Assessing clinical probability of pulmonary embolism in the emergency ward: a simple score

The History of Diagnosing Venous Thromboembolism

An accurate and prompt diagnosis of deep vein thrombosis and/or pulmonary embolism is important to prevent serious complications and mortality. Because the clinical presentation of venous thromboembolism (VTE) is often nonspecific, objective testing by means of radiological imaging is required to confirm the diagnosis. Historically, a diagnosis of VTE involved invasive imaging techniques like contrast venography or conventional pulmonary angiography. Technological developments toward more accurate and less invasive diagnostics have driven the implementation of a variety of newer technologies over the past decades, as well as the derivation and validation of clinical decision rules (CDRs) that can be used to rule out VTE in combination with D-dimer blood tests. In this narrative review, we provide a historical overview of the most notable developments in the imaging techniques and CDRs for VTE diagnosis.

Clinical Presentation and Risk Stratification of Pulmonary Embolism

Pulmonary embolism (PE) presents with a spectrum of symptoms, ranging from asymptomatic cases to life-threatening events. Common symptoms include sudden dyspnea, chest pain, limb swelling, syncope, and hemoptysis. Clinical presentation varies based on thrombus burden, demographics, and time to presentation. Diagnostic evaluation involves assessing symptoms, physical examination findings, and utilizing laboratory tests, including D-dimer. Risk stratification using tools like Wells score, Pulmonary Embolism Severity Index, and Hestia criteria aids in determining the severity of PE. PE is categorized based on hemodynamic status, temporal patterns, and anatomic locations of emboli to guide in making treatment decisions. Risk stratification plays a crucial role in directing management strategies, with elderly and comorbid individuals at higher risk. Early identification and appropriate risk stratification are essential for effective management of PE. As we delve into this review article, we aim to enhance the knowledge base surrounding PE, contributing to improved patient outcomes through informed decision-making in clinical practice.

Machine Learning-Based Predictive Models for Patients with Venous Thromboembolism: A Systematic Review

BACKGROUND

 Venous thromboembolism (VTE) is a chronic disorder with a significant health and economic burden. Several VTE-specific clinical prediction models (CPMs) have been used to assist physicians in decision-making but have several limitations. This systematic review explores if machine learning (ML) can enhance CPMs by analyzing extensive patient data derived from electronic health records. We aimed to explore ML-CPMs' applications in VTE for risk stratification, outcome prediction, diagnosis, and treatment.

METHODS

 Three databases were searched: PubMed, Google Scholar, and IEEE electronic library. Inclusion criteria focused on studies using structured data, excluding non-English publications, studies on non-humans, and certain data types such as natural language processing and image processing. Studies involving pregnant women, cancer patients, and children were also excluded. After excluding irrelevant studies, a total of 77 studies were included.

RESULTS

 Most studies report that ML-CPMs outperformed traditional CPMs in terms of receiver operating area under the curve in the four clinical domains that were explored. However, the majority of the studies were retrospective, monocentric, and lacked detailed model architecture description and external validation, which are essential for quality audit. This review identified research gaps and highlighted challenges related to standardized reporting, reproducibility, and model comparison.

CONCLUSION

 ML-CPMs show promise in improving risk assessment and individualized treatment recommendations in VTE. Apparently, there is an urgent need for standardized reporting and methodology for ML models, external validation, prospective and real-world data studies, as well as interventional studies to evaluate the impact of artificial intelligence in VTE.

Intermediate-Risk and High-Risk Pulmonary Embolism: Recognition and Management: Cardiology Clinics: Cardiac Emergencies

Pulmonary embolism (PE) is the third most common cause of cardiovascular death. Every specialty of medical practitioner will encounter PE in their patients, and should be prepared to employ contemporary strategies for diagnosis and initial risk-stratification. Treatment of PE is based on risk-stratification, with anticoagulation for all patients, and advanced modalities including systemic thrombolysis, catheter-directed therapies, and mechanical circulatory supports utilized in a manner paralleling PE severity and clinical context.

A new nomogram prediction model for pulmonary embolism in older hospitalized patients

Purpose

Diagnosing pulmonary embolism (PE) in older adults is relatively difficult because of the atypical clinical symptoms of PE in older adults accompanied by multiple complications. This study aimed to establish a nomogram model to better predict the occurrence of PE in older adults.

