Diagnosing acute cardiac ischemia in the emergency department: a systematic review of the accuracy and clinical effect of current technologies

Desempenho Diagnóstico da Angiotomografia Computadorizada e da Avaliação Seriada de Troponina Cardíaca Sensível em Pacientes com Dor Torácica e Risco Intermediário para Eventos Cardiovasculares

Fundamento

A angiotomografia coronária (ATC) tem sido usada para avaliação de dor torácica principalmente em pacientes de baixo risco, e poucos dados existem com pacientes em risco intermediário.

Objetivo

Avaliar o desempenho de medidas seriadas de troponinas sensíveis e de ATC em pacientes de risco intermediário.

Métodos

Um total de 100 pacientes com dor torácica, TIMI score 3 ou 4 e troponina negativa foram prospectivamente incluídos. Todos os pacientes foram submetidos à ATC, e aqueles com obstruções ≥ 50% foram encaminhados à cineangiocoronariografia. Pacientes com lesões < 50% recebiam alta hospitalar, receberam alta e foram contatados 30 dias depois por telefonema para avaliação dos desfechos clínicos. Os desfechos foram hospitalização, morte, e infarto agudo do miocárdio em 30 dias. A comparação entre os métodos foi realizada pelo teste de concordância kappa. O desempenho das medidas de troponina e da ATC na detecção de lesões coronárias significativas e desfechos clínicos foi calculado. Os resultados foram considerados estatisticamente significativos quando p <0,05.

Resultados

Estenose coronária ≥ 50% na ATC foi encontrada em 38% dos pacientes e lesões coronárias significativas na angiografia coronária foram encontradas em 31 pacientes. Dois eventos clínicos foram observados. A análise de concordância Kappa mostrou baixa concordância entre as medidas de troponina e ATC na detecção de lesões coronárias significativas (kappa = 0,022, p = 0,78). O desempenho da ATC para detectar lesões coronárias significativas na angiografia coronária ou para prever eventos clínicos em 30 dias foi melhor que as medidas de troponina sensível (acurácia de 91% versus 60%).

Conclusão

ATC teve melhor desempenho que as medidas seriadas de troponina na detecção de doença coronariana significativa em pacientes com dor torácica e risco intermediário para eventos cardiovasculares.

Whether cognitive behavioral therapy is effective for Alzheimer's disease: A protocol for systematic review and network meta-analysis

BACKGROUND

Alzheimer disease (AD) is a progressive neurodegenerative disease characterized by impaired memory and cognitive judgment. It is the leading cause of dementia in the elderly, and its high morbidity and mortality have also brought a significant social burden. So far, there is no method can completely cure Alzheimer's dementia, but there are many non-drug treatments that have been praised by people, especially the cognitive behavioral therapy proposed in recent years. The main purpose of this article is to evaluate the effect of cognitive behavioral therapy on the cognitive function improvement of patients with Alzheimer's dementia.

METHODS

We did a network meta-analysis to identify both direct and indirect evidence in relevant studies. A systematic literature search will be performed in the Cochrane Library, PubMed, and EMBASE from inception to October 2020. We extracted the relevant information from these trials with a predefined data extraction sheet and assessed the risk of bias with the Cochrane risk of bias tool.The outcomes investigated were Mini-Mental State Examination and AD Assessment Scale-Cognitive section scores. We did a pair-wise meta-analysis using the fixed-effects model and then did a random-effects network meta-analysis within a Bayesian framework. The = the Assessment of Multiple Systematic Reviews-2 scale, Preferred Reporting Items for Systematic Reviews and Meta-Analyses scale and Grading of Recommendations Assessment, Development and Evaluation were used to assess the quality and evidence grade of the literature. General characteristics of the eligible randomized controlled trials will be summarized and described. Meanwhile, The ADDIS software will be used to perform the network meta-analysis, and the result figures will be generated by STATA 15.0 software.

RESULTS

Using the draft search strategy of databases and after screening,7 randomized controlled trials met the a priori criteria and were included. This network mate-analysis will be published in a peer-reviewed journal.

CONCLUSION

Our study will provide evidence for cognitive behavioral intervention in AD patients. And provide recommendations and guidelines for the clinic.

PROTOCOL REGISTRATION

INPLASY2020110052.

Monitoring Canine Myocardial Infarction Formation and Recovery via Transthoracic Cardiac Strain Imaging

Myocardial elastography (ME) is an ultrasound-based strain imaging method that aims to determine the degree of ischemia or infarction as a result of the change in the elastic properties of the myocardium. A survival canine model (n = 11) was employed to investigate the ability of ME to image myocardial infarction formation and recovery. Infarcts were generated by ligation of the left anterior descending coronary artery. Canines were survived and imaged for 4 days (n = 7) or 4 weeks (n = 4), allowing sufficient time for recovery via collateral perfusion. A radial strain-based metric, percentage of healthy myocardium by strain (PHMε), was developed as a marker for healthy myocardial tissue. PHMε was strongly linearly correlated with actual infarct size as determined by gross pathology (R2 = 0.80). Mean PHMε was reduced 1-3 days post-infarction (p < 0.05) at the papillary and apical short-axis levels; full infarct recovery was achieved by day 28, with mean PHMε returning to baseline levels. ME was capable of diagnosing individual myocardial segments as non-infarcted or infarcted with high sensitivity (82%), specificity (92%) and precision (85%) (area under the receiver operating characteristic curve = 0.90). The study therefore strengthens the ME premise that it can detect and assess myocardial infarction progression and recovery in vivo and could thus provide an important role in both disease diagnosis and treatment assesssment.

Long-term health outcomes and cost-effectiveness of coronary CT angiography in patients with suspicion for acute coronary syndrome

BACKGROUND

Randomized trials have shown favorable clinical outcomes for coronary CT angiography (CTA) in patients with suspected acute coronary syndrome (ACS). Our goal was to estimate the cost-effectiveness of coronary CTA as compared to alternative management strategies for ACP patients over lifetime.

METHODS

Markov microsimulation model was developed to compare cost-effectiveness of competitive strategies for ACP patients: 1) coronary CTA, 2) standard of care (SOC), 3) AHA/ACC Guidelines, and 4) expedited emergency department (ED) discharge protocol with outpatient testing. ROMICAT-II trial was used to populate the model with low to intermediate risk of ACS patient data, whereas diagnostic test-, treatment effect-, morbidity/mortality-, quality of life- and cost data were obtained from the literature. We predicted test utilization, costs, 1-, 3-, 10-year and over lifetime cardiovascular morbidity/mortality for each strategy. We determined quality adjusted life years (QALY) and incremental cost-effectiveness ratio. Observed outcomes in ROMICAT-II were used to validate the short-term model.

RESULTS

Estimated short-term outcomes accurately reflected observed outcomes in ROMICAT-II as coronary CTA was associated with higher costs ($4,490 vs. $2,513-$4,144) and revascularization rates (5.2% vs. 2.6%-3.7%) compared to alternative strategies. Over lifetime, coronary CTA dominated SOC and ACC/AHA Guidelines and was cost-effective compared to expedited ED protocol ($49,428/QALY). This was driven by lower cardiovascular mortality (coronary CTA vs. expedited discharge: 3-year: 1.04% vs. 1.10-1.17; 10-year: 5.06% vs. 5.21-5.36%; respectively).

