Restrictive or Liberal Red-Cell Transfusion for Cardiac Surgery

TLDR

The study investigated whether a restrictive red‑cell transfusion threshold (hemoglobin < 7.5 g/dL) is noninferior to a liberal threshold (hemoglobin < 9.5 g/dL in OR/ICU or < 8.5 g/dL in ward) for clinical outcomes in moderate‑to‑high risk cardiac surgery patients. In a multicenter, open‑label, noninferiority trial of 5,243 adults with EuroSCORE I ≥ 6, patients were randomized to the two thresholds and followed for a composite outcome of death, myocardial infarction, stroke, or new‑onset renal failure with dialysis by discharge or day 28, plus secondary outcomes. The restrictive strategy met noninferiority, with the composite outcome occurring in 11.4 % versus 12.5 % (OR 0.90, 95 % CI 0.76–1.07), mortality 3.0 % versus 3.6 %, and transfusion 52.3 % versus 72.6 %, and no significant differences in other secondary outcomes. The trial was funded by the Canadian Institutes of Health Research and others and registered as TRICS III (ClinicalTrials.gov NCT020.

Abstract

The effect of a restrictive versus liberal red-cell transfusion strategy on clinical outcomes in patients undergoing cardiac surgery remains unclear.In this multicenter, open-label, noninferiority trial, we randomly assigned 5243 adults undergoing cardiac surgery who had a European System for Cardiac Operative Risk Evaluation (EuroSCORE) I of 6 or more (on a scale from 0 to 47, with higher scores indicating a higher risk of death after cardiac surgery) to a restrictive red-cell transfusion threshold (transfuse if hemoglobin level was <7.5 g per deciliter, starting from induction of anesthesia) or a liberal red-cell transfusion threshold (transfuse if hemoglobin level was <9.5 g per deciliter in the operating room or intensive care unit [ICU] or was <8.5 g per deciliter in the non-ICU ward). The primary composite outcome was death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis by hospital discharge or by day 28, whichever came first. Secondary outcomes included red-cell transfusion and other clinical outcomes.The primary outcome occurred in 11.4% of the patients in the restrictive-threshold group, as compared with 12.5% of those in the liberal-threshold group (absolute risk difference, -1.11 percentage points; 95% confidence interval [CI], -2.93 to 0.72; odds ratio, 0.90; 95% CI, 0.76 to 1.07; P<0.001 for noninferiority). Mortality was 3.0% in the restrictive-threshold group and 3.6% in the liberal-threshold group (odds ratio, 0.85; 95% CI, 0.62 to 1.16). Red-cell transfusion occurred in 52.3% of the patients in the restrictive-threshold group, as compared with 72.6% of those in the liberal-threshold group (odds ratio, 0.41; 95% CI, 0.37 to 0.47). There were no significant between-group differences with regard to the other secondary outcomes.In patients undergoing cardiac surgery who were at moderate-to-high risk for death, a restrictive strategy regarding red-cell transfusion was noninferior to a liberal strategy with respect to the composite outcome of death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis, with less blood transfused. (Funded by the Canadian Institutes of Health Research and others; TRICS III ClinicalTrials.gov number, NCT02042898 .) ).