Restrictive or Liberal Red-Cell Transfusion for Cardiac Surgery

Postoperative haemoglobin and anaemia-associated ischaemic events after major noncardiac surgery: A sex-stratified cohort study

STUDY OBJECTIVE

To determine the sex-specific associations between postoperative haemoglobin and mortality or complications reflecting ischaemia or inadequate oxygen supply after major noncardiac surgery.

DESIGN

A retrospective cohort study with prospective validation.

SETTING

A large university hospital health system in China.

PATIENTS

Men and women undergoing elective major noncardiac surgery.

INTERVENTIONS AND MEASUREMENTS

The primary exposure was nadir haemoglobin within 48 h after surgery. The outcome of interest was a composite of postoperative mortality or ischaemic events including myocardial injury, acute kidney injury and stroke within hospitalisation.

MAIN RESULTS

The study included 26,049 patients (15,757 men and 10,292 women). Low postoperative haemoglobin was a strong predictor of the composite outcome in both sexes, with the risk progressively increasing as the nadir haemoglobin concentration dropped below 130 g l-1 in men and 120 g l-1 in women (adjusted odds ratio [OR] 1.43, 95% CI 1.37-1.50 in men, and OR 1.45, 95% CI 1.35-1.55 in women, per 10 g l-1 decrease in postoperative nadir haemoglobin). Above these sex-specific thresholds, the change of nadir haemoglobin was no longer associated with odds of the composite outcome in either men or women. There was no significant interaction between patient sex and the association between postoperative haemoglobin and the composite outcome (Pinteraction = 0.673). Validation in an external prospective cohort (n = 2120) with systematic postoperative troponin and creatinine measurement confirmed our findings.

CONCLUSIONS

Postoperative haemoglobin levels following major noncardiac surgery were nonlinearly associated with ischaemic complications or mortality, without any clinically important interaction with patient sex.

Impact of Intraoperative Allogeneic Platelet Transfusion on Healthcare-Associated Infections in Cardiac Surgery: Insights From a Large Single-Center Cohort Study

OBJECTIVES

Despite significant improvement in patient blood management, cardiac surgery remains a high hemorrhagic risk procedure. Platelet transfusion is used commonly to treat thrombocytopenia-associated perioperative bleeding. Allogeneic platelet transfusion may induce transfusion-related immunomodulation. However, its association with postoperative healthcare-associated infections is still a matter of debate. The objective was to evaluate the impact of allogeneic platelet transfusion during cardiac surgery on postoperative healthcare-associated infection incidence.

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral academic center.

PARTICIPANTS

Patients undergoing cardiac surgery from 2012 to 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Intraoperative platelet transfusion was defined as exposure in a causal model. The primary outcome was the incidence of healthcare-associated infections comprised of bloodstream infection, hospital-acquired pneumonia, and surgical-site infection. Among 7,662 included patients, 528 patients (6.8%) were exposed to intraoperative platelet transfusion, and 329 patients (4.3%) developed 454 postoperative infections. Bloodstream infection affected 106 patients (1.4%), hospital-acquired pneumonia affected 174 patients (2.3%), and surgical-site infection affected 148 patients (1.9%). Intraoperative platelet transfusion was associated with an increased risk of bloodstream infection after adjustment by multivariable logistic regression (odds ratio [OR] 2.85; 95% CI 1.40-5.8; p = 0.004; n = 7,662), propensity score matching (OR 3.95; 95% CI 1.57-12.0), p = 0.007; n = 766), and propensity score overlap weighting (OR 3.04; 95% CI 1.51-6.1, p = 0.002; n = 7,762). Surgical-site infection and hospital-acquired pneumonia were not significantly associated with platelet transfusion.

CONCLUSIONS

These results suggested that intraoperative allogeneic platelet transfusion is a risk factor for bloodstream infection after cardiac surgery. These results supported the development of patient blood management strategies aimed at minimizing perioperative platelet transfusion in cardiac surgery.

Acute normovolemic hemodilution in cardiac surgery: Rationale and design of a multicenter randomized trial

BACKGROUND

Minimizing the use of blood component can reduce known and unknown blood transfusion risks, preserve blood bank resources, and decrease healthcare costs. Red Blood Cell (RBC) transfusion is common after cardiac surgery and associated with adverse perioperative outcomes, including mortality. Acute normovolemic hemodilution (ANH) may reduce bleeding and the need for blood product transfusion after cardiac surgery. However, its blood-saving effect and impact on major outcomes remain uncertain.

METHODS

This is a single-blinded, multinational, pragmatic, randomized controlled trial with a 1:1 allocation ratio conducted in Tertiary and University hospitals. The study is designed to enroll patients scheduled for elective cardiac surgery with planned cardiopulmonary bypass (CPB). Patients are randomized to receive ANH before CPB or the best available treatment without ANH. We identified an ANH volume of at least 650 ml as the critical threshold for clinically relevant benefits. Larger ANH volumes, however, are allowed and tailored to the patient's characteristics and clinical conditions.

RESULTS

The primary outcome is the percentage of patients receiving RBCs transfusion from randomization until hospital discharge, which we hypothesize will be reduced from 35% to 28% with ANH. Secondary outcomes are all-cause 30-day mortality, acute kidney injury, bleeding complications, and ischemic complications.

CONCLUSION

The trial is designed to determine whether ANH can safely reduce RBC transfusion after elective cardiac surgery with CPB.

STUDY REGISTRATION

This trial was registered on ClinicalTrials.gov in April 2019 with the trial identification number NCT03913481.

Red blood cell transfusion and mortality after transcatheter aortic valve implantation via transapical approach: A propensity-matched comparison from the TRITAVI registry

Objective

Bleeding is frequent during transcatheter aortic valve implantation (TAVI), especially when performed through a transapical approach (TA), and is associated with a worse prognosis. The present study aims to test the implication of red blood cell (RBC) transfusion and the optimal transfusion strategy in this context.

Methods

Among 11,265 participants in the multicenter TRITAVI (Transfusion Requirements in Transcatheter Aortic Valve Implantation) registry, 548 patients (4.9%) who received TA-TAVI at 19 European centers were included. One-to-one propensity score matching was performed to reduce treatment selection bias and potential confounding among transfused versus non-transfused patients. The primary endpoint of the study was the 30-day occurrence of all-cause mortality.

Results

209 patients (38 %) received RBC transfusions. The primary endpoint occurred in 47 (8.6 %) patients. Propensity score matching identified 188 pairs of patients with and without RBC transfusion. In the propensity score-matched analysis, RBC transfusion was associated with increased 30-day mortality (HR 3.35, 95 % CI 1.51 - 7.39; p = 0.002). At multivariable cox regression analysis, RBC transfusion was an independent predictor of 30-day mortality (HR 3.07, 95 % CI 1.01-9.41, p = 0.048), as well as baseline ejection fraction (HR 0.96, 95 % CI 0.92-0.99, p = 0.043), and acute kidney injury (HR 3.95, 95 % CI 1.11-14.05, p = 0.034).

Conclusions

RBC transfusion is an independent predictor of short-term mortality in patients undergoing TA-TAVI, regardless of major bleeding.Clinical trial registration: https://www.clinicaltrials.gov Unique identifier: NCT03740425.

Coronary artery disease and heart failure: Late-breaking trials presented at American Heart Association scientific session 2023

The late-breaking science presented at the 2023 scientific session of the American Heart Association paves the way for future pragmatic trials and provides meaningful information to guide management strategies in coronary artery disease and heart failure (HF). The dapagliflozin in patient with acute myocardial infarction (DAPA-MI) trial showed that dapagliflozin use among patients with acute MI without a history of diabetes mellitus or chronic HF has better cardiometabolic outcomes compared with placebo, with no difference in cardiovascular outcomes. The MINT trial showed that in patients with acute MI and anemia (Hgb < 10 g/dL), a liberal transfusion goal (Hgb ≥ 10 g/dL) was not superior to a restrictive strategy (Hgb 7-8 g/dL) with respect to 30-day all-cause death and recurrent MI. The ORBITA-2 trial showed that among patients with stable angina and coronary stenoses causing ischemia on little or no antianginal therapy, percutaneous coronary intervention results in greater improvements in anginal frequency and exercise times compared with a sham procedure. The ARIES-HM3 trial showed that in patients with advanced HF who received a HeartMate 3 levitated left ventricular assist device and were anticoagulated with a vitamin K antagonist, placebo was noninferior to daily aspirin with respect to the composite endpoint of bleeding and thrombotic events at 1 year. The TEAMMATE trial showed that everolimus with low-dose tacrolimus is safe in children and young adults when given ≥ 6 months after cardiac transplantation. Providing patients being treated for HF with reduced ejection fraction (HFrEF) with specific out-of-pocket (OOP) costs for multiple medication options at the time of the clinical encounter may reduce 'contingency planning' and increase the extent to which patients are taking the medications decided upon. The primary outcome, which was cost-informed decision-making, defined as the clinician or patient mentioning costs of HFrEF medication, occurred in 49% of encounters with the checklist only control group compared with 68% of encounters in the OOP cost group.

