Letter to the Editor Asian Cardiovascular & Thoracic Annals 2014, Vol. 22(3) 375 ß The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0218492313498595 aan.sagepub.com
Topical use of tranexamic acid I read with interest the article by Aoki and colleagues.1 In their study that included 100 consecutive patients who underwent off-pump coronary artery bypass between July 2009 and January 2011, 50 patients in the early phase group (N) did not have tranexamic acid, and 50 in the late phase (group T) were given tranexamic acid. They found that local administration of tranexamic acid decreased the volume of postoperative blood loss by approximately 40%. We published our results of local administration of tranexamic acid in patients undergoing coronary artery bypass and randomized to receive local tranexamic acid or placebo.2 We found that use of local tranexamic acid reduced postoperative drainage with no difference in red blood cell transfusion. I would like to congratulate the authors for their excellent study, and I have some remarks. The study was carried out in two time periods; by doing so, the chance of bias is greater, and I wonder if the surgical, anesthesia, and intensive care teams were the same during these 2 blocks of time. The study is nonrandomized; this is a major limitation and should be mentioned in the limitation section. They used 1 g of tranexamic acid diluted in only 10 mL of saline. A small amount of saline may not allow homogenous distribution in a wide area of potential microvascular bleeding all over the meditational and pericardial cavities. One of the limitations in this study (and our study) is that the plasma level of tranexamic acid was not measured, so systemic absorption of tranexamic acid and its effect on postoperative bleeding is not known. The authors did not mention their protocol for antiplatelet usage in the perioperative period, which can impact on the postoperative drainage. The authors mentioned that graft patency was 94.2% in group T (who received tranexamic acid) versus 97.3% in group N. I wonder how they assessed graft patency? Was postoperative angiography
performed in all cases? What were the failed grafts? Is there any explanation for failure in the early postoperative period in those grafts? The inclusion and exclusion criteria are not clear: did the authors included all newcomers in this study? Lastly, I agree with the authors in their conclusion that locally administered tranexamic acid exhibits the most marked hemostatic effects. At the same time, it is simple, inexpensive, and does not need special preparation. It is worth trying it in order to reduce postoperative drainage after cardiac surgery procedures. A further large scale randomized study that includes measurement of serum tranexamic acid after local administration is warranted to confirm these results and help to understand the mechanism of its action. References 1. Aoki M, Okawa Y, Goto Y, Ogawa S and Baba H. Local administration of tranexamic acid in off-pump coronary artery bypass. Asian Cardiovasc Thorac Ann 2012; 20: 658–662. 2. Fawzy H, Elmistekawy E, Bonneau D, Latter D and Errett L. Can local application of tranexamic acid reduce postcoronary bypass surgery blood loss? A randomized controlled trial. J Cardiothorac Surg 2009; 18(4): 25.
1
Elsayed Elmistekawy1,2 Department of Cardiac Surgery, Ottawa Heart Institute, Ottawa, Canada 2 Department of Cardiothoracic Surgery, Tanta University, Egypt
Corresponding author: Elsayed Elmistekawy, MD, Department of Cardiac Surgery, Ottawa Heart Institute, Ottawa, Canada. Email: [email protected]
Downloaded from aan.sagepub.com at UNIV OF GEORGIA on June 26, 2015
Topical use of tranexamic acid I read with interest the article by Aoki and colleagues.1 In their study that included 100 consecutive patients who underwent off-pump coronary artery bypass between July 2009 and January 2011, 50 patients in the early phase group (N) did not have tranexamic acid, and 50 in the late phase (group T) were given tranexamic acid. They found that local administration of tranexamic acid decreased the volume of postoperative blood loss by approximately 40%. We published our results of local administration of tranexamic acid in patients undergoing coronary artery bypass and randomized to receive local tranexamic acid or placebo.2 We found that use of local tranexamic acid reduced postoperative drainage with no difference in red blood cell transfusion. I would like to congratulate the authors for their excellent study, and I have some remarks. The study was carried out in two time periods; by doing so, the chance of bias is greater, and I wonder if the surgical, anesthesia, and intensive care teams were the same during these 2 blocks of time. The study is nonrandomized; this is a major limitation and should be mentioned in the limitation section. They used 1 g of tranexamic acid diluted in only 10 mL of saline. A small amount of saline may not allow homogenous distribution in a wide area of potential microvascular bleeding all over the meditational and pericardial cavities. One of the limitations in this study (and our study) is that the plasma level of tranexamic acid was not measured, so systemic absorption of tranexamic acid and its effect on postoperative bleeding is not known. The authors did not mention their protocol for antiplatelet usage in the perioperative period, which can impact on the postoperative drainage. The authors mentioned that graft patency was 94.2% in group T (who received tranexamic acid) versus 97.3% in group N. I wonder how they assessed graft patency? Was postoperative angiography
performed in all cases? What were the failed grafts? Is there any explanation for failure in the early postoperative period in those grafts? The inclusion and exclusion criteria are not clear: did the authors included all newcomers in this study? Lastly, I agree with the authors in their conclusion that locally administered tranexamic acid exhibits the most marked hemostatic effects. At the same time, it is simple, inexpensive, and does not need special preparation. It is worth trying it in order to reduce postoperative drainage after cardiac surgery procedures. A further large scale randomized study that includes measurement of serum tranexamic acid after local administration is warranted to confirm these results and help to understand the mechanism of its action. References 1. Aoki M, Okawa Y, Goto Y, Ogawa S and Baba H. Local administration of tranexamic acid in off-pump coronary artery bypass. Asian Cardiovasc Thorac Ann 2012; 20: 658–662. 2. Fawzy H, Elmistekawy E, Bonneau D, Latter D and Errett L. Can local application of tranexamic acid reduce postcoronary bypass surgery blood loss? A randomized controlled trial. J Cardiothorac Surg 2009; 18(4): 25.
1
Elsayed Elmistekawy1,2 Department of Cardiac Surgery, Ottawa Heart Institute, Ottawa, Canada 2 Department of Cardiothoracic Surgery, Tanta University, Egypt
Corresponding author: Elsayed Elmistekawy, MD, Department of Cardiac Surgery, Ottawa Heart Institute, Ottawa, Canada. Email: [email protected]
Downloaded from aan.sagepub.com at UNIV OF GEORGIA on June 26, 2015
