Liberal Versus Restrictive Red Blood Cell Transfusion Strategy in Acute Coronary Syndrome and Anemia: An Updated Systematic Review and Meta-Analysis

Sinda Hidri ¹ Wajeeh Ur Rehman ^2* Karam Gardezi ³ Jassim Zaheen Shah ⁴ Siddhartha Masetti ⁵ Naiela E Almansouri ⁶ Arslan Maan ⁷ Tirth Dave ⁸ Sumeja Catic ⁹ Simranjeet Singh Nagoke ¹⁰ Mohammad Ebad Ur Rehman ^11* Huzaifa Ahmad Cheema ¹² Adeel Ahmad ¹³ Raheel Ahmed ¹⁴ Abdelhamid Ben Selma ¹⁵ Mouhamed Amr Sabouni ¹⁶ Nabil Braiteh ¹⁷ Alon Yarkoni ¹⁸ Keyoor Patel ¹⁸ Afzal Ur Rehman ¹⁸

• ¹ Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States
• ² Department of Internal Medicine, United Health Services Hospital, Johnson City, United States
• ³ Department of Internal Medicine, T.J. Samson Community Hospital, Glasgow, United States
• ⁴ Hamad Medical Corporation, Doha, Qatar
• ⁵ Kingston Public Hospital, Kingston, Jamaica
• ⁶ Faculty of Medicine, University of Tripoli, Tripoli, Libya
• ⁷ St. Luke's Hospital, Chesterfield, United States
• ⁸ Bukovinian State Medical University, Chernivtsi, Ukraine
• ⁹ University of Zenica, Zenica, Bosnia and Herzegovina
• ¹⁰ Government Medical College (Jammu), Jammu, India
• ¹¹ Rawalpindi Medical College, Rawalpindi, Pakistan
• ¹² King Edward Medical University, Lahore, Punjab, Pakistan
• ¹³ Salem Hospital, Mass General Brigham, Salem, Massachusetts, United States
• ¹⁴ Heart Science, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, England, United Kingdom
• ¹⁵ United Health Services Hospital, Johnson City, United States
• ¹⁶ University of Alabama at Birmingham, Birmingham, Alabama, United States
• ¹⁷ MercyOne Siouxland Heart and Vascular Center, MercyOne Des Moines Medical Center, Sioux City, Iowa, United States
• ¹⁸ UHS Heart & Vascular Institute, United Health Services Hospital, Johnson City, United States

Background: It is uncertain whether a liberal red blood cell (RBC) transfusion strategy is superior to a restrictive approach in patients with acute coronary syndrome (ACS) and anemia.We searched MEDLINE, Embase, the Cochrane Library, and ClinicalTrials.gov from inception to April 2024 for randomized controlled trials (RCTs) comparing liberal and restrictive transfusion strategies in ACS patients with concurrent anemia.Results: Five RCTs (4510 patients) were included in this meta-analysis. There was no significant difference between the liberal and restrictive RBC transfusion strategy groups in the risk of major adverse cardiovascular events (MACE) (RR 0.91, 95% CI: 0.68 to 1.21; I 2 =63%) and all-cause mortality (RR 0.85, 95% CI: 0.72, 1.00; I 2 =0%). A liberal transfusion strategy reduced the risk of myocardial infarction (MI) (RR 0.80, 95% CI: 0.66, 0.98; I 2 =0%). There were no significant differences between the two strategies in the risk of revascularization, heart failure, stroke, cardiac mortality, acute kidney injury or failure, and pneumonia, bacteremia, or infection. Liberal transfusion increased the risk of acute lung injury (RR 8.97, 95% CI: 1.65, 48.65; I 2 =0%).Our meta-analysis demonstrated that a liberal RBC transfusion strategy reduced the risk of MI and increased the risk of acute lung injury but did not affect other clinical outcomes compared to a restrictive approach in patients with mainly acute MI and anemia. New large-scale multicenter RCTs are required to confirm or refute our findings and provide more reliable results.