The Relationship Between Transfusion in Cardiac Surgery Patients and Adverse Outcomes

OBJECTIVES

To understand if red blood cell (RBC) transfusions are independently associated with a risk of mortality, prolonged intubation, or infectious, cardiac, or renal morbid outcomes.

DESIGN

A retrospective review.

SETTING

A single-institution university hospital.

PARTICIPANTS

A total of 2,458 patients undergoing coronary bypass artery graft and/or valvular surgery from July 2014 through January 2018.

INTERVENTIONS

No interventions were done.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the occurrence of an adverse event or prolonged intubation. Infectious, cardiac, and renal composite outcomes were also defined. These composites, along with mortality, were analyzed individually and then combined to form the "any adverse events" composite. Preoperative demographic and intraoperative parameters were analyzed as univariate risk factors for adverse outcomes. Logistic regression was used to screen variables, with a p value criterion of p < 0.05 for entry into the model selection procedure. A backward selection algorithm was used with variable entry and retention criteria of p < 0.05 to select the final multivariate model. Multivariate logistic regression models were used to determine whether there was an association between the volume of RBC transfusion and the defined adverse event after adjusting for covariates. A p value < 0.01 was considered statistically significant in the final model of each aim to adjust for multiple comparisons. The final logistic models for each of the following outcomes indicate an increased risk of that outcome per each additional unit of RBC transfused. For prolonged intubation, the odds ratio (OR) was 1.493 (p < 0.0001), OR = 1.358 (p < 0.0001) for infectious composite outcomes, OR = 1.247 (p < 0.0001) for adverse renal outcomes, and OR = 1.467 (p < 0.0001) for any adverse event.

CONCLUSIONS

The authors demonstrated a strong independent association between RBC transfusion volume and adverse outcomes after cardiac surgery. Efforts should be undertaken, such as preoperative anemia management and control of coagulopathy, in order to minimize the need for RBC transfusion.

Anticoagulation and Antiplatelet Regimen in Cardiac Transplant. Clinical Characteristics, Outcomes, and Blood Product Transfusion

BACKGROUND

We aimed to evaluate the characteristics, clinical outcomes, and blood product transfusion (BPT) rates of patients undergoing cardiac transplant (CT) while receiving uninterrupted anticoagulation and antiplatelet therapy.

METHODS

A retrospective, single-center, and observational study of adult patients who underwent CT was performed. Patients were classified into four groups: (1) patients without anticoagulation or antiplatelet therapy (control), (2) patients on antiplatelet therapy (AP), (3) patients on vitamin K antagonists (AVKs), and (4) patients on dabigatran (dabigatran). The primary endpoints were reoperation due to bleeding and perioperative BPT rates (packed red blood cells (PRBC), fresh frozen plasma, platelets). Secondary outcomes assessed included morbidity and mortality-related events.

RESULTS

Of the 55 patients included, 6 (11%) received no therapy (control), 8 (15%) received antiplatelet therapy, 15 (27%) were on AVKs, and 26 (47%) were on dabigatran. There were no significant differences in the need for reoperation or other secondary morbidity-associated events. During surgery patients on dabigatran showed lower transfusion rates of PRBC (control 100%, AP 100%, AVKs 73%, dabigatran 50%, p = 0.011) and platelets (control 100%, AP 100%, AVKs 100%, dabigatran 69%, p = 0.019). The total intraoperative number of BPT was also the lowest in the dabigatran group (control 5.5 units, AP 5 units, AVKs 6 units, dabigatran 3 units; p = 0.038); receiving significantly less PRBC (control 2.5 units, AP 3 units, AVKs 2 units, dabigatran 0.5 units; p = 0.011). A Poisson multivariate analysis showed that only treatment on dabigatran reduces PRBC requirements during surgery, with an expected reduction of 64.5% (95% CI: 32.4%-81.4%).

CONCLUSIONS

In patients listed for CT requiring anticoagulation due to nonvalvular atrial fibrillation, the use of dabigatran and its reversal with idarucizumab significantly reduces intraoperative BPT demand.

Adherence to a restrictive red blood cell transfusion strategy in critically ill patients: An observational study

BACKGROUND

Randomized controlled trials relatively consistently show that restrictive red blood cell (RBC) transfusion strategies are safe and associated with similar outcomes compared to liberal transfusion strategies in critically ill patients. Based on these data, the general threshold for RBC transfusion was changed to 70 g/L at a 9-bed tertiary level intensive care unit in September 2020. Implementation measures included lectures, webinars and feedback during clinical practice. The aim of this study was to investigate how implementation of a restrictive transfusion strategy influenced RBC usage, haemoglobin trigger levels and adherence to prescribed trigger levels.

METHODS

In this registry-based, observational study, critically ill adult patients without massive bleeding were included and divided into a pre-cohort, with admissions prior to the change of transfusion strategy, and a post-cohort, with admissions following the change of transfusion strategy. These cohorts were compared regarding key RBC transfusion-related variables.

RESULTS

In total 5626 admissions were included in the analyses (pre-cohort n = 4373, post-cohort n = 1253). The median volume (interquartile range, IQR) of RBC transfusions per 100 admission days, in the pre-cohort was 6120 (4110-8110) mL versus 3010 (2890-4970) mL in the post-cohort (p < .001). This corresponds to an estimated median saving of 1128 € per 100 admission days after a restrictive RBC transfusion strategy was implemented. In total, 26% of the admissions in the pre-cohort and 19% in the post-cohort (p < .001) received RBC transfusion(s) during days 0-10. Both median (IQR) prescribed trigger levels (determined by intensivist) and actual haemoglobin trigger levels (i.e., levels prior to actual administration of transfusion) were higher in the pre- versus post-cohort (90 [80-100] vs. 80 [72-90] g/L, p < .001 and 89 [82-96] g/L vs. 83 [79-94], p < .001, respectively). Percentage of days without compliance with the prescribed transfusion trigger was higher in the pre-cohort than in the post-cohort (23% vs. 14%, p < .001). Sensitivity analyses, excluding patients with traumatic brain injury, ischemic heart disease and COVID-19 demonstrated similar results.

CONCLUSIONS

Implementation of a restrictive transfusion trigger in a critical care setting resulted in lasting decreased RBC transfusion use and costs, decreased prescribed and actual haemoglobin trigger levels and improved adherence to prescribed haemoglobin trigger levels.

Pre-operative anaemia-does it influence post-operative outcomes after isolated coronary artery bypass grafting?

Introduction

Preoperative anaemia is prevalent in a number of patients undergoing coronary artery bypass grafting. Studies provide conflicting results due to several reasons including variation in the threshold of haematocrit used to define anaemia. We aimed to assess the independent effect of preoperative anaemia on outcomes in patients undergoing off pump coronary artery bypass grafting (OPCAB).

Methods

In this retrospective study, patients with a hemoglobin level less than 11g/dl (haematocrit <33%) were considered to have moderate-to-severe anaemia as per the recommendations of the World Health Organization. Association between haematocrit <33% and mortality as well as adverse post-operative outcomes was assessed. Multivariable logistic regression (MLR) was carried out to assess the independent effect of haematocrit<33% on 30-day mortality and other outcomes.

Results

The study included 4957 consecutive patients undergoing isolated OPCAB surgery between 2015 and 2020. Out of 4957, 635 (12.8%) had haematocrit <33% and 4322 (81.2%) had haematocrit ≥33%. Patients with haematocrit < 33% had a 30-day mortality of 13 (2%) compared to 38 (0.9%) in patients without anaemia and had a greater requirement for blood transfusion (p<0.0001). It was also associated with an increased incidence of renal failure (p<0.0001), tracheostomy (p=.0.012) and risk of re-intubation (p=0.006). On multiple linear regression (MLR), haematocrit < 33% was not an independent predictor of 30-day mortality odds ratio (OR) 1.47, 95% confidence interval (CI) 0.745-2.917; p=0.26. It was however an important independent risk factor for blood transfusion (OR 1.80, 95% CI 1.29-2.50, p<0.001) and renal failure (OR 3.06, 95% CI 1.338-7.012, p=0.008). The receiver operating characteristic (ROC)-area under the curve (AUC) was 0.63 suggesting moderate discriminatory value of haematocrit < 33% for 30-day mortality.

