Perioperative transfusion and long-term mortality after cardiac surgery: a meta-analysis

Quality of registration and adherence to guidelines for blood management in CABG surgeries: a case study

In many hospitals, patients undergoing cardiac surgery receive a higher amount of blood products transfusions compared to other disciplines. Blood transfusion comes with risks and drawbacks, such as increased morbidity and mortality across different patient groups, and specifically patients undergoing cardiac surgery, and high costs. Patient Blood Management (PBM) practices focus on the application of evidence based medical and surgical concepts in order to preserve the patient's own blood. Unfortunately, studies suggest that only a small fraction of published guidelines are implemented and followed into daily clinical practicedue to clear guidance, concerns about risks, and lack of knowledge, interdisciplinary commitment or resources. The widespread adoption of electronic health record (EHR) offers the opportunity to improve clinical outcomes through use of decision support system to guide the healthcare providers through best practices and guidelines. Decision support systems can be active, data-based, patient-specific and act timely, and can be more useful that adding new clinical practice guidelines. This case study quantifies the quality of the data registration and provides the results for adherence to perioperative PBM guidelines for coronary artery bypass grafting (CABG) procedures during a three-year period (2018 to 2020), in the St. Antonius hospital, a single heart center that performs over 10% of the total number of heart operations in the Netherlands. With this case study we identify some of the possible improvement factors for PBM in our center. We also quantify the impact of the quality of the registration in the EHR on the analysis results and on possible implementation of decision support systems.

Blood Transfusion Utilization in Patients with Severe Coronavirus Disease 2019 in the Republic of Korea: A Nationwide Population-Based Study

Background: The coronavirus disease 2019 (COVID-19) pandemic has significantly affected both supply and demand for blood transfusion. This study aimed to investigate the prescription patterns of blood products and identify the risk factors for blood transfusion in patients with severe COVID-19. Methods: This nationwide population-based cohort study was performed in the Republic of Korea between January 2021 and December 2021. Adult patients (≥19 years) with severe COVID-19 who received oxygen therapy were examined. Data were obtained from the National Health Insurance Service database. Results: During the study period, 41,203 patients developed severe COVID-19. The overall transfusion rate was 7.11%, with 14,477 units of packed red blood cells, 4501 units of fresh frozen plasma, 20,532 units of platelet concentrates, and 1875 units of cryoprecipitate. Blood transfusion was independently associated with 90-day mortality (hazard ratio: 1.36, 95% confidence interval: 1.21-1.53, p < 0.001). Multivariate logistic regression analysis identified underlying chronic kidney disease; exposure to surgery, thrombolysis, or thrombectomy; renal replacement therapy; mechanical ventilation; and extracorporeal membrane oxygenation as significant risk factors for blood transfusion in patients with severe COVID-19. Conversely, underlying cerebrovascular diseases, a Charlson Comorbidity Index score of ≥6, admission to intensive care units, and anticoagulant use were identified as protective factors. Conclusions: This study provides an overview of blood transfusion patterns in patients with severe COVID-19. Understanding these patterns may help optimize the stockpiling of medical resources.

Efficacy of intravenous iron supplementation in reducing transfusion risk following cardiac surgery: an updated meta-analysis of randomised controlled trials

BACKGROUND

Previous meta-analyses of intravenous iron supplementation for reducing red blood cell (RBC) transfusion risk after cardiac surgery were inconclusive because of limited data. This updated meta-analysis incorporates recent evidence.

METHODS

Major databases were searched on May 2, 2024 for randomised controlled trials comparing the incidence of RBC transfusion between adult patients receiving intravenous iron supplementation and those receiving controls (i.e. oral iron or placebo) after cardiac surgery. The secondary outcomes included the number of RBC units transfused, postoperative haemoglobin levels, iron status, complications, and length of hospital stay. Trial sequential analysis was conducted to examine the robustness of evidence.

RESULTS

Fourteen randomised controlled trials including 2043 subjects were identified. Intravenous iron supplementation was found to reduce the RBC transfusion risk compared with controls (relative risk 0.77, 95% confidence interval [CI] 0.65-0.91, P=0.002, n=1955, I2=61%, certainty of evidence: moderate). The trial sequential analysis supported the robustness of the evidence. Furthermore, haemoglobin levels were higher in the intravenous iron supplementation group on postoperative days 4-10 (mean difference 0.17 g dl-1, 95% CI 0.06-0.29, n=1989) and >21 days (mean difference 0.66 g/dl-1, 95% CI 0.36-0.95, n=1008). Postoperative iron status also improved with Intravenous iron supplementation, particularly on postoperative days 4-10. There were no significant differences in other outcomes, including mortality.

CONCLUSIONS

Intravenous iron supplementation can reduce RBC transfusion risk and improve postoperative haemoglobin level and iron status after cardiac surgery, supporting the implementation of Intravenous iron supplementation in perioperative blood management strategies.