CONCLUSION

Coronary CTA in patients with suspected ACS renders affordable long-term health benefits as compared to alternative strategies.

Diagnostic Value of Contrast-Enhanced Spectral Mammography for Screening Breast Cancer: Systematic Review and Meta-analysis

BACKGROUND

Contrast-enhanced spectral mammography (CESM) is a new image examination technology that has developed over the past few years. As CESM technology keeps improving, a current meta-analysis review is needed to systematically evaluate the potential diagnostic value of CESM.

METHODS

A total of 18 studies were included in the review. Sensitivity, specificity, and other important parameters of CESM accuracy for breast cancer diagnosis were pooled and analyzed using random-effects models. Summary receiver operating characteristic curves were calculated for overall accuracy estimation.

RESULTS

The summary estimates for CESM in the diagnosis of breast cancer were as follows: the pooled sensitivity and specificity were 0.89 (95% confidence interval [CI], 0.88-0.91) and 0.84 (95% CI, 0.82-0.85), respectively. Positive likelihood ratio was 3.73 (95% CI, 2.68-5.20), negative likelihood ratio was 0.10 (95% CI, 0.06-0.15), and diagnostic odds ratio was 71.36 (95% CI, 36.28-140.39). The area under the curve was 0.96 (standard error = 0.011).

CONCLUSION

CESM has a high diagnostic accuracy for evaluating breast cancer and can be considered as a useful test for initial assessment of breast lesions.

Diagnostic value of interleukins for tuberculous pleural effusion: a systematic review and meta-analysis

BACKGROUND

The ability of interleukins (ILs) to differentiate tuberculous pleural effusion from other types of effusion is controversial. The aim of our study was to summarize the evidence for its use of ruling out or in tuberculous pleural effusion.

METHODS

Two investigators independently searched PubMed, EMBASE, Web of Knowledge, CNKI, WANFANG, and WEIPU databases to identify studies assessing diagnostic role of ILs for tuberculous pleural effusion published up to January, 2017. Study quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2. The pooled diagnostic sensitivity and specificity of ILs were calculated by using Review Manager 5.3. Area under the summary receiver operating characteristic curve (AUC) was used to summarize the overall diagnostic performance of individual markers.

RESULTS

Thirty-eight studies met our inclusion criteria. Pooled sensitivity, specificity and AUC for chosen ILs were as follows: IL-2, 0.67,0.76 and 0.86; IL-6, 0.86, 0.84 and 0.90; IL-12, 0.78, 0.83 and 0.86; IL-12p40, 0.82,0.65 and 0.76; IL-18, 0.87, 0.92 and 0.95; IL-27, 0.93, 0.95 and 0.95; and IL-33, 0.84, 0.80 and 0.88.

CONCLUSIONS

Some of these ILs may assist in diagnosing tuberculous pleural effusion, though no single IL is likely to show adequate sensitivity or specificity on its own. Further studies on a large scale with better study design should be performed to assess the diagnostic potential of ILs.

State-of-the-Art Evaluation of Emergency Department Patients Presenting With Potential Acute Coronary Syndromes

It is well established that clinicians cannot use clinical judgment alone to determine whether an individual patient who presents to the emergency department has an acute coronary syndrome. The history and physical examination do not distinguish sufficiently between the many conditions that can cause acute chest pain syndromes. Cardiac risk factors do not have sufficient discriminatory ability in symptomatic patients presenting to the emergency department. Most patients with non-ST-segment-elevation myocardial infarction do not present with electrocardiographic evidence of active ischemia. The improvement in cardiac troponin assays, especially in conjunction with well-validated clinical decision algorithms, now enables the clinician to rapidly exclude myocardial infarction. In patients in whom unstable angina remains a concern or there is a desire to evaluate for underlying coronary artery disease, coronary computed tomography angiography can be used in the emergency department. Once a process that took ≥24 hours, computed tomography angiography now can rapidly exclude myocardial infarction and coronary artery disease in patients in the emergency department.

Is it feasible to detect epidermal growth factor receptor mutations in circulating tumor cells in nonsmall cell lung cancer?: A meta-analysis

BACKGROUND

The value of circulating tumor cells (CTCs) in detecting epidermal growth factor receptor (EGFR) mutations in patients with nonsmall cell lung cancer (NSCLC) is controversial. We performed a meta-analysis to investigate the diagnostic significance of CTCs with tumor tissues as the standard control.

METHODS

A systematic literature search, including papers published until November 26, 2015, was performed using PubMed, Medline, Embase, Web of Science, and the China National Knowledge Infrastructure, and the references of retrieved articles were screened. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated according to the data selection from the included studies. The evaluation indexes of the diagnostic performance were the summary receiver operating characteristic curve (SROC) and area under the SROC (AUSROC).

RESULTS

Eight eligible articles with a total of 170 participants were identified in our meta-analysis. The pooled sensitivity and specificity were 0.91 [95% CI: 0.55-0.99] and 0.99 [95% CI: 0.59-1.00]. The positive likelihood ratio and negative likelihood ratio were 68 [95% CI: 1.4-3364] and 0.09 [95% CI: 0.01-0.64], respectively. The DOR was 788 [95% CI: 9-71884]. The high diagnostic performance of CTCs in detecting EGFR mutations was indicated by the AUSROC of 0.99 [95% CI: 0.98-1.00].

CONCLUSIONS

CTCs are a feasible and highly specific biomarker for detecting the EGFR mutation status in NSCLC patients.

Diagnostic accuracy of tumor necrosis factor-alpha assay for tuberculous pleurisy: A PRISMA-compliant meta-analysis

BACKGROUND

The diagnosis of tuberculous pleurisy is difficult and traditional methods are not always helpful. Many studies have focused on the tumor necrosis factor-alpha (TNF-α) assay in pleural effusion for the diagnosis of tuberculous pleurisy, but the results remain controversial. This meta-analysis was conducted to determine the overall diagnostic accuracy of TNF-α.

METHODS

Relevant studies were searched from PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI), Wangfang, and Weipu. We pooled the published results and computed the accuracy measures, including sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Receiver operating characteristic curves (SROC) and the area under the curve (AUC) were used to summarize the overall test performance.

RESULTS

Twelve studies with 1022 patients met the inclusion criteria. The pooled sensitivity and specificity were 0.85 (95%CI, 0.81-0.89) and 0.80 (95% CI, 0.77-0.83) respectively. The area under the SROC curve was 0.89.

CONCLUSIONS

The results of meta-analysis suggested that the TNF-α assay plays a vital role in the diagnosis of tuberculous pleurisy, whereas other test results or clinical findings should be interpreted together with the TNF-α assay to improve the overall diagnostic accuracy.

