low anterior resection (LAR), lung resection, mastectomy, and prostate surgery were included. The primary independent variable was in-hospital surgical bleeding events identified by diagnosis of haemorrhage and haematoma complicating a procedure or reopening/re-exploration and surgical arrest of postoperative bleeding. Outcomes included LOS, days spent in critical care, in-hospital complications (diagnoses of infections, acute renal failure, vascular events), and in-hospital mortality, identified during surgery through discharge. Multivariable regression was used to examine the adjusted association of bleeding events with outcomes.

Results

The study included 26,437 neoplasm-directed surgeries (hysterectomy=6092; LAR=2957; lung=1538; mastectomy=12,806; prostate=3044). Incidence proportions of bleeding events were: hysterectomy=1.9% (95% confidence interval=1.1–2.5%); LAR=3.0% (CI=2.3–3.6%); lung=1.8% (CI=1.1–2.5%); mastectomy=1.6% (CI=1.3–1.8%); prostate=1.0% (CI=0.6–1.3%). In adjusted analyses, bleeding events were associated with: prolonged LOS: 3.1 (CI=1.1–6.3) mastectomy to 5.7 (CI=3.6–8.2) LAR days longer; more days spent in critical care: 0.4 (CI=0.03–0.27) mastectomy to 6.5 (CI=2.5–13.6) hysterectomy days more; and higher incidence proportions of all examined complications; all P<0.05.

Conclusion

This study quantifies a substantial clinical and healthcare resource utilization burden associated with surgical bleeding among patients undergoing neoplasm-directed surgery in England hospitals.

The routine use of platelet function tests in elective coronary artery bypass grafting: A prospective observational trial

BACKGROUND

Preoperative use of platelet function tests contributes to the decrease of re-intervention rate due to bleeding and the necessity of transfusion in coronary artery bypass grafting (CABG) patients. The aim was to investigate the predictive value and to justify routine preoperative use of multiple electrode aggregometry in these patients.

METHODS

A prospective observational trial which included 416 consecutive patients subjected to elective isolated CABG was conducted. The Multiplate® test was used to assess platelet function. Platelet function test results, postoperative blood loss, and transfusion requirements were compared between high and low bleeding risk patients. Receiver operating characteristic analysis was performed to assess the sensitivity and specificity of the arachidonic acid (ASPI) and adenosine di-phosphate high sensitive (ADPHS) tests.

RESULTS

ADPHS and ASPI test results significantly predicted total bleeding > 1000 ml (AUC, 0.685, p < .001; 0.695, p = .039). Sensitivity and specificity were 62.9% and 40.0%, for ADPHS ≤602, and 70.8% and 41.8%, for ASPI ≤ 453. The sensitivity and specificity of cut-off values recommended by the manufacturer were 84.2% and 40.0% for ADPHS ≤ 500, while for ASPI < 600 the values were 54.7% and 62.2%. More platelets and cryoprecipitate were transfused in patients with ADPHS ≤ 602.5 (p < .001; p = .035). Patients with ADPHS ≤ 500 had a higher rate of red blood count, platelet and cryoprecipitate transfusion (p<.001p<.001; p = .013). The manufacturer's ASPI test cut-off values showed no statistically significant prediction for a higher transfusion rate.

CONCLUSION

Preoperative platelet function tests should be conducted systematically for all elective CABG patients who were on dual antiplatelet therapy after adjusting test cut-off values for each population.

Changing of haemostatic system in a pig model during different types of hypothermic circulatory arrest

BACKGROUND

Hypothermic circulatory arrest is usually used in aortic surgery, congenital heart defect repairs and other complex surgeries. It is frequently associated with excessive postoperative bleeding and the transfusion of allogeneic blood products. The physiopathology of hypothermic circulatory arrest-induced coagulopathy has never been systematically studied. The aim of the study was to investigate this phenomenon in a pig model.

METHODS

Ten pigs were randomly assigned to 30 min of hypothermic circulatory arrest at either 15 °C (n = 5) or 25 °C (n = 5). Detection of apoptosis and haemostatic system assays were performed in this experiment. Enzyme-linked immunosorbent assays were performed at ten time points in each group to study the changes in the coagulation system in hypothermic circulatory arrest. All of the statistical analyses were performed in SPSS software, version 18.0, and as bilateral tests, and p < 0.05 was considered statistically significant.

RESULTS

There was no significant difference in the effect of different types of hypothermic circulatory arrest on routine laboratory tests and tissue sample analysis (p > 0.05, for all). Our results demonstrated that more severe systemic activation of the coagulation system (TAT and F1+2) was applied in the deep hypothermic circulatory arrest group but not in the moderate hypothermic circulatory arrest group (TAT/p = 0.01, F1+2/p = 0.03). However, this activation of the coagulation system (AT III and PC) was not associated with changes in the anticoagulation pathway (AT III/p = 0.24, PC/p = 0.33). In addition, analysis of biomarkers of the haemostatic system revealed that the consumption of coagulation is more concentrated on extrinsic coagulation factors (FVII/p = 0.01).

CONCLUSIONS

Moderate hypothermic circulatory arrest is more suitable for patients with coagulation dysfunction. We believe the application of deep hypothermic circulatory arrest should pay more attention to changes in coagulation rather than the anticoagulation pathway. Extrinsic coagulation factor supplementation is more effective after deep hypothermic circulatory arrest.