SYSTEMATIC REVIEW PROTOCOL

CRD42024542206 (PROSPERO).

Effect of perioperative blood transfusion on preoperative haemoglobin levels as a risk factor for long-term outcomes in patients undergoing major noncardiac surgery: a prospective multicentre observational study

BACKGROUND

Preoperative anaemia and red blood cell (RBC) transfusions are associated with poorer clinical outcomes. It is unknown whether perioperative RBC transfusions mediate the relationship between preoperative haemoglobin levels and postoperative outcomes.

METHODS

This was a prospective observational study among patients aged ≥50 yr undergoing elective major noncardiac surgery from four Swedish hospitals. The co-primary outcomes were 1-yr major adverse cardiovascular and cerebrovascular events (MACCEs) and all-cause mortality. The secondary outcome was a composite of 30-day mortality, MACCEs, acute kidney injury (AKI), pulmonary embolism, anastomotic leak, and postoperative infection. Mediation analyses were conducted with preoperative haemoglobin as the exposure and RBC transfusion as a mediator.

RESULTS

Among 1060 patients (mean age 70 [SD 9] yr; 472 [45%] women), 171 patients (16.1%) developed 1-yr MACCEs, and 105 patients (9.9%) died within 1 yr. Preoperative haemoglobin levels were significantly associated with both 1-yr MACCEs (b=-0.015, P=0.041) and all-cause mortality (b=-0.028, P<0.001). Volume of RBC transfusion was not directly associated with the outcomes and did not mediate the relationship between preoperative haemoglobin levels and 1-yr MACCEs (b=-0.001, P=0.451) or all-cause mortality (b=-0.002, P=0.293). For the secondary outcome, RBC transfusions had a significant mediating effect between preoperative haemoglobin and the composite 30-day outcome; however, no direct association was observed (b=0.006, P=0.554).

CONCLUSIONS

Preoperative haemoglobin levels were significantly associated with 1-yr MACCEs and all-cause mortality. This effect was not mediated by perioperative RBC transfusions. Further research is needed to confirm these findings.

Ferric carboxymaltose in reducing blood transfusions and infections after cardiac surgery

Objective

Iron supplementation may reduce postoperative anemia, blood transfusions, and infections in patients undergoing surgery. We sought to assess efficacy and safety of prophylactic intravenous iron supplementation in patients without anemia undergoing cardiac surgery.

Methods

In this investigator-initiated industry-sponsored single-center randomized double-blind parallel group trial, we enrolled patients undergoing coronary bypass, aortic or mitral valve or ascending aortic surgery who fulfilled prespecified iron blood test safety criteria. Patients were randomized to receive either a single intravenous 1000 mg dose of ferric carboxymaltose (FCM) or placebo (saline only). Independent unblinded study nurse administered the infusion with masked lines and cannula 2 to 21 days before surgery. Primary efficacy end point was a composite of in-hospital blood transfusions >2 U and nosocomial infection. The trial was registered in Eudract (2017-004901-41).

Results

Altogether 171 patients were screened and 78 randomly assigned to FCM (n = 39) or placebo (n = 39). Trial was prematurely discontinued for futility with regard to reaching the primary end point by the recommendation of the independent data monitoring committee. The primary end point occurred in 3 (7.7%) versus 3 (7.7%) (P = 1.00) of patients assigned to FCM and placebo, respectively, with no difference in blood transfusions >2 U. Fewer hospital readmissions by 3 months follow-up (1 [2.6%] vs 8 [20.5%]; P = .028) were noted in FCM group in a post hoc analysis. Ferritin levels were higher in the FCM group at 3 months indicating more preserved iron stores.

Conclusions

Prophylactic treatment with FCM was safe but did not reduce the need for blood transfusions or postoperative infections at index hospitalization in patients without anemia undergoing cardiac surgery.

Effect of Preoperative Recombinant Human Erythropoietin on the Need for Blood Transfusion and Surgical Outcomes in Adult Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-Analysis with Trial Sequential Analysis

