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Event Rates (event + rate)

Distribution by Scientific Domains

Medical Sciences	82%
Mathematics and Statistics	4%

Distribution within Medical Sciences

Cardiovascular Disease	42%
Geriatric Medicine	8%
Diabetes	4%
Gastroenterology & Hepatology	3%
13 Other Subdomains	40%

Kinds of Event Rates

adverse event rate

cardiac event rate

cardiovascular event rate

Selected Abstracts

Long-Term Incidence of Malignant Ventricular Arrhythmia and Shock Therapy in Patients with Primary Defibrillator Implantation Does Not Differ from Event Rates in Patients Treated for Survived Cardiac Arrest

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2005
ULRICH BACKENKÖHLER M.D.
Introduction: Recent trials have demonstrated benefit of prophylactic defibrillator (ICD) implantation compared to conventional treatment in high-risk patients. However, many patients have rare or no sustained arrhythmias following implantation. Our study addresses the question, whether patients with prophylactic defibrillator implantation have a lower risk for life-threatening ventricular tachycardia (VT) or ventricular fibrillation (VF) compared to sudden cardiac death (SCD) survivors. Methods and Results: Over 7 years we enrolled 245 patients. Occurrence of spontaneous sustained VT/VF resulting in adequate ICD treatment was the endpoint. Incidence, type, and treatment of sustained arrhythmia in 43 previously asymptomatic ICD recipients (group B) were compared to data of 202 survivors of imminent SCD (group A). All patients had severely impaired left ventricular ejection fraction (<45%). Group B patients had long runs (>6 cycles, <30 s) of VT during Holter monitoring and inducible sustained arrhythmia. Incidence of rapid VT and VF (cycle length <240 ms/heart rate >250 bpm) after 4 years (35% in both groups, P = ns) and adequate defibrillator therapies (57% vs 55%, P = ns) were similar in both groups after univariate and multivariate analysis. Cumulative mortality tended to be lower in group B compared to group A, but the difference was not statistically significant. Conclusion: During long-term follow-up, incidence of sustained rapid ventricular arrhythmia in prophylactically treated patients is as high as that of SCD survivors. Benefit from defibrillator implantation for primary prevention (group B) appears to be comparable to that for survived cardiac arrest (group A). [source]

Prognostic Value of 12-Lead Electrocardiogram During Dobutamine Stress Echocardiography

ECHOCARDIOGRAPHY, Issue 5 2000
Milind R. Dhond M.D.
The aim of this study was to assess the prognostic value of the 12-lead electrocardiogram (ECG) obtained during dobutamine stress echocardiography (DSE) in predicting subsequent cardiac events. We retrospectively analyzed 345 patients undergoing DSE in 1992,1994 and selected those patients with negative echo results for ischemia. Of the 200 patients with negative DSE results, a separate analysis of their ECG data was performed with results reported as either positive, negative, or nondiagnostic for ischemia. Follow-up was performed through a physician chart review and direct telephone contact. Event rates were determined for hard (myocardial infarction or cardiac death) and soft (hospitalization for angina and/or congestive heart failure, coronary angioplasty, or coronary artery bypass graft surgery) cardiac events occurring after the negative DSE for up to 6 years after the test. Death was also determined by referencing the patients' data with mortality data available on the Internet. There were 143 patients with ECG data reported as negative and 40 patients with ECG data reported as positive for ischemia. The hard and soft event rates were 1.5% and 9% per patient per year in the ECG negative group and 2% and 11% in the ECG positive group. There were no statistical differences in event rates between the two groups during the 5-year follow-up period. Our results suggest that the ECG result obtained during DSE does not confer any incremental prognostic value over the echo result. [source]