Transfusion-Associated Hyperkalemic Cardiac Arrest in Neonatal, Infant, and Pediatric Patients

Red blood cell (RBC) transfusions are a life-saving intervention, with nearly 14 million RBC units transfused in the United States each year. However, the safety and efficacy of this procedure can be influenced by variations in the collection, processing, and administration of RBCs. Procedures or manipulations that increase potassium (K⁺) levels in stored blood products can also predispose patients to hyperkalemia and transfusion-associated hyperkalemic cardiac arrest (TAHCA). In this mini review, we aimed to provide a brief overview of blood storage, the red cell storage lesion, and variables that increase extracellular [K⁺]. We also summarize cases of TAHCA and identify potential mitigation strategies. Hyperkalemia and cardiac arrhythmias can occur in pediatric patients when RBCs are transfused quickly, delivered directly to the heart without time for electrolyte equilibration, or accumulate extracellular K⁺ due to storage time or irradiation. Advances in blood banking have improved the availability and quality of RBCs, yet, some patient populations are sensitive to transfusion-associated hyperkalemia. Future research studies should further investigate potential mitigation strategies to reduce the risk of TAHCA, which may include using fresh RBCs, reducing storage time after irradiation, transfusing at slower rates, implementing manipulations that wash or remove excess extracellular K⁺, and implementing restrictive transfusion strategies.

Minimally Invasive Aortic Valve Surgery in Octogenarians: Reliable Option or Fallback Solution?

OBJECTIVE

Aortic valve disease is more and more common in western countries. While percutaneous approaches should be preferred in older adults, previous reports have shown good outcomes after surgery. Moreover, advantages of minimally invasive approaches may be valuable for octogenarians. We sought to compare outcomes of conventional aortic valve replacement (CAVR) versus minimally invasive aortic valve replacement (MIAVR) in octogenarians.

METHODS

We retrospectively collected data of 75 consecutive octogenarians who underwent primary, elective, isolated aortic valve surgery through conventional approach (41 patients, group CAVR) or partial upper sternotomy (34 patients, group MIAVR).

RESULTS

Mean age was 81.9 ± 0.9 and 82.3 ± 1.1 years in CAVR and MIAVR patients, respectively (P = 0.09). MIAVR patients had lower 24-hour chest drain output (353.4 ± 207.1 vs 501.7 ± 229.9 mL, P < 0.01), shorter mechanical ventilation (9.6 ± 2.4 vs 11.3 ± 2.3 hours, P < 0.01), lower need for blood transfusions (35.3% vs 63.4%, P = 0.02), and shorter hospital stay (6.8 ± 1.6 vs 8.3 ± 4.3 days, P < 0.01). Thirty-day mortality was zero in both groups. Survival at 1, 3, and 5 years was 89.9%, 80%, and 47%, respectively, in the CAVR group, and 93.2%, 82.4%, and 61.8% in the MIAVR group, with no statistically significant differences (log-rank test, P = 0.35).

CONCLUSIONS

Aortic valve surgery in older patients provided excellent results, as long as appropriate candidates were selected. MIAVR was associated with shorter mechanical ventilation, reduced blood transfusions, and reduced hospitalization length, without affecting perioperative complications or mid-term survival.

Prognostic Value of Preoperative Hemoglobin Levels for Long-Term Outcomes of Acute Type B Aortic Dissection Post-thoracic Endovascular Aortic Repair

Background and Aims: There is scant information available about the prognostic value of preoperative hemoglobin (Hb) levels on the long-term outcomes of acute type B aortic dissection (ABAD) following thoracic endovascular aortic repair (TEVAR).

Methods: A retrospective analysis of consecutive patients from 2010 to 2018 regarding the relationship between Hb level and long-term outcomes was conducted. The primary endpoint was all-cause mortality. Major adverse cardiovascular events (MACEs) included all-cause death, recurrent ruptures, and secondary procedures.

Results: In total, 391 subjects treated by TEVAR were enrolled, with a mean age of 57.1 ± 12.0 years; 79.5% of them were male. Cox multivariate analysis showed that the preoperative Hb level was independently associated with all-cause death [adjusted hazard ratio (HR) 0.797 (per 1 g/dl), 95% confidence interval (CI) 0.693–0.918, p = 0.002] and MACEs (adjusted HR 0.795, 95% CI 0.672–0.871, p = 0.000). The area under the receiver operating characteristic curve of Hb for all-cause death and MACEs were 0.617 (95% CI 0.548–0.687, p = 0.008) and 0.617 (95% CI 0.551–0.684, p = 0.005), respectively. In the linear trend test, Hb concentration was significantly related to all-cause mortality (p for trend = 0.001) and MACEs (p for trend = 0.000). Moreover, in Kaplan–Meier analysis, lower Hb levels (< 12 g/dl) were significantly different from higher Hb (≥12 g/dl) levels for both all-cause death (log-rank p = 0.001) and MACEs (log-rank p = 0.001). Similar results were found when assessing the prognostic value of red blood cell count and anemia.

Conclusions: Preoperative Hb may serve as a prognostic marker for long-range adverse outcomes for ABAD patients post-TEVAR.

Prothrombin complex concentrate vs. fresh frozen plasma in adult patients undergoing heart surgery - a pilot randomised controlled trial (PROPHESY trial)