Methods

Data were collected from older patients (≥65 years old) with suspected PE who were hospitalized between January 2012 and July 2021 and received confirmatory tests (computed tomographic pulmonary angiography or ventilation/perfusion scanning). The PE group and non-PE (control) group were compared using univariable and multivariable analyses to identify independent risk factors. A nomogram prediction model was constructed with independent risk factors and verified internally. The effectiveness of the nomogram model, Wells score, and revised Geneva score was assessed using the area under the receiver operating characteristic curve (AUC).

Results

In total, 447 eligible older patients (290 PE patients and 157 non-PE patients) were enrolled. Logistic regression analysis revealed nine independent risk factors: smoking, inflammation, dyspnea, syncope, mean corpuscular hemoglobin concentration, indirect bilirubin, uric acid, left atrial diameter, and internal diameter of the pulmonary artery. The AUC, sensitivity, and specificity of the nomogram prediction model were 0.763 (95 % confidence interval, 0.721-0.802), 74.48 %, and 67.52 %, respectively. The nomogram showed superior AUC compared to the Wells score (0.763 vs. 0.539, P < 0.0001) and the revised Geneva score (0.763 vs. 0.605, P < 0.0001).

Conclusions

This novel nomogram may be a useful tool to better recognize PE in hospitalized older adults.

A Case Report of Under-Recognized Conditions in Pulmonary Embolism: Patent Foramen Ovale and Right Ventricular Thrombus

Pulmonary embolism (PE) is a potentially life-threatening condition that presents with a spectrum of clinical symptoms ranging from asymptomatic to hemodynamic instability. The early diagnosis in the emergency department is often challenging. Although the association between patent foramen ovale (PFO) and thromboembolic events in patients with PE is well-documented, the significance of the presence of PFO in patients with PE may be underrecognized. In addition, the occurrence of right ventricular thrombus (RVT) in PE is a rare but significant complication with implications for disease management. We report a case of acute-on-chronic PE with concurrent bilateral renal infarction due to a paradoxical embolus, alongside RVT. A 35-year-old male presented at our emergency department with complaints of sudden onset abdominal pain. Bilateral renal infarction was identified on a contrast-enhanced computed tomography (CT). Point-of-care ultrasound showed suggestive findings of PE and RVT. Subsequently, a pulmonary CT angiography confirmed bilateral PE, a PFO, and RVT. The patient was effectively managed with thrombolytic therapy, with extracorporeal membrane oxygenation on standby. This case highlights the need to recognize the diverse clinical manifestations of PE and the importance of considering coexisting PFO and RVT in affected patients. The diagnosis of PE can be complex when symptoms overlap with arterial thrombosis, such as renal infarction secondary to a PFO. In addition, RVT, although uncommon, is a serious complication in patients with PE that may require careful evaluation for thrombolytic or anticoagulant therapy. It is critical to consider the possibility of a PFO in all cases of PE, even in the absence of arterial embolism, and to promptly evaluate for RVT prior to initiating treatment.

Risk Scores in Venous Thromboembolism Guidelines of ESC, ACCP, and ASH: An Updated Review

Venous thromboembolism (VTE) is associated with high morbidity and mortality. Risk scores associated with VTE have been widely used in clinical practice. Among numerous scores published, those included in guidelines are usually typical risk scores which have been extensively validated and globally recognized. This review provides an updated overview of the risk scores associated with VTE endorsed by 3 guidelines which are highly recognized in the field of VTE including the European Society of Cardiology, American College of Chest Physicians, and American Society of Hematology, focusing on the development, modification, validation, and comparison of these scores, to provide a comprehensive and updated understanding of all the classic risk scores associated with VTE to medical readers including but not limited to cardiologists, pulmonologists, hematologists, intensivists, physicians, surgeons, and researchers. Although each score recommended by these guidelines was more or less validated, there may still be room for further improvement. It may still be necessary to seek simpler, more practical, and more universally applicable VTE-related risk scores in the future.

Accuracy of physicians' intuitive risk estimation in the diagnostic management of pulmonary embolism: an individual patient data meta-analysis

BACKGROUND

In patients clinically suspected of having pulmonary embolism (PE), physicians often rely on intuitive estimation ("gestalt") of PE presence. Although shown to be predictive, gestalt is criticized for its assumed variation across physicians and lack of standardization.