Latest news and product developments

PRESCRIBER, Issue 8 2007
Article first published online: 23 JUL 200
Lamotrigine for partial, valproate for generalised A large UK trial has shown that lamotrigine is the most effective choice in the treatment of partial epilepsy (Lancet 2007;369: 1000-15). The SANAD trial, commissioned by the National Institute for Health Research's Health Technology Assessment programme, randomised 1721 patients (for whom carbamazepine monotherapy would have been the treatment of choice) to treatment with carbamazepine, gabapentin, lamotrigine, oxcarbazepine (Trileptal) or topiramate (Topamax). Lamotrigine was associated with a longer time to treatment failure, though time to 12-month remission favoured carbamazepine. Over four years' follow-up, lamotrigine was numerically but not significantly superior. The authors concluded lamotrigine is clinically superior to carbamazepine for partial epilepsy A second arm of the trial, yet to be published, evaluated the treatment of generalised epilepsy and found valproate to be clinically most effective, though topiramate was cost effective for some patients. Chronic pain common in nursing homes Most residents in nursing homes say they have long- term pain but only one in seven say a health professional has ever discussed its treatment with them, according to a report by the Patients' Association (www.patients-association.org.uk). Pain in Older People ,A Hidden Problem was a qualitative study of 77 older residents in care homes in England. Most were frail and suffered long-term illness. The study found that 85 per cent of residents said they were often troubled by aches or pains and these lasted over a year in 74 per cent. Most described their pain as moderate (33 per cent) or severe (38 per cent) but 8 per cent said it was excruciating. Many reported limitations on mobility and social activities despite a high level of stoicism. All but one were taking medication to relive pain; one-third experienced adverse effects but 78 per cent believed drugs offered the most effective treatment. One-quarter said a doctor or nurse had discussed how to stop their pain worsening, and 15 per cent said they had discussed how to treat their pain. Visits from GPs appeared to be uncommon. Atherothrombotic events despite treatment Between one in five and one in seven of high-risk patients experience atherothrombotic events despite evidence-based treatment, the REACH study has shown (J Am Med Assoc 2007;297:1197-1206). REACH (REduction of Atherothrombosis for Continued Health) is an international observational study involving 68 236 patients with atherothrombotic disease or at least three risk factors. Most were taking conventional evidence-based medication. After one year, the incidence of the combined endpoint of cardiovascular death, myocardial infarction, stroke or hospitalisation for atherothrombotic events was approximately 15 per cent for patients with coronary artery disease or cardiovascular disease, and 21 per cent in patients with peripheral artery disease and established coronary disease. Event rates increased with the number of vascular beds affected, rising to 26 per cent in patients with three symptomatic arterial disease locations. Extended CD prescribing by nurses and pharmacists The Medicines and Healthcare products Regulatory Agency (MHRA) is consulting on expanding the prescribing of controlled drugs (CDs) by nonmedical prescribers. Currently, nurse independent prescribers can prescribe 12 CDs, including diamorphine and morphine, but pharmacist independent prescribers may not prescribe any CDs. The proposal is to allow both professions to prescribe any CDs within their competence, with the exception of cocaine, diamorphine or dipipanone for the management of addiction. The closing date for consultation is 15 June. Consultation is also underway on expanding the range of CDs nurses and pharmacists can prescribe under a patient group direction (PGD), and their use for pain relief. The closing date for consultation is 20 April. Intrinsa: transdermal testosterone for women A transdermal formulation of testosterone has been introduced for the treatment of low sexual desire associated with distress in women who have experienced an early menopause following hysterectomy involving a bilateral oophorectomy and are receiving concomitant oestrogen therapy. Manufacturer Procter & Gamble says that Intrinsa, a twice-weekly patch, delivers testosterone 300µg every 24 hours, achieving premenopausal serum testosterone levels. Clinical trials showed that Intrinsa reduced distress in 65-68 per cent and increased satisfying sexual activity in 51-74 per cent of women. A month's treatment (eight patches) costs £28.00. Fish oil for secondary ,not primary ,prevention of CHD Supplementing statin therapy with eicosapentaenoic acid (EPA) reduces the risk of major coronary events in patients with coronary heart disease (CHD) ,but not in patients with no history of CHD Lancet 2007;369:1090-8). The five-year study in 18 645 patients with total cholesterol levels of 6.5mmol per litre or greater found that the incidence of sudden cardiac death, fatal and nonfatal myocardial infarction in CHD patients treated with EPA plus a statin was 8.7 per cent compared with 10.7 per cent with a statin alone (relative risk reduction 19 per cent). A similar relative risk reduction in patients with no CHD was not statistically significant. There was no difference in mortality between the groups but EPA did reduce unstable angina and nonfatal coronary events. Department pilots information prescriptions The Department of Health has announced 20 sites to pilot information prescriptions prior to a nationwide roll-out in 2008. The prescriptions will guide people with long-term conditions such as diabetes and cancer to sources of support and information about their condition. The Department hopes the project will increase patients' understanding of their discussions with health professionals, empower them to locate the information they need, and provide long-term support. NPSA guidelines for safer prescribing The National Patient Safety Agency (www.npsa.nhs.uk) has published five guidelines to improve medication safety in the NHS. Targeting ,high-risk issues', the guidance covers anticoagulant prescribing, liquid medicines for oral or enteral administration, injectable medicines, epidural injections and infusions, and paediatric intravenous infusions. The implementation of each guide is supported by additional tools and resources. Better adherence not matched to outcomes A systematic review has found that interventions can increase adherence to prescribed medication but there is no evidence that clinical outcomes also improve (Arch Intern Med 2007;167:540-9). The review of 37 trials identified 20 reporting increased adherence. The most effective interventions were behavioural changes to reduce dose demands and those involving monitoring and feedback. Improvements in clinical outcomes were variable and did not correspond to changes in adherence. Antidepressant plus mood stabiliser no better US investigators have found that combining a mood stabiliser with an antidepressant is no more effective than a mood stabiliser alone in preventing mood changes (N Engl J Med 2007; published online 28 March, doi.10.1056/NEJMoa064135). The study found durable recovery occurred in 23.5 per cent of patients treated with a mood stabiliser and adjunctive antidepressant therapy for six months compared with 27.3 per cent of those taking a mood stabiliser plus placebo. [source]

Transcatheter versus Surgical Closure of Secundum Atrial Septal Defect in Adults: Impact of Age at Intervention.

CONGENITAL HEART DISEASE, Issue 3 2007
A Concurrent Matched Comparative Study
Abstract Objectives., To compare the short- and mid-term outcomes of surgical (SUR) vs. transcatheter closure of secundum atrial septal defect (ASD) using Amplatzer septal occluder (ASO) in adults with a very similar spectrum of the disease; and to identify predictors for the primary end point. Design., Single-center, concurrent comparative study. Surgically treated patients were randomly matched (2:1) by age, sex, date of procedure, ASD size, and hemodynamic profile. Setting., Tertiary referral center. Patients., One hundred sixty-two concurrent patients with ASD submitted to ASO (n = 54) or SUR closure (n = 108) according with their preferences. Main Outcome Measures., Primary end point was a composite index of major events including failure of the procedure, important bleeding, critical arrhythmias, serious infections, embolism, or any major cardiovascular intervention-related complication. Predictors of these major events were investigated. Results., Atrial septal defects were successfully closed in all patients, and there was no mortality. The primary event rate was 13.2% in ASO vs. 25.0% in SUR (P = .001). Multivariate analysis showed that higher rate of events was significantly associated with age >40 years; systemic/pulmonary output ratio <2.1; and systolic pulmonary arterial pressure >50 mm Hg; while in the ASO group the event rate was only associated with the ASD size (>15 cm2/m2; relative risk = 1.75, 95% confidence interval 1.01,8.8). There were no differences in the event-free survival curves in adults with ages <40 years. Conclusions., The efficacy for closure ASD was similar in both groups. The higher morbidity observed in SUR group was observed only in the patients submitted to the procedure with age >40 years. The length of hospital stay was shorter in the ASO group. Surgical closure is a safe and effective treatment, especially in young adults. There is certainly nothing wrong with continuing to do surgery in countries where the resources are limited. [source]

Safety of pramlintide added to mealtime insulin in patients with type 1 or type 2 diabetes: a large observational study