There is equipoise regarding the use of prothrombin complex concentrate vs. fresh frozen plasma in bleeding patients undergoing cardiac surgery. We performed a pilot randomised controlled trial to determine the recruitment rate for a large trial, comparing the impact of prothrombin complex concentrate vs. fresh frozen plasma on haemostasis (1 h and 24 h post-intervention), and assessing safety. Adult patients who developed bleeding within 24 h of cardiac surgery that required coagulation factor replacement were randomly allocated to receive prothrombin complex concentrate (15 IU.kg^-1 based on factor IX) or fresh frozen plasma (15 ml.kg^-1 ). If bleeding continued after the first administration of prothrombin complex concentrate or fresh frozen plasma administration, standard care was administered. From February 2019 to October 2019, 180 patients were screened, of which 134 (74.4% (95%CI 67-81%)) consented, 59 bled excessively and 50 were randomly allocated; 25 in each arm, recruitment rate 35% (95%CI 27-44%). There were 23 trial protocol deviations, 137 adverse events (75 prothrombin complex concentrate vs. 62 fresh frozen plasma) and 18 serious adverse events (5 prothrombin complex concentrate vs. 13 fresh frozen plasma). There was no increase in thromboembolic events with prothrombin complex concentrate. No patient withdrew from the study, four were lost to follow-up and two died. At 1 h after administration of the intervention there was a significant increase in fibrinogen, Factor V, Factor XII, Factor XIII, α₂ -antiplasmin and antithrombin levels in the fresh frozen plasma arm, while Factor II and Factor X were significantly higher in the prothrombin complex concentrate group. At 24 h, there were no significant differences in clotting factor levels. We conclude that recruitment to a larger study is feasible. Haemostatic tests have provided useful insight into the haemostatic changes following prothrombin complex concentrate or fresh frozen plasma administration. A definitive trial is needed to ascertain the benefits and safety for each.

"TEG talk": expanding clinical roles for thromboelastography and rotational thromboelastometry

Viscoelastic assays (VEAs) that include thromboelastography and rotational thromboelastometry add value to the investigation of coagulopathies and goal-directed management of bleeding by providing a complete picture of clot formation, strength, and lysis in whole blood that includes the contribution of platelets, fibrinogen, and coagulation factors. Conventional coagulation assays have several limitations, such as their lack of correlation with bleeding and hypercoagulability; their inability to reflect the contribution of platelets, factor XIII, and plasmin during clot formation and lysis; and their slow turnaround times. VEA-guided transfusion algorithms may reduce allogeneic blood exposure during and after cardiac surgery and in the emergency management of trauma-induced coagulopathy and hemorrhage. However, the popularity of VEAs for other indications is driven largely by extrapolation of evidence from cardiac surgery, by the drawbacks of conventional coagulation assays, and by institution-specific preferences. Robust diagnostic studies validating and standardizing diagnostic cutoffs for VEA parameters and randomized trials comparing VEA-guided algorithms with standard care on clinical outcomes are urgently needed. Lack of such studies represents the biggest barrier to defining the role and impact of VEA in clinical care.

Does Blood Transfusion Have an Effect on Outcomes After Aortic Valve Replacement Surgery?

OBJECTIVE

Long-term outcomes following surgical aortic valve replacement (AVR) are excellent. However, there is a significant early morbidity burden. Red cell transfusion is common in the perioperative period and deleterious effects of receiving a transfusion on early postoperative morbidity are well described in observational studies. This study aimed to assess the effect of transfusion on ischaemic or infective outcomes after aortic valve replacement.

METHODS

Data from 270 patients enrolled in the Manubrium-limited ministernotomy versus conventional sternotomy for aortic valve replacement (MAVRIC) randomised controlled trial was used to create two cohorts, patients that received red cell transfusions following AVR and those that did not. Propensity score matching was performed to limit the effect of confounding variables. Strict transfusion thresholds were maintained, with patients receiving a transfusion if haemoglobin concentration fell below 80 g/L, or if significant bleeding or haemodynamic instability occurred. The primary outcome was a composite of ischaemic event (myocardial infarction, permanent stroke, gut ischaemia or acute kidney injury) or serious infection (sepsis, endocarditis, respiratory tract or wound infection). Patients were followed for 12 weeks following surgery.

RESULTS

Sixty-three (63) of 270 patients received a red cell transfusion (23.3%). Transfused patients had significantly lower body mass index (BMI), a higher proportion of females, a lower preoperative haemoglobin and haematocrit, a higher EuroSCORE II score, worse renal function and were more likely to have undergone urgent surgery compared to the unadjusted control cohort. Once matched, there was no difference in the primary outcome between cohorts. There was a significantly increased length of hospital stay in the transfused group (median 7 days transfused, median 5 days not-transfused, p=0.001).

CONCLUSIONS

Red cell transfusion, using a transfusion threshold of 80 g/L, does not appear to be associated with adverse ischaemic or infective outcomes after aortic valve replacement.

The Impact of Transfusions on Mortality After Transcatheter or Surgical Aortic Valve Replacement

BACKGROUND

An increasing body of evidence suggests that packed red blood cell (PRBC) transfusion may be associated with increased morbidity and mortality after transcatheter and surgical aortic valve replacement. It remains unclear whether PRBC transfusion is a surrogate marker or truly an independent risk factor for mortality after aortic valve replacement in different populations.

METHODS

The Surgical Replacement and Transcatheter Aortic Valve Implantation (SURTAVI) trial randomized 1660 patients with symptomatic, severe aortic stenosis at intermediate risk for operative death to transcatheter aortic valve replacement or surgical aortic valve replacement. Baseline characteristics and outcomes including all-cause and cardiovascular mortality at 30 days and thereafter were compared between participants with and participants without PRBC transfusion. Cox proportional hazards models with time-varying covariates were fitted to estimate the effect of PRBC transfusion on mortality after adjustment for comorbidities and procedural complications.

RESULTS

Patients receiving PRBC were older, more commonly female and frail, with more comorbidities. The Society of Thoracic Surgeons Predicted Risk of Mortality baseline score was higher in the transfused group. After adjustment for these differences, PRBC transfusion was associated with mortality at 30 days, but not thereafter. The effect of PRBC on mortality (hazard ratio 1.04; 95% confidence interval, 0.96 to 1.11; P = .304) at 30 days was not independent of procedural complications (hazard ratio 21.04; 95% CI, 7.26 to 60.95; P < .001).

