Restrictive versus liberal blood transfusion in patients with coronary artery disease: a meta-analysis

Year in Review 2023: Noteworthy Literature in Cardiothoracic Critical Care

This article reviews noteworthy investigations and society recommendations published in 2023 relevant to the care of critically ill cardiothoracic surgical patients. We reviewed 3,214 articles to identify 18 publications that add to the existing literature across a variety of topics including resuscitation, nutrition, antibiotic management, extracorporeal membrane oxygenation (ECMO), neurologic care following cardiac arrest, coagulopathy and transfusion, steroids in pulmonary infections, and updated guidelines in the management of acute respiratory distress syndrome (ARDS).

Appropriateness of Allogeneic Red Blood Cell Transfusions in Non-Bleeding Patients in a Large Teaching Hospital: A Retrospective Study

In hemodynamically stable patients, both anemia and red blood cell (RBC) transfusion may be detrimental to patients; hence, a decision regarding RBC transfusion should be based on thorough risk-benefit assessment. According to hematology and transfusion medicine organizations, RBC transfusion is indicated when recommended hemoglobin (Hb) triggers are met, and symptoms of anemia are present. The aim of our study was to examine the appropriateness of RBC transfusions in non-bleeding patients at our institution. We performed a retrospective analysis of all RBC transfusions performed between January 2022 and July 2022. The appropriateness of RBC transfusion was based on the most recent Association for the Advancement of Blood and Biotherapies (AABB) guidelines and some additional criteria. The overall incidence of RBC transfusions at our institution was 10.2 per 1000 patient-days. There were 216 (26.1%) RBC units appropriately transfused and 612 (73.9%) RBC units that were transfused with no clear indications. The incidence of appropriate and inappropriate RBC transfusions were 2.6 and 7.5 per 1000 patient-days, respectively. The most frequent clinical situations when RBC transfusion was classified as appropriate were: Hb < 70 g/L plus cognitive problems/headache/dizziness (10.1%), Hb < 60 g/L (5.4%), and Hb < 70 g/L plus dyspnea despite oxygen therapy (4.3%). The most frequent causes of inappropriate RBC transfusions were: no Hb determination pre-RBC transfusion (n = 317) and, among these, RBC transfused as a second unit in a single-transfusion episode (n = 260); absence of anemia sings/symptoms pre-transfusion (n = 179); and Hb concentration ≥80 g/L (n = 80). Although the incidence of RBC transfusions in non-bleeding inpatients in our study was generally low, the majority of RBC transfusions were performed outside recommended indications. Red blood cell transfusions were evaluated as inappropriate mainly due to multiple-unit transfusion episodes, absence of anemia signs and/or symptoms pre- transfusion, and liberal transfusion triggers. There is still the need to educate physicians on appropriate indications for RBC transfusion in non-bleeding patients.

The role of anemia on admission in acute coronary syndrome - An umbrella review of systematic reviews and meta-analyses

INTRODUCTION

The role of erythrocytes in the acute coronary syndrome (ACS) is complex. The aim of this review in terms of PICO (P: patients; I: intervention; C: comparison; O: outcome) was to summarize systematic reviews in patients (P) with acute coronary syndrome, evaluating the effects of (I) 1) iron deficiency, 2) administration of an erythropoiesis-stimulating agent (ESA), 3) anemia on admission, 4) red blood cell transfusion, 5) a restrictive transfusion strategy in comparison (C) to 1) no iron deficiency, 2) no ESA 3) no anemia on admission, 4) no red blood cell transfusion, 5) a liberal transfusion strategy on mortality (O).

METHODS

We used AMSTAR2 to assess the methodological quality of systematic reviews and grade the available research. The primary endpoint was all-cause mortality.

RESULTS

Using the data from 2,787,005 patients, the following conditions were associated with worse outcome in patients with ACS: anemia on admission (RR 2.08 95%CI 1.70-2.55) and transfusion (1.93 95%CI 1.12-3.34) of red blood cells. A liberal transfusion (RR 0.86 95%CI 0.70-1-05), administration of ESA (RR 0.55 95%CI 0.22-1.33) and iron deficiency (OR 1.24 95%CI 0.12-13.13) were not associated with altered all-cause mortality.