The Impact of Unstable Angina Guidelines in the Triage of Emergency Department Patients with Possible Acute Coronary Syndrome

Objective. The primary aim of this study is to determine whether implementing the Agency for Health Care Policy and Research (AHCPR) Unstable Angina Practice Guideline improves emergency physician's decision making in patients with symptoms of possible acute coronary syndrome (ACS), including those for whom the diagnosis of unstable angina is uncertain. Methods. The authors conducted a prospective guideline implementation trial with pre-post design in the emergency departments of 1 university hospital and 1 university-affiliated community teaching hospital from January 2000 to May 2001. They enrolled 1140 adults who presented with chest pain or other symptoms of possible ACS. The intervention included the following: 1) physician training in use of the AHCPR risk groups, 2) algorithm for risk stratification, and 3) group feedback. To determine how accurately physicians interpreted the guideline algorithm, the authors compared their risk ratings with actual guideline risk groups. Results. No significant difference in physician triage decisions was observed between baseline and intervention periods. Analysis of physician's risk ratings during the intervention period revealed low overall concordance with actual guideline risk groups (kappa = 0.31); however, physician's risk ratings showed superior discrimination in identifying patients with confirmed ACS (receiver operating characteristic [ROC] area .81 v. .74, P = 0.008). Strict adherence to guideline recommendations would have resulted in hospitalizing 9% more non-ACS patients without lowering the rate of missed ACS. Conclusion. Implementation of the AHCPR guideline did not improve triage decisions in emergency department patients with possible ACS. Assessing physician triage solely based on concordance with the AHCPR guideline may not accurately reflect the quality of patient care.

Does Concordance with Guideline Triage Recommendations Affect Clinical Care of Patients with Possible Acute Coronary Syndrome?

Background. The Agency for Health Care Policy and Research (AHCPR) Unstable Angina Practice Guideline recommends outpatient management for patients at low risk and admission to a monitored bed for patients at intermediate-high risk of adverse short-term outcomes, but the clinical consequences of adhering to these recommendations are unclear. Methods. This analysis included 7466 adults who presented to the emergency department (ED) with symptoms of possible acute coronary syndrome (ACS) and who participated in 3 prospective clinical effectiveness trials during the period 1993 to 2001. The authors used logistic regression to assess the impact of concordance with guideline triage recommendations on subsequent diagnostic testing, follow-up care, and 30-day mortality and applied propensity score methods to adjust for selection bias. Results. Among low-risk patients (n = 1099), ED discharge was not associated with higher mortality and did not increase the need for emergency care or hospitalization during follow-up (adjusted odds ratio [OR] = 1.0, 95% confidence interval [CI] = 0.63—1.6 for ED revisits); however, 1.7% of discharged low-risk patients had confirmed ACS. Among intermediate- to high-risk patients (n = 6367), admission to a monitored bed was not associated with reduction in 30-day mortality but significantly reduced the need for follow-up ED care (adjusted OR = 0.81, 95% CI = 0.69—0.96). Conclusions. This analysis supports the practice of discharging low-risk ED patients with symptoms of possible ACS but highlights the need to arrange timely follow-up (or to perform additional risk stratification in the ED prior to discharge). It also confirms the benefit of admitting ED patients with intermediate- to high-risk characteristics to a monitored bed.

Comparative Trends and Downstream Outcomes of Coronary Computed Tomography Angiography and Cardiac Stress Testing in Emergency Department Patients With Chest Pain: An Administrative Claims Analysis

OBJECTIVES

Coronary computerized tomography angiography (CCTA) is a rapidly emerging technology for the evaluation of chest pain in the emergency department (ED). We assessed trends in CCTA use and compared downstream healthcare utilization between CCTA and cardiac stress testing modalities.

METHODS

Using administrative claims data (Optum Labs Data Warehouse) from over 100 million geographically diverse privately insured and Medicare Advantage enrollees across the United States, we identified 2,047,799 ED patients from January 2006 to December 2013 who presented with chest pain and had a CCTA or cardiac stress test within 72 hours. Cohorts were established based on CCTA or functional stress testing (myocardial perfusion scintigraphy [MPS], stress echocardiogram [SE], or treadmill exercise electrocardiogram [TMET]) performed within 72 hours of the ED visit. We tracked subsequent invasive cardiac procedures (invasive coronary angiography [ICA], percutaneous coronary intervention [PCI], and coronary artery bypass grafting [CABG]), repeat noninvasive testing, return ED visits, hospitalization, and the rate of acute myocardial infarction (AMI) within 30 days. We used propensity-score matching to adjust for coronary artery disease (CAD) risk factors, Charlson-Deyo comorbidity index, and baseline differences between patients selected for CCTA or cardiac stress testing. Logistic regression was used to measure adjusted associations between testing modality and outcomes.

RESULTS

During the study period, CCTA use increased from 0.8% to 4.5% of all cardiac testing within 72 hours, a change of 434% (p-value for trend < 0.001), while rates of other cardiac stress testing modalities decreased (-22% for TMET [p < 0.001]; -11% for SE [p = 0.11]; -6% for MPS [p = 0.04]. After matching, there was no difference in the 30-day rate of AMI between testing modalities. Compared to MPS, CCTA was associated with higher rates of PCI (odds ratio [OR] = 1.25, 95% confidence interval [CI] = 1.04 to 1.51), and CABG (OR = 1.47; 95% CI = 1.03 to 2.13). Compared to SE and treadmill stress testing, CCTA was associated with more invasive procedures, hospitalizations, return ED visits, and repeat noninvasive testing.

CONCLUSIONS

CCTA use increased fourfold during the study period and was associated with higher rates of PCI, CABG, repeat noninvasive testing, hospitalization, and return ED visits. The authors have no relevant financial information or potential conflicts to disclose.

Using neural networks and just nine patient-reportable factors of screen for AMI

The study investigated the effect of different input selections on the performance of artificial neural networks in screening for acute myocardial infarction (AMI) in Malaysian patients complaining of chest pain. We used hospital data to create neural networks with four input selections and used these to diagnose AMI. A 10-fold cross-validation and committee approach was used. All the neural networks using various input selections outperformed a multiple logistic regression model, although the difference was not statistically significant. The neural networks achieved an area under the ROC curve of 0.792 using nine inputs, whereas multiple logistic regression achieved 0.739 using 64 inputs. Sensitivity levels of over 90 per cent were achieved using low output threshold levels. Specificity levels of over 90 per cent were achieved using threshold levels of 0.4-0.5. Thus neural networks can perform as well as multiple logistic regression models even when using far fewer inputs.

Diagnostic accuracy of pleural fluid tumor necrosis factor-α in tuberculous pleurisy: A meta-analysis

BACKGROUND

Pleurisy is a common extra pulmonary complication of tuberculosis, but current methods for diagnosing it are fairly crude. Here we product a meta-analysis for the available evidence on the ability of tumor necrosis factor-α (TNF-α) in pleural fluid to serve as a diagnostic marker of tuberculous pleurisy (TP).

MATERIALS AND METHODS

We searched the PubMed, EMBASE, and Google Scholar databases systematically for studies measuring sensitivity, specificity and other measures of diagnostic accuracy of pleural fluid TNF-α in the diagnosis of TP were meta-analyzed by Stata, version 12 and meta-disc.

RESULTS

A total of six publications reporting seven case-control studies were identified. Pooled results indicated that pleural fluid TNF-α showed a diagnostic sensitivity of 0.89 (95% confidence interval [95% CI] 0.83-0.93; range, 0.42-1.0) and a diagnostic specificity of 0.82 (95% CI: 0.78-0.86; range, 0.58-0.98). The pooled positive likelihood ratio was 4.78 (95% CI: 3.32-6.89); the negative likelihood ratio, 0.16 (95% CI: 0.1-0.27); the diagnostic odds ratio, 32.43 (95% CI: 14.48-72.6); and the area under the curve was 0.8556 (standard error of mean 0.0559).