This study aimed to examine the value of preoperative recombinant human erythropoietin (rhEPO) administration to adults undergoing elective cardiac surgery. Databases were searched for randomized controlled trials (RCTs) comparing rhEPO plus standard treatment versus standard treatment only. Primary outcomes were the need for and volume of homologous blood transfusion (HBT). Secondary outcomes were the lengths of intensive care unit (ICU) and hospital stay and the incidence of major adverse events. There was very low certainty that rhEPO is associated with a reduction in the need for HBT, with a number needed to treat of 5.6 (95% confidence interval [CI], 3.9-12.5), and low certainty that it is associated with a moderate reduction in HBT volume (Hedges g = -0.55; 95% CI, -0.79 to -0.32). Meta-regression revealed that studies with a higher proportion of females or older patients demonstrated less benefit of rhEPO in terms of reduced consumption of HBT. Trial sequential analysis showed that rhEPO was superior to standard treatment only for reducing the need for and volume of HBT. Regarding secondary outcomes, there was moderate certainty that rhEPO is associated with a limited reduction in the length of ICU (Hedges g = -0.10; 95% CI, -0.19 to -0.01) and hospital stay (Hedges g = -0.13; 95% CI = -0.25 to -0.02), and low certainty for increased risk of myocardial infarction, with a number needed to harm of 36.1 (95% CI, 17.9-127.4). More well-designed, adequately powered RCTs are needed to draw conclusions regarding the value of rhEPO.

Minimal Learning Curve for Minimally Invasive Aortic Valve Replacement

BACKGROUND

 Minimally invasive aortic valve replacement (MiAVR) is an established technique for surgical aortic valve replacement (AVR). Although MiAVR was first described in 1993 and has shown good results compared with full sternotomy AVR (FSAVR) only a minority of patients undergo MiAVR. We recently started using MiAVR via an upper hemisternotomy. We aimed to examine the early results of our initial experience with this technique.

METHODS

 We compared 55 MiAVR patients with a historical cohort of 142 isolated FSAVR patients (December 2016-December 2022). The primary outcome was in-hospital mortality. Secondary outcomes included cardiopulmonary bypass (CPB) and cross-clamp times, blood product intake, in-hospital morbidity, and length of intensive care unit and hospital stay.

RESULTS

 There was no significant difference in preoperative characteristics, including age, laboratory values, and comorbidities. There was no significant difference between the groups regarding in-hospital mortality (FSAVR 3.52 vs. MiAVR 1.82%). There was no significant difference in CPB time (FSAVR 103.5 [interquartile range: 82-119.5] vs. MiAVR 107 min [92.5-120]), aortic cross-clamp time (FSAVR 81 [66-92] vs. MiAVR 90 min [73-99]), and valve size (FSAVR 23 [21-25] vs. MiAVR 23 [21-25]). The incidence of intraoperative blood products transfusion was significantly lower in the MiAVR group (10.91%) compared with the FSAVR group (25.35%, p = 0.03).

CONCLUSION

 Our findings further establish the possibility of reducing invasiveness of AVR without compromising patient safety and clinical outcomes. This is true even in the learning curve period and without requiring any significant change in the operative technique and dedicated equipment.

Year in Review 2023: Noteworthy Literature in Cardiac Anesthesiology

Notable clinical research published in 2023 related to cardiac anesthesia included studies focused on resuscitation and pharmacology, regional anesthesia, technological advances, and novel gene therapies. We reviewed 241 articles to identify 25 noteworthy studies that represent the most significant research related to cardiac anesthesia from the past year. Overall, improvements in clinical practice have enabled decreased morbidity and mortality with a renewed focus on mechanical circulatory support and transplantation.

Blood transfusion is correlated with elevated adult all-cause mortality and cardiovascular mortality in the United States: NHANES 1999 to 2018 population-based matched propensity score study

BACKGROUND AND AIMS

The association of blood transfusion with an increase in medium- and short-term mortality in specific populations has been confirmed. However, the correlation between blood transfusion and long-term mortality in the general population remains unclear. This cohort study evaluated the correlation between blood transfusion and overall and cause-specific mortality in the general American adult population.

METHODS

The authors utilized 10 sets of 2-year cycle data (1999-2018) from the National Health and Nutrition Examination Survey on the outcomes of adults who did and did not receive blood transfusions. Propensity score-matching (1:1) was performed based on age, sex, race, education level, marital status, poverty-income ratio, arteriosclerotic cardiovascular disease, cancer, anemia, hypertension, and diabetes status. After controlling for demographic characteristics and clinical risk factors, Cox regression analysis was performed to evaluate the correlation between blood transfusion and all-cause and cause-specific mortality.

RESULTS

The study included 48,004 adult participants. The risk of all-cause mortality increased by 101 % with blood transfusion, and the risk of cardiovascular mortality increased by 165 %. After propensity score-matching, 6,116 pairs of cases were retained, and the risk of all-cause mortality increased by 84 % with blood transfusion, and the risk of cardiovascular mortality increased by 137 %. The sensitivity analysis results were robust.

CONCLUSIONS

In the general American population, blood transfusion significantly impacts long-term all-cause and cardiovascular mortality and may be an unacknowledged risk factor for death. Thus, the effective management of blood transfusion in the general population may be beneficial.