CONCLUSION

Patients suffering from ACS and anemia on admission are at particular risk for adverse outcome. There is evidence of associations between adverse outcomes and receiving red blood cell transfusions.

Transfusion strategies in patients with acute coronary syndrome and anemia: a meta-analysis

Background

Anemia is a known risk factor for ischemic heart disease and serves as an independent predictor of major adverse cardiovascular events (MACE) in patients with acute coronary syndrome (ACS). This meta-analysis pools data from randomized controlled trials (RCTs) to better define hemoglobin (Hb) thresholds for transfusion in this setting.

Results

MEDLINE, EMBASE, and Cochrane databases were searched using the terms “Acute Coronary Syndrome” AND “Blood Transfusion” including their synonyms. A total of three randomized controlled trials were included. Restrictive transfusion strategy (RTS) was defined as transfusing for Hb ≤ 8 g/dl with a post-transfusion goal of 8 to 10 g/dl. Liberal transfusion strategy (LTS) was defined as Hb ≤ 10 g/dl and post-transfusion goal of at least 11 g/dl. The primary end point was 30-day mortality. Secondary outcomes included recurrent ACS events, new or worsening CHF within 30 days, and major adverse cardiac events (MACE). The primary analytic method used was random effects model. Out of 821 patients, 400 were randomized to LTS, and 421 to RTS. Mean age was 70.3 years in RTS versus 76.4 in LTS. There was no statistically significant difference for 30-day mortality in LTS compared to RTS [odds ratio (OR) 1.69; 95% CI 0.35 to 8.05]. Similarly, there was no difference in MACE (OR 0.74; 95% CI 0.21 to 2.63), CHF (OR 0.82; 95% CI 0.18 to 3.76), or the incidence of recurrent ACS (OR 1.21; 95% CI 0.49 to 2.95).

Conclusions

In the setting of ACS, there is no difference between LTS and RTS for the outcomes of mortality, MACE, recurrent ACS, or CHF at 30 days. Further evidence in the form of high-quality RCTs are needed to compare RTS and LTS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43044-022-00252-2.

Restrictive vs. Liberal Red Blood Cell Transfusion Strategy in Patients With Acute Myocardial Infarction and Anemia: A Systematic Review and Meta-Analysis

Objective: Anemia is frequent in patients with acute myocardial infarction (AMI), and the optimal red blood cell transfusion strategy for AMI patients with anemia is still controversial. We aimed to compare the efficacy of restrictive and liberal red cell transfusion strategies in AMI patients with anemia.

Methods: We systematically searched PubMed, EMBASE, Web of Science, Cochrane Library, and Clinicaltrials.gov, from their inception until March 2021. Studies designed to compare the efficacy between restrictive and liberal red blood cell transfusion strategies in patients with AMI were included. The primary outcome was all-cause mortality, including overall mortality, in-hospital or follow-up mortality. Risk ratios (RR) with 95% confidence intervals (CI) were presented and pooled by random-effects models.

Results: The search yielded a total of 6,630 participants in six studies. A total of 2,008 patients received restrictive red blood cell transfusion while 4,622 patients were given liberal red blood cell transfusion. No difference was found in overall mortality and follow-up mortality between restrictive and liberal transfusion groups (RR = 1.07, 95% CI = 0.82–1.40, P = 0.62; RR = 0.89, 95% CI = 0.56–1.42, P = 0.62). However, restrictive transfusion tended to have a higher risk of in-hospital mortality compared with liberal transfusion (RR = 1.22, 95% CI = 1.00–1.50, P = 0.05). No secondary outcomes, including follow-up reinfarction, stroke, and acute heart failure, differed significantly between the two groups. In addition, subgroup analysis showed no differences in overall mortality between the two groups based on sample size and design.

Conclusion: Restrictive and liberal red blood cell transfusion have a similar effect on overall mortality and follow-up mortality in AMI patients with anemia. However, restrictive transfusion tended to have a higher risk of in-hospital mortality compared with liberal transfusion. The findings suggest that transfusion strategy should be further evaluated in future studies.

