Business Cycle Prediction Using Support Vector Methods

This paper illustrates the Support Vector Method for the classification problem with two and more classes. In particular, the multi-class classification Support Vector Method of Weston and Watkins (1998) is correctly formulated as a quadratic optimization problem. Then, the method is applied to the problem of predicting business phases of the German economy. The generated support vectors are interpreted, in particular with respect to whether they are able to characterize business phase switches. Finally, the classification power of the Support Vector Method and of Linear Discriminant Analysis are compared. The results are two-fold. On the one hand, after the analysis of the results of this study it appears questionable that the Support Vector Method delivers an interpretable (dimension independent) data reduction by identifying the support vectors. Indeed, the support vectors did not appear to be sufficient to characterize the switches between the business phases. On the other hand, the classification power of the Support Vector Method was distinctly better than with Linear Discriminant Analysis. Note however that the Support Vector Method needs very much more computation time than Linear Discriminant Analysis

Assessment for residual disease after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension

Objectives Pulmonary endarterectomy (PEA) is recommended for eligible patients with chronic thromboembolic pulmonary hypertension (CTEPH) and is potentially curative. However, persistent/recurrent CTEPH post-PEA can occur. Here we describe symptom and diagnostic assessment rates for residual disease post-PEA and longitudinal diagnostic patterns before and after riociguat approval for persistent/recurrent CTEPH after PEA. Methods This US retrospective cohort study analysed MarketScan data (1 January 2002–30 September 2018) from patients who underwent PEA following a CTEPH/pulmonary hypertension (PH) claim with at least 730 days of continuous enrolment post-PEA. Data on pre-specified PH symptoms and the types and timings of diagnostic assessments were collected. Results Of 103 patients (pre-riociguat approval, n=55; post-riociguat approval, n=48), residual PH symptoms >3 months after PEA were reported in 89% of patients. Overall, 89% of patients underwent one or more diagnostic tests (mean 4.6 tests/patient), most commonly echocardiography (84%), with only 5% of patients undergoing right heart catheterisation (RHC). In the post- versus pre-riociguat approval subgroup, assessments were more specific for CTEPH with an approximately two-fold increase in 6-min walk distance and N-terminal prohormone of brain natriuretic protein measurements and ventilation/perfusion scans, and a four-fold increase in RHCs. Conclusions Low RHC rates suggest that many patients with PH symptoms post-PEA are not being referred for full diagnostic workup. Changes to longitudinal diagnostic patterns may indicate increased recognition of persistent/recurrent CTEPH post-PEA; however, there remains a need for greater awareness around the importance of continued follow-up for patients with residual PH symptoms post-PEA

Patients selected for dual pathway inhibition in clinical practice have similar characteristics and outcomes to those included in the COMPASS randomized trial: The XATOA Registry

International audienceAbstract Aims To determine the characteristics of patients with coronary artery disease (CAD), peripheral artery disease (PAD), or both, initiating dual pathway inhibition (DPI) using rivaroxaban 2.5 mg twice daily plus aspirin, and to report their clinical outcomes and bleeding rates in clinical practice compared to the COMPASS randomized trial, which provided the basis for using DPI in this patient population. Methods and results XATOA is a prospective registry of 5532 patients: of which, 72.7% had CAD, 58.9% had PAD, and 31.6% had both. The mean age of patients was 68 years and 25.5% were women. The mean follow-up period was 15 months. The most frequently reported reason for initiating DPI was the presence of existing, worsening or newly diagnosed risk characteristics (n = 4753, 85.9%). Before initiating DPI, 75.3% received a single antiplatelet and 18.3% received various antiplatelet combinations. The incidence of major adverse cardiovascular events (MACE), major adverse limb events (MALE) and acute or severe limb ischaemia was 2.26, 3.57, and 1.54 per 100 patient-years, respectively, among the 5532 patients in XATOA. Corresponding rates in COMPASS were 2.18, 0.19, and 0.12 per 100 patient-years, respectively. Major bleeding rates were 0.95 and 1.67 per 100 patient-years in XATOA and COMPASS, respectively. Conclusion High-risk vascular patients are prioritized for DPI in clinical practice, and rates of MACE are similar to COMPASS, but MALE rates are higher in XATOA, consistent with the greater proportion of PAD patients. Major bleeding rates were lower in XATOA. The findings provide support for favourable net clinical benefit of DPI in high-risk vascular patients. One-sentence summary The characteristics of patients initiated on dual pathway inhibition (DPI: rivaroxaban 2.5 mg twice daily plus aspirin) have not previously been defined in clinical practice and the XATOA registry findings demonstrate patient outcomes are consistent with those of the COMPASS trial, despite geographic differences in recruitment and the higher proportion of PAD patients