CONCLUSIONS

Poor health status, procedural complications, PRBC transfusion, and mortality are correlated with each other. Transfusion of PRBC did not independently increase risk for mortality. In this intermediate-risk population, transfusion appears to be a risk marker of chronic conditions and periprocedural complications as opposed to a risk factor for postprocedural mortality. (Clinical trial registration: www.clinicaltrials.gov NCT01586910.).

Institutional Red Blood Cell Transfusion Rates Are Correlated Following Endovascular and Surgical Cardiovascular Procedures: Evidence That Local Culture Influences Transfusion Decisions

Background

The relationship between local hospital culture and transfusion rates following endovascular and surgical cardiovascular procedures has not been well studied.

Methods and Results

Patients undergoing coronary revascularization, aortic valve replacement, lower extremity peripheral vascular intervention, or carotid artery revascularization from up to 852 US hospitals in the Nationwide Readmissions Database were identified. Crude and risk‐standardized red blood cell transfusion rates were determined for each procedure. Pearson correlation coefficients were calculated between respective procedural transfusion rates. Median odds ratios were estimated to reflect between‐hospital variability in red blood cell transfusion rates following the same procedure for a given patient. There was wide variation in red blood cell transfusion rates across different procedures, from 2% following carotid endarterectomy to 29% following surgical aortic valve replacement. For surgical and endovascular modalities, transfusion rates at the same hospital were highly correlated for aortic valve replacement (r=0.67; P<0.001), moderately correlated for coronary revascularization (r=0.56; P<0.001) and peripheral vascular intervention (r=0.51; P<0.001), and weakly correlated for carotid artery revascularization (r=0.19, P<0.001). Median odds ratios were all >2, highest for coronary artery bypass graft surgery and surgical aortic valve replacement, indicating substantial site variation in transfusion rates.

Conclusions

After adjustment for patient‐related factors, wide variation in red blood cell transfusion rates remained across surgical and endovascular procedures employed for the same cardiovascular condition. Transfusion rates following these procedures are highly correlated at individual hospitals and vary widely across hospitals. In aggregate, these findings suggest that local institutional culture significantly influences the decision to transfuse following invasive cardiovascular procedures and highlight the need for randomized data to inform such decisions.

Thromboelastography-guided blood transfusion during cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy: study protocol for a prospective randomised controlled trial

INTRODUCTION

Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is a well-established treatment for peritoneal cancer (PC). However, this kind of combination therapy is associated with a high incidence of complications. Moreover, relative studies have indicated that traditional laboratory testing is insufficient to demonstrate the overall haemostatic physiology of CRS/HIPEC. Thromboelastography (TEG), administered by monitoring dynamic changes in haemostasis, has been shown to contribute to reducing transfusion requirements and improving survival. However, there is no evidence to verify whether TEG can be applied to guide transfusion strategies during CRS/HIPEC. Therefore, we aim to investigate whether TEG-guided blood product transfusion (TEG-BT) therapy is superior to traditional blood product transfusion (T-BT) therapy for guiding perioperative blood transfusion treatment and improving the prognosis of patients undergoing CRS/HIPEC.

METHODS AND ANALYSIS

The TEG-BT versus T-BT study is a single-centre, randomised, blinded outcome assessment clinical trial of 162 patients with PC, aged 18-64 years and undergoing CRS/HIPEC. Participants will be randomly allocated to receive TEG-BT or T-BT. The primary outcome will be the evaluation of perioperative blood transfusion, which refers to the total amount of blood transfusion given from the time patients enter the operating room up to 72 hours postoperatively. The secondary outcomes will include the transfusion volume during surgery, total amount of intraoperative infusion, amount of blood lost during the operation, total blood transfusion between 0 and 72 hours after surgery, lowest haemoglobin level within 72 hours after surgery, intensive care unit duration, overall length of stay, total cost of hospitalisation and adverse events. Data will be analysed according to the intention-to-treat principle.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Scientific Research Ethics Committee of Beijing Shijitan Hospital Affiliated with Capital Medical University (Approval Number: sjtkyll-lx-2020-3). The results will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2000028835).

Controversies in the Clinical Practice of Patient Blood Management

Patient blood management (PBM) has been proposed as a standard of care in modern perioperative medicine. PBM-related interventions usually are implemented as bundles, but randomized controlled trials on the implementation of PBM as a bundle are missing. This special article focuses on the current evidence and controversies in the clinical practice of PBM and on emerging data related to specific PBM-related interventions in patients undergoing cardiac surgery. Strong evidence for many PBM-related interventions is limited because of missing studies or the poor quality of published findings and study endpoints. Restrictive blood transfusion and timely interventions to maintain hemoglobin concentration and to reduce blood loss potentially might result in improved patient outcome, although the latter has yet to be proven.

Long-term Impact of Perioperative Red Blood Cell Transfusion on Patients Undergoing Cardiac Surgery

BACKGROUND

There is a known association between need for transfusion and short-term outcomes in patients undergoing cardiac surgery. However long-term data are lacking in the contemporary literature.

METHODS

All patients who underwent open cardiac surgery from 2010 to 2018 were included, except those undergoing transplant, with a ventricular-assist device, and requiring circulatory arrest. Primary outcome included short- and long-term mortality. Secondary outcomes included postoperative complications and hospital readmissions.