DIABETES OBESITY & METABOLISM, Issue 6 2010
R. Pencek
The objective of this Phase 4, open-label, multicentre, observational study was to fulfil food and drug administration (FDA) postapproval requirement to evaluate in healthcare practices the risk of insulin-induced severe hypoglycaemia following initiation of pramlintide therapy in N = 1297 patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) with inadequate glycaemic control. The duration of the study was approximately 6 months. During the adjustment period (0,3 months), the incidence and event rate of patient-ascertained severe hypoglycaemia (PASH) were 4.8% and 0.33 events/patient-year in patients with T1DM and 2.8% and 0.19 events/patient-year in patients with T2DM. During the maintenance period (>3,6 months), the incidence and event rate of PASH declined in patients with T1DM or T2DM. This study confirms that in healthcare practices, the risk of insulin-induced severe hypoglycaemia following the initiation of pramlintide is low in patients with T1DM or T2DM. [source]

Myocardial perfusion imaging and cardiac events in a cohort of asymptomatic patients with diabetes living in southern France

DIABETIC MEDICINE, Issue 4 2006
A. Sultan
Abstract Aims, To assess the association between abnormal stress myocardial perfusion imaging (MPI) and cardiac events (CE) in asymptomatic patients with diabetes and with , 1 additional risk factor. Predictors of abnormal stress MPI were also evaluated. Methods, Four hundred and forty-seven consecutive patients who underwent stress MPI were prospectively followed for 2.1 [0.5,4.1] years for the subsequent occurrence of hard CE (myocardial infarction and sudden or coronary death) and soft CE (unstable angina and ischaemic heart failure requiring hospitalization). Re-vascularization procedures performed as a result of the screening protocol were not included in the analysis. Results, Follow-up was successful in 419 of 447 patients (94%), of whom 71 had abnormal MPI at baseline. Medical therapy was intensified in all subjects and especially in those with abnormal MPI. Twenty-three patients with abnormal MPI underwent a re-vascularization procedure. CEs occurred in 14 patients, including six of 71 patients (8.5%) with abnormal MPI and eight of 348 patients (2.3%) with normal MPI (P < 0.005). Only two patients developed a hard CE and 12 a soft CE. In multivariate analysis, abnormal MPI was the strongest predictor for CEs [odds ratio (OR) (95% CI) = 5.6 (1.7,18.5)]. Low-density lipoprotein cholesterol , 3.35 mmol/l [OR (95% CI) = 7.3; 1.5,34.7] and age > median [OR (95% CI) = 6.0 (1.2,28.6)] were additional independent predictors for CE. The independent predictors for abnormal MPI were male gender, plasma triglycerides , 1.70 mmol/l, creatinine clearance < 60 ml/min and HbA1c > 8%, with male gender the strongest [OR (95% CI) = 4.0 (1.8,8.8)]. Conclusions, Asymptomatic patients with diabetes in this study had a very low hard cardiac event rate over an intermediate period. This could be explained by the effects of intervention or by the low event rate in the background population. Randomized studies of cardiac heart disease screening are required in asymptomatic subjects with diabetes to determine the effectiveness of this intervention. Diabet. Med. (2006) [source]

A damage mechanics model for power-law creep and earthquake aftershock and foreshock sequences

GEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2000
Ian G. Main
It is common practice to refer to three independent stages of creep under static loading conditions in the laboratory: namely transient, steady-state, and accelerating. Here we suggest a simple damage mechanics model for the apparently trimodal behaviour of the strain and event rate dependence, by invoking two local mechanisms of positive and negative feedback applied to constitutive rules for time-dependent subcritical crack growth. In both phases, the individual constitutive rule for measured strain , takes the form ,(t),=,,0,[1,+,t/m,]m, where , is the ratio of initial crack length to rupture velocity. For a local hardening mechanism (negative feedback), we find that transient creep dominates, with 0,<,m,<,1. Crack growth in this stage is stable and decelerating. For a local softening mechanism (positive feedback), m,<,0, and crack growth is unstable and accelerating. In this case a quasi-static instability criterion , , , can be defined at a finite failure time, resulting in the localization of damage and the formation of a throughgoing fracture. In the hybrid model, transient creep dominates in the early stages of damage and accelerating creep in the latter stages. At intermediate times the linear superposition of the two mechanisms spontaneously produces an apparent steady-state phase of relatively constant strain rate, with a power-law rheology, as observed in laboratory creep test data. The predicted acoustic emission event rates in the transient and accelerating phases are identical to the modified Omori laws for aftershocks and foreshocks, respectively, and provide a physical meaning for the empirical constants measured. At intermediate times, the event rate tends to a relatively constant background rate. The requirement for a finite event rate at the time of the main shock can be satisfied by modifying the instability criterion to having a finite crack velocity at the dynamic failure time, dx/dt , VR,, where VR is the dynamic rupture velocity. The same hybrid model can be modified to account for dynamic loading (constant stress rate) boundary conditions, and predicts the observed loading rate dependence of the breaking strength. The resulting scaling exponents imply systematically more non-linear behaviour for dynamic loading. [source]

A review of the therapeutic agents used in the management of polycythaemia vera

HEMATOLOGICAL ONCOLOGY, Issue 2 2007
Mary Frances McMullin
Abstract The acquired clonal disorder Polycythaemia Vera leads to increased erythropoiesis, myelopoiesis and megakaryopoeisis. These anomalies result in an increased incidence of thromboembolic events, transformation to acute leukaemia and myelofibrosis. Treatments which aim to reduce the event rate may increase anaemia but may also affect the rate of complications. This paper reviews the evidence for the treatments which have been used in the management of the disorders over a 50 plus year period. Assessment of this evidence and its limitations form the basis for the current suggested management plans. Copyright © 2007 John Wiley & Sons, Ltd. [source]

A Descriptive Comparison of Ultrasound-guided Central Venous Cannulation of the Internal Jugular Vein to Landmark-based Subclavian Vein Cannulation