Conclusion

Haematocrit < 33% is an important risk factor for adverse outcomes following isolated, primary, elective OPCAB.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-024-01746-1.

Transfusion strategy trials excluding patients transfused outside the trial study period are more likely to report a trend favoring restrictive strategies: a meta-analysis

OBJECTIVES

Some large, randomized trials investigating red cell transfusion strategies have significant numbers of transfusions administered outside the trial study period. We sought to investigate the potential impact of this methodological issue.

STUDY DESIGN AND SETTING

Meta-analysis of randomized controlled trials (RCTs) comparing liberal vs restrictive transfusion strategies in cardiac surgery and acute myocardial infarction patients. The outcome of interest was 30-day or in-hospital mortality.

RESULTS

In cardiac surgery, the pooled risk ratio for mortality was 0.83 (95% confidence interval [CI] 0.62-1.12, P = .22) times lower in the restrictive group when compared to the liberal group in trials applying a transfusion strategy throughout the patient's entire perioperative period, and 1.33 (95% CI 0.84-2.11, P = .22) times higher in the restrictive group in trials not applying transfusion strategies throughout the entire perioperative period. When combined, the risk ratio for mortality was 0.98 (95% CI 0.73-1.32, P = .89). In patients with acute myocardial infarction, the risk ratio for mortality was 0.72 (95% CI 0.40-1.28, P = .26) times lower in the restrictive group when compared to the liberal group in 1 trial excluding patients administered the intervention prerandomization and 1.19 (95% CI 0.96-1.47, P = .11) times higher in the restrictive group in 1 trial including patients receiving the intervention prerandomization. When combined the risk ratio for mortality was 1.00 (0.62-1.59, P = .99).

CONCLUSION

Though not statistically significant, there was a consistent difference in trends between RCTs administering significant numbers of transfusion outside the trial study period compared to those that did not. The implications of our results may extend to RCTs in other settings that ignore if and how frequently an investigated therapy is administered outside the trial window.

Impact of Significant Hemoglobin Drop Without Bleeding in Patients Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

Hemoglobin (Hgb) drop without bleeding is common among patients undergoing transcatheter aortic valve replacement; however, the clinical implications of significant Hgb drop have not been fully evaluated.

METHODS AND RESULTS

Consecutive patients undergoing transcatheter aortic valve replacement at our institution from 2011 to 2021 were retrospectively reviewed. Three groups were assessed: no Hgb drop and no bleed (NoD-NoB [reference group]), Hgb drop with bleed, and Hgb drop and no bleed (D-NoB). Hgb drop was defined as ≥3 g/dL decrease from pre- to post-transcatheter aortic valve replacement. Outcomes of interest were in-hospital death and 1-year all-cause mortality. A total of 1851 cases with complete Hgb data were included: NoD-NoB: n=1579 (85.3%); D-NoB: n=49 (2.6%); Hgb drop with bleed: n=223 (12.6%). Compared with NoD-NoB, the D-NoB group was older (81.1 versus 78.9 years of age) with higher preprocedure Hgb (12.9 versus 11.7 g/dL). In-hospital death rate was higher among patients with D-NoB versus NoD-NoB (4.5% versus 0.8%, P<0.001) and similar to Hgb drop with bleed (4.5% versus 4.1%, P=0.999). Predictors of in-hospital death were D-NoB (odds ratio [OR], 3.45 [95% CI, 1.32-8.69]) and transfusion (OR, 10.6 [95% CI, 4.25-28.2]). Landmark survival analysis found that D-NoB experienced 1-year mortality rate comparable to NoD-NoB, whereas Hgb drop with bleed had higher midterm mortality (hazard ratio [HR], 3.2 [95% CI, 1.83-5.73]), and transfusion continued to impact mortality (HR, 2.5 [95% CI, 1.79-3.63]).

CONCLUSIONS

Hgb drop without bleeding is common among patients undergoing transcatheter aortic valve replacement and may represent a higher risk of periprocedural death. Blood transfusion increases short- and midterm mortality risk in patients with and without bleeding, supporting a restrictive transfusion strategy.

Cardiac Surgery-Associated Acute Kidney Injury

AKI is a common and serious complication of cardiac surgery that has a significant impact on patient morbidity and mortality. The Kidney Disease Improving Global Outcomes definition of AKI is widely used to classify and identify AKI associated with cardiac surgery (cardiac surgery-associated AKI [CSA-AKI]) on the basis of changes in serum creatinine and/or urine output. There are various preoperative, intraoperative, and postoperative risk factors for the development of CSA-AKI which should be recognized and addressed as early as possible to expedite its diagnosis, reduce its occurrence, and prevent or ameliorate its devastating complications. Crucial issues are the inaccuracy of serum creatinine as a surrogate parameter of kidney function in the perioperative setting of cardiothoracic surgery and the necessity to discover more representative markers of the pathophysiology of AKI. However, except for the tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 ratio, other diagnostic biomarkers with an acceptable sensitivity and specificity are still lacking. This article provides a comprehensive review of various aspects of CSA-AKI, including pathogenesis, risk factors, diagnosis, biomarkers, classification, prevention, and treatment management.

Nonanemic Iron Deficiency in Cardiac Surgery: A Retrospective Observational Study

OBJECTIVES

Anemia and iron deficiency in patients having cardiac surgery increases their perioperative risk. Nonanemic iron deficiency (NAID) in this group is less well-described. We aimed to investigate the incidence and outcomes of patients with NAID undergoing cardiac surgery.

DESIGN

Retrospective observational study.

SETTING

A single, tertiary referral center.

PARTICIPANTS

Adult patients who were preassessed and underwent cardiac surgery during the study period had data collected. We enrolled 537 patients enrolled and divided them into 4 groups according to hemoglobin and ferritin: NAID, nonanemic iron replete, iron-deficiency anemia (IDA), and non-iron-deficiency anemia.

INTERVENTIONS

This study was not interventional, but assessed the impact of anemia and iron deficiency on patient outcomes.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the incidence of NAID. Secondary outcomes included the number of patients who became anemic awaiting surgery, allogeneic transfusion burden, length of stay, postoperative complications, and death. 179 of 537 patients (33.3%) had NAID. Seventeen patients (9.5%) became anemic in the NAID group compared with 7 (3.3%) in the nonanemic iron replete group while awaiting for surgery (p = 0.02). Patients with NAID were more likely to receive allogeneic transfusions (33% vs 23%; p = 0.04) and had poorer recovery of hemoglobin at follow-up (13.2 ± 1.46 g/dL vs 13.9 ± 1.46 g/dL; p < 0.001).

CONCLUSIONS

NAID is common and can lead to progression to anemia and increased transfusion. Iron replacement should be considered in patients with NAID in the preoperative setting. A prospective interventional trial is required to demonstrate the benefit of being iron replete.

Impact of Diabetes in Patients With Acute Myocardial Infarction Undergoing Coronary Artery Bypass Surgery Within 48 Hours

BACKGROUND

Diabetic patients with coronary artery disease may benefit from elective coronary artery bypass graft (CABG) surgery. It is unknown whether this merit is transferable to patients with acute myocardial infarction (AMI) undergoing surgery.

METHOD

A total of 1,427 patients underwent CABG within 48 hours of being diagnosed with AMI at the current institution between 2001 and 2019. Of these patients, 206 (14.4%) had insulin-dependent diabetes mellitus (IDDM) and 148 (10.4%) had non-insulin dependent diabetes mellitus (NIDDM). Retrospective data analysis was performed.

RESULTS

Patients with NIDDM showed the highest perioperative risk profile, with a EuroScore II of 11.6 (±10.3) compared with 7.8 (±8.0) in non-diabetic patients and 8.4 (±7.8) in patients with IDDM (p<0.001). Sub-analysis demonstrated a higher proportion of non-ST-elevation myocardial infarction patients in the NIDDM cohort compared with the IDDM cohort (70.9% vs 56.8%; p=0.005). Postoperatively, NIDDM patients had more sepsis (p<0.01) and longer ventilation times (p<0.001) compared with non-DM and IDDM patients (p<0.01). Wound healing complications were rare, but almost twice as high in NIDDM patients compared with non-DM and IDDM patients (4.7% vs 0.9% vs 2.4%, respectively). The 30-day mortality was highest in the NIDDM cohort (18.3% vs 11.3% vs 7.8%; p=0.012). Analysis of survival for up to 15 years revealed a significantly reduced survival of diabetic patients compared with non-diabetic patients, with lowest survival rates in NIDDM patients (p<0.001).

