Aprotinin use during cardiac surgery: recent alterations and effects on blood product utilization

Use of Aprotinin versus Tranexamic Acid in Cardiac Surgery Patients with High-Risk for Excessive Bleeding (APACHE) trial: a multicentre retrospective comparative non-randomized historical study

OBJECTIVES

Following the reintroduction of aprotinin into the European market, the French Society of Cardiovascular and Thoracic Anaesthesiologists recommended its prophylactic use at half-dose for high-risk cardiac surgery patients. We examined whether the use of aprotinin instead of tranexamic acid could significantly reduce severe perioperative bleeding.

METHODS

This multicentre, retrospective, historical study included cardiac surgery patients treated with aprotinin or tranexamic acid between December 2017 and September 2020. The primary efficacy end point was the severe or massive perioperative bleeding (class 3-4 of the universal definition of perioperative bleeding). The safety secondary end points included the occurrence of thromboembolic events and all-cause mortality within 30 days after surgery.

RESULTS

Among the 693 patients included in the study, 347 received aprotinin and 346 took tranexamic acid. The percentage of patients with severe or massive bleeding was similar in the 2 groups (42.1% vs 43.6%, Adjusted odds ratio [ORadj] = 0.87, 95% confidence interval: 0.62-1.23, P = 0.44), as was the perioperative need for blood products (81.0% vs 83.2%, ORadj = 0.75, 95% confidence interval: 0.48-1.17, P = 0.20). However, the median (Interquartile range) 12 h postoperative blood loss was significantly lower in the aprotinin group (383 ml [241-625] vs 450 ml [290-730], P < 0.01). Compared to tranexamic acid, the intraoperative use of aprotinin was associated with increased risk for thromboembolic events (adjusted Hazard ratio 2.30 [95% Cl: 1.06-5.30]; P = 0.04).

CONCLUSIONS

Given the modest reduction in blood loss at the expense of a significant increase in thromboembolic adverse events, aprotinin use in high-risk cardiac surgery patients should be based on a carefully considered benefit-risk assessment.

Antifibrinolytics and cardiac surgery: The past, the present, and the future

Cardiac surgery is usually associated with significant blood loss, which often necessitates blood transfusion. In order to decrease the risks associated with the latter, pharmacological as well as nonpharmacological strategies have been used to reduce blood loss. Among the pharmacological approaches, antifibrinolytic drugs are the mainstay. Aprotinin, which was the first ubiquitously used drug, fell into disrepute only to re-emerge after much debate. The decline of aprotinin paved the way for the lysine analogs. However, we must be aware with the side effects of these drugs as well as the dose modification required in special situations. Nonsaccharide glycosaminoglycans have been under investigation to overcome the drawbacks of the lysine analogs. It remains to be seen whether these drugs can replace the traditional antifibrinolytics.

The safety and efficacy of antifibrinolytic therapy in neonatal cardiac surgery

Background

Neonates undergoing open-heart surgery are particularly at risk of postoperative bleeding requiring blood transfusion. Aprotinin has attained high efficacy in reducing the requirement for a blood transfusion following a cardiopulmonary bypass, but is seldom studied in the neonatal age group. The aim of this study was to compare the efficacy and adverse effects of aprotinin and tranexamic acid in neonates undergoing open-heart surgery at a single centre.

Methods

Between October 2003 and March 2008, perioperative data of 552 consecutive neonatal patients undergoing open-heart surgery in Children’s Hospital Boston were reviewed. Among them, 177 did not receive antifibrinolytic therapy (Group A); 100 were treated with tranexamic acid only (Group B); and 275 patients received aprotinin with or without tranexamic acid (Group C). Except for antifibrinolytic therapy, the anaesthesiological and surgical protocols remained identical. Postoperative complications and in-hospital mortality were the primary study endpoints.

Results

Body weight and Risk Adjustment for Congenital Heart Surgery (RACHS-1) scores were statistically comparable among the three groups. No statistically significant differences were observed between the duration of hospitalization, chest tube drainage, reexploration for bleeding, and kidney function impairment. In Group C, less blood was transfused within 24 hours than in GroupB. Operative mortality was similar among the three groups.

Conclusion

No further risk and kidney injury were observed in the use of aprotinin in neonatal cardiac surgery, aprotinin demonstrated a reduced requirement for blood transfusion compared with tranexamic acid. Our data provide reasonable evidence that aprotinin and tranexamic acid are safe and efficacious as antifibrinolytic modalities in neonatal patients undergoing cardiac surgery.

Risks of harms using antifibrinolytics in cardiac surgery: systematic review and network meta-analysis of randomised and observational studies

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.

Aprotinin revisited

In 2008, we saw the withdrawal of aprotinin from the US markets after preliminary results from a large, randomized clinical trial in Canada. This drug, a potent antifibrinolytic, was used primarily in complex and/or redo cardiac surgery as an adjunct to decrease postoperative bleeding and complications. The Canadian study raised questions previously brought up in similar studies-does aprotinin increase the risk of mortality and renal failure after cardiac surgery? Recently, a re-review of the Canadian data noted flaws in the study, as well as in the interpretation of the results. The present review revisits the aprotinin controversy.

2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines

BACKGROUND

Practice guidelines reflect published literature. Because of the ever changing literature base, it is necessary to update and revise guideline recommendations from time to time. The Society of Thoracic Surgeons recommends review and possible update of previously published guidelines at least every three years. This summary is an update of the blood conservation guideline published in 2007.

METHODS

The search methods used in the current version differ compared to the previously published guideline. Literature searches were conducted using standardized MeSH terms from the National Library of Medicine PUBMED database list of search terms. The following terms comprised the standard baseline search terms for all topics and were connected with the logical 'OR' connector--Extracorporeal circulation (MeSH number E04.292), cardiovascular surgical procedures (MeSH number E04.100), and vascular diseases (MeSH number C14.907). Use of these broad search terms allowed specific topics to be added to the search with the logical 'AND' connector.

RESULTS

In this 2011 guideline update, areas of major revision include: 1) management of dual anti-platelet therapy before operation, 2) use of drugs that augment red blood cell volume or limit blood loss, 3) use of blood derivatives including fresh frozen plasma, Factor XIII, leukoreduced red blood cells, platelet plasmapheresis, recombinant Factor VII, antithrombin III, and Factor IX concentrates, 4) changes in management of blood salvage, 5) use of minimally invasive procedures to limit perioperative bleeding and blood transfusion, 6) recommendations for blood conservation related to extracorporeal membrane oxygenation and cardiopulmonary perfusion, 7) use of topical hemostatic agents, and 8) new insights into the value of team interventions in blood management.

CONCLUSIONS

Much has changed since the previously published 2007 STS blood management guidelines and this document contains new and revised recommendations.