Isn't it about time we learned how to use blood transfusion in patients with ischemic heart disease?

Effect of a Restrictive vs Liberal Blood Transfusion Strategy on Major Cardiovascular Events Among Patients With Acute Myocardial Infarction and Anemia: The REALITY Randomized Clinical Trial

IMPORTANCE

The optimal transfusion strategy in patients with acute myocardial infarction and anemia is unclear.

OBJECTIVE

To determine whether a restrictive transfusion strategy would be clinically noninferior to a liberal strategy.

DESIGN, SETTING, AND PARTICIPANTS

Open-label, noninferiority, randomized trial conducted in 35 hospitals in France and Spain including 668 patients with myocardial infarction and hemoglobin level between 7 and 10 g/dL. Enrollment could be considered at any time during the index admission for myocardial infarction. The first participant was enrolled in March 2016 and the last was enrolled in September 2019. The final 30-day follow-up was accrued in November 2019.

INTERVENTIONS

Patients were randomly assigned to undergo a restrictive (transfusion triggered by hemoglobin ≤8; n = 342) or a liberal (transfusion triggered by hemoglobin ≤10 g/dL; n = 324) transfusion strategy.

MAIN OUTCOMES AND MEASURES

The primary clinical outcome was major adverse cardiovascular events (MACE; composite of all-cause death, stroke, recurrent myocardial infarction, or emergency revascularization prompted by ischemia) at 30 days. Noninferiority required that the upper bound of the 1-sided 97.5% CI for the relative risk of the primary outcome be less than 1.25. The secondary outcomes included the individual components of the primary outcome.

RESULTS

Among 668 patients who were randomized, 666 patients (median [interquartile range] age, 77 [69-84] years; 281 [42.2%] women) completed the 30-day follow-up, including 342 in the restrictive transfusion group (122 [35.7%] received transfusion; 342 total units of packed red blood cells transfused) and 324 in the liberal transfusion group (323 [99.7%] received transfusion; 758 total units transfused). At 30 days, MACE occurred in 36 patients (11.0% [95% CI, 7.5%-14.6%]) in the restrictive group and in 45 patients (14.0% [95% CI, 10.0%-17.9%]) in the liberal group (difference, -3.0% [95% CI, -8.4% to 2.4%]). The relative risk of the primary outcome was 0.79 (1-sided 97.5% CI, 0.00-1.19), meeting the prespecified noninferiority criterion. In the restrictive vs liberal group, all-cause death occurred in 5.6% vs 7.7% of patients, recurrent myocardial infarction occurred in 2.1% vs 3.1%, emergency revascularization prompted by ischemia occurred in 1.5% vs 1.9%, and nonfatal ischemic stroke occurred in 0.6% of patients in both groups.

CONCLUSIONS AND RELEVANCE

Among patients with acute myocardial infarction and anemia, a restrictive compared with a liberal transfusion strategy resulted in a noninferior rate of MACE after 30 days. However, the CI included what may be a clinically important harm.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02648113.

Restrictive vs liberal red blood cell transfusion strategies in patients with acute myocardial infarction and anemia: Rationale and design of the REALITY trial

Background

Anemia is common in patients with acute myocardial infarction (AMI), and is an independent predictor of mortality. The optimal transfusion strategy in these patients is unclear.

Hypothesis

We hypothesized that a “restrictive” transfusion strategy (triggered by hemoglobin ≤8 g/dL) is clinically noninferior to a “liberal” transfusion strategy (triggered by hemoglobin ≤10 g/dL), but is less costly.

Methods

REALITY is an international, randomized, multicenter, open‐label trial comparing a restrictive vs a liberal transfusion strategy in patients with AMI and anemia. The primary outcome is the incremental cost‐effectiveness ratio (ICER) at 30 days, using the primary composite clinical outcome of major adverse cardiovascular events (MACE; comprising all‐cause death, nonfatal stroke, nonfatal recurrent myocardial infarction, or emergency revascularization prompted by ischemia) as the effectiveness criterion. Secondary outcomes include the ICER at 1 year, and MACE (and its components) at 30 days and at 1 year.

Results

The trial aimed to enroll 630 patients. Based on estimated event rates of 11% in the restrictive group and 15% in the liberal group, this number will provide 80% power to demonstrate clinical noninferiority of the restrictive group, with a noninferiority margin corresponding to a relative risk equal to 1.25. The sample size will also provide 80% power to show the cost‐effectiveness of the restrictive strategy at a threshold of €50 000 per quality‐adjusted life year.

Conclusions

REALITY will provide important guidance on the management of patients with AMI and anemia.

Assessing productive efficiency and operating scale of community blood centers

BACKGROUND

In recent years demand for blood products has decreased, and as a result, the blood product marketplace has become much more competitive. Reducing inefficiency in the procurement and processing of blood products at blood centers can reduce costs while assuring that demand for blood products is met.

STUDY DESIGN AND METHODS

This study uses data envelopment analysis to compare the productive efficiency of 65 community blood centers to determine to what extent efficiency can be improved, what cost savings and increases in platelet (PLT) production may be obtained by eliminating inefficiency, and what scales of operation are the most efficient from a budgetary and staffing standpoint. Data were collected from the 2012 to 2013 AABB Directory of Community Blood Centers and Hospital Blood Banks.

RESULTS

The study found that 27 of 65 blood centers are efficient. The remaining 38 blood centers can reduce budget and staff levels and may be able to expand output. If inefficient centers were to eliminate all inefficiency, the total savings would be $671 million, approximately 20% of the aggregated budget ($3.45 billion) of all centers in the study. In addition, the centers would also see a 36% increase in PLT production. Inefficiency of some large blood centers stems from operating at too large a scale, while inefficiency of most small blood centers is scale independent.

CONCLUSION

The results suggest that reducing inefficiency in blood procurement may be a good strategy to maximize competitiveness in the blood product marketplace. These findings further suggest that the trend of blood center consolidation may be ill advised from a cost containment perspective.

An evidence-based approach to red blood cell transfusions in asymptomatically anaemic patients

INTRODUCTION

Surgeons and physicians encounter blood transfusions on a daily basis but a robust evidence-based strategy on indications and timing of transfusion in asymptomatic anaemic patients is yet to be determined. For judicious use of blood products, the risks inherent to packed red blood cells, the patient's co-morbidities and haemoglobin (Hb)/haematocrit levels should be considered. This review critiques and summarises the latest available evidence on the indications for transfusions in healthy and cardiac disease patients as well as the timing of transfusions relative to surgery.

METHODS

An electronic literature search of the MEDLINE(®), Google Scholar™ and Trip databases was conducted for articles published in English between January 2006 and January 2015. Studies discussing timing and indications of transfusion in medical and surgical patients were retrieved. Bibliographies of studies were checked for other pertinent articles that were missed by the initial search.

FINDINGS

Six level 1 studies (randomised controlled trials or systematic reviews) and six professional society guidelines were included in this review. In healthy patients without cardiac disease, a restrictive transfusion trigger of Hb 70-80g/l is safe and appropriate whereas in cardiac patients, the trigger is Hb 80-100g/l. The literature on timing of transfusions relative to surgery is limited. For the studies available, preoperative transfusions were associated with a decreased incidence of subsequent transfusions and timing of transfusions did not affect the rates of colorectal cancer recurrence.