CONCLUSIONS

Non-insulin dependent diabetes mellitus patients undergoing CABG within 48 hours of being diagnosed with AMI are at increased risk of short-term and long-term complications. Therefore, this particular group should undergo a careful evaluation concerning the expected risks and benefits of CABG in this setting.

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.

The Adherence to an Intraoperative Blood Product Transfusion Algorithm Is Associated With Reduced Blood Product Transfusions in Cardiac Surgical Patients Undergoing Coronary Artery Bypass Grafts and Aortic and/or Valve Replacement Surgery: A Single-Center, Observational Study

OBJECTIVE

To demonstrate the value of a viscoelastic-based intraoperative transfusion algorithm to reduce non-RBC product administration in adult cardiac surgical patients.

DESIGN

A prospective observational study.

SETTING

At a quaternary academic teaching hospital.

PARTICIPANTS

Cardiac surgical patients.

INTERVENTIONS

Viscoelastic-based intraoperative transfusion algorithm.

MEASUREMENTS AND MAIN RESULTS

The study authors compared intraoperative blood product transfusion rates in 184 cardiac surgical patients to 236 historic controls after implementing a viscoelastic-based algorithm. The authors found a non-significant reduction in transfusion of 23.8% for fresh frozen plasma (FFP) units (0.84 ± 1.4 v 0.64 ± 1.38; p = ns), 33.4% for platelet units (0.90 ± 1.39 v 0.60 ± 131; p = ns), and 15.8% for cryoprecipitate units (0.19 ± 0.54 v 0.16 ± 0.50; p = ns). They found a 43.9% reduction in red blood cell (RBC) units transfused (1.98 ± 2.24 v 0.55 ± 1.36; p = 0.008). There were no statistically significant differences in time to extubation (8.0 hours (4.0-21.0) v 8.0 (4.0-22.3), reoperation for bleeding (15 [12.3%] v 10 [10.6%]), intensive care unit length of stay (ICU LOS) (51.0 hours [28.0-100.5] v 53.5 [33.3-99.0]) or hospital LOS (9.0 days [6.0-15.0] v 10.0 [7.0-17.0]). Deviation from algorithm adherence was 32.7% (48/147). Packed RBC, FFP, platelets, cryoprecipitate, and cell saver were significantly reduced in the Algorithm Compliant Cohort compared with historic controls, whereas times to extubation, ICU LOS, and hospital LOS did not reach significance.

CONCLUSIONS

After the implementation of a viscoelastic-based algorithm, patients received fewer packed RBC, FFP, platelets, cryoprecipitate, and cell saver. Algorithm-compliant patients received fewer transfusions; however, reductions in times to extubation, ICU LOS, and hospital LOS were not statistically significant compared with historic controls.

Physiologic Determinants of Near-Infrared Spectroscopy-Derived Cerebral and Tissue Oxygen Saturation Measurements in Critically Ill Patients

OBJECTIVES

Near-infrared spectroscopy (NIRS) is a potentially valuable modality to monitor the adequacy of oxygen delivery to the brain and other tissues in critically ill patients, but little is known about the physiologic determinants of NIRS-derived tissue oxygen saturations. The purpose of this study was to assess the contribution of routinely measured physiologic parameters to tissue oxygen saturation measured by NIRS.

DESIGN

An observational sub-study of patients enrolled in the Role of Active Deresuscitation After Resuscitation-2 (RADAR-2) randomized feasibility trial.

SETTING

Two ICUs in the United Kingdom.

PATIENTS

Patients were recruited for the RADAR-2 study, which compared a conservative approach to fluid therapy and deresuscitation with usual care. Those included in this sub-study underwent continuous NIRS monitoring of cerebral oxygen saturations (SctO2) and quadriceps muscle tissue saturations (SmtO2).

INTERVENTION

Synchronized and continuous mean arterial pressure (MAP), heart rate (HR), and pulse oximetry (oxygen saturation, Spo2) measurements were recorded alongside NIRS data. Arterial Paco2, Pao2, and hemoglobin concentration were recorded 12 hourly. Linear mixed effect models were used to investigate the association between these physiologic variables and cerebral and muscle tissue oxygen saturations.

MEASUREMENTS AND MAIN RESULTS

Sixty-six patients were included in the analysis. Linear mixed models demonstrated that Paco2, Spo2, MAP, and HR were weakly associated with SctO2 but only explained 7.1% of the total variation. Spo2 and MAP were associated with SmtO2, but together only explained 0.8% of its total variation. The remaining variability was predominantly accounted for by between-subject differences.

CONCLUSIONS

Our findings demonstrated that only a small proportion of variability in NIRS-derived cerebral and tissue oximetry measurements could be explained by routinely measured physiologic variables. We conclude that for NIRS to be a useful monitoring modality in critical care, considerable further research is required to understand physiologic determinants and prognostic significance.

Noninvasive hemoglobin monitoring for maintaining hemoglobin concentration within the target range during major noncardiac surgery: A randomized controlled trial

STUDY OBJECTIVE

The effect of noninvasive CO-oximetry hemoglobin (SpHb) monitoring on the clinical outcomes of patients undergoing surgery remains unclear. This trial aimed to evaluate whether SpHb monitoring helps maintain hemoglobin levels within a predefined target range during major noncardiac surgeries with a potential risk of intraoperative hemorrhage.

DESIGN

A single-center, prospective, randomized controlled trial.

SETTING

University hospital.

PATIENTS

One hundred and thirty patients undergoing elective noncardiac surgery with a potential risk of hemorrhage.

INTERVENTIONS

Patients were randomly allocated to undergo either SpHb-guided management (SpHb group) or usual care (control group).

MEASUREMENTS

The primary outcome was the rate of deviation of the total hemoglobin concentration (determined from laboratory testing) from a pre-specified target range (8-14 g/dL). This was defined as the number of laboratory tests revealing such deviations divided by the total number of laboratory tests performed during the surgery.

MAIN RESULTS

The primary outcome occurred significantly less frequently in the SpHb group as compared to that in the control group (15/555 [2.7%]) vs. 68/598 [11.4%]; relative risk, 0.24; 95% confidence interval, 0.13-0.41; P < 0.001). Fewer point-of-care blood tests were performed in the SpHb group than in the control group (median [interquartile range], 2 [1-4] vs. 4 [2-5]; P < 0.001). There were no significant intergroup differences in the number of patients who received red blood cell transfusions during surgery (SpHb vs. control, 33.8% vs. 46.2%; P = 0.201). The incidence of unnecessary red blood cell preparation (>2 units) was lower in the SpHb group than in the control group (3.1% vs. 16.9%; P = 0.024).

CONCLUSIONS

Compared with routine care, SpHb-guided management resulted in significantly lower rates of hemoglobin deviation outside the target range intraoperatively in patients undergoing major noncardiac surgeries with a potential risk of hemorrhage.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (identifier: NCT03816514).

Exploring the Impact of Age, Frailty, and Multimorbidity on the Effect of ICU Interventions: A Systematic Review of Randomized Controlled Trials

OBJECTIVES

To date, age, frailty, and multimorbidity have been used primarily to inform prognosis in older adults. It remains uncertain, however, whether these patient factors may also predict response to critical care interventions or treatment outcomes.

DATA SOURCES

We conducted a systematic search of top general medicine and critical care journals for randomized controlled trials (RCTs) examining critical care interventions published between January 1, 2011, and December 31, 2021.

STUDY SELECTION

We included RCTs of critical care interventions that examined any one of three subgroups-age, frailty, or multimorbidity. We excluded cluster RCTs, studies that did not report interventions in an ICU, and studies that did not report data examining subgroups of age, frailty, or multimorbidity.

DATA EXTRACTION

We collected study characteristics (single vs. multicountry enrollment, single vs. multicenter enrollment, funding, sample size, intervention, comparator, primary outcome and secondary outcomes, length of follow-up), study population (inclusion and exclusion criteria, average age in intervention and comparator groups), and subgroup data. We used the Instrument for assessing the Credibility of Effect Modification Analyses instrument to evaluate the credibility of subgroup findings.

DATA SYNTHESIS

Of 2037 unique citations, we included 48 RCTs comprising 50,779 total participants. Seven (14.6%) RCTs found evidence of statistically significant effect modification based on age, whereas none of the multimorbidity or frailty subgroups found evidence of statistically significant subgroup effect. Subgroup credibility ranged from very low to moderate.