CONCLUSION

Pleural fluid TNF-α levels shows relatively high sensitivity but insufficient specificity for diagnosing TP. Pleural fluid TNF-α measurement may be useful in combination with clinical manifestations and conventional tests such as microbiological examination or pleural biopsy.

Carbohydrate antigen 19-9 for differential diagnosis of pancreatic carcinoma and chronic pancreatitis

AIM: To evaluate the utility of carbohydrate antigen 19-9 (CA19-9) for differential diagnosis of pancreatic carcinoma and chronic pancreatitis.

METHODS: We searched the literature for studies reporting the sensitivity, specificity, and other accuracy measures of serum CA19-9 levels for differentiating pancreatic carcinoma and chronic pancreatitis. Pooled analysis was performed using random-effects models, and receiver operating characteristic (ROC) curves were generated. Study quality was assessed using Standards for Reporting Diagnostic Accuracy and Quality Assessment for Studies of Diagnostic Accuracy tools.

RESULTS: A total of 34 studies involving 3125 patients with pancreatic carcinoma and 2061 patients with chronic pancreatitis were included. Pooled analysis of the ability of CA19-9 level to differentiate pancreatic carcinoma and chronic pancreatitis showed the following effect estimates: sensitivity, 0.81 (95%CI: 0.80-0.83); specificity, 0.81 (95%CI: 0.79-0.82); positive likelihood ratio, 4.08 (95%CI: 3.39-4.91); negative likelihood ratio, 0.24 (95%CI: 0.21-0.28); and diagnostic odds ratio, 19.31 (95%CI: 14.40-25.90). The area under the ROC curve was 0.88. No significant publication bias was detected.

CONCLUSION: Elevated CA19-9 by itself is insufficient for differentiating pancreatic carcinoma and chronic pancreatitis, however, it increases suspicion of pancreatic carcinoma and may complement other clinical findings to improve diagnostic accuracy.

Diagnostic value of [18F] FDG-PET and PET/CT in urinary bladder cancer: a meta-analysis

An early diagnosis of urinary bladder cancer is crucial for early treatment and management. The objective of this systematic review was to assess the overall diagnostic accuracy of 18 F FDG-PET and PET/CT in urinary bladder cancer with meta-analysis. The PubMed and CNKI databases were searched for the eligible studies published up to June 01, 2014. The sensitivity, specificity, and other measures of accuracy of 18 F FDG-PET and PET/CT in the diagnosis of urinary bladder cancer were pooled along with 95 % confidence intervals (CI). Summary receiver operating characteristic (ROC) curves were used to summarize overall test performance. Ten studies met our inclusion criteria. The summary estimates for 18 F FDG-PET and PET/CT in the diagnosis of urinary bladder cancer in meta-analysis were as follows: a pooled sensitivity, 0.82 (95 % confidence interval [CI], 0.75 to 0.88); a pooled specificity, 0.92 (95 % CI, 0.87 to 0.95); positive likelihood ratio, 6.80 (95 % CI, 4.31 to 10.74); negative likelihood ratio, 0.27 (95 % CI, 0.19 to 0.36); and diagnostic odds ratio, 25.18 (95 % CI, 17.58 to 70.4). The results indicate that 18 F FDG-PET and PET/CT are relatively high sensitive and specific for the diagnosis of urinary bladder cancer.

Diagnostic value of magnetic resonance cholangiopancreatography in choledocholithiasis

AIM: To evaluate the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) in patients with choledocholithiasis.

METHODS: We systematically searched MEDLINE, EMBASE, Web of Science, and Cochrane databases for studies reporting on the sensitivity, specificity and other accuracy measures of diagnostic effectiveness of MRCP for detection of common bile duct (CBD) stones. Pooled analysis was performed using random effects models, and receiver operating characteristic curves were generated to summarize overall test performance. Two reviewers independently assessed the methodological quality of studies using standards for reporting diagnostic accuracy and quality assessment for studies of diagnostic accuracy tools.

RESULTS: A total of 25 studies involving 2310 patients with suspected choledocholithiasis and 738 patients with CBD stones met the inclusion criteria. The average inter-rater agreement on the methodological quality checklists was 0.96. Pooled analysis of the ability of MRCP to detect CBD stones showed the following effect estimates: sensitivity, 0.90 (95%CI: 0.88-0.92, χ² = 65.80; P < 0.001); specificity, 0.95 (95%CI: 0.93-1.0, χ² = 110.51; P < 0.001); positive likelihood ratio, 13.28 (95%CI: 8.85-19.94, χ² = 78.95; P < 0.001); negative likelihood ratio, 0.13 (95%CI: 0.09-0.18, χ² = 6.27; P < 0.001); and diagnostic odds ratio, 143.82 (95%CI: 82.42-250.95, χ² = 44.19; P < 0.001). The area under the receiver operating characteristic curve was 0.97. Significant publication bias was not detected (P = 0.266).

CONCLUSION: MRCP has high diagnostic accuracy for the detection of choledocholithiasis. MRCP should be the method of choice for suspected cases of CBD stones.

Clinical diagnostic utility of CA 15-3 for the diagnosis of malignant pleural effusion: A meta-analysis

Malignant pleural effusion (MPE) is one of the most common pleura-associated conditions observed in clinical practice. The development of MPE usually defines advanced cancer with a poor prognosis. Carbohydrate antigen 15-3 (CA 15-3), as an effective pleural fluid biomarker, has been an object of ongoing research in the detection of MPE. The aim of this meta-analysis was to establish the overall diagnostic accuracy of the measurement of pleural CA 15-3 for diagnosing MPE. The databases Medline (using PubMed as the search engine), Embase, Ovid, Web of Science and Cochrane database (up to December 2013) were searched to identify relevant studies. No lower date limit was applied. All literature published in English was reviewed. Sensitivity, specificity, likelihood ratio and diagnostic odds ratio (DOR) were pooled using a random-effect model. Summary receiver operating characteristic (SROC) curve analysis was conducted to evaluate the overall diagnostic value. The methodological quality was assessed in line with the Quality Assessment for Studies of Diagnostic Accuracy statement. Twenty-one studies with a total of 2,861 cases were included in present meta-analysis. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and DOR of CA 15-3 in the diagnosis of MPE were 0.58 [95% confidence interval (CI), 0.56–0.61], 0.91 (95% CI, 0.90–0.93), 8.93 (95% CI, 4.45–17.93), 0.46 (95% CI, 0.37–0.56) and 24.89 (95% CI, 10.39–59.63), respectively. In addition, the area under the curve (AUC) was 0.84. In conclusion, due to the significantly high specificity of pleural CA 15-3 in detecting MPE, it may play a pivotal role in screening to identify patients who may benefit from further invasive pathologic examination, particularly in those presenting clinical manifestations of MPE but with negative cytological findings of the pleural fluid. However, ruling out MPE by testing CA15-3 alone is not recommended due to its limited sensitivity, and it is recommended that the results of CA15-3 assays are interpreted in parallel with conventional test results and other clinical findings.

Diagnostic value of mutation-specific antibodies for immunohistochemical detection of epidermal growth factor receptor mutations in non-small cell lung cancer: a meta-analysis

Background

Various studies have assessed the diagnostic accuracy of EGFR mutation-specific antibodies in non-small cell lung cancer (NSCLC). We performed a meta-analysis of existing data to investigate the diagnostic value of mutation-specific antibodies for detection of EGFR mutations in NSCLC.