Alternative blood transfusion triggers: a narrative review

BACKGROUND

Anemia, characterized by low hemoglobin levels, is a global public health concern. Anemia is an independent factor worsening outcomes in various patient groups. Blood transfusion has been the traditional treatment for anemia; its triggers, primarily based on hemoglobin levels; however, hemoglobin level is not always an ideal trigger for blood transfusion. Additionally, blood transfusion worsens clinical outcomes in certain patient groups. This narrative review explores alternative triggers for red blood cell transfusion and their physiological basis.

MAIN TEXT

The review delves into the physiology of oxygen transport and highlights the limitations of using hemoglobin levels alone as transfusion trigger. The main aim of blood transfusion is to optimize oxygen delivery, necessitating an individualized approach based on clinical signs of anemia and the balance between oxygen delivery and consumption, reflected by the oxygen extraction rate. The narrative review covers different alternative triggers. It presents insights into their diagnostic value and clinical applications, emphasizing the need for personalized transfusion strategies.

CONCLUSION

Anemia and blood transfusion are significant factors affecting patient outcomes. While restrictive transfusion strategies are widely recommended, they may not account for the nuances of specific patient populations. The search for alternative transfusion triggers is essential to tailor transfusion therapy effectively, especially in patients with comorbidities or unique clinical profiles. Investigating alternative triggers not only enhances patient care by identifying more precise indicators but also minimizes transfusion-related risks, optimizes blood product utilization, and ensures availability when needed. Personalized transfusion strategies based on alternative triggers hold the potential to improve outcomes in various clinical scenarios, addressing anemia's complex challenges in healthcare. Further research and evidence are needed to refine these alternative triggers and guide their implementation in clinical practice.

Sex Differences in Red Blood Cell Transfusions and 30-Day Mortality in Cardiac Surgery: A Single Center Observational Study

In cardiac surgery, women have higher short-term mortality and a higher risk of receiving red blood cell (RBC) transfusions than men. This study's aim was to evaluate possible sex differences in RBC transfusions in cardiac surgery and their association with preoperative hemoglobin levels, body mass index, and 30-day mortality. A single-center retrospective study was conducted with 1583 patients (1181 men and 402 women) undergoing cardiac surgery. A total of 64.4% of the women and 33.0% of the men received an RBC transfusion. In a multivariable analysis, female sex was an independent predictor of RBC transfusion (OR 3.88, 95% CI 2.95-5.11, p < 0.001). Other independent predictors of RBC transfusion were age, preoperative hemoglobin level, and body mass index. The women were more likely to receive RBC transfusions than the men, regardless of the type of cardiac surgery. Decreased transfusion risk was found in all higher-than-normal weight categories in the women, but only in the severe obesity category in the men. Preoperative hemoglobin was similarly associated with RBC transfusion in the men and women. The crude 30-day mortality rate was higher in the women than in the men (2.5% vs. 0.9%, p = 0.018). In both sexes, RBC transfusion was associated with an increased probability of death within 30 days.

Outcomes following perioperative red blood cell transfusion in patients undergoing elective major abdominal surgery: a systematic review and meta-analysis

BACKGROUND

Perioperative red blood cell transfusion is a double-edged sword for surgical patients. While transfusion of red cells can increase oxygen delivery by increasing haemoglobin levels, its impact on short- and long-term postoperative outcomes, particularly in patients undergoing elective major abdominal surgery, is unclear.

METHODS

We conducted a systematic review and meta-analysis on the effect of perioperative blood transfusions on postoperative outcomes in elective major abdominal surgery. PubMed, Cochrane, and Scopus databases were searched for studies with data collected between January 1, 2000 and June 6, 2020. The primary outcome was short-term mortality, including all-cause 30-day or in-hospital mortality. Secondary outcomes included long-term all-cause mortality, any morbidity, infectious complications, overall survival, and recurrence-free survival. No randomised controlled trials were found. Thirty-nine observational studies were identified, of which 37 were included in the meta-analysis.

RESULTS

Perioperative blood transfusion was associated with short-term all-cause mortality (odds ratio [OR] 2.72, 95% confidence interval [CI] 1.89-3.91, P<0.001), long-term all-cause mortality (hazard ratio 1.35, 95% CI 1.09-1.67, P=0.007), any morbidity (OR 2.18, 95% CI 1.81-2.64, P<0.001), and infectious complications (OR 1.90, 95% CI 1.60-2.26, P<0.001). Perioperative blood transfusion remained associated with short-term mortality in the sensitivity analysis after excluding studies that did not control for preoperative anaemia (OR 2.27, 95% CI 1.59-3.24, P<0.001).

CONCLUSIONS

Perioperative blood transfusion in patients undergoing elective major abdominal surgery is associated with poorer short- and long-term postoperative outcomes. This highlights the need to implement patient blood management strategies to manage and preserve the patient's own blood and reduce the need for red blood cell transfusion.

TRIAL REGISTRATION

PROSPERO (CRD42021254360).