OBJECTIVES

To assess the diagnostic accuracy of gestalt in the diagnosis of PE and gain insight into its possible variation.

METHODS

We performed an individual patient data meta-analysis including patients suspected of having PE. The primary outcome was diagnostic accuracy of gestalt for the diagnosis of PE, quantified as risk ratio (RR) between gestalt and PE based on 2-stage random-effect log-binomial meta-analysis regression as well as gestalts' sensitivity and specificity. The variability of these measures was explored across different health care settings, publication period, PE prevalence, patient subgroups (sex, heart failure, chronic lung disease, and items of the Wells score other than gestalt), and age.

RESULTS

We analyzed 20 770 patients suspected of having PE from 16 original studies. The prevalence of PE in patients with and without a positive gestalt was 28.8% vs 9.1%, respectively. The overall RR was 3.02 (95% CI, 2.35-3.87), and the overall sensitivity and specificity were 74% (95% CI, 68%-79%) and 61% (95% CI, 53%-68%), respectively. Although variation was observed across individual studies (I2, 90.63%), the diagnostic accuracy was consistent across all subgroups and health care settings.

CONCLUSION

A positive gestalt was associated with a 3-fold increased risk of PE in suspected patients. Although variation was observed across studies, the RR of gestalt was similar across prespecified subgroups and health care settings, exemplifying its diagnostic value for all patients suspected of having PE.

Sex differences in guideline-consistent diagnostic testing for acute pulmonary embolism among adult emergency department patients aged 18-49

BACKGROUND

Pulmonary embolism (PE) is a frequent diagnostic consideration in emergency department (ED) patients, yet diagnosis is challenging because symptoms of PE are nonspecific. Guidelines recommend the use of clinical decision tools to increase efficiency and avoid harms from overtesting, including D-dimer screening in patients not at high risk for PE. Women undergo testing for PE more often than men yet have a lower yield from testing. Our study objective was to determine whether patient sex influenced the odds of received guideline-consistent care.

METHODS

We performed a retrospective cohort study at two large U.S. academic EDs from January 1, 2016, to December 31, 2018. Nonpregnant patients aged 18-49 years were included if they presented with chest pain, shortness of breath, hemoptysis, or syncope and underwent testing for PE with D-dimer or imaging. Demographic and clinical data were exported from the electronic medical record (EMR). Pretest risk scores were calculated using manually abstracted EMR data. Diagnostic testing was then compared with recommended testing based on pretest risk. The primary outcome was receipt of guideline-consistent care, which required an elevated screening D-dimer prior to imaging in all non-high-risk patients.

RESULTS

We studied 1991 discrete patient encounters; 37% (735) of patients were male and 63% (1256) were female. Baseline characteristics, including revised Geneva scores, were similar between sexes. Female patients were more likely to receive guideline-consistent care (70% [874/1256] female vs. 63% [463/735] male, p < 0.01) and less likely to be diagnosed with PE (3.1% [39/1256] female vs. 5.3% [39/735] male, p < 0.05). The most common guideline deviation in both sexes was obtaining imaging without a screening D-dimer in a non-high-risk patient (75% [287/382] female vs. 75% [205/272] male).

CONCLUSIONS

In this cohort, females were more likely than males to receive care consistent with current guidelines and less likely to be diagnosed with PE.

Echocardiographic Evaluation of Pulmonary Embolism: A Review

Pulmonary embolism (PE) is the third most common cause of cardiovascular death in the United States. Appropriate risk stratification is an important component of the initial evaluation for acute management of these patients. Echocardiography plays a crucial role in the risk stratification of patients with PE. In this literature review, we describe the current strategies in risk stratification of patients with PE using echocardiography and the role of echocardiography in the diagnosis of PE.

Diagnostic management of acute pulmonary embolism: a prediction model based on a patient data meta-analysis

AIMS

Risk stratification is used for decisions regarding need for imaging in patients with clinically suspected acute pulmonary embolism (PE). The aim was to develop a clinical prediction model that provides an individualized, accurate probability estimate for the presence of acute PE in patients with suspected disease based on readily available clinical items and D-dimer concentrations.