CONCLUSIONS

Most critical care RCTs do not examine for subgroup effects by frailty or multimorbidity. Although age is more commonly considered, the cut-point is variable, and relative effect modification is rare. Although interventional effects are likely similar across age groups, shared decision-making based on individual patient preferences must remain a priority. RCTs focused specifically on critically ill older adults or those living with frailty and/or multimorbidity are crucial to further address this research question.

The effect of immunosuppressive therapies on the endothelial host response in critically ill COVID-19 patients

While several effective therapies for critically ill patients with COVID-19 have been identified in large, well-conducted trials, the mechanisms underlying these therapies have not been investigated in depth. Our aim is to investigate the association between various immunosuppressive therapies (corticosteroids, tocilizumab and anakinra) and the change in endothelial host response over time in critically ill COVID-19 patients. We conducted a pre-specified multicenter post-hoc analysis in a Dutch cohort of COVID-19 patients admitted to the ICU between March 2020 and September 2021 due to hypoxemic respiratory failure. A panel of 18 immune response biomarkers in the complement, coagulation and endothelial function domains were measured using ELISA or Luminex. Biomarkers were measured on day 0-1, day 2-4 and day 6-8 after start of COVID-19 treatment. Patients were categorized into four treatment groups: no immunomodulatory treatment, corticosteroids, anakinra plus corticosteroids, or tocilizumab plus corticosteroids. The association between treatment group and the change in concentrations of biomarkers was estimated with linear mixed-effects models, using no immunomodulatory treatment as reference group. 109 patients with a median age of 62 years [IQR 54-70] of whom 72% (n = 78) was male, were included in this analysis. Both anakinra plus corticosteroids (n = 22) and tocilizumab plus corticosteroids (n = 38) were associated with an increase in angiopoietin-1 compared to no immune modulator (n = 23) (beta of 0.033 [0.002-0.064] and 0.041 [0.013-0.070] per day, respectively). These treatments, as well as corticosteroids alone (n = 26), were further associated with a decrease in the ratio of angiopoietin-2/angiopoietin-1 (beta of 0.071 [0.034-0.107], 0.060 [0.030-0.091] and 0.043 [0.001-0.085] per day, respectively). Anakinra plus corticosteroids and tocilizumab plus corticosteroids were associated with a decrease in concentrations of complement complex 5b-9 compared to no immunomodulatory treatment (0.038 [0.006-0.071] and 0.023 [0.000-0.047], respectively). Currently established treatments for critically ill COVID-19 patients are associated with a change in biomarkers of the angiopoietin and complement pathways, possibly indicating a role for stability of the endothelium. These results increase the understanding of the mechanisms of interventions and are possibly useful for stratification of patients with other inflammatory conditions which may potentially benefit from these treatments.

Differential responses of cerebral and renal oxygenation to altered perfusion conditions during experimental cardiopulmonary bypass in sheep

We tested whether the brain and kidney respond differently to cardiopulmonary bypass (CPB) and to changes in perfusion conditions during CPB. Therefore, in ovine CPB, we assessed regional cerebral oxygen saturation (rSO2 ) by near-infrared spectroscopy and renal cortical and medullary tissue oxygen tension (PO2 ), and, in some protocols, brain tissue PO2 , by phosphorescence lifetime oximetry. During CPB, rSO2 correlated with mixed venous SO2 (r = 0.78) and brain tissue PO2 (r = 0.49) when arterial PO2 was varied. During the first 30 min of CPB, brain tissue PO2 , rSO2 and renal cortical tissue PO2 did not fall, but renal medullary tissue PO2 did. Nevertheless, compared with stable anaesthesia, during stable CPB, rSO2 (66.8 decreasing to 61.3%) and both renal cortical (90.8 decreasing to 43.5 mm Hg) and medullary (44.3 decreasing to 19.2 mm Hg) tissue PO2 were lower. Both rSO2 and renal PO2 increased when pump flow was increased from 60 to 100 mL kg-1  min-1 at a target arterial pressure of 70 mm Hg. They also both increased when pump flow and arterial pressure were increased simultaneously. Neither was significantly altered by partially pulsatile flow. The vasopressor, metaraminol, dose-dependently decreased rSO2 , but increased renal cortical and medullary PO2 . Increasing blood haemoglobin concentration increased rSO2 , but not renal PO2 . We conclude that both the brain and kidney are susceptible to hypoxia during CPB, which can be alleviated by increasing pump flow, even without increasing arterial pressure. However, increasing blood haemoglobin concentration increases brain, but not kidney oxygenation, whereas vasopressor support with metaraminol increases kidney, but not brain oxygenation.

Examining Bleeding Risk, Transfusion-related Complications, and Strategies to Reduce Transfusions in Lung Transplantation

Blood product transfusions for bleeding management in lung transplantation affect recipient outcomes. Interventions are needed to reduce perioperative bleeding risk and optimize outcomes.

Effect of blood conservation protocol on the utilisation of blood and outcome of patients undergoing open heart surgery

INTRODUCTION

Cardiac surgery is fraught with increased consumption of blood and blood products. Various strategies for blood conservation have been described. Our aim was to study the impact of a structured blood conservation protocol (BCP) on the utilization of blood and patient outcome.

METHODS

Retrospective analysis of prospectively collected data comparing adult patients undergoing open heart surgery with BCP with those undergoing surgery without BCP. The primary objective was to compare the amount of blood utilized and the hematocrit at discharge. The secondary objective was to compare the parameters of patient outcomes. The level of significance was set at 0.05.

RESULTS

The proportion of patients requiring transfusion (19.1% [9/47] vs 58.9% [33/56]; p < 0.001) and the quantity of blood transfused (12 units vs 45 units; p 0.003) in the BCP group was significantly lower. Interestingly, the hematocrit level at discharge was comparable between the groups (30.9 (4.8) versus 31.8 (2.4), p-0.671). The average cost incurred for transfusing blood in the BCP group was ₹ 370.2 as compared to ₹1165.1 in the other (p < 0.001). BCP reduced the odds of overall blood transfusion by 79.8% (OR 0.202 (0.084-0.485); p < 0.001) and intraoperative blood transfusion by 95.3% (OR 0.047 (0.010-0.213); p < 0.001). The morbidity and mortality were comparable between the groups.

CONCLUSION

Implementing a structured blood conservation protocol in patients undergoing open heart surgery significantly reduces the need for blood transfusion. It also has a promising impact on patient recovery after surgery and significant positive cost implications.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

Postoperative anemia in cardiac surgery patients: a narrative review

PURPOSE

Anemia reduces the blood's ability to carry and deliver oxygen. Following cardiac surgery, anemia is very common and affects up to 90% of patients. Nevertheless, there is a paucity of data examining the prognostic value of postoperative anemia. In this narrative review, we present findings from the relevant literature on postoperative anemia in cardiac surgery patients, focusing on the incidence, risk factors, and prognostic value of postoperative anemia. We also explore the potential utility of postoperative anemia as a therapeutic target to improve clinical outcomes.

SOURCE

We conducted a targeted search of MEDLINE, Embase, and the Cochrane Database of Systematic Reviews up to September 2022, using a combination of search terms including postoperative (post-operative), perioperative (peri-operative), anemia (anaemia), and cardiac surgery.

PRINCIPAL FINDINGS

The reported incidence of postoperative anemia varied from 29% to 94% across the studies, likely because of variations in patient inclusion criteria and classification of postoperative anemia. Nonetheless, the weight of the evidence suggests that postoperative anemia is common and is an independent risk factor for adverse postoperative outcomes such as acute kidney injury, stroke, mortality, and functional outcomes.

CONCLUSIONS

In cardiac surgery patients, postoperative anemia is a common and prognostically important risk factor for postoperative morbidity and mortality. Nevertheless, there is a lack of data on whether active management of postoperative anemia is feasible or effective in improving patient outcomes.

Healthcare exposures and associated risk of endocarditis after open-heart cardiac valve surgery

BACKGROUND

Infective endocarditis (IE) following cardiac valve surgery is associated with high morbidity and mortality. Data on the impact of iatrogenic healthcare exposures on this risk are sparse. This study aimed to investigate risk factors including healthcare exposures for post open-heart cardiac valve surgery endocarditis (PVE).

METHODS

In this population-linkage cohort study, 23,720 patients who had their first cardiac valve surgery between 2001 and 2017 were identified from an Australian state-wide hospital-admission database and followed-up to 31 December 2018. Risk factors for PVE were identified from multivariable Cox regression analysis and verified using a case-crossover design sensitivity analysis.

