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

Restrictive vs Liberal Blood Transfusions for Patients With Acute Myocardial Infarction and Anemia by Heart Failure Status: An RCT Subgroup Analysis

BACKGROUND

Red blood cell transfusion can cause fluid overload. We evaluated the interaction between heart failure (HF) at baseline and transfusion strategy on outcomes in acute myocardial infarction (AMI).

METHODS

We used data from the randomized REALITY trial. HF was defined as history of HF or Killip class > 1 at randomization. Primary outcome was major adverse cardiovascular events (MACE): composite of all-cause death, nonrecurrent AMI, stroke, or emergency revascularization prompted by ischemia at 30 days.

RESULTS

Among 658 randomized patients, 311 (47.3%) had HF. Patients with HF had higher rates of MACE at 30 days and 1 year and higher rates of nonfatal new-onset HF. There was no interaction between HF and effect of randomized assignment on the primary outcome or nonfatal new-onset HF. A liberal transfusion strategy was associated with increased all-cause death at 30 days and at 1 year in patients with HF (Pinteraction = 0.009 and P = 0.049, respectively). The main numerical difference in cause of death between restrictive and liberal strategies was death by HF at 30 days (4 vs 11).

CONCLUSIONS

HF is frequent in patients with AMI and anemia and is associated with higher risk of MACE (including all-cause death) and nonfatal new-onset HF. Although there was no interaction of HF with effect of transfusion strategy on MACE, a liberal transfusion strategy was associated with higher all-cause death that appears driven by a higher risk of early death caused by HF.

CLINICAL TRIAL REGISTRATION

NCT02648113.

Impact of transfusion strategy on platelet aggregation and biomarkers in myocardial infarction patients with anemia

BACKGROUND

Higher rates of thrombotic events have been reported in myocardial infarction (MI) patients requiring blood transfusion. The impact of blood transfusion strategy on thrombosis and inflammation is still unknown.

OBJECTIVE

To compare the impact of a liberal vs. a restrictive transfusion strategy on P2Y12 platelet reactivity and biomarkers in the multicentric randomized REALITY trial.

METHODS

Patients randomized to a liberal (hemoglobin ≤10 g/dL) or a restrictive (hemoglobin ≤8 g/dL) transfusion strategy had VASP-PRI platelet reactivity measured centrally in a blinded fashion and platelet reactivity unit (PRU) measured locally using encrypted VerifyNow; at baseline and after randomization. Biomarkers of thrombosis (P-selectin, PAI-1, vWF) and inflammation (TNF-α) were also measured. The primary endpoint was the change in the VASP-PRI (difference from baseline and post randomization) between the randomized groups.

RESULTS

A total of 100 patients randomized were included in this study (n = 50 in each group). Transfused patients received on average 2.4 ± 1.6 units of blood. We found no differences in change of the VASP PRI (difference 1.2% 95% CI (-10.3-12.7%)) or by the PRU (difference 13.0 95% CI (-21.8-47.8)) before and after randomization in both randomized groups. Similar results were found in transfused patients (n = 71) regardless of the randomized group, VASP PRI (difference 1.7%; 95% CI (-9.5-1.7%)) or PRU (difference 27.0; 95% CI (-45.0-0.0)). We did not find an impact of transfusion strategy or transfusion itself in the levels of P-selectin, PAI-1, vWF, and TNF-α.

CONCLUSION

In this study, we found no impact of a liberal vs. a restrictive transfusion strategy on platelet reactivity and biomarkers in MI patients with anemia. A conclusion that should be tempered due to missing patients with exploitable biological data that has affected our power to show a difference.

Economic evaluation of restrictive vs. liberal transfusion strategy following acute myocardial infarction (REALITY): trial-based cost-effectiveness and cost-utility analyses

AIMS

To estimate the cost-effectiveness and cost-utility ratios of a restrictive vs. liberal transfusion strategy in acute myocardial infarction (AMI) patients with anaemia.

METHODS AND RESULTS

Patients (n = 666) with AMI and haemoglobin between 7-8 and 10 g/dL recruited in 35 hospitals in France and Spain were randomly assigned to a restrictive (n = 342) or a liberal (n = 324) transfusion strategy with 1-year prospective collection of resource utilization and quality of life using the EQ5D3L questionnaire. The economic evaluation was based on 648 patients from the per-protocol population. The outcomes were 30-day and 1-year cost-effectiveness, with major adverse cardiovascular events (MACEs) averted as the effectiveness outcome. and a 1-year cost-utility ratio.The 30-day incremental cost-effectiveness ratio was €33 065 saved per additional MACE averted with the restrictive vs. liberal strategy, with an 84% probability for the restrictive strategy to be cost-saving and MACE-reducing (i.e. dominant). At 1 year, the point estimate of the cost-utility ratio was €191 500 saved per quality-adjusted life year gained; however, the cumulated MACE was outside the pre-specified non-inferiority margin, resulting in a decremental cost-effectiveness ratio with a point estimate of €72 000 saved per additional MACE with the restrictive strategy.

CONCLUSION

In patients with AMI and anaemia, the restrictive transfusion strategy was dominant (cost-saving and outcome-improving) at 30 days. At 1 year, the restrictive strategy remained cost-saving, but clinical non-inferiority on MACE was no longer maintained.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02648113.

ONE SENTENCE SUMMARY

The use of a restrictive transfusion strategy in patients with acute myocardial infarction is associated with lower healthcare costs, but more evidence is needed to ascertain its long-term clinical impact.

Treatment of acute upper gastrointestinal bleeding occurred after percutaneous coronary intervention for acute myocardial infarction in patients with acute renal impairment: a case report

Upper gastrointestinal (UGI) bleeding after percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) in ordinary patients is a common complication and poses a dilemma for clinical doctors to treat. In patients with renal impairment, that is more difficult and has rarely been reported. This case report involves an 82-year-old man who received regular hemodialysis and underwent PCI for acute inferior wall ST-segment elevation myocardial infarction. On the third day after PCI, the patient developed acute UGI bleeding, and gastroscopy confirmed that he had developed compound gastroduodenal ulcers (active stage) with hyperemia of the surrounding mucosa. After fasting, blood transfusion, acid inhibition, gastric protection and symptomatic support treatment, the patient’s UGI bleeding remained uncontrolled. Finally, upper gastrointestinal bleeding was stopped by empiric transcatheter arterial embolization (TAE). The patient’s condition was controlled through active treatment, and he was eventually discharged from the hospital. Bleeding complications after coronary stenting often present a dilemma, particularly in patients with renal impairment. Therefore, patients such as this should be thoroughly evaluated before any treatment. In the case of no obvious hemorrhagic spots found on endoscopic examination and failure of conservative medical treatment, empiric transcatheter arterial embolization TAE is a well-tolerated and effective treatment for UGI bleeding.

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.