ACADEMIC EMERGENCY MEDICINE, Issue 4 2010
Daniel Theodoro MD
Abstract Objectives:, The safest site for central venous cannulation (CVC) remains debated. Many emergency physicians (EPs) advocate the ultrasound-guided internal jugular (USIJ) approach because of data supporting its efficiency. However, a number of physicians prefer, and are most comfortable with, the subclavian (SC) vein approach. The purpose of this study was to describe adverse event rates among operators using the USIJ approach, and the landmark SC vein approach without US. Methods:, This was a prospective observational trial of patients undergoing CVC of the SC or internal jugular veins in the emergency department (ED). Physicians performing the procedures did not undergo standardized training in either technique. The primary outcome was a composite of adverse events defined as hematoma, arterial cannulation, pneumothorax, and failure to cannulate. Physicians recorded the anatomical site of cannulation, US assistance, indications, and acute complications. Variables of interest were collected from the pharmacy and ED record. Physician experience was based on a self-reported survey. The authors followed outcomes of central line insertion until device removal or patient discharge. Results:, Physicians attempted 236 USIJ and 132 SC cannulations on 333 patients. The overall adverse event rate was 22% with failure to cannulate being the most common. Adverse events occurred in 19% of USIJ attempts, compared to 29% of non,US-guided SC attempts. Among highly experienced operators, CVCs placed at the SC site resulted in more adverse events than those performed using USIJ (relative risk [RR] = 1.89, 95% confidence interval [CI] = 1.05 to 3.39). Conclusions:, While limited by observational design, our results suggest that the USIJ technique may result in fewer adverse events compared to the landmark SC approach. ACADEMIC EMERGENCY MEDICINE 2010; 17:416,422 © 2010 by the Society for Academic Emergency Medicine [source]

Risk Stratification of Individuals with the Brugada Electrocardiogram: A Meta-Analysis

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2006
ANIL K. GEHI M.D.
Objectives: We performed a meta-analysis of prognostic studies of patients with a Brugada ECG to assess predictors of events. Background: The Brugada syndrome is an increasingly recognized cause of idiopathic ventricular fibrillation; however, there is wide variation in the prognosis of patients with the Brugada ECG. Methods and Results: We retrieved 30 prospective studies of patients with the Brugada ECG, accumulating data on 1,545 patients. Summary estimates of the relative risk (RR) of events (sudden cardiac death [SCD], syncope, or internal defibrillator shock) for a variety of potential predictors were made using a random-effects model. The overall event rate at an average of 32 months follow-up was 10.0% (95% CI 8.5%, 11.5%). The RR of an event was increased (P < 0.001) among patients with a history of syncope or SCD (RR 3.24 [95% CI 2.13, 4.93]), men compared with women (RR 3.47 [95% CI 1.58, 7.63]), and patients with a spontaneous compared with sodium-channel blocker induced Type I Brugada ECG (RR 4.65 [95% CI 2.25, 9.58]). The RR of events was not significantly increased in patients with a family history of SCD (P = 0.97) or a mutation of the SCN5A gene (P = 0.18). The RR of events was also not significantly increased in patients inducible compared with noninducible by electrophysiologic study (EPS) (RR 1.88 [95% CI 0.62, 5.73], P = 0.27); however, there was significant heterogeneity of the studies included. Conclusions: Our findings suggest that a history of syncope or SCD, the presence of a spontaneous Type I Brugada ECG, and male gender predict a more malignant natural history. Our findings do not support the use of a family history of SCD, the presence of an SCN5A gene mutation, or EPS to guide the management of patients with a Brugada ECG. [source]

The Prognostic Value of Combined Fractional Flow Reserve and TIMI Frame Count Measurements in Patients with Stable Angina Pectoris and Acute Coronary Syndrome

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 5 2010
ALI M. ESEN M.D.
Background:,The aim of this study was to evaluate the prognostic value of different fractional flow reserve (FFR) cutoff values and corrected thrombolysis in myocardial infarction frame (TIMI) count (CTFC) measurements in a series of consecutive patients with moderate coronary lesions, including patients with unstable angina, myocardial infarction, and/or positive noninvasive functional test findings. Methods:,We included 162 consecutive coronary patients in whom revascularization of a moderate coronary lesion was deferred based on a FFR value ,0.75. Patients were divided according to the results of the intracoronary pressure and flow measurements into four groups: group A: 0.75 , FFR , 0.85 and CTFC > 28 (n=22), group B: 0.75 , FFR , 0.85 and CTFC , 28 (n = 55), group C: 0.85 < FFR and CTFC > 28 (n = 19), and group D: 0.85 < FFR and CTFC , 28 (n = 66). Adverse cardiac events and the presence of angina were evaluated at follow-up. Results:,At a mean follow-up of 18 ± 10 months, cardiac event rate in patients with 0.75 , FFR , 0.85 and FFR > 0.85 were 22% and 9%, respectively (P = 0.026) and also, a trend was observed toward a higher cardiac event rate in case of an abnormal CTFC (CTFC > 28) compared to a normal CTFC (24% vs 12%, P = 0.066). Furthermore, a significantly higher cardiac event rate was observed when group A was compared to group D (31.8% vs 7.6%, respectively, P = 0.004). Conclusion:,Patients with potential microvascular dysfunction and borderline FFR values should be interpreted with caution, and management strategies should be guided not only by pressure measurement, but also by possibly supplementary clinical risk stratification and noninvasive tests. (J Interven Cardiol 2010;23:421,428) [source]

Incidence and risk factors for pulmonary embolism in the postpartum period

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2010
J. M. MORRIS
Summary.,Background: Pregnancy and the postpartum period are times of hypercoagulability, increasing the risk of pulmonary embolism. Better quantification of risk factors can help target women who are most likely to benefit from postpartum thromboprophylaxis with heparin. Objectives: To determine the incidence rate and timing of postpartum pulmonary embolism, and assess perinatal risk factors predictive of the event. Patients/Methods: Antenatal, delivery and postpartum admission records of a cohort of 510 889 pregnancies were analysed. Pulmonary embolism was identified from ICD-10 codes at delivery, transfer or upon readmission at any time in the postpartum period. Results: Pulmonary embolism occurred in 375 women and was most common postpartum. The rate of postpartum pulmonary embolism without an antecedent thrombotic event was 0.45 per 1000 births. By the end of 4 weeks postpartum, the weekly rate approached the background rate of pulmonary embolism in the population. Although the Caesarean section rate rose significantly throughout the study period, and pulmonary embolism was more common following abdominal birth, the rate of pulmonary embolism following Caesarean birth fell. Regression modelling demonstrated that stillbirth (adjusted odds ratio [aOR] =5.97), lupus (aOR = 8.83) and transfusion of a coagulation product (aOR = 8.84) were most strongly associated with pulmonary embolism postpartum. Conclusions: Pulmonary embolism most commonly occurs up to 4 weeks postpartum and following abdominal birth. Despite this the absolute event rate is low and a broadly inclusive risk factor approach to the use of pharmacological thromboprophylaxis will require many women to be exposed to heparin to prevent an embolic event. [source]