RESULTS

In 23,720 study participants (median age 73, 63% male), the cumulative incidence of PVE 15 years after cardiac valve surgery was 7.8% (95% CI 7.3-8.3%). Thirty-seven percent of PVE was healthcare-associated, which included red cell transfusions (16% of healthcare exposures) and coronary angiograms (7%). The risk of PVE was elevated for 90 days after red cell transfusion (HR = 3.4, 95% CI 2.1-5.4), coronary angiogram (HR = 4.0, 95% CI 2.3-7.0), and healthcare exposures in general (HR = 4.0, 95% CI 3.3-4.8) (all p < 0.001). Sensitivity analysis confirmed red cell transfusion (odds ratio [OR] = 3.9, 95% CI 1.8-8.1) and coronary angiogram (OR = 2.6, 95% CI 1.5-4.6) (both p < 0.001) were associated with PVE. Six-month mortality after PVE was 24% and was higher for healthcare-associated PVE than for non-healthcare-associated PVE (HR = 1.3, 95% CI 1.1-1.5, p = 0.002).

CONCLUSIONS

The risk of PVE is significantly higher for 90 days after healthcare exposures and associated with high mortality.

Association between intraoperative blood salvage and coagulation disorder after cardiopulmonary bypass

BACKGROUND

This study investigated whether intraoperative blood salvage was associated with coagulation disorder diagnosed by conventional coagulation tests and thromboelastography (TEG) after cardiopulmonary bypass (CPB).

STUDY DESIGN AND METHODS

This was a prospective, observational study. Ninety-two patients who underwent cardiovascular surgery with CPB were enrolled. We evaluated coagulation function in patients with or without cell salvage blood transfusion at the following time points: before CPB, just after protamine administration, and 1 h after protamine administration. We evaluated platelet count, fibrinogen concentration, and TEG parameters. Patients were considered to have coagulation disorder if one or more of the following criteria were present: (1) residual heparin, (2) low platelet count, (3) low fibrinogen level, (4) low clotting factor level, and (5) hyperfibrinolysis.

RESULTS

Fifty-three of 92 patients (57.6%) received intraoperative cell salvage. Coagulation disorder was observed in 56 of 92 patients (60.9%) after CPB. There was no significant difference between patients with or without intraoperative blood salvage in terms of the incidence of coagulation disorder (p = 0.542) or the total volume of blood from the drain after CPB (p = 0.437). Intraoperative blood salvage was not associated with coagulation disorder diagnosed by either TEG or conventional coagulation tests (odds ratio 1.329, 95% confidence interval: 0.549-3.213, p = 0.547). There were no significant interactions between patients with or without intraoperative blood salvage regarding coagulation parameters derived from TEG.

CONCLUSIONS

The incidence of coagulation disorder and the total blood volume from the drain after CPB did not differ significantly between patients with or without intraoperative blood salvage.

Real-world causal evidence for planned predictive enrichment in critical care trials: A scoping review

BACKGROUND

Randomised clinical trials in critical care are prone to inconclusiveness due, in part, to undue optimism about effect sizes and suboptimal accounting for heterogeneous treatment effects. Although causal evidence from rich real-world critical care can help overcome these challenges by informing predictive enrichment, no overview exists.

METHODS

We conducted a scoping review, systematically searching 10 general and speciality journals for reports published on or after 1 January 2018, of randomised clinical trials enrolling adult critically ill patients. We collected trial metadata on 22 variables including recruitment period, intervention type and early stopping (including reasons) as well as data on the use of causal evidence from secondary data for planned predictive enrichment.

RESULTS

We screened 9020 records and included 316 unique RCTs with a total of 268,563 randomised participants. One hundred seventy-three (55%) trials tested drug interventions, 101 (32%) management strategies and 42 (13%) devices. The median duration of enrolment was 2.2 (IQR: 1.3-3.4) years, and 83% of trials randomised less than 1000 participants. Thirty-six trials (11%) were restricted to COVID-19 patients. Of the 55 (17%) trials that stopped early, 23 (42%) used predefined rules; futility, slow enrolment and safety concerns were the commonest stopping reasons. None of the included RCTs had used causal evidence from secondary data for planned predictive enrichment.

CONCLUSION

Work is needed to harness the rich multiverse of critical care data and establish its utility in critical care RCTs. Such work will likely need to leverage methodology from interventional and analytical epidemiology as well as data science.

Transfusion of non-red blood cell blood products does not reduce survival following cardiac surgery

OBJECTIVES

The literature supports the assertion that patients undergoing cardiac surgery who receive perioperative packed red blood cell (pRBC) transfusions have increased associated mortality. The aim of the current study is to assess whether there is an association between non-pRBC blood product transfusions and increased mortality.

METHODS

Data from our center's Society of Thoracic Surgeons database included patients who underwent cardiac surgery from 2010 to 2018. Patients with pRBC transfusions or circulatory arrest were excluded. Propensity matching was performed (1:1; caliper = 0.2 times the standard deviation of logit of propensity score). Kaplan-Meier estimates and Cox regression were used. Cardiac transplant, ventricular assist devices, transcatheter aortic valves, and patients who had experienced circulatory arrest were excluded from this analysis.

RESULTS

A total of 8042 patients met criteria for analysis. Following propensity matching (1:1), 395 patients requiring perioperative non-pRBC blood products (platelets, fresh-frozen plasma, and cryoprecipitate) were matched with 395 nontransfusion patients, yielding equitable patient cohorts. Median follow-up was 4.5 (3.0-6.4) years. Patients received platelets (327 [82.8%]), fresh-frozen plasma (141 [35.7%]), and cryoprecipitate (60 [15.2%]). There was no significant difference in the postoperative mortality (6 [1.5%] vs 4 [1.0%]; P = .52). Reoperation (20 [5.0%] vs 8 [2.0%]; P < .02) and prolonged ventilation (36 [9.1%] vs 19 [4.8%]; P < .02) were greater in the transfusion group. Emergent operation (odds ratio [OR] 2.86 [1.72-4.78]; P < .001), intra-aortic balloon pump (OR 3.24 [1.64-6.39]; P < .001), and multivalve operation (OR 4.34 [2.83-6.67]; P < .001) were significantly associated with blood product use. Blood product transfusion (hazard ratio; 1.15 [0.89-1.48]; P = .3) was not significantly associated with increased mortality risk. There was no significant long-term survival difference between cohorts.

CONCLUSIONS

Patients who undergo cardiac surgery requiring blood products alone, without pRBC transfusion, have similar postoperative and long-term survival compared with patients not requiring blood products. These data are based on a limited patient sample, and future studies will aid in improving the generalizability of these results.

Transfusion policy in pediatric extracorporeal membrane oxygenation patients: Less could be more

OBJECTIVE

To evaluate a restrictive transfusion policy of red blood cells (RBC) and platelets in pediatric patients submitted to extracorporeal membrane oxygenation (ECMO).

METHODS

Retrospective descriptive study of pediatric patients supported with ECMO, from January 2010 to December 2019. Hemoglobin, platelet, lactate and mixed venous oxygen saturation (SvO2) values of each patient while on ECMO, were collected. Transfusion efficiency and tissue oxygenation were statistically evaluated comparing pre-transfusion hemoglobin, lactate and SvO2 with post-transfusion values. Ranges of hemoglobin and platelets were established, and the number of transfusions registered. The bleeding complications and outcome were documented.

RESULTS

Of a total of 1016 hemoglobin values, the mean value before transfusion was 8.6 g/dl. Hemoglobin and SvO2 increased significantly post-transfusion. Red blood cell transfusion varied with hemoglobin values: when hemoglobin value was less than 7 g/dl, 89% (41/46) were transfused but just 23% (181/794) when greater or equal to 7 g/dl. In the presence of active bleeding, the frequency of RBC transfusion increased from 32% to 62%, with hemoglobin between 7 g/dl and 8 g/dl.The mean value for platelet transfusion was 32 x 109/L. Thirty-eight (43%) platelet values between 20 x 109/L and 30x109/L, and 31 (40%) between 30 x 109/L and 40 x 109/L led to platelet transfusion; between 40 x 109/L and 50 x 109/L, only 7 (9%) prompted platelet transfusion.Comparing the 2010-2015 to 2016-2019 periods there was a decrease in RBC and platelet transfusion threshold with similar survival (p = .528). Survival to discharge was 68%.

CONCLUSIONS

Using a restrictive RBC and platelet transfusion policy was safe and allowed a good outcome in this case series. The presence of active bleeding was an important decision factor when hemoglobin was above 7 g/dl and platelets were above 30 x 109/L.

