Real-world performance and accuracy of stress echocardiography: the EVAREST observational multi-centre study.

AIMS: Stress echocardiography is widely used to identify obstructive coronary artery disease (CAD). High accuracy is reported in expert hands but is dependent on operator training and image quality. The EVAREST study provides UK-wide data to evaluate real-world performance and accuracy of stress echocardiography. METHODS AND RESULTS: Participants undergoing stress echocardiography for CAD were recruited from 31 hospitals. Participants were followed up through health records which underwent expert adjudication. Cardiac outcome was defined as anatomically or functionally significant stenosis on angiography, revascularization, medical management of ischaemia, acute coronary syndrome, or cardiac-related death within 6 months. A total of 5131 patients (55% male) participated with a median age of 65 years (interquartile range 57-74). 72.9% of studies used dobutamine and 68.5% were contrast studies. Inducible ischaemia was present in 19.3% of scans. Sensitivity and specificity for prediction of a cardiac outcome were 95.4% and 96.0%, respectively, with an accuracy of 95.9%. Sub-group analysis revealed high levels of predictive accuracy across a wide range of patient and protocol sub-groups, with the presence of a resting regional wall motion abnormalitiy significantly reducing the performance of both dobutamine (P < 0.01) and exercise (P < 0.05) stress echocardiography. Overall accuracy remained consistently high across all participating hospitals. CONCLUSION: Stress echocardiography has high accuracy across UK-based hospitals and thus indicates stress echocardiography is being delivered effectively in real-world practice, reinforcing its role as a first-line investigation in the assessment of patients with stable chest pain.

Publisher Correction: Genetic tool development in marine protists: emerging model organisms for experimental cell biology.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Genetic tool development in marine protists: emerging model organisms for experimental cell biology.

Diverse microbial ecosystems underpin life in the sea. Among these microbes are many unicellular eukaryotes that span the diversity of the eukaryotic tree of life. However, genetic tractability has been limited to a few species, which do not represent eukaryotic diversity or environmentally relevant taxa. Here, we report on the development of genetic tools in a range of protists primarily from marine environments. We present evidence for foreign DNA delivery and expression in 13 species never before transformed and for advancement of tools for eight other species, as well as potential reasons for why transformation of yet another 17 species tested was not achieved. Our resource in genetic manipulation will provide insights into the ancestral eukaryotic lifeforms, general eukaryote cell biology, protein diversification and the evolution of cellular pathways.

Multislice computed tomography coronary angiography in patients admitted with a suspected acute coronary syndrome.

OBJECTIVES: The aim of this prospective clinical study was to assess the accuracy and clinical relevance of multislice computed tomography coronary angiography (MSCTCA) in patients presenting with acute chest pain. BACKGROUND: Multislice computed tomography coronary angiography has shown ability to detect accurately coronary artery disease (CAD) in selected elective patient groups. METHODS: One hundred and twenty patients presenting with acute chest pain (<24 h) underwent MSCTCA (Siemens Sensation 16) before a scheduled inpatient conventional coronary angiogram (CCA). Exclusion criteria included patients with STEMI, non-sinus rhythm, contraindication to beta blockers and renal impairment. Blinded visual assessment of MSCTCA to detect CAD was performed on an 11-segment model. The accuracy of MSCTCA was compared to CCA to detect significant stenoses (> or =50%). RESULTS: One hundred and thirteen patients underwent both investigations. The prevalence of significant CAD was 74%. 1,243 native segments were assessed by MSCTCA. The overall ability of MSCTCA to detect the presence of > or =1 significant stenosis in all native segments had a sensitivity of 92% (95%CI 83-97%), specificity of 55% (95%CI 35-74%), positive predictive value of 86% (95%CI 76-93%) and negative predictive value of 70% (95%CI 47-87%). 22% of all segments (mostly distal) were non-analyzable. Coronary calcification was a major cause of false positivity. CONCLUSION: In a prospective study of unselected patients presenting with acute chest pain, the diagnostic accuracy of 16-slice CT coronary angiography was moderate and less than reported from studies in elective patients. The clinical relevance of this technology to screen patients with acute chest pain is limited.

Comparison of radiation doses from multislice computed tomography coronary angiography and conventional diagnostic angiography.

OBJECTIVES: The aim of this study was to quantify and compare effective doses from conventional angiography and multislice computed tomography (MSCT) coronary angiography using a 16-slice scanner. BACKGROUND: Multislice computed tomography is now a viable modality for cardiac imaging. However, for any diagnostic use of ionizing radiation, the risk to the patient must be considered and justified. METHODS: Multislice computed tomography angiography and conventional angiography were used to assess 180 patients with suspected coronary artery disease. Estimates of effective dose were derived from exposure data recorded for each patient examination. For each modality, a comparable calculation technique was used, based on Monte Carlo modeling of the standard Cristy phantom. RESULTS: In a subset of 91 directly comparable patients the mean effective dose for MSCT coronary angiography was 14.7 mSv (SD 2.2) and that for conventional angiography was 5.6 mSv (SD 3.6). A significant difference in effective dose was seen between the two protocols. CONCLUSIONS: The mean effective dose for MSCT coronary angiography was significantly higher than that for conventional angiography. As MSCT cardiac scanners become increasingly available, operators must be aware of the radiation dose and the factors that affect it.