RESULTS

The total patient population included 14,281 patients with a median follow-up of 4.03 years (range, 2.25-6.1). Outcomes were stratified into patients with (n = 6239) or without (n = 8042) packed red blood cell (PRBC) use. Patients with PRBC transfusions had significantly (P < .001) worse postoperative outcomes compared with those without PRBC use, including higher operative mortality (6.89% vs 0.98%), return to the operating room (17.8% vs 1.61%), pneumonia (7.84% vs 0.98%), stroke (3.22% vs 1.51%), sepsis (2.66% vs 0.20%), renal failure (8.42% vs 1.12%), and dialysis (5.74% vs 0.42%). On multivariate analysis PRBC transfusion was an independent predictor of mortality (hazard ratio [[HR], 2.39; 95% confidence interval [CI], 2.08-2.64; P < .001) and hospital readmission (HR, 1.15; 95% CI, 1.09-1.21; P < .001). Total units of PRBCs were directly associated with mortality (HR, 1.09; 95% CI, 1.08-1.09; P < .001) and hospital readmissions (HR, 1.02; 95% CI, 1.01-1.03; P < .005).

CONCLUSIONS

Patients with perioperative PRBC transfusions have increased operative and long-term mortality and hospital readmissions. Total units of PRBCs transfused were directly associated with mortality and readmissions.

Duration of Venoarterial Extracorporeal Membrane Oxygenation and Mortality in Postcardiotomy Cardiogenic Shock

OBJECTIVE

The optimal duration of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in patients affected by postcardiotomy cardiogenic shock (PCS) remains controversial. The present study was conducted to investigate the effect of VA-ECMO duration on hospital outcomes.

DESIGN

Retrospective analysis of an international registry.

SETTING

Multicenter study including 19 tertiary university hospitals.

PARTICIPANTS

Between January 2010 and March 2018, data on PCS patients receiving VA-ECMO were retrieved from the multicenter PC-ECMO registry.

INTERVENTIONS

Patients were stratified according to the following different durations of VA-ECMO therapy: ≤three days, four-to-seven days, eight-to-ten days, and >ten days.

MEASUREMENTS AND MAIN RESULTS

A total of 725 patients, with a mean age of 62.9 ± 12.9 years, were included. The mean duration of VA-ECMO was 7.1 ± 6.3 days (range 0-39 d), and 39.4% of patients were supported for ≤three days, 29.1% for four-seven days, 15.3% for eight-ten days, and finally 20.7% for >ten days. A total of 391 (53.9%) patients were weaned from VA-ECMO successfully; however, 134 (34.3%) of those patients died before discharge. Multivariate logistic regression showed that prolonged duration of VA-ECMO therapy (four-seven days: adjusted rate 53.6%, odds ratio [OR] 0.28, 95% confidence interval [CI] 0.18-0.44; eight-ten days: adjusted rate 61.3%, OR 0.51, 95% CI 0.29-0.87; and >ten days: adjusted rate 59.3%, OR 0.49, 95% CI 0.31-0.81) was associated with lower risk of mortality compared with VA-ECMO lasting ≤three days (adjusted rate 78.3%). Patients requiring VA-ECMO therapy for eight-ten days (OR 1.96, 95% CI 1.15-3.33) and >10 days (OR 1.85, 95% CI 1.14-3.02) had significantly greater mortality compared with those on VA-ECMO for 4 to 7 days.

CONCLUSIONS

PCS patients weaned from VA-ECMO after four-seven days of support had significantly less mortality compared with those with shorter or longer mechanical support.

Potential Consequences of the Red Blood Cell Storage Lesion on Cardiac Electrophysiology

Background The red blood cell (RBC) storage lesion is a series of morphological, functional, and metabolic changes that RBCs undergo following collection, processing, and refrigerated storage for clinical use. Since the biochemical attributes of the RBC unit shifts with time, transfusion of older blood products may contribute to cardiac complications, including hyperkalemia and cardiac arrest. We measured the direct effect of storage age on cardiac electrophysiology and compared it with hyperkalemia, a prominent biomarker of storage lesion severity. Methods and Results Donor RBCs were processed using standard blood-banking techniques. The supernatant was collected from RBC units, 7 to 50 days after donor collection, for evaluation using Langendorff-heart preparations (rat) or human induced pluripotent stem cell-derived cardiomyocytes. Cardiac parameters remained stable following exposure to "fresh" supernatant from red blood cell units (day 7: 5.8±0.2 mM K+), but older blood products (day 40: 9.3±0.3 mM K+) caused bradycardia (baseline: 279±5 versus day 40: 216±18 beats per minute), delayed sinus node recovery (baseline: 243±8 versus day 40: 354±23 ms), and increased the effective refractory period of the atrioventricular node (baseline: 77±2 versus day 40: 93±7 ms) and ventricle (baseline: 50±3 versus day 40: 98±10 ms) in perfused hearts. Beating rate was also slowed in human induced pluripotent stem cell-derived cardiomyocytes after exposure to older supernatant from red blood cell units (-75±9%, day 40 versus control). Similar effects on automaticity and electrical conduction were observed with hyperkalemia (10-12 mM K+). Conclusions This is the first study to demonstrate that "older" blood products directly impact cardiac electrophysiology, using experimental models. These effects are likely caused by biochemical alterations in the supernatant from red blood cell units that occur over time, including, but not limited to hyperkalemia. Patients receiving large volume and/or rapid transfusions may be sensitive to these effects.

A biodegradable microneedle sheet for intracorporeal topical hemostasis

Management of bleeding is critical for improving patient outcomes. While various hemostatic products are used in daily practice, technical improvement is still needed. To addresses this problem, we newly developed a microneedle hemostatic sheet based on microneedle technology. We demonstrated the unique features of this microneedle hemostatic sheet, including reduced hemostatic time, biodegradable polymer composition that allows intracorporeal use without increasing infectious risk incorporation of microneedles to fix the sheet to the wound even on the left ventricular wall of a swine while beating, and a mesh structure with flexibility comparable to that of bonding surgical tape and sufficient rigidity to penetrate human aorta tissue and swine left ventricular wall. One potential application of the microneedle hemostatic sheet is intracorporeal topical hemostasis for parenchymatous organs, large vessels, and heart wall during trauma or surgery, in addition to new, widespread applications.