Methods

We systematically retrieved relevant studies from PubMed, Web of Knowledge, and Google Scholar. Data from studies that met the inclusion criteria were extracted for further exploration of heterogeneity, including calculation of the average sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and analysis of SROC(summary receiver operating characteristic) curves.

Results

Fifteen studies met our inclusion criteria. A summary of the meta-analysis of the efficacy of the anti-E746-A750 antibody was as follows: sensitivity, 0.60 (95% CI, 0.55–0.64); specificity, 0.98 (95% CI, 0.97–0.98); PLR, 33.50 (95% CI, 13.96–80.39); NLR, 0.39 (95% CI, 0.30–0.51) and DOR, 111.17 (95% CI, 62.22–198.63). A similar meta-analysis was performed for the anti-L858R antibody with results as follows: sensitivity, 0.76 (95% CI, 0.71–0.79); specificity, 0.96 (95% CI, 0.95–0.97); PLR, 24.42 (95% CI, 11.66–51.17); NLR, 0.22 (95% CI, 0.12–0.39) and DOR, 126.66 (95% CI, 54.60–293.82).

Conclusion

Immunohistochemistry alone is sufficient for the detection of EGFR mutations if the result is positive. Molecular-based analyses are necessary only if the anti-E746-A750 antibody results are negative. Immunohistochemistry seems more suitable for clinical screening for EGFR mutations prior to molecular-based analysis.

Diagnostic value of computed tomography scanning in differentiating malignant from benign solitary pulmonary nodules: a meta-analysis

An early diagnosis of lung cancer is crucial for early treatment and management. The objective of this systematic review was to assess the overall diagnostic accuracy of chest computed tomography (CT) scanning in differentiating malignant from benign solitary pulmonary nodules (SPNs) with meta-analysis. The PubMed and China National Knowledge Infrastructure (CNKI) database were searched for eligible studies published up to March 2014. The sensitivity, specificity, and other measures of accuracy of chest CT scanning in the diagnosis of SPNs were pooled along with 95 % confidence intervals (CI). Summary receiver operating characteristic (ROC) curves were used to summarize overall test performance. Thirty-two studies met our inclusion criteria. The summary estimates for chest CT scanning in the diagnosis of SPNs in the meta-analysis were as follows: pooled sensitivity, 0.89 (95 % CI, 0.88 to 0.91); pooled specificity, 0.70 (95 % CI, 0.68 to 0.73); positive likelihood ratio, 2.88 (95 % CI, 2.46 to 3.37); negative likelihood ratio, 0.16 (95 % CI, 0.12 to 0.21); and diagnostic odds ratio, 23.83 (95 % CI, 16.18 to 35.11). The results indicate that CT scanning has relatively high sensitivity and moderate specificity for the diagnosis of SPNs. Given the low cost and growing prevalence of the technology, CT scanning should be recommended as the initial test for the evaluation of SPNs.

Effectiveness of interferon-gamma release assays for differentiating intestinal tuberculosis from Crohn’s disease: A meta-analysis

AIM: To investigate the clinical usefulness of interferon-gamma release assays (IGRAs) in the differential diagnosis of intestinal tuberculosis (ITB) from Crohn’s disease (CD) by meta-analysis.

METHODS: A systematic search of English language studies was performed. We searched the following databases: Medline, Embase, Web of Science and the Cochrane Library. The Standards for Reporting Diagnostic Accuracy initiative and Quality Assessment for Studies of Diagnostic Accuracy tool were used to assess the methodological quality of the studies. Sensitivity, specificity, and other measures of the accuracy of IGRAs in the differential diagnosis of ITB from CD were pooled and analyzed using random-effects models. Receiver operating characteristic curves were applied to summarize overall test performance. Two reviewers independently judged study eligibility while screening the citations.

RESULTS: Five studies met the inclusion criteria. The average inter-rater agreement between the two reviewers for items in the quality checklist was 0.95. Analysis of IGRAs for the differential diagnosis of ITB from CD produced summary estimates as follows: sensitivity, 0.74 (95%CI: 0.68-0.80); specificity, 0.87 (95%CI: 0.82-0.90); positive likelihood ratio, 5.98 (95%CI: 3.79-9.43); negative likelihood ratio, 0.28 (95%CI: 0.18-0.43); and diagnostic odds ratio, 26.21 (95%CI: 14.15-48.57). The area under the curve was 0.92. The evaluation of publication bias was not significant (P = 0.235).

CONCLUSION: Although IGRAs are not sensitive enough, they provide good specificity for the accurate diagnosis of ITB, which may be helpful in the differential diagnosis of ITB from CD.

Understanding the direction of bias in studies of diagnostic test accuracy

Ordering and interpreting diagnostic tests is a critical part of emergency medicine (EM). In evaluating a study of diagnostic test accuracy, emergency physicians (EPs) need to recognize whether the study uses case-control or cross-sectional sampling and account for common biases. The authors group biases in studies of test accuracy into five categories: incorporation bias, partial verification bias, differential verification bias, imperfect gold standard bias, and spectrum bias. Other named biases are either equivalent to these biases or subtypes within these broader categories. The authors go beyond identifying a bias and predict the direction of its effect on sensitivity and specificity, providing numerical examples from published test accuracy studies. Understanding the direction of a bias may permit useful inferences from even a flawed study of test accuracy.

Variation of a test's sensitivity and specificity with disease prevalence

BACKGROUND

Anecdotal evidence suggests that the sensitivity and specificity of a diagnostic test may vary with disease prevalence. Our objective was to investigate the associations between disease prevalence and test sensitivity and specificity using studies of diagnostic accuracy.

METHODS

We used data from 23 meta-analyses, each of which included 10-39 studies (416 total). The median prevalence per review ranged from 1% to 77%. We evaluated the effects of prevalence on sensitivity and specificity using a bivariate random-effects model for each meta-analysis, with prevalence as a covariate. We estimated the overall effect of prevalence by pooling the effects using the inverse variance method.

RESULTS

Within a given review, a change in prevalence from the lowest to highest value resulted in a corresponding change in sensitivity or specificity from 0 to 40 percentage points. This effect was statistically significant (p < 0.05) for either sensitivity or specificity in 8 meta-analyses (35%). Overall, specificity tended to be lower with higher disease prevalence; there was no such systematic effect for sensitivity.

INTERPRETATION

The sensitivity and specificity of a test often vary with disease prevalence; this effect is likely to be the result of mechanisms, such as patient spectrum, that affect prevalence, sensitivity and specificity. Because it may be difficult to identify such mechanisms, clinicians should use prevalence as a guide when selecting studies that most closely match their situation.

