Use and outcomes of antifibrinolytic therapy in patients undergoing cardiothoracic surgery at 20 academic medical centers in the United States.

Background: Several clinical trials have shown an association between the use of aprotinin in cardiothoracic surgery (CTS) patients and an increased risk of adverse renal, cardiovascular, and cerebrovascular events. Other antifibrinolytic agents-aminocaproic acid (AA) and tranexamic acid (TA)-have not shown elevated risks. Using a large administrative data set, we sought to examine these findings.

Methods: In our observational database study of CTS patients who were discharged from 20 academic medical centers from October 2002 through September 2005, we assessed the use of antifibrinolytic therapy on select patient outcomes using descriptive and inferential statistics to compare the various groups.

Results: For the CTS patients, AA was used in 9,751 (15.5% of patients) and aprotinin was used in 6,855 (10.9% of patients). Only 17 patients from four hospitals received TA; therefore, TA was excluded from further analysis. A quarterly analysis showed a slow decline in the use of AA, with a gradual increase in the use of aprotinin over the study time period. Variation by hospital using each option was considerable (range, 0%-50%). Statistically significant differences in mortality rates (P < 0.001) occurred with AA (2.6%), aprotinin (5.2%), and control patients (n = 46,123), who did not use any antifibrinolytic agents (3.9%). Rates of acute renal failure were 6.2% with AA, 10.9% with aprotinin, and 6.1% in controls; hemodialysis rates were 2.8%, 6.4%, and 2.6%, respectively. Postoperative acute myocardial infarction occurred in only two cases of patients receiving AA, in none of those using aprotinin, and in 63 controls.

Conclusion: Although the use of aprotinin has been increasing, compared with AA, the overall use of antifibrinolytic agents in patients undergoing CTS has remained relatively stable over a three-year period, at under 30%. Significant differences in patient outcomes were observed between the two treatment groups. Given the growing body of evidence for the use of antifibrinolytic therapy, hospitals might be best served by examining existing patterns of use and by instituting restrictions of aprotinin for patients facing an increased risk for bleeding during CTS.