MiR-223 levels predicting perioperative bleeding in off-pump coronary artery bypass grafting

Background

To investigate the predictive value of platelet-related microRNAs (miRNAs) for bleeding during and after off-pump coronary artery bypass grafting (OPCABG) and the influence of dual antiplatelet therapy (DAPT) on miRNAs.

Methods

This prospective study included 59 patients scheduled for OPCABG. The plasma miR-126 and miR-223 levels were measured and platelet aggregation was determined by thromboelastography during DAPT. The plasma miRNA levels were compared between patients treated with ticagrelor or clopidogrel. Multivariable logistic regression analysis was performed to determine the independent risk factors for bleeding during and after surgery. Active bleeding was defined as a blood loss >1.5 mL/kg/h for 6 consecutive hours within the first 24 hours or in case of reoperation during the first 12 postoperative hours. Severe perioperative bleeding was defined using the universal definition of perioperative bleeding in adult cardiac surgery.

Results

Higher circulating miR-223 levels [odds ratio (OR) =1.348, 95% confidence interval (CI): 1.001–1.814, P=0.047] and lower body mass index (OR =0.648, 95% CI: 0.428–0.980, P=0.040) were independent predictors for severe perioperative bleeding in OPCABG. Ticagrelor treatment led to significant increases in circulating miR-223 levels compared with clopidogrel treatment.

Conclusions

The plasma miR-223 levels served as a predictor for bleeding during and after OPCABG. Circulating miR-223 levels were significantly elevated with ticagrelor treatment compared with clopidogrel treatment. MiR-223 may be a novel biomarker for bleeding in cardiac surgery and can help explain the different efficacies of ticagrelor and clopidogrel.

The effect of transfusion of blood products on ventricular assist device support outcomes

AIMS

Perioperative blood transfusions are common among patients undergoing left ventricular assist device (LVAD) implantation. The association between blood product transfusion at the time of LVAD implantation and mortality has not been described.

METHODS AND RESULTS

This was a retrospective cohort study of all patients who underwent continuous flow LVAD implantation at a single, large, tertiary care, academic centre, from 2008 to 2014. We assessed used of packed red blood cells (pRBCs), platelets, and fresh frozen plasma (FFP). Outcomes of interest included all-cause mortality and acute right ventricular (RV) failure. Standard regression techniques were used to examine the association between blood product exposure and outcomes of interest. A total of 170 patients were included in this study (mean age: 56.5 ± 15.5 years, 79.4% men). Over a median follow-up period of 11.2 months, for every unit of pRBC transfused, the hazard for mortality increased by 4% [hazard ratio (HR) 1.04; 95% CI 1.02-1.07] and odds for acute RV failure increased by 10% (odds ratio 1.10; 95% CI 1.05-1.16). This association persisted for other blood products including platelets (HR for mortality per unit 1.20; 95% CI 1.08-1.32) and FFP (HR for mortality per unit 1.08; 95% CI 1.04-1.12). The most significant predictor of perioperative blood product exposure was a lower pre-implant haemoglobin.

CONCLUSIONS

Perioperative blood transfusions among patients undergoing LVAD implantation were associated with a higher risk for all-cause mortality and acute RV failure. Of all blood products, FFP use was associated with worst outcomes. Future studies are needed to evaluate whether pre-implant interventions, such as intravenous iron supplementation, will improve the outcomes of LVAD candidates by decreasing need for transfusions.

Primary isolated CABG restrictive blood transfusion protocol reduces transfusions and length of stay

BACKGROUND

Cardiac surgery accounts for 10-15% of blood transfusions in the US, despite benefits and calls of limiting its use. We sought to evaluate the impact of a restrictive transfusion protocol on blood use and clinical outcomes in patients undergoing isolated primary coronary artery bypass grafting (CABG).

METHODS

Blood conservation measures, instituted in 2012, include preoperative optimization, intraoperative anesthesia, and pump fluid restriction with retrograde autologous priming and vacuum-assisted drainage, use of aminocaproic acid and cell saver, intra- and postoperative permissive anemia, and administration of iron and low-dose vasopressors if needed. Medical records of patients who underwent isolated primary CABG from 2009 to 2012 (group A; n = 375) and 2013 to 2016 (group B; n = 322) were compared.

RESULTS

CABG with grafting to three or four coronary arteries was performed in 262 (70%) and 222 (69%) patients and bilateral internal thoracic artery grafting in 202 (54%) and 196 (61%) patients in groups A and B, respectively. Mean preoperative and intraoperative hematocrit was 40.3% and 40.7%, 28.9% and 29.4% in groups A and B, respectively. Total blood transfusion was 24% and 6.5%, intraoperative transfusion 11% and 1.2%, and postoperative transfusion 20% and 5.6% (P < .0001 for all) in groups A and B, respectively. Median postoperative length of stay was 5.0 days in group A and 4.5 days in group B (P = .02), with no significant differences in mortality or morbidity.

CONCLUSIONS

A restrictive transfusion protocol reduced blood transfusions and postoperative length of stay without adversely affecting outcomes following isolated primary CABG.

Clinical and economic impact of oxidized regenerated cellulose for surgeries in a Chinese tertiary care hospital

Aim: To assess the impact of oxidized regenerated cellulose (ORC) on blood transfusion and hospital costs associated with surgeries. Patients & methods: This retrospective cohort study selected ten surgeries to create propensity-score matching groups to compare ORC versus nonORC (conventional hemostatic techniques such as manual pressure, ligature and electrocautery). Results: NonORC was associated with both higher blood transfusion volume and higher hospital costs than ORC in endoscopic transnasal sphenoidal surgery, nonskull base craniotomy, hepatectomy, cholangiotomy, gastrectomy and lumbar surgery. However, nonORC was associated with better outcomes than ORC in open colorectal surgery, mammectomy and hip arthroplasty surgery. Conclusion: When compared with conventional hemostatic technique, using ORC could impact blood transfusion and hospital costs differently by surgical settings.