Elevated serum bilirubin in assessing the likelihood of perforation in acute appendicitis: a diagnostic meta-analysis

Hyperbilirubinemia associates with perforated acute appendicitis, but the precise test characteristics have not been determined by sufficiently powered studies. A systematic literature search of reports on hyperbilirubinemia in acute appendicitis was performed. After review and quality assessment of eight studies encompassing a total of 4974 patients the sensitivity, specificity and other measures of accuracy of hyperbilirubinemia as a predictor of perforation in acute appendicitis were pooled using a random-effects model. Summary estimates for hyperbilirubinemia (cutoff 1 mg/dl) as a predictor of perforation in acute appendicitis were as follows: sensitivity, 0.49 (95% confidence interval [CI], 0.45-0.52); specificity, 0.82 (95% CI, 0.80-0.83); positive likelihood ratio, 2.51 (95% CI, 1.58-4.00); negative likelihood ratio, 0.58 (95% CI, 0.44-0.76); diagnostic odds ratio was 4.42 (95% CI, 2.21-8.83). In summary receiving operating characteristic (SROC) analysis, the area under curve was 0.73. The presence of hyperbilirubinemia does not alone distinguish a perforation in acute appendicitis. Serum bilirubin level is of some value as a predictor of appendiceal perforation. Patients with hyperbilirubinemia combined with symptoms and signs consistent with severe acute appendicitis should be considered for early appendectomy.

Assessment by meta-analysis of interferon-gamma for the diagnosis of tuberculous peritonitis

AIM: To investigate the performance and diagnostic accuracy of interferon-gamma (IFN-γ) for tuberculous peritonitis (TBP) by meta-analysis.

METHODS: A systematic search of English language studies was performed. We searched the following electronic databases: MEDLINE, EMBASE, Web of Science, BIOSIS, LILACS and the Cochrane Library. The Standards for Reporting Diagnostic Accuracy initiative and Quality Assessment for Studies of Diagnostic Accuracy tool were used to assess the methodological quality of the studies. Sensitivity, specificity, and other measures of the accuracy of IFN-γ concentration in the diagnosis of peritoneal effusion were pooled using random-effects models. Receiver operating characteristic (ROC) curves were applied to summarize overall test performance. Two reviewers independently judged study eligibility while screening the citations.

RESULTS: Six studies met the inclusion criteria. The average inter-rater agreement between the two reviewers for items in the quality checklist was 0.92. Analysis of IFN-γ level for TBP diagnosis yielded a summary estimate: sensitivity, 0.93 (95%CI, 0.87-0.97); specificity, 0.99 (95%CI, 0.97-1.00); positive likelihood ratio (PLR), 41.49 (95%CI, 18.80-91.55); negative likelihood ratio (NLR), 0.11 (95%CI, 0.06-0.19); and diagnostic odds ratio (DOR), 678.02 (95%CI, 209.91-2190.09). χ² values of the sensitivity, specificity, PLR, NLR and DOR were 5.66 (P = 0.3407), 6.37 (P = 0.2715), 1.38 (P = 0.9265), 5.46 (P = 0.3621) and 1.42 (P = 0.9220), respectively. The summary receiver ROC curve was positioned near the desirable upper left corner and the maximum joint sensitivity and specificity was 0.97. The area under the curve was 0.99. The evaluation of publication bias was not significant (P = 0.922).

CONCLUSION: IFN-γ may be a sensitive and specific marker for the accurate diagnosis of TBP. The level of IFN-γ may contribute to the accurate differentiation of tuberculosis (TB) ascites from non-TB ascites.

Accuracy of whole-body FDG-PET and FDG-PET/CT in M staging of nasopharyngeal carcinoma: a systematic review and meta-analysis

BACKGROUND

A meta-analysis was conducted to evaluate the accuracy of whole-body positron emission tomography (PET) or PET/CT in M staging of nasopharyngeal carcinoma (NPC).

METHODS

Through a search of relevant English language studies from October 1996 to September 2011, pooled estimated sensitivity, specificity, positive likelihood ratios, negative likelihood ratios, and summary receiver operating characteristic (SROC) curves of whole-body PET or PET/CT in M staging of NPC were calculated.

RESULTS

Three PET and 5 PET/CT studies were identified. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of FDG-PET or PET/CT were 0.83 (95% confidence interval [CI], 0.77-0.88), 0.97 (95% CI, 0.95-0.98), 23.38 (95% CI, 16.22-33.69), and 0.19 (95% CI, 0.13-0.25), respectively. The area under curve was 0.9764 and Q* index estimate was 0.9307 for FDG-PET or PET/CT.

CONCLUSION

Current evidence confirms the good diagnostic performance of the whole-body FDG-PET or PET/CT in M staging of NPC.

Diagnostic value of fine-needle aspiration biopsy for breast mass: a systematic review and meta-analysis

BACKGROUND

Fine-needle aspiration biopsy (FNAB) of the breast is a minimally invasive yet maximally diagnostic method. However, the clinical use of FNAB has been questioned. The purpose of our study was to establish the overall value of FNAC in the diagnosis of breast lesions.

METHODS

After a review and quality assessment of 46 studies, sensitivity, specificity and other measures of accuracy of FNAB for evaluating breast lesions were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall accuracy. The sensitivity and specificity for the studies data (included unsatisfactory samples) and underestimation rate of unsatisfactory samples were also calculated.

RESULTS

The summary estimates for FNAB in diagnosis of breast carcinoma were as follows (unsatisfactory samples was temporarily exluded): sensitivity, 0.927 (95% confidence interval [CI], 0.921 to 0.933); specificity, 0.948 (95% CI, 0.943 to 0.952); positive likelihood ratio, 25.72 (95% CI, 17.35 to 28.13); negative likelihood ratio, 0.08 (95% CI, 0.06 to 0.11); diagnostic odds ratio, 429.73 (95% CI, 241.75 to 763.87); The pooled sensitivity and specificity for 11 studies, which reported unsatisfactory samples (unsatisfactory samples was considered to be positive in this classification) were 0.920 (95% CI, 0.906 to 0.933) and 0.768 (95% CI, 0.751 to 0.784) respectively. The pooled proportion of unsatisfactory samples that were subsequently upgraded to various grade cancers was 27.5% (95% CI, 0.221 to 0.296).

CONCLUSIONS

FNAB is an accurate biopsy for evaluating breast malignancy if rigorous criteria are used. With regard to unsatisfactory samples, futher invasive procedures are required in order to minimize the chance of a missed diagnosis of breast cancer.

Efficacy of ventilator waveforms observation in detecting patient-ventilator asynchrony

OBJECTIVES

The value of visual inspection of ventilator waveforms in detecting patient-ventilator asynchronies in the intensive care unit has never been systematically evaluated. This study aims to assess intensive care unit physicians' ability to identify patient-ventilator asynchronies through ventilator waveforms.

DESIGN

Prospective observational study.

SETTING

Intensive care unit of a University Hospital.

PATIENTS

Twenty-four patients receiving mechanical ventilation for acute respiratory failure.

INTERVENTION

Forty-three 5-min reports displaying flow-time and airway pressure-time tracings were evaluated by 10 expert and 10 nonexpert, i.e., residents, intensive care unit physicians. The asynchronies identified by experts and nonexperts were compared with those ascertained by three independent examiners who evaluated the same reports displaying, additionally, tracings of diaphragm electrical activity.