High-energy neutrino emission from low-mass microquasars

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2010
J. F. Zhang
ABSTRACT In this paper we study the high-energy neutrino emission from low-mass microquasars (LMMQs) by assuming that an acceleration region for particles is located in the inner jet, based on the framework of a hadronic jet model. Adopting the parametrized formulae for inelastic pp interactions and the recent p, parametrizations, we calculate the spectral energy distributions (SEDs) of various photon and neutrino spectra. Furthermore, we also consider the electromagnetic cascade processes due to ,, absorption. We then apply the jet model to the microquasar (MQ) GX 339,4, and calculate the expected neutrino event rate for three years of observations using the newest effective area of the KM3NeT detector in the Mediterranean Sea. The resulting results indicate that (1) photon spectra can roughly reproduce observations from radio to X-ray energies, and can also predict emission fluxes at high and very high energies (VHE); (2) GX 339,4 is a potential neutrino source, neutrinos from which are likely to be identified with some years of observations from the next-generation -scale neutrino telescopes. [source]

Microlensing by cosmic strings

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2008
Konrad Kuijken
ABSTRACT We consider the signature and detectability of gravitational microlensing of distant quasars by cosmic strings. Because of the simple image configuration such events will have a characteristic lightcurve, in which a source would appear to brighten by exactly a factor of 2, before reverting to its original apparent brightness. We calculate the optical depth and event rate, and conclude that current predictions and limits on the total length of strings on the sky imply optical depths of , 10,8 and event rates of fewer than one event per 109 sources per year. Disregarding those predictions but replacing them with limits on the density of cosmic strings from the cosmic microwave background fluctuation spectrum, leaves only a small region of parameter space (in which the sky contains about 3 × 105 strings with deficit angle of the order of 0.3 milli-seconds) for which a microlensing survey of exposure 107 source years, spanning a 20,40-year period, might reveal the presence of cosmic strings. [source]

Supermassive black hole merger rates: uncertainties from halo merger theory

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2006
Adrienne L. Erickcek
ABSTRACT The merger of two supermassive black holes is expected to produce a gravitational-wave signal detectable by the Laser Interferometer Space Antenna(LISA). The rate of supermassive-black-hole mergers is intimately connected to the halo merger rate, and the extended Press-Schechter (EPS) formalism is often employed when calculating the rate at which these events will be observed by LISA. This merger theory is flawed and provides two rates for the merging of the same pair of haloes. We show that the two predictions for the LISA supermassive-black-hole-merger event rate from EPS merger theory are nearly equal because mergers between haloes of similar masses dominate the event rate. An alternative merger rate may be obtained by inverting the Smoluchowski coagulation equation to find the merger rate that preserves the Press,Schechter halo abundance, but these rates are only available for power-law power spectra. We compare the LISA event rates derived from the EPS merger formalism to those derived from the merger rates obtained from the coagulation equation and find that the EPS LISA event rates are 30 per cent higher for a power spectrum spectral index that approximates the full , cold dark matter result of the EPS theory. [source]

Once-Daily Prolonged-Release Tacrolimus (ADVAGRAF) Versus Twice-Daily Tacrolimus (PROGRAF) in Liver Transplantation

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2010
P. Trune
The efficacy and safety of dual-therapy regimens of twice-daily tacrolimus (BID; Prograf) and once-daily tacrolimus (QD; Advagraf) administered with steroids, without antibody induction, were compared in a multicenter, 1:1-randomized, two-arm, parallel-group study in 475 primary liver transplant recipients. A double-blind, double-dummy 24-week period was followed by an open extension to 12 months posttransplant. The primary endpoint, event rate of biopsy-proven acute rejection (BPAR) at 24 weeks, was 33.7% for tacrolimus BID versus 36.3% for tacrolimus QD (Per-protocol set; p = 0.512; treatment difference 2.6%, 95% confidence interval ,7.3%, 12.4%), falling within the predefined 15% noninferiority margin. At 12 months, BPAR episodes requiring treatment were similar for tacrolimus BID and QD (28.1% and 24.7%). Twelve-month patient and graft survival was 90.8% and 85.6% for tacrolimus BID and 89.2% and 85.3% for tacrolimus QD. Adverse event (AE) profiles were similar for both tacrolimus BID and QD with comparable incidences of AEs and serious AEs. Tacrolimus QD was well tolerated with similar efficacy and safety profiles to tacrolimus BID. [source]

Long QT Syndrome in African-Americans

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 1 2010
Thomas Fugate II B.S.
Background: We evaluated the risk factors and clinical course of Long QT syndrome (LQTS) in African-American patients. Methods: The study involved 41 African-Americans and 3456 Caucasians with a QTc , 450 ms from the U.S. portion of the International LQTS Registry. Data included information about the medical history and clinical course of the LQTS patients with end points relating to the occurrence of syncope, aborted cardiac arrest, or LQTS-related sudden cardiac death from birth through age 40 years. The statistical analyses involved Kaplan-Meier time to event graphs and Cox regression models for multivariable risk factor evaluation. Results: The QTc was 29 ms longer in African-Americans than Caucasians. Multivarite Cox analyses with adjustment for decade of birth revealed that the cardiac event rate was similar in African-Americans and Caucasians with LQTS and that beta-blockers were equally effective in reducing cardiac events in the two racial groups. Conclusions: The clinical course of LQTS in African-Americans is similar to that of Caucasians with comparable risk factors and benefit from beta-blocker therapy in the two racial groups. Ann Noninvasive Electrocardiol 2010;15(1):73,76 [source]

Flexible Estimation of Differences in Treatment-Specific Recurrent Event Means in the Presence of a Terminating Event