METHODS AND RESULTS

An individual patient data meta-analysis was performed based on sixteen cross-sectional or prospective studies with data from 28 305 adult patients with clinically suspected PE from various clinical settings, including primary care, emergency care, hospitalized and nursing home patients. A multilevel logistic regression model was built and validated including ten a priori defined objective candidate predictors to predict objectively confirmed PE at baseline or venous thromboembolism (VTE) during follow-up of 30 to 90 days. Multiple imputation was used for missing data. Backward elimination was performed with a P-value <0.10. Discrimination (c-statistic with 95% confidence intervals [CI] and prediction intervals [PI]) and calibration (outcome:expected [O:E] ratio and calibration plot) were evaluated based on internal-external cross-validation. The accuracy of the model was subsequently compared with algorithms based on the Wells score and D-dimer testing. The final model included age (in years), sex, previous VTE, recent surgery or immobilization, haemoptysis, cancer, clinical signs of deep vein thrombosis, inpatient status, D-dimer (in µg/L), and an interaction term between age and D-dimer. The pooled c-statistic was 0.87 (95% CI, 0.85-0.89; 95% PI, 0.77-0.93) and overall calibration was very good (pooled O:E ratio, 0.99; 95% CI, 0.87-1.14; 95% PI, 0.55-1.79). The model slightly overestimated VTE probability in the lower range of estimated probabilities. Discrimination of the current model in the validation data sets was better than that of the Wells score combined with a D-dimer threshold based on age (c-statistic 0.73; 95% CI, 0.70-0.75) or structured clinical pretest probability (c-statistic 0.79; 95% CI, 0.76-0.81).

CONCLUSION

The present model provides an absolute, individualized probability of PE presence in a broad population of patients with suspected PE, with very good discrimination and calibration. Its clinical utility needs to be evaluated in a prospective management or impact study.

REGISTRATION

PROSPERO ID 89366.

Prognostic value of echocardiographic indices in risk stratification of intermediate-risk pulmonary embolism

Background

Regarding risk stratification of intermediate-risk pulmonary embolism, data are still not sufficient. Transthoracic echocardiography parameters may be useful in risk evaluation in those patients. Some novel echocardiographic indices mainly tricuspid regurgitation peak gradient (TRPG), pulmonary artery acceleration time, and tricuspid annulus plane systolic excursion (TAPSE) were evaluated showing that they may be used for risk stratification of normotensive cases with acute pulmonary embolism (APE).

Results

The studied cases were subdivided into two classes:

Class I with intermediate-low-risk pulmonary embolism included 32 patients (53.3%) and class II with intermediate high-risk pulmonary embolism involved 28 cases (46.7%). Dyspnea, tachypnea, troponin level, RVD, RVD/LVD, TR velocity, and TRPG/TAPSE were statistically higher in cases of class II than that of class I (p < 0.001). On the other hand, TAPSE and PA acceleration time were markedly lower in the case of class II than that of class I (p < 0.001). Ten cases (35.7%) of group II required thrombolytic agents with a significant difference (p<0.001).

Conclusions

RVD/LVD ratio, TAPSE, TRPG/TAPSE ratio, and PA acceleration time are echocardiographic parameters that might be helpful for risk stratification of cases with moderate-risk pulmonary embolism. The addition of elevated levels of cardiac troponins to imaging and clinical findings can improve PE-related risk identification.

Trial registration

NCT04020250. Registered on 16 July 2019.

Utility of probability scores for the diagnosis of pulmonary embolism in patients with SARS-CoV-2 infection: A systematic review

BACKGROUND AND OBJECTIVE

Clinical prediction models determine the pre-test probability of pulmonary embolism (PE) and assess the need for tests for these patients. Coronavirus infection is associated with a greater risk of PE, increasing its severity and conferring a worse prognosis. The pathogenesis of PE appears to be different in patients with and without SARS-CoV-2 infection. This systematic review aims to discover the utility of probability models developed for PE in patients with COVID-19 by reviewing the available literature.

METHODS

A literature search on the PubMed, Scopus, and EMBASE databases was carried out. All studies that reported data on the use of clinical prediction models for PE in patients with COVID-19 were included. Study quality was assessed using the Newcastle-Ottawa scale for non-randomized studies.

RESULTS

Thirteen studies that evaluated five prediction models (Wells score, Geneva score, YEARS algorithm, and PERC and PEGeD clinical decision rules) were included. The different scales were used in 1,187 patients with COVID-19. Overall, the models showed limited predictive ability. The two-level Wells score with low (or unlikely) clinical probability in combination with a D-dimer level <3000ng/mL or a normal bedside lung ultrasound showed an adequate correlation for ruling out PE.

