Major Outcomes in Atrial Fibrillation Patients with One Risk Factor: Impact of Time in Therapeutic Range

BACKGROUND: The benefits and harms of oral anticoagulation (OAC) therapy in patients with only one stroke risk factor (i.e. CHA2DS2-VASc= 1 in males, or 2 in females) has been subject of debate. METHODS: We analysed all patients with only one stroke risk factor from the merged datasets of SPORTIF III and V trials. Anticoagulation control was defined according to time in therapeutic range (TTR). RESULTS: Of the original trial cohort, 1,097 patients had only one stroke risk factor. Stroke/systemic thromboembolic event had an incidence of 0.9 per 100 patient-years, with an incidence of 1.6 per 100 patient-years for all-cause death and 2.3%/patient-years for the composite outcome of stroke/systemic thromboembolic event/all-cause death. There were no significant differences in the risk for stroke/systemic thromboembolic event between sexes, nor between the different stroke risk factors amongst these atrial fibrillation patients with only one stroke risk factor. Cox regression analysis in patients treated with warfarin only found TTR to be inversely associated with stroke/systemic thromboembolic event (p=0.034) and all-cause death (p=0.015). Chronic heart failure was significantly associated with the outcome of all-cause death (p=0.0019) and the composite outcome of stroke/systemic thromboembolic event/all-cause death (p=0.021). There was a significant inverse linear association between TTR and the cumulative risk for both stroke/systemic thromboembolic event and all-cause death (both p<0.001). CONCLUSIONS: In atrial fibrillation patients with only one additional stroke risk factor (i.e. CHA2DS2-VASc= 1 in males or 2 in females), rates of major adverse events (stroke/systemic thromboembolic event, mortality) were high, despite anticoagulation. TTR in warfarin-treated patients was inversely associated with the occurrence of both stroke/systemic thromboembolic event and all-cause death

The Variance Profile

The variance profile is defined as the power mean of the spectral density function of a stationary stochastic process. It is a continuous and non-decreasing function of the power parameter, p, which returns the minimum of the spectrum (p → −∞), the interpolation error variance (harmonic mean, p = −1), the prediction error variance (geometric mean, p = 0), the unconditional variance (arithmetic mean, p = 1) and the maximum of the spectrum (p → ∞). The variance profile provides a useful characterisation of a stochastic processes; we focus in particular on the class of fractionally integrated processes. Moreover, it enables a direct and immediate derivation of the Szego-Kolmogorov formula and the interpolation error variance formula. The paper proposes a non-parametric estimator of the variance profile based on the power mean of the smoothed sample spectrum, and proves its consistency and its asymptotic normality. From the empirical standpoint, we propose and illustrate the use of the variance profile for estimating the long memory parameter in climatological and financial time series and for assessing structural change.Predictability; Interpolation; Non-parametric spectral estimation; Long memory.

Risultati clinico-strumentali del trattamento dell'artrosi trapezio-metacarpale mediante artroplastica di interposizone

