Observational Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Sep 26, 2015; 7(9): 571-578
Published online Sep 26, 2015. doi: 10.4330/wjc.v7.i9.571
Single vs double antiplatelet therapy in acute coronary syndrome: Predictors of bleeding after coronary artery bypass grafting
Vincenzo Tarzia, Giacomo Bortolussi, Edward Buratto, Carla Paolini, Carlo Dal Lin, Giulio Rizzoli, Tomaso Bottio, Gino Gerosa
Vincenzo Tarzia, Giacomo Bortolussi, Edward Buratto, Giulio Rizzoli, Tomaso Bottio, Gino Gerosa, Division of Cardiac Surgery, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, 35128 Padua, Italy
Carla Paolini, Carlo Dal Lin, Division of Cardiology, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, 35128 Padua, Italy
Author contributions: Tarzia V, Bortolussi G, Buratto E, Paolini C, Dal Lin C, Rizzoli G, Bottio T and Gerosa G contributed to study conception and design; Tarzia V, Bortolussi G, Buratto E, Paolini C, Dal Lin C and Rizzoli G contributed to data acquisition, data analysis and interpretation, and writing of article; Tarzia V, Bortolussi G, Buratto E, Paolini C, Dal Lin C, Rizzoli G, Bottio T and Gerosa G contributed to editing, reviewing and final approval of article.
Institutional review board statement: The study was reviewed and approved by the Padua University Institutional Review Board.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors have no conflict of interest to declare.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Vincenzo Tarzia, MD, Division of Cardiac Surgery, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, Via Giustiniani, 2, 35128 Padova, Italy. v.tarzia@gmail.com
Telephone: +39-049-8212410 Fax: +39-049-8212409
Received: April 3, 2015
Peer-review started: April 3, 2015
First decision: April 28, 2015
Revised: July 30, 2015
Accepted: August 20, 2015
Article in press: August 21, 2015
Published online: September 26, 2015
Processing time: 170 Days and 9.9 Hours
Abstract

AIM: To investigate the contribution of anti-platelet therapy and derangements of pre-operative classical coagulation and thromboelastometry parameters to major bleeding post-coronary artery bypass grafting (CABG).

METHODS: Two groups of CABG patients were studied: Group A, treated with aspirin alone (n = 50), and Group B treated with aspirin and clopidogrel (n = 50). Both had similar preoperative, clinical, biologic characteristics and operative management. Classic coagulation parameters and rotational thromboelastometry (ROTEM) profiles were determined preoperatively for both groups and the same heparin treatment was administered. ROTEM profiles (INTEM and EXTEM assays) were analyzed, both for traditional parameters, and thrombin generation potential, expressed by area-under-curve (AUC).

RESULTS: There was no significant difference between rates of major bleeding between patients treated with aspirin alone, compared with those treated with aspirin and clopidogrel (12% vs 16%, P = 0.77). In the 14 cases of major bleeding, pre-operative classic coagulation and traditional ROTEM parameters were comparable. Conversely we observed that the AUC in the EXTEM test was significantly lower in bleeders (5030 ± 1115 Ohm*min) than non-bleeders (6568 ± 548 Ohm*min) (P < 0.0001).

CONCLUSION: We observed that patients with a low AUC value were at a significantly higher risk of bleeding compared to patients with higher AUC, regardless of antiplatelet treatment. This suggests that thrombin generation potential, irrespective of the degree of platelet inhibition, correlates with surgical bleeding.

Keywords: Platelet inhibitors; Thromboelastometry; Bleeding; Acute coronary syndrome; Coronary artery bypass grafting

Core tip: To establish the timing of discontinuation of double antiplatelet therapy before coronary artery bypass grafting (CABG), it is crucial to identify predictors of bleeding. We analysed preoperatively classic parameters and thromboelastometry on 100 patients operated for CABG after presenting with acute coronary syndrome, to investigate the contribution of anti-platelet therapy and derangements of pre-operative coagulation status to major bleeding post-CABG. We observed that patients with a low area-under-curve (AUC) value in EXTEM were at a significantly higher risk of bleeding compared to patients with higher AUC, regardless of anti-platelet treatment. This suggests that thrombin generation potential, irrespective of the degree of platelet inhibition, correlates with surgical bleeding.