Effects of a protocol-based management of type A aortic dissections

BACKGROUND

Ascending aortic dissections (AADs) require prompt diagnosis and surgical treatment. We present the results of implementing a multidisciplinary aortic dissection protocol on the outcomes of AAD treatment at a nonteaching hospital.

METHODS

From January 2002-December 2013, 54 patients with the diagnosis of AAD were treated at our institution. Thirty-seven (68.5%) were male with a mean age of 62.3 y. Cardiogenic shock was present in 25.9% of patients. An AAD protocol, focused on educating physicians on presenting signs and symptoms, adequate triaging, and the need for immediate surgical intervention, was implemented, alongside the standardization of surgical treatment. We divided the cohort into two eras, based on AAD program's implementation in 2006, to better assess the impact of this protocol.

RESULTS

Patients from the early era had significantly longer time from Emergency Department to the operating room, more postoperative occurrence of prolonged ventilation, and a longer postoperative hospital stay at 8.7 ± 8 versus 3.1 ± 2.6 h (P = 0.002), 63% versus 18% (P = 0.002), and 63% versus 18% (P = 0.002), respectively. The overall mortality for the cohort was 9.3%, decreasing from 12.5% before 2006 to 7.9% after 2006.

CONCLUSIONS

The implementation of a multidisciplinary aortic dissection protocol has resulted in faster diagnosis and transport of AAD cases from the emergency room to the operating room, improving outcomes. Our data support the concept that nonteaching institutions can deliver excellent care to patients with acute aortic emergencies.

Appearance of metastable B2 phase during solidification of Ni50Zr50 alloy: electrostatic levitation and molecular dynamics simulation studies

High-energy x-ray diffraction measurements of undercooled, electrostatically levitated Ni50Zr50 liquid droplets were performed. The observed solidification pathway proceeded through the nucleation and growth of the metastable B2 phase, which persisted for several seconds before the rapid appearance of the stable B33 phase. This sequence is shown to be consistent with predictions from classical nucleation theory using data obtained from molecular dynamics (MD) simulations. A plausible mechanism for the B2-B33 transformation is proposed and investigated through further MD simulations.

Theoretical calculation of the melting curve of Cu-Zr binary alloys

Helmholtz free energies of the dominant binary crystalline solids found in the Cu-Zr system at high temperatures close to the melting curve are calculated. Our theoretical approach combines fundamental measure density functional theory (applied to the hard-sphere reference system) and a perturbative approach to include the attractive interactions. The studied crystalline solids are Cu(fcc), Cu_{51}Zr_{14}(β), CuZr(B2), CuZr_{2}(C11b), Zr(hcp), and Zr(bcc). The calculated Helmholtz free energies of crystalline solids are in good agreement with results from molecular-dynamics (MD) simulations. Using the same perturbation approach, the liquid phase free energies are calculated as a function of composition and temperature, from which the melting curve of the entire composition range of this system can be obtained. Phase diagrams are determined in this way for two leading embedded atom method potentials, and the results are compared with experimental data. Theoretical melting temperatures are compared both with experimental values and with values obtained directly from MD simulations at several compositions.

Two-year weight-loss maintenance in primary care-based Diabetes Prevention Program lifestyle interventions

Objective:

To investigate whether the effects on weight loss and cardiometabolic risk factor reduction of two technology-mediated lifestyle interventions for 15 months in a primary care-based translation trial sustained at 24 months (that is, 9 months after the end of intervention).

Design:

This study analyzed data from an extended follow-up of participants in the original ‘E-LITE' (Evaluation of Lifestyle Interventions to Treat Elevated Cardiometabolic Risk in Primary Care)-randomized controlled trial, which demonstrated the effectiveness of two adapted Diabetes Prevention Program (DPP) lifestyle interventions compared with usual primary care.

Subjects:

E-LITE randomized 241 overweight or obese participants with pre-diabetes and/or metabolic syndrome to receive usual care alone (n=81) or usual care plus a coach-led (n=79) or self-directed intervention (n=81). The interventions provided coach-led group behavioral weight-loss treatment or a take-home, self-directed DVD using the same 12-week curriculum, followed by 12 additional months of technology-mediated coach contact and self-monitoring support. Participants received no further intervention after month 15. A blinded assessor conducted 24-month visits by following the measurement protocols of the original trial. Measurements include weight and cardiometabolic risk factors (waist circumference, fasting plasma glucose, resting blood pressure, triglycerides, high- and low-density lipoprotein cholesterol, total cholesterol and triglyceride to high-density lipoprotein cholesterol ratio).