BIOMETRICS, Issue 3 2009
Qing Pan
Summary In this article, we consider the setting where the event of interest can occur repeatedly for the same subject (i.e., a recurrent event; e.g., hospitalization) and may be stopped permanently by a terminating event (e.g., death). Among the different ways to model recurrent/terminal event data, the marginal mean (i.e., averaging over the survival distribution) is of primary interest from a public health or health economics perspective. Often, the difference between treatment-specific recurrent event means will not be constant over time, particularly when treatment-specific differences in survival exist. In such cases, it makes more sense to quantify treatment effect based on the cumulative difference in the recurrent event means, as opposed to the instantaneous difference in the rates. We propose a method that compares treatments by separately estimating the survival probabilities and recurrent event rates given survival, then integrating to get the mean number of events. The proposed method combines an additive model for the conditional recurrent event rate and a proportional hazards model for the terminating event hazard. The treatment effects on survival and on recurrent event rate among survivors are estimated in constructing our measure and explain the mechanism generating the difference under study. The example that motivates this research is the repeated occurrence of hospitalization among kidney transplant recipients, where the effect of expanded criteria donor (ECD) compared to non-ECD kidney transplantation on the mean number of hospitalizations is of interest. [source]

Carotid artery stent placement is safe in the very elderly (,80 years),

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2008
Carlos A. Velez MD
Abstract Background: Carotid artery stent (CAS) placement is an alternative to carotid endarterectomy (CEA) for stroke prevention. Clinical adoption of CAS depends on its safety and efficacy compared to CEA. There are conflicting reports in the literature regarding the safety of CAS in the elderly. To address these safety concerns, we report our single-center 13-year CAS experience in very elderly (,80 years of age) patients. Methods: Between 1994 and 2007, 816 CAS procedures were performed at the Ochsner Clinic Foundation. Very elderly patients, those ,80 years of age, accounted for 126 (15%) of all CAS procedures. Independent neurologic examination was performed before and after the CAS procedure. Results: The average patient age was 82.9 ± 2.9 years. Almost one-half (44%) were women and 40% were symptomatic from their carotid stenoses. One-third of the elderly patients met anatomic criteria for high surgical risk as their indication for CAS. The procedural success rate was 100% with embolic protection devices used in 50%. The 30-day major adverse coronary or cerebral events (MACCE) rate was 2.7% (n = 3) with all events occurring in the symptomatic patient group [death = 0.9% (n = 1), myocardial infarction = 0%, major (disabling) stroke = 0.9% (n = 1), and minor stroke = 0.9% (n = 1)]. Conclusion: Elderly patients, ,80 years of age, may undergo successful CAS with a very low adverse event rate as determined by an independent neurological examination. We believe that careful case selection and experienced operators were keys to our success. © 2008 Wiley-Liss, Inc. [source]

Transcatheter closure of high-risk muscular ventricular septal defects with the CardioSEAL occluder: Initial report from the CardioSEAL VSD Registry

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 5 2007
D. Scott Lim MD
Abstract Objectives: The CardioSEAL VSD registry was created to track safety of the device to close high-risk Ventricular Septal Defect (VSD). Background: This is the first report from the multi-centered CardioSEAL VSD registry reviewing demographics and initial results. Methods: Centers recruited patients with VSD who were high-risk for surgery due to medical condition or anatomic features. Results: 18 centers contributed data on 55 high-risk patients who had 61 VSD-occlusion procedures, with age of range of 5 days to 65 years and using one to six devices. Implantation approach was transvenous in 48, perventricular in five, and by combined approach in two patients. Ninety-two percent of intended VSD device implants were judged successful. Twenty-two patients had single VSD closed by single device in 18 and by two devices in four patients. All patients <8 kg underwent perventricular device implantation. Thirty-three patients had multiple VSDs which were closed by a single device in 23, and multiple devices in 10. At discharge echocardiography showed total residual flow through all VSDs in which devices were used was classified as "Small" or less in 74%, "More than small" in 11%, and "Uncertain" in 15%. Eight major adverse events occurred in 5/61 cases (8% event rate), with 3/81 devices embolized (4% embolization rate), 5/81 devices surgically explanted (6% explant rate), and no deaths judged to be procedure-related. Conclusion: This initial report from the multi-centered CardioSEAL VSD registry demonstrates the safety of the device to close high-risk VSDs. © 2007 Wiley-Liss, Inc. [source]

Relationship between a Clear-cut Alternative Noncardiac Diagnosis and 30-day Outcome in Emergency Department Patients with Chest Pain

ACADEMIC EMERGENCY MEDICINE, Issue 3 2007
Judd E. Hollander MD
Background: Accurate identification of patients with acute coronary syndromes (ACSs) in the emergency department (ED) remains problematic. Studies have not been able to identify a cohort of patients that are safe for immediate ED discharge; however, prior studies have not examined the utility of a clear-cut alternative noncardiac diagnosis. Objectives: To compare the 30-day event rate in ED chest pain patients who were diagnosed with a clear-cut alternative noncardiac diagnosis with the 30-day event rate in the cohort of patients in whom a definitive diagnosis could not be made in the ED. Methods: This was a prospective cohort study of consecutive ED patients with potential ACS. Data included demographics, medical and cardiac history, laboratory and electrocardiogram results, and whether or not the treating physician ascribed the condition to a clear-cut alternative noncardiac diagnosis. The main outcome was death, acute myocardial infarction (AMI), or revascularization within 30 days, as determined by phone follow-up or medical record review. Results: The investigators enrolled 1,995 patients in the ED who had potential ACSs. Overall, 77 had a final hospital diagnosis of AMI (4%). Within 30 days, 73 patients received revascularization (4%), and 26 died (1%). There were 599 (30%) patients given a clear-cut alternative noncardiac diagnosis. Comparing the patients with a clear-cut alternative noncardiac diagnosis with those without an obvious noncardiac diagnosis, the presence of a clear-cut alternative noncardiac diagnosis was associated with a reduced risk of an in-hospital triple-composite endpoint (death, MI, and revascularization), with a risk ratio of 0.32 (95% confidence interval [CI] = 0.19 to 0.55) and 30-day triple-composite endpoint with a risk ratio of 0.45 (95% CI = 0.29 to 0.69); however, patients with a clear-cut alternative noncardiac diagnosis still had a 4% event rate at 30 days (95% CI = 2.4% to 5.6%). Conclusions: In the ED chest pain patient, the presence of a clear-cut alternative noncardiac diagnosis reduces the likelihood of a composite outcome of death and cardiovascular events within 30 days. However, it does not reduce the event rate to an acceptable level to allow ED discharge of these patients. [source]

Therapeutic strategies, immediate and mid-term outcomes in non-ST-segment elevation acute coronary syndromes with respect to age: A single-center registry of 488 consecutive patients

CLINICAL CARDIOLOGY, Issue 8 2004
Mario Leoncini M.D.
Abstract Background: Elderly patients with non-ST-elevation acute coronary syndromes (NSTE-ACS) may receive benefit from an early invasive strategy. However, aged patients often suffer from comorbidities that may contraindicate an invasive approach and affect prognosis adversely. The impact of comorbidities on an invasive approach to NSTE-ACS in the elderly has not been fully investigated. Hypothesis: This study sought to examine the outcome of an unselected population of patients with NSTE-ACS stratified according to age and treatment approach. Methods: The feasibility and efficacy of an invasive strategy for NSTE-ACS and the 6-month outcome were assessed in 253 unselected consecutive patients , 70 years (elderly) and compared with those of 235 unselected consecutive patients < 70 years. Results: Angiography was not performed in 69 patients (86% , 70 years) because of contraindications. In the whole population, the 6-month event rate was significantly higher in elderly compared with younger patients (22 vs. 14%; odds ratio 1.8, 95% confidence interval 1.1-2.9; p<0.02). This difference was driven by the high event rate observed in the elderly with contraindications to angiography (47 vs. 16% in the elderly treated invasively; p < 0.002). On the other hand, no significant difference was observed in the 6-month event rate between elderly and younger patients undergoing an invasive approach (16 vs. 13%; p=0.36). Contraindications to angiography,namely, creatinine , 1.5 mg/dl and elevated troponin I at admission,were the only independent predictors of 6-month outcome. Conclusions: The invasive approach was feasible in 77% of patients , 70 years. Those with contraindications to angiography showed a poor mid-term prognosis. The early invasive strategy was associated with more favorable outcomes regardless of age. [source]

A Risk Adjusted Method for Comparing Adverse Outcomes among Practitioners in Pediatric and Congenital Cardiac Catheterization

CONGENITAL HEART DISEASE, Issue 4 2008
Lisa Bergersen MD
ABSTRACT Objective., We sought to develop a method to adjust for case mix diversity and allow comparison of adverse outcome rates among practitioners in pediatric and congenital cardiac catheterization. Patients and Methods., A single institutional database that captured demographic and procedural data was used to identify patient and procedural characteristics associated with adverse events (AE) and any high severity event classified as preventable or possibly preventable (P/PP). Diagnostic and procedural risk groups were created and indicators of hemodynamic vulnerability were defined. Expected event rates by the practitioners adjusting for case mix were calculated. Standardized adverse event ratios (SAER), defined as the observed rate divided by the expected rate for each practitioner were calculated with 95% confidence intervals. Results., The database included 1727 hemodynamic (30%) and interventional (70%) cases performed by seven practitioners in 18 months. During 147 cases, at least one P/PP AE occurred; among the seven practitioners observed, event rates ranged from 3.2 to 14.2%. In multivariable analysis, risk factors for all P/PP events included highest procedure risk group (odds ratio [OR] 2.1 for group 2, and 2.8 for group 3, relative to group 1, P = .001 and P < .001, respectively) and weight less than 4 kg (OR 2.8, P < .001). High severity P/PP events occurred in 67 cases with rates ranging from 2.0 to 6.6% by the practitioners. For these events, risk factors included: highest procedure risk group (OR 4.5 for group 2, and 4.9 for group 3, both P < .001) and an indicator of hemodynamic vulnerability (OR 1.8, P = .026). For the seven practitioners, the SAER ranged from 0.41 to 1.32 for any P/PP AE and from 0.69 to 1.44 for P/PP high severity events. In this cohort, we did not identify any statistically significant performance differences. Conclusion., Despite wide variations in case mix complexity in pediatric and congenital cardiac catheterization, this study demonstrates a method for risk adjustment which allows equitable comparisons among practitioners at a single institution. [source]

A Randomized, Bilateral, Prospective Comparison of Calcium Hydroxylapatite Microspheres versus Human-Based Collagen for the Correction of Nasolabial Folds

DERMATOLOGIC SURGERY, Issue 2007
STACY SMITH MD
BACKGROUND Current soft tissue fillers are a compromise between ease of use, duration of correction, reactivity, and cost. A product utilizing calcium hydroxylapatite (CaHA) is currently being used as a soft tissue filler. OBJECTIVE The objective was to compare the efficacy and safety of CaHA microspheres versus human-based collagen for the correction of nasolabial folds. MATERIALS AND METHODS Four centers enrolled 117 subjects with moderate to deep nasolabial folds. Subjects received CaHA on one side of the face and human collagen on the other. Up to two touch-ups were allowed. A blinded panel of experts evaluated subject photographs from initial and follow-up visits. RESULTS Seventy-nine percent of subjects had superior improvement on the CaHA side through 6 months (p<.0001). For optimal correction, significantly less volume and fewer injections were needed for CaHA than for collagen (p<.0001). Adverse event rates were comparable, with some increase in bruising and edema for CaHA-treated sides. Adverse event duration was similar for both groups and generally resolved within 14 to 21 days. CONCLUSION This CaHA-based product gives significantly longer-lasting correction of nasolabial folds compared to human collagen. Less total material and fewer injections are required. The adverse event profile of the product is similar to the collagen-based product. [source]

Bariatric surgery vs. advanced practice medical management in the treatment of type 2 diabetes mellitus: rationale and design of the Surgical Therapy And Medications Potentially Eradicate Diabetes Efficiently trial (STAMPEDE)

DIABETES OBESITY & METABOLISM, Issue 5 2010
Sangeeta R. Kashyap
Obesity and Type 2 diabetes mellitus (T2DM) are closely interrelated, and are two of the most common chronic, debilitating diseases worldwide. Surgical approaches to weight loss (bariatric surgery) result in marked improvement of T2DM, however randomized trials directly comparing the efficacy of surgical and medical approaches are lacking. The Surgical Therapy and Medications Potentially Eradicate Diabetes Efficiently (STAMPEDE) trial was designed to evaluate the efficacy of two bariatric surgery procedures involving gastric restriction only (laparascopic sleeve gastrectomy) and gastric bypass (Roux-en-Y) to advanced medical therapy in patients with T2DM with modest obesity with BMI of 27,42 kg/m2. This single site, prospective, randomized controlled trial will enroll 150 subjects who will be followed. The primary end point will be the rate of biochemical resolution of T2DM at 1 year as measured by HbA1c < 6%. The safety and adverse event rates will also be compared between the three arms of the study. [source]

