85 research outputs found
Coherent population trapping in two-electron three-level systems with aligned spins
The possibility of coherent population trapping in two electron states with
aligned spins (ortho-system) is evidenced. From the analysis of a three-level
atomic system containing two electrons, and driven by the two laser fields
needed for coherent population trapping, a conceptually new kind of
two-electron dark state appears. The properties of this trapping are studied
and are physically interpreted in terms of a dark hole, instead of a dark
two-electron state. This technique, among many other applications, offers the
possibility of measuring, with subnatural resolution, some superposition-state
matrix-elements of the electron-electron correlation that due to their time
dependent nature are inaccesible by standard measuring procedures.Comment: 10 pages and 4 figure
Evaluation of eplerenone in the subgroup of EPHESUS patients with baseline left ventricular ejection fraction ≤30%
Aims: Because of the prognostic importance of LV dysfunction following an AMI and the increasing use of electrical and/or mechanical interventions in patients with LV systolic dysfunction, this retrospective analysis of EPHESUS patients with LVEF ≤30% at baseline was conducted to determine the value of eplerenone in this setting. Methods and Results: In EPHESUS, 6632 patients with LVEF ≤40% and clinical heart failure (HF) post‐AMI who were receiving standard therapy were randomized to eplerenone 25 mg/day titrated to 50 mg/day or placebo for a mean follow‐up of 16 months. Treatment with eplerenone in the subgroup of patients with LVEF ≤30% ( N =2106) resulted in relative risk reductions of 21% versus placebo in both all‐cause mortality ( P =0.012) and cardiovascular (CV) mortality/CV hospitalization ( P =0.001), and 23% for CV mortality ( P =0.008). The relative risk of sudden cardiac death (SCD) was reduced 33% ( P =0.01) and HF mortality/HF hospitalization was reduced 25% ( P =0.005) with eplerenone compared with placebo. Within 30 days of randomization, eplerenone resulted in relative risk reductions of 43% for all‐cause mortality ( P =0.002), 29% for CV mortality/CV hospitalization ( P =0.006), and 58% for SCD ( P =0.008). Conclusions: Treatment with eplerenone plus standard therapy in patients with post‐AMI HF and LVEF ≤30% provided significant incremental benefits in reducing both early and late mortality and morbidity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102725/1/ejhf2005-11-008.pd
Quality of Vitamin K Antagonist Control and 1-Year Outcomes in Patients with Atrial Fibrillation: A Global Perspective from the GARFIELD-AF Registry.
AIMS: Vitamin K antagonists (VKAs) need to be individually dosed. International guidelines recommend a target range of international normalised ratio (INR) of 2.0-3.0 for stroke prevention in atrial fibrillation (AF). We analysed the time in this therapeutic range (TTR) of VKA-treated patients with newly diagnosed AF in the ongoing, global, observational registry GARFIELD-AF. Taking TTR as a measure of the quality of patient management, we analysed its relationship with 1-year outcomes, including stroke/systemic embolism (SE), major bleeding, and all-cause mortality. METHODS AND RESULTS: TTR was calculated for 9934 patients using 136,082 INR measurements during 1-year follow-up. The mean TTR was 55.0%; values were similar for different VKAs. 5851 (58.9%) patients had TTR<65%; 4083 (41.1%) TTR≥65%. The proportion of patients with TTR≥65% varied from 16.7% in Asia to 49.4% in Europe. There was a 2.6-fold increase in the risk of stroke/SE, 1.5-fold increase in the risk of major bleeding, and 2.4-fold increase in the risk of all-cause mortality with TTR<65% versus ≥65% after adjusting for potential confounders. The population attributable fraction, i.e. the proportion of events attributable to suboptimal anticoagulation among VKA users, was 47.7% for stroke/SE, 16.7% for major bleeding, and 45.4% for all-cause mortality. In patients with TTR<65%, the risk of first stroke/SE was highest in the first 4 months and decreased thereafter (test for trend, p = 0.021). In these patients, the risk of first major bleed declined during follow-up (p = 0.005), whereas in patients with TTR≥65%, the risk increased over time (p = 0.027). CONCLUSION: A large proportion of patients with AF had poor VKA control and these patients had higher risks of stroke/SE, major bleeding, and all-cause mortality. Our data suggest that there is room for improvement of VKA control in routine clinical practice and that this could substantially reduce adverse outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT01090362
Prasugrel versus Clopidogrel for Acute Coronary Syndromes without Revascularization
peer reviewedBACKGROUND: The effect of intensified platelet inhibition for patients with unstable angina or myocardial infarction without ST-segment elevation who do not undergo revascularization has not been delineated. METHODS: In this double-blind, randomized trial, in a primary analysis involving 7243 patients under the age of 75 years receiving aspirin, we evaluated up to 30 months of treatment with prasugrel (10 mg daily) versus clopidogrel (75 mg daily). In a secondary analysis involving 2083 patients 75 years of age or older, we evaluated 5 mg of prasugrel versus 75 mg of clopidogrel. RESULTS: At a median follow-up of 17 months, the primary end point of death from cardiovascular causes, myocardial infarction, or stroke among patients under the age of 75 years occurred in 13.9% of the prasugrel group and 16.0% of the clopidogrel group (hazard ratio in the prasugre
Predictors of NOAC versus VKA use for stroke prevention in patients with newly diagnosed atrial fibrillation: Results from GARFIELD-AF.