Restrictive or Liberal Transfusion Strategy in Myocardial Infarction and Anemia

BACKGROUND

A strategy of administering a transfusion only when the hemoglobin level falls below 7 or 8 g per deciliter has been widely adopted. However, patients with acute myocardial infarction may benefit from a higher hemoglobin level.

METHODS

In this phase 3, interventional trial, we randomly assigned patients with myocardial infarction and a hemoglobin level of less than 10 g per deciliter to a restrictive transfusion strategy (hemoglobin cutoff for transfusion, 7 or 8 g per deciliter) or a liberal transfusion strategy (hemoglobin cutoff, <10 g per deciliter). The primary outcome was a composite of myocardial infarction or death at 30 days.

RESULTS

A total of 3504 patients were included in the primary analysis. The mean (±SD) number of red-cell units that were transfused was 0.7±1.6 in the restrictive-strategy group and 2.5±2.3 in the liberal-strategy group. The mean hemoglobin level was 1.3 to 1.6 g per deciliter lower in the restrictive-strategy group than in the liberal-strategy group on days 1 to 3 after randomization. A primary-outcome event occurred in 295 of 1749 patients (16.9%) in the restrictive-strategy group and in 255 of 1755 patients (14.5%) in the liberal-strategy group (risk ratio modeled with multiple imputation for incomplete follow-up, 1.15; 95% confidence interval [CI], 0.99 to 1.34; P = 0.07). Death occurred in 9.9% of the patients with the restrictive strategy and in 8.3% of the patients with the liberal strategy (risk ratio, 1.19; 95% CI, 0.96 to 1.47); myocardial infarction occurred in 8.5% and 7.2% of the patients, respectively (risk ratio, 1.19; 95% CI, 0.94 to 1.49).

CONCLUSIONS

In patients with acute myocardial infarction and anemia, a liberal transfusion strategy did not significantly reduce the risk of recurrent myocardial infarction or death at 30 days. However, potential harms of a restrictive transfusion strategy cannot be excluded. (Funded by the National Heart, Lung, and Blood Institute and others; MINT ClinicalTrials.gov number, NCT02981407.).

Hemoglobin levels and clinical outcomes after extracorporeal circulation auxiliary to open heart surgery: a retrospective cohort study

BACKGROUND

Extracorporeal circulation auxiliary to open heart surgery is a common procedure used to treat heart diseases. However, the optimal transfusion strategy for patients undergoing this surgery remains a subject of debate. This study aims to investigate the association between hemoglobin levels and clinical outcomes in patients undergoing extracorporeal circulation auxiliary to open heart surgery, with the ultimate goal of improving surgical success rates and enhancing patients' quality of life.

METHODS

A retrospective analysis was conducted on data from the Medical Information Mart for Intensive Care IV 2.2 (MIMIC-IV 2.2) database, including 4144 patients. The patients were categorized into five groups based on their minimum hemoglobin levels during hospitalization. Baseline characteristics, clinical scores, laboratory results, and clinical outcome data were collected. Statistical analyses utilized descriptive statistics, ANOVA or Kruskal-Wallis tests, Kaplan-Meier method, and Log-rank test.

RESULTS

The results revealed a significant correlation between hemoglobin levels and in-hospital mortality, as well as mortality rates at 30 days, 60 days, and 180 days (p < 0.001). Patients with lower hemoglobin levels exhibited higher mortality rates. However, once hemoglobin levels exceeded 7g/dL, no significant difference in mortality rates was observed (p = 0.557). Additionally, lower hemoglobin levels were associated with prolonged hospital stay, ICU admission time, and mechanical ventilation time (p < 0.001). Furthermore, hemoglobin levels were significantly correlated with complication risk, norepinephrine dosage, and red blood cell transfusion volume (p < 0.001). However, there was no significant difference among the groups in terms of major complications, specifically sepsis (p > 0.05).

CONCLUSION

The study highlights the importance of managing hemoglobin levels in patients undergoing heart surgery with extracorporeal circulation. Hemoglobin levels can serve as valuable indicators for predicting clinical outcomes and guiding treatment decisions. Physicians should carefully consider hemoglobin levels to optimize transfusion strategies and improve postoperative patient outcomes. Further research and intervention studies are warranted to validate and implement these findings in clinical practice.

Individualized red-cell transfusion strategy for non-cardiac surgery in adults: a randomized controlled trial

BACKGROUND

Red-cell transfusion is critical for surgery during the peri-operative period; however, the transfusion threshold remains controversial mainly owing to the diversity among patients. The patient's medical status should be evaluated before making a transfusion decision. Herein, we developed an individualized transfusion strategy using the West-China-Liu's Score based on the physiology of oxygen delivery/consumption balance and designed an open-label, multicenter, randomized clinical trial to verify whether it reduced red cell requirement as compared with that associated with restrictive and liberal strategies safely and effectively, providing valid evidence for peri-operative transfusion.

METHODS

Patients aged >14 years undergoing elective non-cardiac surgery with estimated blood loss > 1000 mL or 20% blood volume and hemoglobin concentration <10 g/dL were randomly assigned to an individualized strategy, a restrictive strategy following China's guideline or a liberal strategy with a transfusion threshold of hemoglobin concentration <9.5 g/dL. We evaluated two primary outcomes: the proportion of patients who received red blood cells (superiority test) and a composite of in-hospital complications and all-cause mortality by day 30 (non-inferiority test).

RESULTS

We enrolled 1182 patients: 379, 419, and 384 received individualized, restrictive, and liberal strategies, respectively. Approximately 30.6% (116/379) of patients in the individualized strategy received a red-cell transfusion, less than 62.5% (262/419) in the restrictive strategy (absolute risk difference, 31.92%; 97.5% confidence interval [CI]: 24.42-39.42%; odds ratio, 3.78%; 97.5% CI: 2.70-5.30%; P <0.001), and 89.8% (345/384) in the liberal strategy (absolute risk difference, 59.24%; 97.5% CI: 52.91-65.57%; odds ratio, 20.06; 97.5% CI: 12.74-31.57; P <0.001). No statistically significant differences were found in the composite of in-hospital complications and mortality by day 30 among the three strategies.

CONCLUSION

The individualized red-cell transfusion strategy using the West-China-Liu's Score reduced red-cell transfusion without increasing in-hospital complications and mortality by day 30 when compared with restrictive and liberal strategies in elective non-cardiac surgeries.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01597232.

Longitudinal incremental propensity score interventions for limited resource settings

Many real-life treatments are of limited supply and cannot be provided to all individuals in the population. For example, patients on the liver transplant waiting list usually cannot be assigned a liver transplant immediately at the time they reach highest priority because a suitable organ is not immediately available. In settings with limited supply, investigators are often interested in the effects of treatment strategies in which a limited proportion of patients receive an organ at a given time, that is, treatment regimes satisfying resource constraints. Here, we describe an estimand that allows us to define causal effects of treatment strategies that satisfy resource constraints: incremental propensity score interventions (IPSIs) for limited resources. IPSIs flexibly constrain time-varying resource utilization through proportional scaling of patients' natural propensities for treatment, thereby preserving existing propensity rank ordering compared to the status quo. We derive a simple class of inverse-probability-weighted estimators, and we apply one such estimator to evaluate the effect of restricting or expanding utilization of "increased risk" liver organs to treat patients with end-stage liver disease.

Risk Factors and Early Outcomes for Gastrointestinal Complications in Patients Undergoing Open Surgery for Type A Aortic Dissection

BACKGROUND

Gastrointestinal complications need to be paid more attention, especially in critically ill patients. The purpose of this study was to identify the risk factors and short-term outcomes of gastrointestinal complications after open surgery for type A aortic dissection.

METHODS

A retrospective single-institutional study including patients who underwent open surgery for type A aortic dissection during 2012-2020 was conducted. Univariate analysis and logistic regression analysis were used to identify risk factors associated with gastrointestinal complications. The related clinical outcomes were compared between the patients with and without gastrointestinal complications.

RESULTS

Among the 2746 patients, 150 developed gastrointestinal complications. The development of gastrointestinal complications contributed to the higher rate of mortality (P = .008), longer stay in the intensive care unit (P < .001), and longer hospital stay (P < .001). Logistic regression analysis showed that age (odds ratio [OR] 1.020; 95% confidence interval [CI] 1.005-1.057; P = .011), American Society of Anesthesiologists classification greater than grade III (OR 1.724; 95%CI 1.179-2.521, P = .005), pre-induction mean arterial pressure (OR 0.978; 95%CI 0.965-0.990, P = .001), aortic cross-clamp time (OR 1.012; 95%CI 1.005-1.019, P = .001), cardiopulmonary bypass time (OR 1.007; 95%CI 1.002-1.011, P = .002), and intraoperative transfusion of red blood cells (OR 1.214; 95%CI 1.122-1.314, P = .001) were independent risk factors for gastrointestinal complications.

