must be at least some other mechanisms platelet dysfunction that influence the risk of bleeding. As long as the molecular mechanisms of dysplasia and dysfunction of platelets in MDS are unknown, we can only rely on platelet counts. Ulrich Germing, 1 Uwe Platzbecker, 2 Aristoteles Giagounidis 3 and Carlo Aul 3 1 Department of Haematology, Oncology and Clinical Immunology, Heinrich-Heine-University, Du ¨sseldorf, 2 Department of Haematology and Oncology University, Dresden, and 3 Department of Haematology, Oncology and Clinical Immunology, St Johannes Hospital, Duisburg, Germany E-mail: germing@med.uni-duesseldorf.de References Bennett, J.M. (2000) World Health Organization classification of the acute leukemias and myelodysplastic syndromes. International Journal of Hematology, 72, 131–133. Bennett, J.M., Catovsky, D., Daniel, M.T., Flandrin, G., Galton, D.A.G., Gralnick, H.R. & Sultan, C. (1982) Proposals for the classification of the myelodysplastic syndromes. British Journal of Haematology, 51, 189–199. Bowles, K.M., Warner, B.A. & Baglin, T.P. (2006) Platelet mass has prognostic value in patients with myelodysplastic syndromes. British Journal of Haematology, 135, 198–200. Greenberg, P., Cox, C., LeBeau, M.M., Fenaux, P., Morel, P., Sanz, G., Sanz, M., Vallespi, T., Hamblin, T., Oscier, D., Ohyashiki, K., Toyama, K., Aul, C., Mufti, G. & Bennett, J. (1997) International scoring system for evaluating prognosis in myelodysplastic syndromes. Blood, 89, 2079–2088. Keywords: platelet count, platelet morphology, platelet mass, myelodysplastic syndromes. First published online 6 June 2007 doi:10.1111/j.1365-2141.2007.06655.x Recurrent venous thromboembolism during coumarin therapy. Data from the computerised registry of patients with venous thromboembolism Current guidelines from the American College of Chest Physicians recommend that patients with venous thrombo- embolism (VTE) be treated initially with heparin, followed by long-term treatment with anti-vitamin K (AVK) drugs (Bu ¨ller et al, 2004). However, even after adequate anticoagulant therapy some 3–5% of patients have recurrence of their VTE (Douketis et al, 2000; Prandoni et al, 2002; Veeger et al, 2005). The computerised registry of patients with venous thrombo- embolism (RIETE) is an ongoing, multicentre, observational registry of consecutive patients with acute VTE (Monreal et al, 2003; Trujillo-Santos et al, 2006). We compared the clinical characteristics, treatment patterns and 3-month outcome in patients with new VTE (group 1), those with recurrent VTE after termination of AVK (group 2), and those with recurrent VTE during AVK therapy (group 3). Consecutive patients with symptomatic, acute deep vein thrombosis (DVT) or pulmonary embolism (PE), confirmed by objective tests are enrolled in RIETE. The following parameters are recorded: patient’s baseline characteristics; risk factors for VTE; the treatment received upon diagnosis; and the outcome within 3 months. Fatal PE, in the absence of autopsy, was defined as death shortly after PE, in the absence of any alternative cause of death. Fatal bleeding was defined as any death occurring shortly after a major bleed. Bleeding complications were classified as ‘major’, if they were overt and required a transfusion of 2 units of blood or more, or were retroperitoneal or intracranial. During the observation period, special attention was paid to any signs or symptoms suggesting either VTE recurrences or bleeding complications. Each episode of clinically suspected recurrent DVT or PE was documented by repeat objective tests. The statistical package for the social sciences (spss) version 11.5 (SPSS Inc., Chicago, IL, USA) was used to calculate odds ratios and corresponding 95% confidence intervals, and a P-value <0Æ05 was considered to be statistically significant. Of the 15 862 patients with acute VTE who had been followed for 3 months as of July 2006, 2538 (16%) had a prior episode of VTE. In 177 (7Æ0%) the current episode developed during AVK therapy. Ninety-nine further patients taking AVK for other reasons (i.e. atrial fibrillation and heart diseases) were not considered in this analysis. Thus, there were 13 324 patients in group 1; 2361 in group 2 and 177 in group 3. Correspondence ª 2007 The Authors 400 Journal Compilation ª 2007 Blackwell Publishing Ltd, British Journal of Haematology, 138, 396–403