Abstract

AIM: To characterize the association between diabetes and transfusion and clinical outcomes in cardiac surgery, and to evaluate whether restrictive transfusion thresholds are harmful in these patients. MATERIALS AND METHODS The multinational, open-label, randomized controlled TRICS-III trial assessed a restrictive transfusion strategy (hemoglobin [Hb] transfusion threshold <75 g/L) compared to a liberal strategy (Hb <95 g/L for operating room or ICU; or < 85 g/L for ward) in patients undergoing cardiac surgery on cardiopulmonary bypass with a moderate-to-high risk of death (EuroSCORE ≥6). Diabetes status was collected preoperatively. The primary composite outcome was all-cause death, stroke, myocardial infarction, and new-onset renal failure requiring dialysis at 6 months. Secondary outcomes included components of the composite outcome at 6 months, and transfusion and clinical outcomes at 28 days. RESULTS Of the 5092 patients analyzed, 1396 (27.4%) had diabetes (Restrictive: n = 679, Liberal n = 717). Patients with diabetes had more cardiovascular disease than patients without diabetes. Neither the presence of diabetes (OR [95%CI]1.10[0.93-1.31]) or the restrictive strategy increased the risk for the primary composite outcome (diabetes OR [95%CI]1.04[0.68-1.59] vs. no diabetes OR 1.02[0.85-1.22],p(interaction) = 0.92). In patients with versus without diabetes, a restrictive transfusion strategy was more effective at reducing red blood cell transfusion (diabetes OR [95%CI] 0.28[0.21-0.36]; no diabetes OR [95%CI] 0.40[0.35-0.47];p(interaction) = 0.04). CONCLUSIONS The presence of diabetes did not modify the effect of a restrictive transfusion strategy on the primary composite outcome, but improved its efficacy on red cell transfusion. Restrictive transfusion triggers are safe and effective in patients with diabetes undergoing cardiac surgery. This article is protected by copyright. All rights reserved.

Abstract

BACKGROUND -Cardiac surgery is frequently complicated by coagulopathic bleeding that is difficult to optimally manage using standard hemostatic testing. We hypothesized that point-of-care hemostatic testing within the context of an integrated transfusion algorithm would improve the management of coagulopathy in cardiac surgery and thereby reduce blood transfusions. METHODS -We conducted a pragmatic multi-centered stepped-wedge cluster randomized controlled trial of a POC-based transfusion algorithm in consecutive patients undergoing cardiac surgery with cardiopulmonary bypass at 12 hospitals from Oct 6, 2014 to May 1, 2015. Following a 1-month data collection at all participating hospitals, a transfusion algorithm incorporating point-of-care hemostatic testing was sequentially implemented at 2 hospitals at a time in 1-month intervals, with the implementation order randomly assigned. No other aspects of care were modified. The primary outcome was red cell transfusion from surgery to postoperative day seven. Other outcomes included transfusion of other blood products, major bleeding, and major complications. The analysis adjusted for secular time-trends, within-hospital clustering, and patient-level risk factors. All outcomes and analyses were pre-specified before study initiation. RESULTS -Among the 7402 patients studied, 3555 underwent surgery during the control phase and 3847 during the intervention phase. Overall, 3329 (45.0%) received red cells, 1863 (25.2%) received platelets, 1645 (22.2%) received plasma, and 394 (5.3%) received cryoprecipitate. Major bleeding occurred in 1773 (24.1%) patients and major complications occurred in 740 (10.2%) patients. The trial intervention reduced rates of red cell transfusion (adjusted relative risk [RR], 0.91; 95% CI, 0.85 to 0.98; P = 0.02; Number needed to treat [NNT] 24.7), platelet transfusion (RR, 0.77; 95% CI, 0.68 to 0.87; P < 0.001; NNT 16.7), and major bleeding (RR, 0.83; 95% CI, 0.72 to 0.94; P = 0.004; NNT 22.6), but had no effect on other blood product transfusions or major complications. CONCLUSIONS -Implementation of point-of-care hemostatic testing within the context of an integrated transfusion algorithm reduces red cell transfusions, platelet transfusions, and major bleeding following cardiac surgery. Our findings support the broader adoption of point-of-care hemostatic testing into clinical practice. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT02200419.

Abstract

INTRODUCTION : Acute kidney injury (AKI) is a serious complication of cardiac surgery, and preoperative anemia and perioperative erythrocyte transfusion are important risk factors. Prophylactic erythrocyte transfusion in anemic patients may, therefore, protect against AKI. METHODS : In this unblinded, parallel-group, randomized pilot trial, 60 anemic patients (hemoglobin 10-12 g/dL) undergoing cardiac surgery with cardiopulmonary bypass were randomized (1: 1) to prophylactic transfusion (2 units of erythrocytes transfused 1 to 2 days before surgery (n = 29) or standard of care (transfusions as indicated; n = 31). Between-group differences in severity of perioperative anemia, transfusion, and AKI (more than 25% drop in estimated glomerular filtration rate) were measured. The relationships between transfusion, iron levels, and AKI were also measured. RESULTS : Perioperative anemia and erythrocyte transfusions were lower in the prophylactic transfusion group--median (25th, 75th percentiles) for nadir hemoglobin was 8.3 (7.9, 9.1) versus 7.6 (6.9, 8.2) g/dL (P = 0.0008) and for transfusion was 0 (0, 2) versus 2 (1, 4) units (P = 0.0002)--but between-group AKI rates were comparable (11 patients per group). In 35 patients with iron studies, perioperative transfusions were directly related to postoperative transferrin saturation (correlation coefficient 0.6; P = 0.0002), and high (more than 80%) transferrin saturation was associated with AKI (5/5 vs. 8/30; P = 0.005), implicating transfusion-related iron overload as a cause of AKI. CONCLUSIONS : In anemic patients, prophylactic erythrocyte transfusion reduces perioperative anemia and erythrocyte transfusions, and may reduce plasma iron levels. Adequately powered studies assessing the effect of this intervention on AKI are warranted.