Abstract

OBJECTIVE To estimate the relative risks of death, myocardial infarction, stroke, and renal failure or dysfunction between antifibrinolytics and no treatment following the suspension of aprotinin from the market in 2008 for safety reasons and its recent reintroduction in Europe and Canada. DESIGN Systematic review and network meta-analysis. DATA SOURCES A Cochrane review of antifibrinolytic treatments was chosen as the starting point for this systematic review. Medline, Embase, and the Cochrane register of trials were searched with no date restrictions for observational evidence. STUDY SELECTION Propensity matched or adjusted observational studies with two or more of the interventions of interest (aprotinin, tranexamic acid, epsilon-aminocaproic acid, and no treatment) that were carried out in patients undergoing cardiac surgery. DATA ANALYSIS Network meta-analysis was used to compare treatments, and odds ratios with 95% credible intervals were estimated. Meta-analyses were carried out for randomised controlled trials alone and for randomised controlled trials with observational studies. RESULTS 106 randomised controlled trials and 11 observational studies (43 270 patients) were included. Based on the results from analysis of randomised controlled trials, tranexamic acid was associated on average with a reduced risk of death compared with aprotinin (odds ratio 0.64, 95% credible interval 0.41 to 0.99). When observational data were incorporated, comparisons showed an increased risk of mortality with aprotinin on average relative to tranexamic acid (odds ratio 0.71, 95% credible interval 0.50 to 0.98) and epsilon-aminocaproic acid (0.60, 0.43 to 0.87), and an increased risk of renal failure or dysfunction on average relative to all comparators: odds ratio 0.66 (95% credible interval 0.45 to 0.88) compared with no treatment, 0.66 (0.48 to 0.91) versus tranexamic acid, and 0.65 (0.45 to 0.88) versus epsilon-aminocaproic acid. CONCLUSION Although meta-analyses of randomised controlled trials were largely inconclusive, inclusion of observational data suggest concerns remain about the safety of aprotinin. Tranexamic and epsilon-aminocaproic acid are effective alternatives that may be safer for patients.

Abstract

CONTEXT Even though red blood cells (RBCs) are lifesaving in neonatal intensivecare, transfusing older RBCs may result in higher rates of organ dysfunction,nosocomial infection, and length of hospital stay. OBJECTIVE To determine if RBCs stored for 7 days or less compared with usual standards decreased rates ofmajor nosocomial infection and organ dysfunction in neonatal intensive care unitpatients requiring at least 1 RBC transfusion. DESIGN, SETTING, AND PARTICIPANTS Double-blind, randomized controlled trial in 377 premature infants with birthweights less than 1250 g admitted to 6 Canadian tertiary neonatal intensive careunits between May 2006 and June 2011. INTERVENTION Patients were randomlyassigned to receive transfusion of RBCs stored 7 days or less (n = 188) vsstandard-issue RBCs in accordance with standard blood bank practice (n = 189). MAIN OUTCOME MEASURES The primary outcome was a composite measure of majorneonatal morbidities, including necrotizing enterocolitis, retinopathy ofprematurity, bronchopulmonary dysplasia, and intraventricular hemorrhage, as wellas death. The primary outcome was measured within the entire period of neonatalintensive care unit stay up to 90 days after randomization. The rate ofnosocomial infection was a secondary outcome. RESULTS The mean age of transfusedblood was 5.1 (SD, 2.0) days in the fresh RBC group and 14.6 (SD, 8.3) days inthe standard group. Among neonates in the fresh RBC group, 99 (52.7%) had theprimary outcome compared with 100 (52.9%) in the standard RBC group (relativerisk, 1.00; 95% CI, 0.82-1.21). The rate of clinically suspected infection in thefresh RBC group was 77.7% (n = 146) compared with 77.2% (n = 146) in the standardRBC group (relative risk, 1.01; 95% CI, 0.90-1.12), and the rate of positivecultures was 67.5% (n = 127) in the fresh RBC group compared with 64.0% (n = 121)in the standard RBC group (relative risk, 1.06; 95% CI, 0.91-1.22). CONCLUSION In this trial, the use of fresh RBCs compared with standard blood bank practicedid not improve outcomes in premature, very low-birth-weight infants requiring atransfusion. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00326924;Current Controlled Trials Identifier: ISRCTN65939658.