Minimally invasive posterior pedicle screw fixation versus open instrumentation in patients with thoracolumbar spondylodiscitis

BACKGROUND

Due to the aging society, the incidence of pyogenic spondylodiscitis is still rising. Although surgical treatment for spondylodiscitis in general is increasingly accepted, an optimal surgical strategy for treatment of pyogenic spinal infection has not yet been established. The aim of this study was to investigate the suitability of percutaneous posterior pedicle screw fixation for surgical treatment in patients with spondylodiscitis of the thoracolumbar spine.

METHODS

We conducted a retrospective review of a consecutive cohort of patients undergoing surgical treatment for spondylodiscitis of the thoracolumbar spine between January 2017 and December 2019. We assessed intraoperative and clinical data, comparing for the classic open and the percutaneous approach. In total, we analyzed 125 cases (39 female, 86 male). The mean age was 69.49 years ± 12.63 years.

RESULTS

Forty-seven (37.6%) patients were operated on by a percutaneous approach for pedicle screw fixation, and 78 (62.4%) received open surgery. There was no significant difference in the mean age of patients between both groups (p= 0.57). The time of surgery for percutaneous fixation was statistically significantly shorter (p= 0.03). Furthermore, the estimated intraoperative blood loss was significantly lower in the minimally invasive group (p < 0.001). No significant difference could be observed regarding the recurrence rate of spondylodiscitis and the occurrence of surgical site infections (p= 0.2 and 0.5, respectively).

CONCLUSION

Percutaneous posterior pedicle screw fixation appears to be a feasible option for the surgical treatment of a selected patient group with spondylodiscitis of the thoracic and lumbar spine.

Systematic reviews and meta-analyses comparing mortality in restrictive and liberal haemoglobin thresholds for red cell transfusion: an overview of systematic reviews

BACKGROUND

There are no overviews of systematic reviews investigating haemoglobin thresholds for transfusion. This is important as the literature on transfusion thresholds has grown considerably in recent years. Our aim was to synthesise evidence from systematic reviews and meta-analyses of the effects of restrictive and liberal transfusion strategies on mortality.

METHODS

This was a systematic review of systematic reviews (overview). We searched MEDLINE, Embase, Web of Science Core Collection, PubMed, Google Scholar, and the Joanna Briggs Institute EBP Database, from 2008 to 2018. We included systematic reviews and meta-analyses of randomised controlled trials comparing mortality in patients assigned to red cell transfusion strategies based on haemoglobin thresholds. Two independent reviewers extracted data and assessed methodological quality. We assessed the methodological quality of included reviews using AMSTAR 2 and the quality of evidence pooled using an algorithm to assign GRADE levels.

RESULTS

We included 19 systematic reviews reporting 33 meta-analyses of mortality outcomes from 53 unique randomised controlled trials. Of the 33 meta-analyses, one was graded as high quality, 15 were moderate, and 17 were low. Of the meta-analyses presenting high- to moderate-quality evidence, 12 (75.0%) reported no statistically significant difference in mortality between restrictive and liberal transfusion groups and four (25.0%) reported significantly lower mortality for patients assigned to a restrictive transfusion strategy. We found few systematic reviews addressed clinical differences between included studies: variation was observed in haemoglobin threshold concentrations, the absolute between group difference in haemoglobin threshold concentration, time to randomisation (resulting in transfusions administered prior to randomisation), and transfusion dosing regimens.

CONCLUSIONS

Meta-analyses graded as high to moderate quality indicate that in most patient populations no difference in mortality exists between patients assigned to a restrictive or liberal transfusion strategy.

TRIAL REGISTRATION

PROSPERO CRD42019120503.

Liberal Transfusion versus Restrictive Transfusion and Outcomes in Critically Ill Adults: A Meta-Analysis

Objective

We aimed to determine whether the restrictive red-cell transfusion strategy was superior to the liberal one in reducing all-cause mortality in critically ill adults.

