Ann Thorac Surg 2004;77:874
© 2004 The Society of Thoracic Surgeons
Original articles: cardiovascular
Invited commentary
Ranjit John, MD
Division of Cardiothoracic Surgery Milstein Hospital Room 7-435 177 Fort Washington Ave New York, NY 10032 USA
Yoshifumi Naka, MD, PhD
Division of Surgery New York-Presbyterian Hospital Milstein Building 177 Fort Washington Ave New York, NY 10032 USA
e-mail: ranjitj{at}pol.net
e-mail: yn33{at}columbia.edu
Despite markedly improving results with VAD implantation, bleeding primarily, and to a lesser extent thromboembolism remain major obstacles to achieving further success in patients with end-stage heart failure. Thus any endeavor that aims to reduce the incidence of these complications is to be strongly encouraged. In this paper, the authors attempt to show for the first time an association between the PlA genotypes with bleeding and thromboembolism in patients on VAD support. In general, VAD implantation is associated with an increased risk of bleeding in the early postoperative period and an increased risk of thromboembolism late in the postoperative period. Alterations in the coagulation pathways after VAD implantation are well known and have been described for all types of existing devices. Furthermore, standard protocols do exist for anticoagulation regimens for the prevention of thromboembolism for the various devices in current use.
The presence of the PlA2 allele is known to potentially affect both platelet activation and aggregation, and thus may influence either bleeding or thombosis. The significance of PlA polymorphism in clinical situations where arterial thrombosis may be important has been evaluated. It is not surprising, therefore, that the first evidence of the clinical relevance of PlA polymorphism was detected in the setting of acute coronary syndromes. Subsequently, a relationship between PlA polymorphism and coronary in-stent stenosis was documented. However, it is important to note that a consistent clinically significant relationship between PlA polymorphism and coronary artery disease is not well supported from existing studies. As a corollary of this unsubstantiated relationship, no recommended anticoagulation regimen based on PlA polymorphism also exists in the management of coronary artery disease states.
In this study, the PlA genotype was determined in 41 patients after VAD implantation. A statistically significant association was seen between the A1A1 genotype and bleeding; however, only a trend was seen between the A1A2 genotype and thromboembolism. It is important to note that genotyping was performed in patients with three different types of VADS. In conclusion, despite the interesting association between bleeding in VAD patients and PlA polymorphism, the clinical significance of these findings are unclear. As the authors themselves note, the paper reports some interesting findings albeit the numbers are too small to support multivariate logistic regression analysis. Until more conclusive findings are obtained (presumably with a larger cohort of patients), the clinical significance of determining PlA polymorphism in order to tailor post-VAD anticoagulation therapy remains uncertain. [1, 2]
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- Goldschmidt-Clermont PJ, Cooke GE, Eaton GM, Binkley PF. PlA2, a variant of GPIIIa implicated in coronary thromboembolic complications. J Am Coll Cardiol 2000;36:90–3
- Ridker PM, Hennekins CH, Schmitz C, Stampler MJ, Lindpainter K. PlA1/A2 polymorphism of platelet glycoprotein IIIa and risks of myocardial infarction, stroke and venous thrombosis. Lancet 1997;349:385–8.
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