INTRODUCTION: A principal aim of the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) was to document changes in treatment practice for patients with newly diagnosed atrial fibrillation during an era when non-vitamin K antagonist oral anticoagulants (NOACs) were becoming more widely adopted. In these analyses, the key factors which determined the choice between NOACs and vitamin K antagonists (VKAs) are explored. METHODS: Logistic least absolute shrinkage and selection operator regression determined predictors of NOAC and VKA use. Data were collected from 24,137 patients who were initiated on AC ± antiplatelet (AP) therapy (NOAC [51.4%] or VKA [48.6%]) between April 2013 and August 2016. RESULTS: The most significant predictors of AC therapy were country, enrolment year, care setting at diagnosis, AF type, concomitant AP, and kidney disease. Patients enrolled in emergency care or in the outpatient setting were more likely to receive a NOAC than those enrolled in hospital (OR 1.16 [95% CI: 1.04-1.30], OR: 1.15 [95% CI: 1.05-1.25], respectively). NOAC prescribing seemed to be favored in lower-risk groups, namely, patients with paroxysmal AF, normotensive patients, and those with moderate alcohol consumption, but also the elderly and patients with acute coronary syndrome. By contrast, VKAs were preferentially used in patients with permanent AF, moderate to severe kidney disease, heart failure, vascular disease, and diabetes and with concomitant AP. CONCLUSION: GARFIELD-AF data highlight marked heterogeneity in stroke prevention strategies globally. Physicians are adopting an individualized approach to stroke prevention where NOACs are favored in patients with a lower stroke risk but also in the elderly and patients with acute coronary syndrome
Effect of nesiritide in patients with acute decompensated heart failure
Background Nesiritide is approved in the United States for early relief of dyspnea in patients with acute heart failure. Previous meta-analyses have raised questions regarding renal toxicity and the mortality associated with this agent. Methods We randomly assigned 7141 patients who were hospitalized with acute heart failure to receive either nesiritide or placebo for 24 to 168 hours in addition to standard care. Coprimary end points were the change in dyspnea at 6 and 24 hours, as measured on a 7-point Likert scale, and the composite end point of rehospitalization for heart failure or death within 30 days. Results Patients randomly assigned to nesiritide, as compared with those assigned to placebo, more frequently reported markedly or moderately improved dyspnea at 6 hours (44.5% vs. 42.1%, P = 0.03) and 24 hours (68.2% vs. 66.1%, P = 0.007), but the prespecified level for significance (P≤0.005 for both assessments or P≤0.0025 for either) was not met. The rate of rehospitalization for heart failure or death from any cause within 30 days was 9.4% in the nesiritide group versus 10.1% in the placebo group (absolute difference, −0.7 percentage points; 95% confidence interval [CI], −2.1 to 0.7; P = 0.31). There were no significant differences in rates of death from any cause at 30 days (3.6% with nesiritide vs. 4.0% with placebo; absolute difference, −0.4 percentage points; 95% CI, −1.3 to 0.5) or rates of worsening renal function, defined by more than a 25% decrease in the estimated glomerular filtration rate (31.4% vs. 29.5%; odds ratio, 1.09; 95% CI, 0.98 to 1.21; P = 0.11). Conclusions Nesiritide was not associated with an increase or a decrease in the rate of death and rehospitalization and had a small, nonsignificant effect on dyspnea when used in combination with other therapies. It was not associated with a worsening of renal function, but it was associated with an increase in rates of hypotension. On the basis of these results, nesiritide cannot be recommended for routine use in the broad population of patients with acute heart failure. (Funded by Scios; ClinicalTrials.gov number, NCT00475852.
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