Abstract

Despite recent trends in decreasing transfusion thresholds and the development of technologies designed to avoid allogeneic exposure, allogeneic red blood cell (RBC) transfusions remain an important supportive and life-saving measure for neonatal intensive care patients experiencing illness and anemia. Reluctantly, a number of laboratory and observational studies have indicated that the amount of time RBCs are stored can affect oxygen delivery to tissues. Consequently, older RBCs may result in higher rates of organ dysfunction, nosocomial infection, and lengths of stay. Because of such harmful effects, an evaluation of the association between age of blood and nosocomial infection and organ dysfunction is warranted. The aim of the study was to determine if RBCs stored for 7 days or less (fresh RBCs) compared to current standard transfusion practice decreases major nosocomial infection and organ dysfunction in neonates admitted to the neonatal intensive care unit and requiring at least one RBC transfusion. This study is a double-blind, multicenter, randomized controlled trial design. The trial will be an effectiveness study evaluating the effectiveness of stored vs fresh RBCs in neonates requiring transfusion. Neonatal patients requiring at least one unit of RBCs will be randomized to receive either (1) RBCs stored no longer than 7 days or (2) standard practice. The study was conducted in Canadian university-affiliated level III (tertiary) neonatal intensive care units. The primary outcome for this study will be a composite measure of major neonatal morbidities (necrotizing enterocolitis, retinopathy of prematurity, bronchopulmonary dysplasia, intraventricular hemorrhage, and mortality). Secondary outcomes include individual items of the composite measure and nosocomial infection (bacteremia, septic shock, and pneumonia). The sample size calculations have been estimated based on the formula for 2 independent proportions using an alpha of . 05, a (1-beta) of . 80, and a 10% noncompliance factor. The baseline rate for our composite measure is estimated to be 65% as indicated by the literature. Assuming a 15% absolute risk reduction with the use of RBCs stored 7 days or less, our estimated total sample size required will be 450 (225 patients per treatment arm). The Age of Red Blood Cells in Premature Infants (ARIPI) trial is registered at the US National Institutes of Health (ClinicalTrials. gov) no. NCT00326924 and current controlled trials ISRCTN65939658.

Abstract

BACKGROUND Aprotinin is a serine protease inhibitor used to limit perioperative bleeding and reduce the need for donated blood transfusions during cardiac surgery. Randomized controlled trials of aprotinin evaluating its effect on the outcome of perioperative transfusion have been published since 1987, and systematic reviews were conducted in 1992 and 1997. METHODS A systematic search was conducted for all RCTs of aprotinin that used placebo controls or were open-label with no active control treatment. Data collected included the primary outcome, objective of each study, whether a systematic review was cited or conducted as part of the background and/or rationale for the study and the number of previously published RCTs cited. Cumulative meta-analyses were performed. RESULTS Sixty-four randomized, controlled trials of aprotinin were found, conducted between 1987 and 2002, reporting an endpoint of perioperative transfusion. Median trial size was 64 subjects, with a range of 20 to 1784. A cumulative meta-analysis indicated that aprotinin greatly decreased the need for perioperative transfusion, stabilizing at an odds ratio of 0.25 (p < 10 - 6) by the 12th study, published in June of 1992. The upper limit of the confidence interval never exceeded 0.65 and results were similar in all subgroups. Citation of previous RCTs was extremely low, with a median of 20% of prior trials cited. Only 7 of 44 (15%) of subsequent reports referenced the largest trial (N = 1784), which was 28 times larger than the median trial size. CONCLUSIONS This study demonstrates that investigators evaluating aprotinin were not adequately citing previous research, resulting in a large number of RCTs being conducted to address efficacy questions that prior trials had already definitively answered. Institutional review boards and journals could reduce the number of redundant trials by requiring investigators to conduct adequate searches for prior evidence and conducting systematic reviews.