Outcomes in minimally invasive double valve surgery

OBJECTIVE

To review current literature evidence on outcomes of minimally invasive double valve surgeries (MIS).

METHODS

A comprehensive electronic literature search was done from inception to 20th June 2020 identifying articles that discussed outcomes of minimally invasive approach in double valve surgeries either as a solo cohort or as comparative to conventional sternotomies. No limit was placed on time and place of publication and the evidence has been summarized in narrative manner within the manuscript.

RESULTS

Majority of current literature reported similar perioperative and clinical outcomes between MIS and conventional median sternotomy; except that MIS has better cosmetic effects and pain control. Nevertheless, minimal invasive techniques are associated with longer cardiopulmonary bypass and aortic cross-clamp times which may have impact on the reported outcomes and overall morbidity and mortality rates.

CONCLUSION

Minimally invasive double valve surgery continues to develop, but scarcity in the literature suggests uptake is slow, possibly due to the learning curve associated with MIS. Many outcomes appear to be comparable to conventional sternotomy. There is need for larger, multi-center, and randomized trial to fully evaluate and establish the early, mid- and long-term morbidity and mortality rates associated with both techniques.

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.

Blood management in a patient with anti-Oka antibody who underwent cardiac surgery using cardiopulmonary bypass: a case report

Background

Cardiac surgery under cardiopulmonary bypass (CPB) is often associated with massive bleeding and blood transfusion. For patients requiring specific blood products, meticulous blood management is critical to reduce blood loss, as well as the need for transfusion. Here, we have described the intraoperative blood management in a patient with anti-Ok^a antibody, who underwent cardiac surgery with CPB.

Case presentation

A 79-year-old woman was scheduled for open aortic valve replacement and tricuspid valve annuloplasty under hypothermic CPB. Her blood type was A RhD(+) Ok(a−), and anti-Ok^a, an extremely rare antibody against erythrocyte antigen, was detected. Eight units of Ok(a−) frozen thawed red cells (FTRCs), and six units of red blood cells donated by three Ok(a−) individuals were collected just prior to surgery. Although she was anemic, acute normovolemic hemodilution was conducted after anesthesia induction to preserve the autologous whole blood. Four units of FTRCs were loaded in the CPB priming solution, and modified ultrafiltration was adopted during CPB to prevent further hemodilution. After CPB termination, two units of FTRCs, four units of fresh frozen plasma, and ten units of platelet concentrate were intensively transfused, facilitating surgical hemostasis and stable hemodynamics. The autologous whole blood was returned to the patient in the intensive care unit. Since the hemoglobin and hematocrit levels were maintained postoperatively, no additional transfusion was required throughout her hospital stay.

Conclusions

Multidisciplinary intraoperative blood management in a patient with anti-Ok^a antibody facilitated successful cardiac surgery using CPB, along with effective use of limited blood products.

Red blood cell transfusion in obstetrics and its implication for patient blood management: a retrospective analysis in Switzerland from 1998 to 2016

PURPOSE

Peripartum hemorrhage (PPH) remains one of the main causes of maternal mortality worldwide. Treatment includes administration of packed red blood cells (RBC) in severe cases and patient blood management (PBM) may reduce it significantly. In our study, we wanted to retrospectively assess red blood cell administration in PPH to evaluate the impact of PBM in Switzerland.

METHODS

Using data from the Swiss obstetric hospital registry (Arbeitsgemeinschaft Schweizer Frauenkliniken, ASF), we included patients with deliveries from 1998 to 2016. We examined available obstetric data as well as blood loss and RBC administration in the acute and subacute peripartal phase. We categorized data into two time intervals: 1998-2011 and 2012-2016, as new PPH guidelines in Switzerland were established in 2012.

RESULTS

PPH incidence increased between 1998 and 2016 significantly. The number of vaginal instrumental deliveries and cesarean sections increased as well. Administration of three or more RBC units, as defined in the ASF registry, in the acute and subacute phase in Switzerland has decreased after 2012. Conversely, we saw an increase in the administration of one to two RBC units in the acute and subacute phase. Nevertheless, overall RBC administration has been decreasing from 1998 to 2016.

CONCLUSION

The increase of patients obtaining one or two units of RBC for PPH suggests that there may be a potential for effective implication of PBM in obstetrics. Reduction of RBC transfusion in the context of PPH may not only decrease maternal morbidity, but decrease economic costs as well.

Is There a "Blind Spot" in Point-of-Care Testing for Residual Heparin After Cardiopulmonary Bypass? A Prospective, Observational Cohort Study

Identifying the cause of a bleeding complication after cardiac surgery can be crucial. This study sought to clarify whether the application of unprocessed autologous pump blood influences anti-factor Xa activity after cardiac surgery and evaluated 2 point-of-care methods regarding their ability to identify an elevated anti-factor Xa activity at different timepoints after cardiopulmonary bypass. Anti-factor Xa activity, heparin/protamine titration and the clotting time ratio of thromboelastometry in the INTEM and HEPTEM were measured at baseline (T1), after the application of protamine (T2) and after the complete application of autologous pump blood (T3). Anti-factor Xa activity decreased significantly between T2 and T3 as well did the absolute number of patients with an elevated anti-factor Xa activity. Receiver Operating Curve analyses were performed for both point-of-care methods. At T2 neither could identify patients with an elevated anti-factor Xa activity, while both methods were able to do so at T3 with high sensitivity and specificity. This difference suggests that an interference in the detection of residual heparinization with point-of-care methods exists right after the application of protamine, which seems to subside after a short time span. Nevertheless, results of point-of-care testing for residual heparinization after cardiopulmonary bypass need to be interpreted considering the protamine-heparin ratio and the timepoint of protamine administration.