Methods

The MEDLINE, EMBASE, PubMed, Web of Science, and Cochrane Library Central Register of Controlled Trials databases were searched from inception to January 2019 to identify meta-analyses or systematic reviews and published randomized controlled trials which were restrictive versus liberal blood transfusion with mortality as the endpoint in critically ill adults. We used two search routes whereby one search was restricted to systematic reviews, reviews, or meta-analysis, and the other was not restricted. There were no date restrictions, but language was limited to English and the population was restricted to critically ill adults. The data of study methods, participant characteristics, and outcomes were extracted and analyzed independently by 2 reviewers. The main outcome was all-cause mortality.

Results

Through screening the obtained records, we enrolled 7 randomized clinical trials that included information on restrictive versus liberal red-cell transfusion and mortality of intensive care unit (ICU) patients. Involving a total of 7,363 ICU adult patients, ICU mortality (risk ratio [RR] 0.82, 95% confidence interval [CI] 0.62, 1.08, p = 0.15), 28/30-day mortality (RR 0.98, 95% CI 0.84, 1.13, p = 0.74), 60-day mortality (RR 1.01, 95% CI 0.87, 1.16, p = 0.91), 90-day mortality (RR 1.02, 95% CI 0.92, 1.14, p = 0.69), 120-day mortality (RR 1.29, 95% CI 0.67, 2.47, p = 0.44), and 180-day mortality (RR 0.91, 95% CI 0.75, 1.12, p = 0.38) were not statistically significantly different when the restrictive transfusion strategy was compared with the liberal transfusion strategy. However, we surprisingly discovered that 112 out of 469 (24%) patients who received a unit RBC transfusion when hemoglobin was less than 7 g/dL, and 142 out of 469 (30.3%) who received a unit of RBC transfused with hemoglobin less than 9 g/dL, had died during hospitalization (RR 0.79, 95% CI 0.64, 0.97, p = 0.03). The results showed that the restrictive transfusion strategy could decrease in-hospital mortality compared with the liberal transfusion strategy. It was safe to utilize a restrictive transfusion threshold of less than 7 g/dL in stable critically ill adults.

Conclusions

In this study, we found that the restrictive red-cell transfusion strategy potentially reduced in-hospital mortality in critically ill adults with anemia compared with the liberal strategy.

Restrictive versus liberal strategy for red blood-cell transfusion in hip fracture patients: A systematic review and meta-analysis

BACKGROUND

Most clinical guidelines recommend a restrictive red-blood-cell (RBC) transfusion threshold. However, indications for transfusion in patients with a hip fracture have not been definitively evaluated or remain controversial. We compared the pros and cons of restrictive versus liberal transfusion strategies in patients undergoing hip fracture surgery.

METHODS

Electronic databases were searched to identify randomized controlled trials (RCTs) and retrospective cohort studies (RCSs) to investigate the effects of a restrictive strategy versus its liberal counterpart in patients undergoing hip fracture surgery. The main clinical outcomes included delirium, mortality, infections, cardiogenic complications, thromboembolic events, cerebrovascular accidents, and length of hospital stay. The meta-analysis program of the Cochrane Collaboration (RevMan version 5.3.0) was used for data analysis. Statistical heterogeneity was assessed by both Cochran chi-squared test (Q test) and I test. Both Begg and Egger tests were used to assess potential publication bias.

RESULTS

We identified 7 eligible RCTs and 2 eligible RCSs, involving 3,575 patients in total. In patients undergoing hip fracture surgery, we found no differences in frequency of delirium, mortality, the incidence rates of all infections, pneumonia, wound infection, all cardiovascular events, congestive heart failure, thromboembolic events or length of hospital stay between restrictive and liberal thresholds for RBC transfusion (P >.05). However, we found that the use of restrictive transfusion thresholds is associated with higher rates of acute coronary syndrome (P <.05) while liberal transfusion thresholds increase the risk of cerebrovascular accidents (P <.05).

CONCLUSION

In patients undergoing hip fracture surgery, clinicians should evaluate the patient's condition in detail and adopt different transfusion strategies according to the patient's specific situation rather than merely using a certain transfusion strategy.