Risk Stratification and Prognosis in Octogenarians Undergoing Stress Echocardiographic Study

ECHOCARDIOGRAPHY, Issue 8 2007
F. A. C. C., Farooq A. Chaudhry M.D.
Background: The prognostic value of stress echocardiography (SE) for the diagnosis and risk stratification of coronary artery disease in octogenarians is not well defined. Methods: Follow-up of 5 years (mean 2.9 ± 1.0 years) for confirmed nonfatal myocardial infarction (n = 17) and cardiac death (n = 37) was obtained in 335 patients, age ,80 years (mean age 84 ± 3 years, 44% male), undergoing SE (33% treadmill, 67% dobutamine). Left ventricular (LV) regional wall motion was assessed by a consensus of two echocardiographers and scored as per standard five-point scale, 16-segment model of wall motion analysis. Ischemic LV wall segment was defined as deterioration in the thickening and excursion during stress (increase in wall-motion score index (WMSI) ,1). Results: By univariate analysis, inducible ischemia (chi-square = 38.4, P < 0.001), left ventricular ejection fraction (chi-square = 41.2, P < 0.001), a history of previous myocardial infarction (chi-square = 22.3, P < 0.01), hypertension (chi-square = 33, P < 0.01), and age (chi-square = 27.7, P < 0.01) were significant predictors of future cardiac events. WMSI, an index of inducible ischemia, provided incremental prognostic information when forced into a multivariable model where clinical and rest echocardiography variables were entered first. WMSI effectively stratified octogenarians into low- and high-risk groups (annualized event rates of 1.2 versus 5.8%/year, P < 0.001). Conclusions: Stress echocardiography yields incremental prognostic information in octogenarians and effectively stratifies them into low- and high-risk groups. Precise therapeutic decision making in very elderly patients should incorporate combined clinical and stress echocardiography data. [source]

Prognostic Value of 12-Lead Electrocardiogram During Dobutamine Stress Echocardiography

A randomized controlled trial of adding the nicotine patch to rimonabant for smoking cessation: efficacy, safety and weight gain

ADDICTION, Issue 2 2009
Nancy A. Rigotti
ABSTRACT Aims Because smoking cessation rates might be improved by combining drugs and by reducing post-cessation weight gain, we tested the smoking cessation efficacy, safety and effect on body weight of adding the nicotine patch to rimonabant, a cannabanoid type-1 receptor antagonist that reduces body weight. Design Randomized double-blind placebo-controlled trial. Setting Fifteen US research centers. Participants A total of 755 smokers (,15 cigarettes/day). Intervention Rimonabant (20 mg daily) was given open-label for 9 weeks. The 735 participants completing week 1 were randomized at day 8 (target quit day) to add a nicotine patch (n = 369) or placebo patch (n = 366) for 10 weeks (21 mg daily for 8 weeks plus a 2-week taper). Participants received weekly smoking counseling and were followed for 24 weeks. Measurements Biochemically validated 4-week continuous abstinence at end-of-treatment (weeks 6,9; primary end-point); 7-day point prevalence abstinence at weeks 9 and 24; sustained abstinence (weeks 6,24); change in body weight; and adverse events. Findings Rimonabant plus nicotine patch was superior to rimonabant plus placebo in validated continuous abstinence at weeks 6,9 (39.0% versus 21.3%; odds ratio 2.36, 95% confidence interval: 1.71,2.37; P < 0.01) and in all other efficacy measures. Mean end-of-treatment weight gain among quitters did not differ between groups (0.04 kg for combination versus 0.49 kg for rimonabant only, P = 0.15) and was similar in weight-concerned smokers. Serious adverse event rates did not differ between groups. Depression- and anxiety-related adverse events occurred in 32 (4.2%) and 44 (5.8%) subjects, respectively; eight (1.1%) and nine (1.2%) subjects stopped the drug due to depression and anxiety, respectively. Conclusions Adding a nicotine patch to rimonabant was well tolerated and increased smoking cessation rates over rimonabant alone. There was little post-cessation weight gain in either group, even among weight-concerned smokers, during drug treatment. [source]

Helicobacter pylori Eradication Therapy May Facilitate Gastric Ulcer Healing After Endoscopic Mucosal Resection: A Prospective Randomized Study

HELICOBACTER, Issue 6 2008
Jae Hee Cheon
Abstract Background and Aim:, It remains unclear whether Helicobacter pylori eradication therapy affects the healing rate of iatrogenic ulcers following endoscopic mucosal resection (EMR) for gastric tumors. The aim of our study was to prospectively evaluate the effect of H. pylori eradication therapy on gastric ulcer healing after EMR. Methods:, After EMR, patients were randomly assigned to either the H. pylori eradication group (Hp group) (lansoprazole 30 mg, amoxicillin 1000 mg, and clarithromycin 500 mg, twice a day for 7 days) or the noneradication group (proton pump inhibitor, PPI group) (lansoprazole 30 mg, twice a day for 7 days). Four weeks after EMR, the ulcer stages and size were compared between the two groups. Moreover, ulcer-related symptoms, bleeding rates, adverse effects, and drug compliance were compared. Results:, A total of 64 patients were enrolled. Of these, 17 patients were excluded from the study. The two groups were comparable in terms of baseline clinicopathologic characteristics. Four weeks after EMR, the two groups did not differ with respect to ulcer stage (p = .475) or ulcer-related symptoms (p = .399). However, the ulcer reduction ratio was significantly higher in the Hp group (0.028 ± 0.024 vs. 0.065 ± 0.055, p < .05). No differences were observed between the two groups with regard to drug compliance, adverse drug event rates, or bleeding rates. Conclusions:, Our results suggest that H. pylori eradication therapy might improve the ulcer healing rate after EMR. [source]