MEASUREMENTS AND MAIN RESULTS

Data were examined according to both breath-by-breath analysis and overall report analysis. Sensitivity, specificity, and positive and negative predictive values were determined. Sensitivity and positive predictive value were very low with breath-by-breath analysis (22% and 32%, respectively) and fairly increased with report analysis (55% and 44%, respectively). Conversely, specificity and negative predictive value were high with breath-by-breath analysis (91% and 86%, respectively) and slightly lower with report analysis (76% and 82%, respectively). Sensitivity was significantly higher for experts than for nonexperts for breath-by-breath analysis (28% vs. 16%, p < .05), but not for report analysis (63% vs. 46%, p = .15). The prevalence of asynchronies increased at higher ventilator assistance and tidal volumes (p < .001 for both), whereas it decreased at higher respiratory rates and diaphragm electrical activity (p < .001 for both). At higher prevalence, sensitivity decreased significantly (p < .001).

CONCLUSIONS

The ability of intensive care unit physicians to recognize patient-ventilator asynchronies was overall quite low and decreased at higher prevalence; expertise significantly increased sensitivity for breath-by-breath analysis, whereas it only produced a trend toward improvement for report analysis.

Accuracy of whole-body PET and PET-CT in initial M staging of head and neck cancer: a meta-analysis

BACKGROUND

A meta-analysis was conducted to evaluate the accuracy of whole-body positron emission tomography (PET) and PET-CT in initial M staging of head and neck cancer.

METHODS

After a systematic review of English language studies, sensitivity, specificity, and other measures of whole-body PET and PET-CT were pooled. Summary receiver operating characteristic (SROC) curves were also used to summarize overall test performance.

RESULTS

Eight PET and 7 PET-CT studies were identified. The pooled sensitivity estimates for PET and PET-CT were 0.848 (95% confidence interval [CI], 0.776-0.905) and 0.875 (95% CI, 0.787-0.936). The pooled specificity estimates were 0.952 (95% CI, 0.933-0.967) and 0.950 (95% CI, 0.931-0.964). The Q* index estimates for PET-CT (0.9409) were not significantly higher than for PET (0.9154; p > .05).

CONCLUSION

Whole-body PET and PET-CT have good diagnostic performance in initial M staging of head and neck cancer; although PET-CT tends to have higher accuracy than PET.

Prognostic value of adenosine stress cardiovascular magnetic resonance and dobutamine stress echocardiography in patients with low-risk chest pain

Excluding obstructive coronary artery disease (CAD) as the etiology of acute chest pain in patients without diagnostic electrocardiographic changes or elevated serum cardiac biomarkers is challenging. Stress testing is a valuable risk-stratifying technique reserved for the subset of these patients with low-risk chest pain who have an intermediate clinical probability of obstructive CAD. Given the risks of radiation inherent to nuclear and computed tomography imaging, both adenosine stress cardiovascular magnetic resonance (AS-CMR) imaging and dobutamine stress echocardiography (DSE) are attractive alternative stress modalities. An essential characteristic of stress modalities is their negative prognostic value; as one must exclude clinically-relevant CAD such that patients can be discharged safely. Therefore, the aim of this study was to validate a favorable negative prognostic value for both AS-CMR and DSE in patients presenting with low-risk acute chest pain. This retrospective study included 255 patients with low-risk acute chest pain and no prior history of CAD presenting to the emergency department at our institution, with 89 patients evaluated by AS-CMR and 166 by DSE. Median follow-up was 292 days, and consisted of medical record review. The primary end-point was the composite of cardiac death, nonfatal acute myocardial infarction, obstructive CAD on invasive coronary angiography (ICA) or recurrent chest pain requiring hospital admission. Test characteristics such as sensitivity and specificity could not be evaluated as patients were not routinely evaluated with ICA. All patients completed the stress protocol without adverse events during testing. 82/89 patients (92.1%) and 164/166 patients (98.8%) had negative AS-CMR and DSE studies, respectively. Both AS-CMR and DSE had excellent negative prognostic values for the primary endpoint, 100 and 99%, respectively. Both AS-CMR and DSE are effective stress modalities for excluding clinically significant coronary artery disease in patients presenting acute low-risk chest pain. Patients without findings to suggest ischemia have an excellent intermediate-term prognosis.

Compliance with outpatient stress testing in low-risk patients presenting to the emergency department with chest pain

Recent evidence suggests that stress testing prior to emergency department (ED) release in low-risk chest pain patients identifies those who can be safely discharged home. When immediate stress testing is not feasible, rapid outpatient stress testing has been recommended. The objective of this study was to determine compliance rate and incidence of adverse cardiac events in patients presenting to the ED with low-risk chest pain referred for outpatient stress testing. Retrospective chart and social security death index review were conducted in 448 consecutive chest pain patients who presented to a university hospital and level I trauma center between April 30 and December 31, 2007. Patients were evaluated with an accelerated chest pain protocol defined as a 4-hour ED rule out and referral for outpatient stress testing within 72 hours of ED release. Only patients without known cardiac disease, a thrombolysis in myocardial infarction risk score ≤2, negative serial ECGs and cardiac biomarkers, and benign ED course were eligible for the protocol. Primary outcome measures included compliance with outpatient stress testing and documented 30-day incidence of adverse cardiac events following ED release. The social security death index was queried to determine 12-month incidence of all-cause mortality in enrolled patients. Logistic regression analysis of characteristics associated with outpatient stress test compliance was determined and incidence of adverse cardiac events in those who were and were not compliant with outpatient stress testing was compared. Significance was set at P < 0.05. A total of 188 patients (42%) completed outpatient stress testing, but only 27 (6%) completed testing within 72 hours of ED discharge. Compliance was correlated with insurance and race, but not patient age, gender, or thrombolysis in myocardial infarction risk score. No significant differences in adverse cardiac events were documented in patients who did and did not comply with outpatient stress testing. Compliance with outpatient stress testing is poor in low-risk chest pain patients following ED release. Despite poor compliance, the documented incidence of adverse cardiac events in this low-risk cohort was lower than that reported in patients with negative provocative testing prior to ED release.

Risk stratification for suspected acute coronary syndromes and heart failure in the emergency department

Many professional societies publish acute intervention guidelines, and most are predicated on the knowledge of an accurate diagnosis. In the emergency department patients do not arrive with a diagnosis, rather they present with symptoms that must be evaluated in the context of their estimated illness severity. Unique to emergency medicine practice, and within a relatively short time frame, all emergency patients must go somewhere else. Appropriate dispositions may be home, admission to a chest pain center, hospitalization to a regular medical floor, or transfer to an intensive care unit, but they cannot stay in the emergency department. This disposition process must occur, even in the setting of great diagnostic uncertainty. Since an accurate diagnosis is a time dependent event, requiring data collection and analysis, emergency department disposition decisions may be based on risk estimates rather than an established diagnosis. Owing to the subjective nature of the early evaluation process, biomarkers currently determine much of the risk stratification process. In this manuscript, we discuss the value of biomarkers as an adjunct to the diagnosis and risk stratification process for patients presenting to the emergency department with suspected acute coronary syndromes and acute heart failure.