CONCLUSIONS

The incidence of gastrointestinal complications after open surgery for type A aortic dissection was 5.5%, resulting in increased mortality and prolonged hospital stay. It is necessary to take suitable strategies to reduce the incidence of gastrointestinal complications.

The Year in Coagulation and Transfusion: Selected Highlights from 2022

This is an annual review to cover highlights in transfusion and coagulation in patients undergoing cardiovascular surgery. The goal of this article is to provide readers with a focused summary of the most important transfusion and coagulation topics published in 2022. This includes a discussion covering the management of anemia and red blood cell transfusion, the management of factor Xa inhibitors, updates in coagulation testing, updates in the use of factor concentrates, advances in platelet therapy, advances in anticoagulation management of patients on extracorporeal membrane oxygenation and other forms of mechanical circulatory support, and advances in the diagnosis and management of heparin-induced thrombocytopenia.

Perioperative Acute Kidney Injury: Implications, Approach, Prevention

Acute kidney injury remains a common and significant contributor to perioperative morbidity. Acute kidney injury worsens patient outcomes, and anesthesiologists should make significant efforts to prevent, assess, and treat perioperative renal injury. The authors discuss the impact of renal injury on patient outcomes and putative underlying mechanisms, evidence underlying treatments for acute kidney injury, and practices that may prevent the development of perioperative renal injury.

Acute Kidney Injury after Cardiac Surgery: Prediction, Prevention, and Management

Acute kidney injury (AKI) is a common complication in cardiac surgery patients, with a reported incidence of 20 to 30%. The development of AKI is associated with worse short- and long-term mortality, and longer hospital length of stay. The pathogenesis of cardiac surgery-associated AKI is poorly understood but likely involves an interplay between preoperative comorbidities and perioperative stressors. AKI is commonly diagnosed by using increases in serum creatinine or decreased urine output and staged using a standardized definition such as the Kidney Disease Improving Global Outcomes classification. Novel biomarkers under investigation may provide earlier detection and better prediction of AKI, enabling mitigating therapies early in the perioperative period. Recent clinical trials of cardiac surgery patients have demonstrated the benefit of goal-directed oxygen delivery, avoidance of hyperthermic perfusion and specific fluid and medication strategies. This review article highlights both advances and limitations regarding the prevention, prediction, and treatment of cardiac surgery-associated AKI.

Red Blood Cell Transfusion in the Intensive Care Unit

Importance

Red blood cell (RBC) transfusion is common among patients admitted to the intensive care unit (ICU). Despite multiple randomized clinical trials of hemoglobin (Hb) thresholds for transfusion, little is known about how these thresholds are incorporated into current practice.

Objective

To evaluate and describe ICU RBC transfusion practices worldwide.

Design, Setting, and Participants

International, prospective, cohort study that involved 3643 adult patients from 233 ICUs in 30 countries on 6 continents from March 2019 to October 2022 with data collection in prespecified weeks.

Exposure

ICU stay.

Main Outcomes and Measures

The primary outcome was the occurrence of RBC transfusion during ICU stay. Additional outcomes included the indication(s) for RBC transfusion (consisting of clinical reasons and physiological triggers), the stated Hb threshold and actual measured Hb values before and after an RBC transfusion, and the number of units transfused.

Results

Among 3908 potentially eligible patients, 3643 were included across 233 ICUs (median of 11 patients per ICU [IQR, 5-20]) in 30 countries on 6 continents. Among the participants, the mean (SD) age was 61 (16) years, 62% were male (2267/3643), and the median Sequential Organ Failure Assessment score was 3.2 (IQR, 1.5-6.0). A total of 894 patients (25%) received 1 or more RBC transfusions during their ICU stay, with a median total of 2 units per patient (IQR, 1-4). The proportion of patients who received a transfusion ranged from 0% to 100% across centers, from 0% to 80% across countries, and from 19% to 45% across continents. Among the patients who received a transfusion, a total of 1727 RBC transfusions were administered, wherein the most common clinical indications were low Hb value (n = 1412 [81.8%]; mean [SD] lowest Hb before transfusion, 7.4 [1.2] g/dL), active bleeding (n = 479; 27.7%), and hemodynamic instability (n = 406 [23.5%]). Among the events with a stated physiological trigger, the most frequently stated triggers were hypotension (n = 728 [42.2%]), tachycardia (n = 474 [27.4%]), and increased lactate levels (n = 308 [17.8%]). The median lowest Hb level on days with an RBC transfusion ranged from 5.2 g/dL to 13.1 g/dL across centers, from 5.3 g/dL to 9.1 g/dL across countries, and from 7.2 g/dL to 8.7 g/dL across continents. Approximately 84% of ICUs administered transfusions to patients at a median Hb level greater than 7 g/dL.

Conclusions and Relevance

RBC transfusion was common in patients admitted to ICUs worldwide between 2019 and 2022, with high variability across centers in transfusion practices.

Red Blood Cell Transfusion: 2023 AABB International Guidelines

Importance

Red blood cell transfusion is a common medical intervention with benefits and harms.

Objective

To provide recommendations for use of red blood cell transfusion in adults and children.

Evidence Review

Standards for trustworthy guidelines were followed, including using Grading of Recommendations Assessment, Development and Evaluation methods, managing conflicts of interest, and making values and preferences explicit. Evidence from systematic reviews of randomized controlled trials was reviewed.

Findings

For adults, 45 randomized controlled trials with 20 599 participants compared restrictive hemoglobin-based transfusion thresholds, typically 7 to 8 g/dL, with liberal transfusion thresholds of 9 to 10 g/dL. For pediatric patients, 7 randomized controlled trials with 2730 participants compared a variety of restrictive and liberal transfusion thresholds. For most patient populations, results provided moderate quality evidence that restrictive transfusion thresholds did not adversely affect patient-important outcomes. Recommendation 1: for hospitalized adult patients who are hemodynamically stable, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). In accordance with the restrictive strategy threshold used in most trials, clinicians may choose a threshold of 7.5 g/dL for patients undergoing cardiac surgery and 8 g/dL for those undergoing orthopedic surgery or those with preexisting cardiovascular disease. Recommendation 2: for hospitalized adult patients with hematologic and oncologic disorders, the panel suggests a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (conditional recommendations, low certainty evidence). Recommendation 3: for critically ill children and those at risk of critical illness who are hemodynamically stable and without a hemoglobinopathy, cyanotic cardiac condition, or severe hypoxemia, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). Recommendation 4: for hemodynamically stable children with congenital heart disease, the international panel suggests a transfusion threshold that is based on the cardiac abnormality and stage of surgical repair: 7 g/dL (biventricular repair), 9 g/dL (single-ventricle palliation), or 7 to 9 g/dL (uncorrected congenital heart disease) (conditional recommendation, low certainty evidence).

Conclusions and Relevance

It is good practice to consider overall clinical context and alternative therapies to transfusion when making transfusion decisions about an individual patient.

Home transfusions are implemented using diverse approaches in Japan

BACKGROUND AND OBJECTIVES

Japan's ageing society has increased the need for home healthcare, including home transfusions. We hence aimed to elucidate the purpose and utilization of home transfusions in Japan, which has not been clarified to date.

MATERIALS AND METHODS

Clinics throughout Japan that provide home care and have experience in performing blood transfusions were surveyed. The study period was February to December 2019, and information of patients receiving home red blood cell transfusions, including patient background, pre-transfusion laboratory data and the purpose of the transfusions, was collected.

RESULTS

Haematological malignancies and solid tumours accounted for 70% of the patients' underlying diseases, with the former being significantly more common in urban areas. Regarding the purpose of the home transfusions, haematologists focused on symptom improvement, whereas gastroenterology surgeons focused on life support. Furthermore, maintenance of life was more likely to be the aim in the group of patients with the lowest level of activities of daily living. The main items that were significantly associated with a low haemoglobin level before transfusion included age ≥90 years and a gastroenterologist being the physician in charge.

CONCLUSION

Home transfusions were found to be performed in a restrictive and diverse manner in Japan. Life support is the second most common purpose of home transfusion in Japan, and optimizing effective home transfusion remains a challenge.