Introduzione: La rizoartrosi (artrosi trapezio-metacarpale) rappresenta il 10% delle localizzazioni artrosiche di tutto il corpo. L’ artroplastica di interposizione secondo Robinson prevede l’esecuzione di trapeziectomia ed innesto tendineo con emi Abduttore Lungo del Pollice (APL) inserito nel gap creato dalla trapeziectomia. Lo scopo dello studio è quello di valutare i risultati clinici e strumentali dell’artroplastica di interposizione ad un follow-up di medio-lungo termine valutando mediante studio RMN l’evoluzione del innesto, ed una sua eventuale associazione con gli risultati clinici. Materiali e Metodi: Da Luglio 2006 a Maggio 2012, sono stati trattati chirurgicamente 75 pazienti affetti da rizoartrosi.64 pazienti rientravano nei criteri di inclusione dello studio. La valutazione clinica è stata effettuata mediante Grind test, Kapandji test, DASH score, VAS score, valutazione della ROM in abduzione radiale, e soddisfazione soggettiva del paziente. L’esame strumentale è stato effettuato mediante RX in antero-posteriore e laterale, sono state inoltre analizzate sequenze T1-, T2-, STIR-, Spin Echo e Gradient Echo-MRI alla RMN. Risultati: 44 pazienti (68.75%) sono risultati pienamente soddisfatti, 16 pazienti (25%) hanno riportato grande beneficio e hanno ripreso tutte le attività quotidiane con limitazione minima. Solo 4 pazienti (6.25%) non sono stati soddisfatti dell’intervento. La distanza scafo-metacarpale (SMD) valutata radiograficamente nel 1 mese post operatorio ha mostrato un valore medio di 6.6±1.7SD mm. All’ultimo follow-up il valore medio (SMD) è risultato essere di 4.3±1.2SD mm, con una migrazione prossimale media di 2.3±0.9SD mm. La valutazione con RMN ha mostrato nel 100% dei pazienti la presenza di tessuto fibroso residuo nello spazio tra la base del primo metacarpo e lo scafoide. Nel 37.5% dei pazienti è stata osservata la presenza di edema osseo subcondrale. Il 50% dei pazienti mostravano sinovite reattiva alla RMN. Discussione/Conclusioni: L’artroplastica di interposizione è un trattamento sicuro e validato per il trattamento dei pazienti affetti da rizoartrosi di stadio III-IV secondo Eaton-Littler che garantisce buoni risultati clinici ed il ritorno alle normali attività di vita quotidiana. La quantità di tessuto fibroso residuo interposto dopo la trapeziectomia sembra essere correlate a migliori risultati clinico / radiografici e maggiore soddisfazione da parte dei pazienti

Terahertz dipole nanoantenna arrays: resonance characteristics

Resonant dipole nanoantennas promise to considerably improve the capabilities of terahertz spectroscopy, offering the possibility of increasing its sensitivity through local field enhancement, while in principle allowing unprecedented spatial resolutions, well below the diffraction limit. Here, we investigate the resonance properties of ordered arrays of terahertz dipole nanoantennas, both experimentally and through numerical simulations. We demonstrate the tunability of this type of structures, in a range (∼1–2 THz) that is particularly interesting and accessible by means of standard zinc telluride sources. We additionally study the near-field resonance properties of the arrays, finding that the resonance shift observed between near-field and far-field spectra is predominantly ascribable to ohmic damping

Update on Extended Treatment for Venous Thromboembolism

The importance of assessing the probability of venous thromboembolism recurrence, a condition that includes deep vein thrombosis and pulmonary embolism, lies in the fact that it is the most important factor in deciding the duration of anticoagulant treatment. Risk of recurrence depends mostly on the presence of a risk factor for developing venous thromboembolism, with patients with unprovoked events being at the higher risk of recurrence. The risk of recurrence needs to be balanced with the risk of bleeding and the potential severity of these thrombotic and hemorrhagic events. In patients with an unprovoked venous thromboembolism who complete treatment for the acute (first 10 days) and post-acute phase of the disease (from day 10 to 3-6 months), decision has to be made regarding prolonged antithrombotic therapy to prevent recurrences. The main goal of extended treatment is preventing recurrences with a safe profile in terms of bleeding risk. Many therapeutic options are now available for these patients, including antiplatelet therapy with aspirin or direct oral anticoagulants. Moreover, apixaban and rivaroxaban at prophylactic doses have demonstrated efficacy in preventing recurrences with a low risk of bleeding

LexMeter. Validation of an automated system for the assessment of lexical competence of medical students as a prerequisite for the development of an adaptive e-learning system

