Treatment of very old patients with non valvular atrial fibrillation. The valuable opportunity offered by New Oral Anticoagulants, to be cautiously used

Atrial Fibrillation (AF) is the most frequent cardiac arrhythmia and its incidence increases with age reaching a 10% prevalence in the oldest old. Patients with AF have a five-fold increase in the risk of stroke. Current guidelines on AF management recommend the prescription of oral anticoagulant therapy in patients at medium and high risk of thromboembolic events. Advanced age is a risk factor for stroke in AF, but despite clear evidences a high rate of OAT under prescription is reported and particularly in the oldest old. Among the main causes of this phenomenon an enhanced risk of bleeding is often reported: this due to several factors: risk of falls, the presence of comorbidity and polifarmacy and a reduction in compliance and adherence that are common in the elderly. In recent years the international scenario in the management of OAT has significantly changed since the introduction of the new oral anticoagulants (NOA): Dabigatran, a direct thrombin inhibitor, and two oral factor Xa inhibitors Rivaroxaban and Apixaban, which have all been tested in randomized clinical trial (RELY, ROCKET-AF e ARISTOTLE) which have demonstrated non inferiority compared to warfarin in the prevention of thromboembolic events with an optimal safety profile. NOA could be an important therapeutic opportunity for stroke prevention in elderly patients with AF even if the substantial differences in mean age, anthropometric measures and comorbidity of the patients enrolled in these trials compared with those of the real world setting, oblige some caution and discussion

Age, left atrial dimension and arterial stiffness after external cardioversion of atrial fibrillation. A vascular component in arrhythmia maintenance? Results from a preliminary study.

BACKGROUND AND AIMS: Atrial fibrillation (AF) is the most frequent arrhythmia in elderly patients. Aims of this study were to evaluate the predictors of arterial stiffness after external cardioversion (ECV) of AF and to establish whether a link exists between vascular properties and left atrial diameter (LAD). METHODS: We studied 33 patients (age 73 ± 12 years). After 5 h from ECV of persistent AF, an echocardiogram was recorded and arterial stiffness was evaluated with cardio-ankle vascular stiffness index (CAVI). RESULTS: In multivariate analysis (R = 0.538, p = 0.006), CAVI (mean 9.60 ± 1.63) increased with age (p = 0.018) and with an AF length ≤3 months (p = 0.022). LAD was significantly related to CAVI (p = 0.007) even after adjustment for interventricular septum thickness (p = 0.018) (R = 0.574, p = 0.002). CONCLUSIONS: In patients with AF, immediately after ECV, arterial stiffness is associated with age and AF length, and could represent an important factor for left atrium remodeling and, therefore, for AF maintenance

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements