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

Abstract

BackgroundRed 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). MethodsWe 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. ResultsAmong 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). ConclusionsHF 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 RegistrationNCT02648113.