Midterm outcomes of subcoronary stentless porcine valve versus stented aortic valve replacement

INTRODUCTION

Stentless porcine xenografts are versatile bioprosthetic valves with the advantage of improved hemodynamics that mimic the function of the native aortic valve. However, these bioprostheses are challenging to implant in the subcoronary position.

METHODS

All consecutive patients who underwent a bioprosthetic aortic valve replacement (AVR) were included from our institutional database. Cox regression analysis was preformed to determine significant predictors for mid term mortality as well as all cause, cardiac, and heart failure readmission.

RESULTS

Patients in the subcoronary stentless group were older and more likely to be female and were likely to have a higher Society of Thoracic Surgery risk of mortality. Survival was superior in the stented AVR cohort at 30-days (96.4% vs 90.5%; P < .001), 1-year (90.5% vs 71.6%; P < .001), and 5-year (74.5% vs 56.9%; P < .001) follow up. Acute kidney injury (16.22% vs 5.22%; P < .001) and blood product transfusion (70.27% vs 44.0%; P < .001) were higher in the stentless group. Multivariable analysis revealed subcoronary stentless implantation as a significant independent risk factor for mortality (hazards ratio: 1.92 [1.35,2.72]; P < .001).

CONCLUSION

Stentless porcine xenograft implantation with the Freestyle bioprosthetic in the subcoronary position can be successfully performed in select patients, but its use is associated with increased perioperative morbidity and mortality affecting midterm outcomes. Individual patient selection and surgeon experience are important to ensure favorable outcomes.

Risks associated with perioperative anaemia and perioperative blood transfusion in patients undergoing neurosurgical operation

OBJECTIVE

To investigate the prevalence of preoperative anaemia and the risks associated with perioperative anaemia and blood transfusion in patients who underwent neurological surgery.

BACKGROUND

Perioperative anaemia has an important impact on neurosurgery patients. The prevalence and risks of perioperative anaemia and blood transfusion in Chinese patients are still unknown.

METHODS

Logistic regression was used to predict adverse outcomes of red blood cell (RBC) transfusion and different levels of anaemia. Anaemia and transfusion were compared as independent variables by using a 1:1 match on propensity score.

RESULTS

The prevalence of preoperative anaemia in neurosurgical patients was 20.05%; 10.33% patients received RBC transfusion. Perioperative RBC and plasma transfusion rates (P < .001) and average hospital costs (P = .0365) were higher in preoperative moderate-to-severe anaemia patients than in no anaemia patients. Perioperative RBC transfusion patients had longer hospital length of stay (LOS) (P < .001) and higher average hospital costs (P < .001) than no-transfusion patients. The rates of return to the operating room (OR) within 30 days and intensive care unit stay did not demonstrate any significant difference in anaemia and transfusion cohorts, respectively.

CONCLUSION

The status of preoperative anaemia in Chinese neurosurgical patients is associated with increased transfusion rates and hospital costs. Perioperative RBC transfusion is associated with increased length and cost of hospitalisation.

The Use of Hemostatic Blood Products in Children Following Cardiopulmonary Bypass and Associated Outcomes

To describe the use of hemostatic transfusions in children following cardiac surgery with cardiopulmonary bypass and the association of hemostatic transfusions postoperatively with clinical outcomes.

Estimating the Epidemiological and Economic Impact of Implementing Preoperative Anaemia Measures in the German Healthcare System: The Health Economic Footprint of Patient Blood Management

INTRODUCTION

This study aimed to quantify the potential epidemiological and health economic benefits of implementing preoperative anaemia measures (PAMs) in clinical practice in the German healthcare system.

METHODS

An evidence-based health economic model was developed to assess the possible impact of implementing PAMs, the first pillar of patient blood management (PBM), in a German population. The analysis of two risk factors-iron-deficiency anaemia (IDA) and receipt of a red blood cell concentrate (RBC) transfusion during elective surgery-allowed the estimation of relative risks (RRs), average cost per patient, average length of hospital stay, and avoided hospital deaths after the implementation of PAMs.

RESULTS

A total of 4,591,060 patients who had undergone elective surgery during 2015 were identified, of which 29,170 (0.64%) were diagnosed with preoperative IDA. These patients had an increased RR of receiving a RBC transfusion during surgery (RR 5.031; 95% confidence interval [CI] 4.928, 5.136) and increased mortality risk (RR 3.630; 95% CI 3.401, 3.874) versus patients without IDA. Patients who received a RBC transfusion during surgery had a 24.6-times higher risk of death than those who did not (RR 24.593; 95% CI 24.121, 25.075). Average cost of treatment was €7883 in patients with IDA, €21,744 in patients with IDA and RBC transfusion, and €4560 in patients without risk factors. The model identified 29,714 patients (0.65%) who had received a RBC transfusion and who potentially had IDA but remained undiagnosed before surgery. Hypothetical implementation of PAMs would have resulted in an estimated annual net hospital direct cost saving of €1029 million (1.58%) of total hospital direct costs of the German healthcare system and 3036 hospital deaths (0.07%) avoided.

CONCLUSIONS

This model estimated the impact of implementing PAMs for patients with IDA undergoing elective surgery. A significant number of deaths, costly treatments, and hospital days could have been avoided by the introduction of PAMs in routine clinical practice in Germany.