Letter by Augoustides Regarding Article, “Increased Mortality, Postoperative Morbidity, and Cost After Red Blood Cell Transfusion in Patients Having Cardiac Surgery”
To the Editor:
I read with great interest the excellent article by Dr Murphy and colleagues detailing the deleterious effects associated with red blood cell transfusion in cardiac surgery.1 Their multivariate analysis has demonstrated that red cell transfusion is significantly associated with increased mortality, morbidity, and cost after cardiac surgery.
However, the data analysis as presented does not account for aprotinin exposure, which was until recently a common antifibrinolytic used in cardiac surgery to minimize transfusion. This is a most significant confounder, given the following:
Aprotinin has been significantly associated with increased mortality, morbidity, and consequent cost after cardiac surgery.2
Aprotinin has been withdrawn this year from the global market because of a preliminary finding in a multicenter prospective trial in Canada (Blood Conservation using Antifibrinolytics: A Randomized Trial in High-Risk Cardiac Surgery Patients [BART]) that aprotinin was associated with a higher mortality in complex cardiac surgery.3
Consequently, it would be valuable to know whether aprotinin exposure in this study was considered. If so, it would be reasonably apparent whether this confounder has had a significant role in this study.
I congratulate the authors on a most thought-provoking study. I look forward to their analysis of this confounder. I have no doubt that it will assist in our understanding of the deleterious outcomes associated with transfusion in cardiac surgery.
Murphy GJ, Reeves BC, Rogers CA, Rizvi SIA, Culliford L, Angelini GD. Increased mortality, postoperative morbidity, and cost after red blood cell transfusion in patients having cardiac surgery. Circulation. 2007; 116: 2544–2552.
Trasylol Home Page. http://www.trasylol.com. Accessed December 12, 2007.