Xarelto plus Acetylsalicylic acid: Treatment patterns and Outcomes in patients with Atherosclerosis (XATOA): Rationale and design of a prospective registry study to assess rivaroxaban 2.5 mg twice daily plus aspirin for prevention of atherothrombotic events in coronary artery disease, peripheral artery disease, or both

International audienceAims: The role and selection of antithrombotic therapy to improve limb outcomes in chronic lower extremity artery disease (LEAD) is still debated. We conducted a meta-analysis to examine the efficacy and safety of antithrombotic and more intense antithrombotic therapy on limb outcomes and limb salvage in patients with chronic LEAD.Methods and results: Study inclusion criteria were: enrolment of patients with LEAD, randomized allocation to more vs. less intense antithrombotic therapy [more vs. less intense single-antiplatelet therapy (SAPT); dual-antiplatelet therapy vs. SAPT; dual antithrombotic therapy vs. SAPT or oral anticoagulant]; enrolment of ≥200 patients; reporting of at least one of following outcomes: limb amputation or revascularization. Seven randomized studies enrolling 30 447 patients were included. Over a median follow-up of 24 months, more vs. less intense antithrombotic therapy or placebo significantly reduced the risk of limb revascularization [relative risk (RR) 0.89, 95% confidence interval (CI) 0.83-0.94] and limb amputation (RR 0.63, 95% CI 0.46-0.86), as well as stroke (RR 0.82, 95% CI 0.70-0.97). There was no statistically significant effect on the risk of myocardial infarction (RR 0.98, 95% CI 0.87-1.11), all-cause (RR 0.93, 95% CI 0.86-1.01), and cardiovascular death (RR 0.97, 95% CI 0.86-1.08). Risk of major bleeding increased (RR 1.23, 95% CI 1.04-1.44).Conclusion: In patients with LEAD, more intense antithrombotic therapy reduces the risk of limb amputation and revascularization as well as stroke with an increase in the risk of bleeding events

Diagnosis and Treatment Patterns of Chronic Thromboembolic Pulmonary Hypertension in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia: A Registry Study

Background: Patients with chronic thromboembolic pulmonary hypertension (CTEPH) in countries with limited resources have, to date, been poorly represented in registries. Objective: This work assesses the epidemiology, diagnosis, hemodynamic and functional parameters, and treatment of CTEPH in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia. Methods: A prospective, cohort, phase IV, observational registry with 3-year follow-up (n = 212) in patients aged ≥ 18 years diagnosed with CTEPH was created. Clinical, hemodynamic, and functional parameters were obtained at an initial visit, follow-up visits, and a final visit at the end of 3 years’ observation or end of follow-up. Data were recorded on electronic case report forms. Parameters evaluated included 6-minute walking distance (6MWD), use of pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA), pulmonary hypertension (PH)-targeted therapy, and survival. All statistical analyses were exploratory and descriptive, and were performed in the overall population. Results: The most common symptoms were typical of those expected for CTEPH. Almost 90% of patients underwent right heart catheterization at diagnosis or initial study visit. In total, 66 patients (31%) underwent PEA before the initial visit; 95 patients (45%) were considered operable, 115 (54%) were inoperable, and two (1%) had no operability data. Only 26 patients (12%) had been assessed for BPA at their initial visit. PH-targeted therapy was documented at diagnosis for 77 patients (36%), most commonly a phosphodiesterase type 5 inhibitor (23%). Use of PH-targeted therapy increased to 142 patients (67%) at the initial visit, remaining similar after 3 years. Use of riociguat increased from 6% of patients at diagnosis to 38% at 3 years. Between baseline and end of observation, results for patients with paired data showed an increase in 6MWD. Survival at the end of observation was 88%. Conclusions: These data highlight the current diagnosis and management of CTEPH in the participating countries. They show that early CTEPH diagnosis remains challenging, and use of off-label PH-targeted therapy is common. ClinicalTrials.gov: NCT02637050; registered December 2015. Graphical Abstract: (Figure presented.)