Distance learning is used in medical education, even if some recent meta-analyses indicated that it is no more effective than traditional methods. To exploit the technological capabilities, adaptive distance learning systems aim to bridge the gap between the educational offer and the learner’s need. A decrease of lexical competence has been noted in many western countries, so lexical competence could be a possible target for adaptation. The “Adaptive message learning” project (Am-learning) is aimed at designing and implementing an adaptive e-learning system, driven by lexical competence. The goal of the project is to modulate texts according to the estimated skill of learners, to allow a better comprehension. LexMeter is the first of the four modules of the Am-learning system. It outlines an initial profile of the learner’s lexical competence and can also produce cloze tests, a test based on a completion task. A validation test of LexMeter was run on 443 medical students of the first, third, and sixth year at the University “Sapienza” of Rome. Six cloze tests were automatically produced, with 10 gaps each. The tests were different for each year and with varying levels of difficulty. A last cloze test was manually created as a control. The difference of the mean score between the easy tests and the tests with a medium level of difficulty was statistically significant for the third year students but not for first and sixth year. The score of the automatically generated tests showed a slight but significant correlation with the control test. The reliability (Cronbach alpha) of the different tests fluctuated under and above 0.60, as an acceptable level. In fact, classical item analysis revealed that the tests were on the average too simple. Lexical competence is a relevant outcome and its assessment allows an early detection of students at risk. Cloze tests can also be used to assess specific knowledge of technical jargon and to train reasoning skill

Atrial fibrillation as a clinical model of multimorbidity: current evidence, experimental data and a proposal for management

La Fibrillazione Atrial (FA) rappresenta una delle più diffuse aritmie cardiache nella popolazione generale. Nel corso degli ultimi anni, è emerso in maniera sempre più rilevante come i pazienti con FA siano ad elevato rischio di eventi cardiovascolari e morte, oltre che di eventi tromboembolici. Il rischio di morte e morte cardiovascolare è associato indipendentemente con diverse comorbidità sia cardiovascolari che non. Il concetto di multimorbidità è diventato di grande attualità nella valutazione clinica, soprattutto dei pazienti anziani. Attraverso l'analisi di cinque differenti corti di pazienti con FA (retrospettivo, RCT, European-wide, pazienti anziani ospedalizzati) si è potuto mettere in evidenza come esista uno stretto rapporto tra FA e multimorbidità e come nei pazienti con FA la multimorbidità sia in grado di influenza la gestione, l'andamento clinico e soprattutto il rischio di eventi clinici maggiori. L'uso di strategie integrate che contemplino la valutazione della multimorbidità da parte di medici, come l'internista, capaci di gestire accuratamente la multimorbidità, sono raccomandate al fine di ottenere una significativa riduzione del rischio di eventi clinici

Adherence to antithrombotic therapy guidelines improves mortality among elderly patients with atrial fibrillation: insights from the REPOSI study

Atrial fibrillation (AF) is associated with a substantial risk of thromboembolism and mortality, significantly reduced by oral anticoagulation. Adherence to guidelines may lower the risks for both all cause and cardiovascular (CV) deaths. Methods: Our objective was to evaluate if antithrombotic prophylaxis according to the 2012 European Society of Cardiology (ESC) guidelines is associated to a lower rate of adverse outcomes. Data were obtained from REPOSI; a prospective observational study enrolling inpatients aged ≥65 years. Patients enrolled in 2012 and 2014 discharged with an AF diagnosis were analysed. Results: Among 2535 patients, 558 (22.0 %) were discharged with a diagnosis of AF. Based on ESC guidelines, 40.9 % of patients were on guideline-adherent thromboprophylaxis, 6.8 % were overtreated, and 52.3 % were undertreated. Logistic analysis showed that increasing age (p = 0.01), heart failure (p = 0.04), coronary artery disease (p = 0.013), peripheral arterial disease (p = 0.03) and concomitant cancer (p = 0.003) were associated with non-adherence to guidelines. Specifically, undertreatment was significantly associated with increasing age (p = 0.001) and cancer (p < 0.001), and inversely associated with HF (p = 0.023). AF patients who were guideline adherent had a lower rate of both all-cause death (p = 0.007) and CV death (p = 0.024) compared to those non-adherent. Kaplan–Meier analysis showed that guideline-adherent patients had a lower cumulative risk for both all-cause (p = 0.002) and CV deaths (p = 0.011). On Cox regression analysis, guideline adherence was independently associated with a lower risk of all-cause and CV deaths (p = 0.019 and p = 0.006). Conclusions: Non-adherence to guidelines is highly prevalent among elderly AF patients, despite guideline-adherent treatment being independently associated with lower risk of all-cause and CV deaths. Efforts to improve guideline adherence would lead to better outcomes for elderly AF patient