HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Idris M. Ali Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ali, I. M. Articles by Landymore, R. W. Search for Related Content PubMed PubMed Citation Articles by Ali, I. M. Articles by Landymore, R. W.

J Thorac Cardiovasc Surg 1994;107:1377
© 1994 Mosby, Inc.

LETTERS TO THE EDITOR

The use of tranexamic acid in cardiac operations

Victoria General Hospital
Dalhousie University
Cardiovascular Surgery Department
1278 Tower Rd.
Halifax, Nova Scotia B3H 2Y9, Canada

To the Editor:

We read with interest the recent article by Dr. Øvrum and colleagues, ¹ who report the effects of transexamic acid on postoperative bleeding in patients undergoing coronary artery bypass. We believe this article failed to recognize the pharmacologic actions of tranexamic acid on fibrinolysis. ²

Cardiopulmonary bypass stimulates fibrinolysis, which contributes to postoperative bleeding after heart operations. ^{3, 4} For antifibrinolytic drugs to exert their beneficial effects on postoperative bleeding after cardiac operations, these drugs must be administered before fibrinolysis becomes accelerated. In other words, transexamic acid should be administered at the beginning of the operation and during cardiopulmonary bypass. Øvrum and colleagues report that transexamic acid caused a slight reduction in postoperative bleeding after coronary bypass (565 ± 239 ml in patients receiving transexamic acid versus 656 ± 257 ml in the control group). These results should have been expected, because the drug was administered only after termination of cardiopulmonary bypass. Øvrum and colleagues also indicate that postoperative myocardial infarction (MI) was more prevalent in those patients receiving transexamic acid. The differences, however, did not reach statistical significance; thus this study has not shown that transexamic acid is responsible for an increased number of MIs in the treated group.

At our institution we have recently reviewed our experience with epsilon-aminocaproic acid (Amicar), a drug that has similar effects on fibrinolysis. We used epsilon-aminocaproic acid in patients who were receiving intravenous heparin and oral aspirin up until their operation, thus placing them at risk of postoperative bleeding. Forty-six patients undergoing coronary bypass were randomized to receive epsilon-aminocaproic acid or placebo. Epsilon-aminocaproic acid was administered in a dosage of 75 mg/kg per hour at the time of skin incision and then the dosage was reduced to 15 mg/kg per hour and continued until the termination of bypass. The two groups were well matched with respect to age, length of pump time, and number of bypasses. The treated group lost 461 ± 75 ml of blood after the operation versus 870 ± 110 ml in those patients receiving epsilon-aminocaproic acid (p < 0.001). No difference in the prevalence of MI, stroke, or deep vein thrombosis was noted.

We agree with Dr. Øvrum that antifibrinolytic drugs will not reduce postoperative bleeding after cardiac operations when administered after the fibrinolytic process has become well established. However, we have demonstrated, like others, ^{4, 5} that antifibrinolytic drugs are extremely effective and clinically safe when administered during the appropriate time frame.

References

1. Ovrum E, Holen EA, Abdelnoor M, Oystese R, Ringdal CP. Transexamic acid (Cyklokapron) is not necessary to reduce blood loss after coronary artery bypass operations. J THORAC CARDIOVASC SURG 1993;105:78-83.[Abstract]
   
2. Verstraete M. Clinical application of inhibitors of fibrinolysis. Drugs 1985;29:236-61.[Medline]
   
3. Umlas J. Fibrinolysis and disseminated intravascular coagulation in open-heart surgery. Transfusion 1976;16:460-3.[Medline]
   
4. Vander Salm TJ, Ansell JE, O'Kike ON, et al. The role of epsilon-aminocaproic acid in reducing bleeding after cardiac operation: a double-blind randomized study. J THORAC CARDIOVASC SURG 1988;96:538-40.
   
5. Horrow J, Hlavacek J, Strong MD, et al. Prophylactic tranexamic acid decreases bleeding after cardiac operations. J THORAC CARDIOVASC SURG 1990;99:70-4.[Abstract]
   

This Article Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Idris M. Ali Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ali, I. M. Articles by Landymore, R. W. Search for Related Content PubMed PubMed Citation Articles by Ali, I. M. Articles by Landymore, R. W.