A liberal strategy of red blood cell transfusion reduces cardiogenic shock in elderly patients undergoing cardiac surgery

OBJECTIVE: The aim of this study was to compare outcomes in patients undergoing cardiac surgery who are aged 60 years or more or less than 60 years after implementation of a restrictive or a liberal transfusion strategy. METHODS: This is a substudy of the Transfusion Requirements After Cardiac Surgery (TRACS) randomized controlled trial. In this subgroup analysis, we separated patients into those aged 60 years or more (elderly) and those aged less than 60 years randomized to a restrictive or a liberal strategy of red blood cell transfusion. The primary outcome was a composite defined as a combination of 30-day all-cause mortality and severe morbidity. RESULTS: Of the 502 patients included in the Transfusion Requirements After Cardiac Surgery study, 260 (51.8%) were aged 60 years or more and 242 (48.2%) were aged less than 60 years and were included in this study. The primary end point occurred in 11.9% of patients in the liberal strategy group and 16.8% of patients in the restrictive strategy group (P = .254) for those aged 60 years or more and in 6.8% of patients in the liberal strategy group and 5.6% of patients in the restrictive strategy group for those aged less than 60 years (P = .714). However, in the older patients, cardiogenic shock was more frequent in patients in the restrictive transfusion group (12.8% vs 5.2%, P = .031). Thirty-day mortality, acute respiratory distress syndrome, and acute renal injury were similar in the restrictive and liberal transfusion groups in both age groups. CONCLUSIONS: Although there was no difference between groups regarding the primary outcome, a restrictive transfusion strategy may result in an increased rate of cardiogenic shock in elderly patients undergoing cardiac surgery compared with a more liberal strategy. Cardiovascular risk of anemia may be more harmful than the risk of blood transfusion in older patients.