Results:

At month 24, mean±s.e. changes in body mass index (trial primary outcome) and weight (kg) from baseline were –1.9±0.3 (P=0.001) and –5.4±0.9 (P<0.001) in the coach-led intervention, and –1.6±0.3 (P=0.03) and –4.5±0.9 (P=0.001) in the self-directed intervention, compared with –0.9±0.3 and 2.4±0.9 in the usual care group. In addition, both interventions led to a greater percentage of participants maintaining ⩾7% weight loss and sustained improvements in waist circumference and fasting plasma glucose levels than usual care.

Conclusion:

This study shows sustained benefits of the two primary care-based, technology-mediated DPP lifestyle interventions. The findings warrant replication in long-term studies involving diverse populations.

Left ventricular stroke volume quantification by contrast echocardiography - comparison of linear and flow-based methods to cardiac magnetic resonance

BACKGROUND

Echocardiography (echo)-quantified LV stroke volume (SV) is widely used to assess systolic performance after acute myocardial infarction (AMI). This study compared 2 common echo approaches - predicated on flow (Doppler) and linear chamber dimensions (Teichholz) - to volumetric SV and global infarct parameters quantified by cardiac magnetic resonance (CMR).

METHODS

Multimodality imaging was performed as part of a post-AMI registry. For echo, SV was measured by Doppler and Teichholz methods. Cine-CMR was used for volumetric SV and LVEF quantification, and delayed-enhancement (DE) CMR for infarct size.

RESULTS

Overall, 142 patients underwent same day echo and CMR. On echo, mean SV by Teichholz (78 ± 17 mL) was slightly higher than Doppler (75 ± 16 mL; Δ = 3 ± 13 mL; P = 0.02). Compared to SV on CMR (78 ± 18 mL), mean difference by Teichholz (Δ = -0.2 ± 14; P = 0.89) was slightly smaller than Doppler (Δ = -3 ± 14; P = 0.02), but limits of agreement were similar between CMR and echo methods (Teichholz: -28, 27 mL, Doppler: -31, 24 mL). For Teichholz, differences with CMR SV were greatest among patients with anteroseptal or lateral wall hypokinesis (P < 0.05). For Doppler, differences were associated with aortic valve abnormalities or root dilation (P = 0.01). SV by both echo methods decreased stepwise in relation to global LV injury as assessed by CMR-quantified LVEF and infarct size (P < 0.01).

CONCLUSIONS

Teichholz and Doppler calculated SV yield similar magnitude of agreement with CMR. Teichholz differences with CMR increase with septal or lateral wall contractile dysfunction, whereas Doppler yields increased offsets in patients with aortic remodeling.

The worldwide environment of cardiovascular disease: prevalence, diagnosis, therapy, and policy issues: a report from the American College of Cardiology

The environment in which the field of cardiology finds itself has been rapidly changing. This supplement, an expansion of a report created for the Board of Trustees, is intended to provide a timely snapshot of the socio-economic, political, and scientific aspects of this environment as it applies to practice both in the United States and internationally. This publication should assist healthcare professionals looking for the most recent statistics on cardiovascular disease and the risk factors that contribute to it, drug and device trends affecting the industry, and how the practice of cardiology is changing in the United States.

Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) in the liver--update 2012: a WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

Assessment of adiponectin and the risk of recurrent cardiovascular events in patients presenting with an acute coronary syndrome: observations from the Pravastatin Or atorVastatin Evaluation and Infection Trial-Thrombolysis in Myocardial Infarction 22 (PROVE IT-TIMI 22)

BACKGROUND

Adiponectin, an adipocytokine, is secreted by fatty cells and exerts a regulatory role in atherogenesis, modulating foam cell formation and cellular adhesion. In stable atherosclerosis, plasma adiponectin has been reported to be associated with both increased and decreased cardiovascular risk. Recent data have suggested a possible discordant adverse risk relationship in acute coronary syndrome (ACS). Therefore, we investigated the association between adiponectin and cardiovascular events in patients with ACS.

METHODS

We measured plasma adiponectin in 3,931 patients stabilized following ACS and assessed the relationship with 2-year outcome. Patients were followed for all-cause death and major cardiovascular events. Using multivariable Cox regression, we adjusted for age, sex, race, ACS type, diabetes, smoking status, triglycerides, blood pressure, body mass index, estimated glomerular filtration rate, treatment group (atorvastatin), B-type natriuretic peptide, and C-reactive protein.

RESULTS

Adiponectin correlated negatively with age, diabetes, body mass index, and triglycerides (each, P < .001) but showed a positive relationship with the risk of death (P = .01), myocardial infarction (P = .01), and heart failure (P < .001). After adjusting for clinical risk factors, B-type natriuretic peptide, and C-reactive protein, adiponectin greater than the median (4,477 ng/mL) was independently associated with an increased risk of death or myocardial infarction (hazard ratio 1.58, 95% CI 1.10-2.28, P = .013) and congestive heart failure (hazard ratio 2.17, 95% CI 1.21-3.89, P = .010).

