Restrictive vs liberal blood transfusion strategy in patients with symptomatic coronary artery disease: meta-analysis from randomized controlled trials

Abstract

\n \n \n Anemia is common in patients with symptomatic coronary artery disease. Observational studies investigated blood transfusion threshold in symptomatic coronary artery disease but results were conflicting. Meta-analyses evaluating transfusion threshold utilized data mainly from observational trials but no meta-analysis, to our knowledge, used data solely from randomized clinical trials.\n \n \n \n The goal of our study is to evaluate efficacy and safety outcomes in anemic patients presenting with symptomatic coronary artery disease using pooled data from randomized clinical trials.\n \n \n \n We queried Medline, Embase and Cochrane data bases for randomized clinical trials comparing restrictive blood transfusion (defined as transfusion when hemoglobin is less than 8 gm/dl) vs liberal blood transfusion (transfusion when hemoglobin is less than 10 gm/dl) in patients presenting with symptomatic artery disease or acute coronary syndrome. We identified 3 randomized controlled trials; MINT, CRIT and REALITY trials. Data were pooled from 3 trials. Efficacy outcomes evaluated were all-cause mortality and New or recurrent myocardial infarction. Safety outcomes were congestive heart failure at 30-day follow up.\n \n \n \n A total of 820 patients were included in our meta-analysis; 420 patients in restrictive blood transfusion protocol and 400 in liberal blood transfusion protocol\n There was no difference between two groups at 30-day follow up in all identified outcomes (all-cause mortality, new or recurrent myocardial infarction, and Congestive heart failure).\n 55 patients died (22/420 in restrictive group and 33/400 in liberal group). Risk ratio of all-cause mortality in restrictive group was 0.63 [95% CI (0.38–1.07), P=0.09, I2=30%].\n 15/420 in restrictive group and 16/400 in liberal group had new or recurrent myocardial infarction. Risk ratio of myocardial infarction in restrictive group was 0.91 [95% CI (0.46–1.80), P=0.78, I2=0%].\n 20/420 patients in restrictive group and 24/400 in liberal group had congestive heart failure with risk ratio of 0.80 [95% CI (0.19–3.37), P=0.30, I2=76%] in restrictive group.\n \n \n \n Our meta-analysis showed similar outcomes between restrictive and liberal transfusion policies in patients presenting with symptomatic coronary artery disease of acute myocardial infarction. Our findings are consistent with available data about restricting transfusion in general population. Restricting blood transfusion might be cost-effective. Further studies are warranted to evaluate long term safety and efficacy of such approach.\n \n \n \n Type of funding sources: None.\n