PCR-single-strand conformational polymorphism method for rapid detection of rifampin-resistant Mycobacterium tuberculosis: systematic review and meta-analysis

The reference standard methods for drug susceptibility testing of Mycobacterium tuberculosis, such as culture on Lowenstein-Jensen or Middlebrook 7H10/11 medium, are very slow to give results; and due to the emergence of multidrug-resistant M. tuberculosis and extensively drug-resistant M. tuberculosis, there is an urgent demand for new, rapid, and accurate drug susceptibility testing methods. PCR-single-strand conformational polymorphism (PCR-SSCP) analysis has been proposed as a rapid method for the detection of resistance to rifampin, but its accuracy has not been systematically evaluated. We performed a systematic review and meta-analysis to evaluate the accuracy of PCR-SSCP analysis for the detection of rifampin-resistant tuberculosis. We searched the Medline, Embase, Web of Science, BIOSIS, and LILACS databases and contacted authors if additional information was required. Ten studies met our inclusion criteria for rifampin resistance detection. We applied the summary receiver operating characteristic (SROC) curve to perform the meta-analysis and to summarize diagnostic accuracy. The sensitivity of PCR-SSCP analysis for the rapid detection of rifampin-resistant tuberculosis was 0.79 (95% confidence interval [CI], 0.75 to 0.82), the specificity was 0.96 (95% CI, 0.94 to 0.98), the positive likelihood ratio was 16.10 (95% CI, 5.87 to 44.13), the negative likelihood ratio was 0.20 (95% CI, 0.10 to 0.40), and the diagnostic odds ratio was 100.93 (95% CI, 31.95 to 318.83). PCR-SSCP analysis is a sensitive and specific test for the rapid detection of rifampin-resistant M. tuberculosis. Additional studies in countries with a high prevalence of multidrug-resistant M. tuberculosis and also cost-effectiveness analysis are required in order to obtain a complete picture on the utility of this method for rapid drug resistance detection in M. tuberculosis.

Efficacy and safety of the computed tomography coronary angiography based approach for patients with acute chest pain at an emergency department: one month clinical follow-up study

To evaluate the safety and efficacy of the computed tomography coronary angiography (CTCA) for evaluation of acute chest pain in real world population, we prospectively enrolled 296 patients with acute chest pain at emergency department (ED) from November 2005 to February 2007. The patients were grouped based on the clinical information and CTCA result. The patients with a low risk profile and no significant coronary stenosis (>50%) in CTCA were discharged immediately (Group 1, n=103). On the other hand, the patients with an intermediate risk profile without significant stenosis were observed in ED for 24 hr (Group 2, n=104). The patients with significant stenosis underwent further coronary evaluation and management accordingly (Group 3, n=89). While no false negative case was found in Group 1, seven cases (6.73%) were found in Group 2, mostly during the observation period. In Group 3, there were 54 (60.67%) cases of acute coronary syndrome including 10 myocardial infarctions. The overall accuracy of CTCA for acute coronary syndrome was 88.5% (sensitivity), 85.1% (specificity), 60.7% (positive predictive value) and 96.6% (negative predictive value). In conclusion, clinical decision based on CTCA is safe and effective for low risk patients. Further validation is needed in patients with intermediate risk profile.

Value of quantitative analysis of circulating cell free DNA as a screening tool for lung cancer: a meta-analysis

OBJECTIVE

Quantitative analysis of circulating cell free DNA is considered as a possible aid for lung cancer screening. We aimed to comprehensively review the evidence for use of circulating cell free DNA to screen for lung cancer.

METHODS

After a systematic review of English language studies, sensitivity, specificity, and other measures of accuracy of circulating DNA assay in the diagnosis of lung cancer were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall test performance.

RESULTS

Ten studies met our inclusion criteria. The summary estimates for quantitative analysis of circulating cell free DNA in lung cancer screening in the studies included were as follows: sensitivity, 0.80 (95% confidence interval (CI), 0.77-0.83); specificity, 0.77 (95% CI, 0.74-0.80); positive likelihood ratio, 4.54 (95% CI, 2.66-7.76); negative likelihood ratio, 0.28 (95% CI, 0.19-0.40); and diagnostic odds ratio, 20.33 (95% CI, 10.12-40.86).

CONCLUSIONS

The current evidence suggests that the diagnostic accuracy of quantitative analysis of circulating DNA is not lower than conventional serum biomarkers for lung cancer screening, at least. However, it is not recommend for lung cancer screening alone, because its discrimination power is not very perfect. The value of circulating DNA assay in combination with conventional markers for lung cancer detection deserved further investigation.

Prognostic value of adenosine stress cardiovascular magnetic resonance in patients with low-risk chest pain

BACKGROUND

Approximately 5% of patients with an acute coronary syndrome are discharged from the emergency room with an erroneous diagnosis of non-cardiac chest pain. Highly accurate non-invasive stress imaging is valuable for assessment of low-risk chest pain patients to prevent these errors. Adenosine stress cardiovascular magnetic resonance (AS-CMR) is an imaging modality with increasing application. The goal of this study was to evaluate the negative prognostic value of AS-CMR among low-risk acute chest pain patients.

METHODS

We studied 103 patients, mean 56.7 + or - 12.3 years of age, with chest pain and no electrocardiographic evidence of ischemia and negative cardiac biomarkers of necrosis, who were admitted to the Cardiac Decision Unit of our institution. All patients underwent AS-CMR. A negative AS-CMR was defined as absence of all the following: regional wall motion abnormalities at rest; perfusion defects during stress (adenosine) and rest; and myocardial scar on late gadolinium enhancement images. The patients were followed for a mean of 277 (range 161-462) days. The primary end point was defined as the combination of cardiac death, nonfatal acute myocardial infarction, re-hospitalization for chest pain, obstructive coronary artery disease (>50% coronary stenosis on invasive angiography) and coronary revascularization.

RESULTS

In 14 patients (13.6%), AS-CMR was positive. The remaining 89 patients (86.4%), who had negative AS-CMR, were discharged. No patient with negative AS-CMR reached the primary end-point during follow-up. The negative predictive value of AS-CMR was 100%.

CONCLUSION

AS-CMR holds promise as a useful tool to rule out significant coronary artery disease in patients with low-risk chest pain. Patients with negative AS-CMR have an excellent short and mid-term prognosis.

A computationally efficient method for determining the size and location of myocardial ischemia

The purpose of this paper is to introduce a new method for solving the inverse problem of locating ischemic regions in the heart. The electrical activity in the human heart is modeled by the bidomain equations, which can be expanded to compute the potentials on the body surface. The associated inverse problem is to use ECG recordings to gain information about ischemias. We propose an algorithm for doing this, combining the level set method with a simpler minimization problem. Instead of trying to determine the shape, as in the level set method, we simply make the approximation that the ischemia is spherical. The effects of ischemia on the electrical attributes of heart tissue are examined. The new method is tested with computer simulations on synthetic body surface potential maps (BSPMs) in a realistic geometry, using realistic values for the parameters. It is shown to be, in some respects, superior to the level set approach and may be a step toward a practical algorithm useful in medical diagnostics.

Towards a computational method for imaging the extracellular potassium concentration during regional ischemia

We investigate the possibility of using body surface potential maps to image the extracellular potassium concentration during regional ischemia. The problem is formulated as an inverse problem based on a linear approximation of the bidomain model, where we minimize the difference between the results of the model and observations of body surface potentials. The minimization problem is solved by a one-shot technique, where the original PDE system, an adjoint problem, and the relation describing the minimum, are solved simultaneously. This formulation of the problem requires the solution of a 5 x 5 system of linear partial differential equations. The performance of the model is investigated by performing tests based on synthetic data. We find that the model will in many cases detect the correct position and approximate size of the ischemic regions, while some cases are more difficult to locate. It is observed that a simple post-processing of the results produces images that are qualitatively very similar to the true solution.