CONCLUSIONS

Higher adiponectin concentrations early after ACS are independently associated with a higher risk of recurrent cardiovascular events. This finding is directionally opposite to that observed in patients at risk for atherosclerosis and reveals the need for investigation to elucidate differences in the pathobiology of adiponectin in stable versus unstable coronary artery disease.

Safety in magnetic resonance units: an update

The number of anaesthetists who are involved in magnetic resonance (MR) units is increasing. Magnetic resonance systems are becoming more powerful and interventional procedures are now possible. This paper updates information relating to safety terminology, occupational exposure, reactions to gadolinium-based contrast agents and the risk of nephrogenic systemic fibrosis. Magnetic resonance examinations of patients with pacemakers are still generally contra-indicated but have been carried out in specialist centres under strictly controlled conditions. As availability of MR increases, so the education of anaesthetists, who are occasionally required to provide a service, must be considered.

Anaesthesia in MR units was first described in the 1980s. Guidelines on the provision of anaesthetic services in MR units were published by the Association of Anaesthetists of Great Britain and Ireland (AAGBI) in 2002 [1]. Since then, the number of hospitals with MR units, and hence the number of patients requiring anaesthesia for MR, has increased. While the issues relating to setting up anaesthetic services in MR have not changed, there have been a number of developments that warrant this update:

Safety terminology and guidelines have changed.

MR systems utilise higher magnetic-field strengths and more open designs are available.

Interventional and intra-operative MR are now routine in some centres.

Mobile MR scanners are increasingly used to reduce waiting lists.

Although still generally contra-indicated, some patients with pacemakers have been scanned under strictly controlled conditions in specialist centres.

‘MR safe’ medical implants are now being produced.

New equipment is now available for use in MR.

Out-of-hours availability of MR investigations has increased.

Reports of allergic reactions to MR contrast media have increased.

Gadolinium based contrast agents (Gd-CAs) are associated with a varying degree of risk of nephrogenic systemic fibrosis in patients with impaired renal function.

Chemical Scent Constituents in the Urine of the Red Fox (Vulpes vulpes L.) During the Winter Season

Four volatile chemical compounds have been identified as apparently unique constituents in urines of red foxes (both sexes) during the winter season when mating occurs. Quinaldine was found only in male fox urine. Several other compounds identified are found in other species also. Some or all of these compounds may function in olfactory communication in the red fox.

Changes in tropospheric composition and air quality due to stratospheric ozone depletion and climate change

It is well-understood that reductions in air quality play a significant role in both environmental and human health. Interactions between ozone depletion and global climate change will significantly alter atmospheric chemistry which, in turn, will cause changes in concentrations of natural and human-made gases and aerosols. Models predict that tropospheric ozone near the surface will increase globally by up to 10 to 30 ppbv (33 to 100% increase) during the period 2000 to 2100. With the increase in the amount of the stratospheric ozone, increased transport from the stratosphere to the troposphere will result in different responses in polluted and unpolluted areas. In contrast, global changes in tropospheric hydroxyl radical (OH) are not predicted to be large, except where influenced by the presence of oxidizable organic matter, such as from large-scale forest fires. Recent measurements in a relatively clean location over 5 years showed that OH concentrations can be predicted by the intensity of solar ultraviolet radiation. If this relationship is confirmed by further observations, this approach could be used to simplify assessments of air quality. Analysis of surface-level ozone observations in Antarctica suggests that there has been a significant change in the chemistry of the boundary layer of the atmosphere in this region as a result of stratospheric ozone depletion. The oxidation potential of the Antarctic boundary layer is estimated to be greater now than before the development of the ozone hole. Recent modeling studies have suggested that iodine and iodine-containing substances from natural sources, such as the ocean, may increase stratospheric ozone depletion significantly in polar regions during spring. Given the uncertainty of the fate of iodine in the stratosphere, the results may also be relevant for stratospheric ozone depletion and measurements of the influence of these substances on ozone depletion should be considered in the future. In agreement with known usage and atmospheric loss processes, tropospheric concentrations of HFC-134a, the main human-made source of trifluoroacetic acid (TFA), is increasing rapidly. As HFC-134a is a potent greenhouse gas, this increasing concentration has implications for climate change. However, the risks to humans and the environment from substances, such as TFA, produced by atmospheric degradation of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) are considered minimal. Perfluoropolyethers, commonly used as industrial heat transfer fluids and proposed as chlorohydrofluorocarbon (CHFC) substitutes, show great stability to chemical degradation in the atmosphere. These substances have been suggested as substitutes for CHFCs but, as they are very persistent in the atmosphere, they may be important contributors to global warming. It is not known whether these substances will contribute significantly to global warming and its interaction with ozone depletion but they should be considered for further evaluation.