An evolutionary algorithm with acceleration operator to generate a subset of typical testors

This paper is focused on introducing a Hill-Climbing algorithm as a way to solve the problem of generating typical testors - or non-reducible descriptors - from a training matrix. All the algorithms reported in the state-of-the-art have exponential complexity. However, there are problems for which there is no need to generate the whole set of typical testors, but it suffices to find only a subset of them. For this reason, we introduce a Hill-Climbing algorithm that incorporates an acceleration operation at the mutation step, providing a more efficient exploration of the search space. The experiments have shown that, under the same circumstances, the proposed algorithm performs better than other related algorithms reported so far. Zapotitlán 2013 Elsevier B.V. All rights reserved

Clinical outcome in patients with venous thromboembolism receiving concomitant anticoagulant and antiplatelet therapy

Introduction: Patients with arterial disease receiving antiplatelet agents may develop venous thromboembolism (VTE) and need anticoagulant therapy, although concomitant use of these drugsmay increase bleeding risk. We analyzed RIETE data and compared clinical outcomes depending on decision to discontinue or maintain antiplatelet therapy at VTE diagnosis. Methods: Consecutive patients with acute VTE were enrolled in RIETE. Only patients receiving antiplatelet therapy at baseline were included in this analysis. Primary outcomes were: rate of subsequent ischemic events, major bleeding or death during anticoagulation course. Results: 1178 patientswho received antiplatelet drugs at VTE diagnosis were included. Antiplatelet therapy was discontinued in 62% of patients. During anticoagulation course, patients also receiving antiplatelet therapy had higher rates of lower limb amputations (2.28 vs. 0.21 events per 100 patients-years; p < 0.01), any ischemic events (5.7 vs. 2.28 events per 100 patients-years; p < 0.05) or death (23.6 vs. 13.9 deaths per 100 patientsyears; p < 0.01). No differences in the rate of major bleeding or recurrent VTEwere revealed. In matched analysis, patients on antiplatelet therapy were found to have a significantly higher rate of limb amputations (odds ratio: 15.3; 95% CI: 1.02-229) and an increased number of composite outcomes including all-cause deaths, arterial and VTE events (odds ratio: 1.46; CI: 1.03-2.06), with no differences in major bleeding rate. Conclusion: Concomitant anticoagulant and antiplatelet therapy in patients with VTE and arterial disease is not associated with increased risk for bleeding, recurrent VTE or death. The worse outcome observed in patients who continued antiplatelet therapy requires further investigations

Outcomes in Neurosurgical Patients Who Develop Venous Thromboembolism

International audienceOBJECTIVES: Registro Informatizado de Enfermedad TromboEmbólica (RIETE) database was used to investigate whether neurosurgical patients with venous thromboembolism (VTE) were more likely to die of bleeding or VTE and the influence of anticoagulation on these outcomes.METHODS:Clinical characteristics, treatment details, and 3-month outcomes were assessed in those who developed VTE after neurosurgery.RESULTS: Of 40 663 patients enrolled, 392 (0.96%) had VTE in less than 60 days after neurosurgery. Most patients in the cohort (89%) received initial therapy with low-molecular-weight heparin, (33% received subtherapeutic doses). In the first week, 10 (2.6%) patients died (8 with pulmonary embolism [PE], no bleeding deaths; P = .005). After the first week, 20 (5.1%) patients died (2 with fatal bleeding, none from PE). Overall, this cohort was more likely to develop a fatal PE than a fatal bleed (8 vs 2 deaths, P = .058).CONCLUSIONS: Neurosurgical patients developing VTE were more likely to die from PE than from bleeding in the first week, despite anticoagulation

Long-term anticoagulant therapy of patients with venous thromboembolism. What are the practices?

Current guidelines of antithrombotic therapy suggest early initiation of vitamin K antagonists (VKA) in non-cancer patients with venous thromboembolism (VTE), and long-term therapy with low-molecular weight heparin (LMWH) for those with cancer. We used data from RIETE (international registry of patients with VTE) to report the use of long-term anticoagulant therapy over time and to identify predictors of anticoagulant choice (regarding international guidelines) in patients with- and without cancer. Among 35,280 patients without cancer, 82% received long-term VKA (but 17% started after the first week). Among 4,378 patients with cancer, 66% received long term LMWH as monotherapy. In patients without cancer, recent bleeding (odds ratio [OR] 2.70, 95% CI 2.26-3.23), age >70 years (OR 1.15, 95% CI 1.06-1.24), immobility (OR 2.06, 95% CI 1.93-2.19), renal insufficiency (OR 2.42, 95% CI 2.15-2.71) and anemia (OR 1.75, 95% CI 1.65-1.87) predicted poor adherence to guidelines. In those with cancer, anemia (OR 1.83, 95% CI 1.64-2.06), immobility (OR 1.51, 95% CI 1.30-1.76) and metastases (OR 3.22, 95% CI 2.87-3.61) predicted long-term LMWH therapy. In conclusion, we report practices of VTE therapy in real life and found that a significant proportion of patients did not receive the recommended treatment. The perceived increased risk for bleeding has an impact on anticoagulant treatment decision

Fondaparinux in the initial and long-term treatment of venous thromboembolism

Background: Even in the absence of evidence on its long-term efficacy and safety, a number of patients with venous thromboembolism (VTE) receive long-term therapy with fondaparinux alone in everyday practice. Methods: We used the Registro Informatizado de Enfermedad Tromboembólica (RIETE) registry to compare the rate of VTE recurrences and major bleeding at 10 and 90 days in patients with and without cancer. For long-term therapy, fondaparinux was compared with vitamin K antagonists (VKA) in patients without cancer and with low-molecular- weight heparin (LMWH) in those with cancer Results Of 47,378 patients recruited, 46,513 were initially treated with heparin, 865 with fondaparinux. Then, 263 patients (78 with cancer) were treated for at least 3 months with fondaparinux. After propensity-score matching, there were no differences between patients receiving initial therapy with heparin or fondaparinux. Among patients with cancer, there were no differences between fondaparinux and LMWH. Among patients without cancer, the long-term use of fondaparinux was associated with an increased risk of major bleeding (3.24 % vs. 0.95 %, p < 0.05). Conclusions: An unexpected high rate of major bleeding was observed in non-cancer patients treated with longterm fondaparinux. Our small sample does not allowto derive relevant conclusions on the use of fondaparinux in cancer patients