CONCLUSIONS

Our systematic review suggests that the clinical prediction models available for PE that were developed in the general population are not applicable to patients with COVID-19. Therefore, their use is in clinical practice as the only diagnostic screening tool is not recommended. New clinical probability models for PE that are validated in these patients are needed.

[Utility of probability scores for the diagnosis of pulmonary embolism in patients with SARS-CoV-2 infection: A systematic review]

Background and objective

Clinical prediction models determine the pre-test probability of pulmonary embolism (PE) and assess the need for tests for these patients. Coronavirus infection is associated with a greater risk of PE, increasing its severity and conferring a worse prognosis. The pathogenesis of PE appears to be different in patients with and without SARS-CoV-2 infection. This systematic review aims to discover the utility of probability models developed for PE in patients with COVID-19 by reviewing the available literature.

Methods

A literature search on the PubMed, Scopus, and EMBASE databases was carried out. All studies that reported data on the use of clinical prediction models for PE in patients with COVID-19 were included. Study quality was assessed using the Newcastle-Ottawa scale for non-randomized studies.

Results

Thirteen studies that evaluated five prediction models (Wells score, Geneva score, YEARS algorithm, and PERC and PEGeD clinical decision rules) were included. The different scales were used in 1,187 patients with COVID-19. Overall, the models showed limited predictive ability. The two-level Wells score with low (or unlikely) clinical probability in combination with a D-dimer level < 3000 ng/mL or a normal bedside lung ultrasound showed an adequate correlation for ruling out PE.

Conclusions

Our systematic review suggests that the clinical prediction models available for PE that were developed in the general population are not applicable to patients with COVID-19. Therefore, their use is in clinical practice as the only diagnostic screening tool is not recommended. New clinical probability models for PE that are validated in these patients are needed.

PrEdictive value of coMbined pre-test proBability and blOod gas anaLysis In pulmonary emboliSM-the EMBOLISM study

In patients with suspected pulmonary embolism (PE), the number of unnecessary computed tomography pulmonary angiography (CTPA) scans remains high, especially in patients with low pre-test probability (PTP). So far, no study showed any additional benefit of capillary blood gas analysis (BGA) in diagnostic algorithms for PE. In this retrospective analysis of patients with suspected PE and subsequent CTPA, clinical data, D-dimer levels and BGA parameters (including standardized PaO2) were analyzed. Logistic regression analyses were performed to identify independent predictors for PE and reduce unnecessary CTPA examinations in patients with low PTP according to Wells score. Of 1538 patients, PE was diagnosed in 433 patients (28.2%). The original Wells score (odds ratio: 1.381 [95% CI 1.300-1.467], p < 0.001) and standardized PaO2 (odds ratio: 0.987 [95% CI 0.978-0.996], p = 0.005) were independent predictors for PE. After cohort adjustment for low PTP a D-dimer cut-off < 1.5 mg/L (278 patients (18.1%) with 18 PE (6.5%)) was identified in which a standardized PaO2 > 65 mmHg reduced the number of unnecessary CTPA by 31.9% with a 100% sensitivity. This approach was further validated in additional 53 patients with low PTP. In this validation group CTPA examinations were reduced by 32.7%. No patient with PE was missed. With our novel algorithm combining BGA testing with low PTP according to Wells score, we were able to increase the D-Dimer threshold to 1.5 mg/L and reduce CTPA examinations by approximately 32%.

Importance of oxidative stress in the evaluation of acute pulmonary embolism severity

Background

Pulmonary embolism (PE) is a common and potentially life-threatening disorder. Our study was aimed to investigate whether oxidative stress markers can be used as clinical markers in the evaluation of acute PE (APE) severity.

Methods

47 patients with objectively documented diagnosis of APE were recorded. Of these patients, 14 had low-risk PE, 16 had moderate-risk PE, and 17 had high-risk PE. 21 healthy subjects were also enrolled in this study. Ischemia-modified albumin (IMA), prooxidants-antioxidants balance (PAB), advanced protein oxidation products (AOPPs), and ferric reducing antioxidant power (FRAP) were measured as oxidative stress parameters to evaluate the role of oxidative stress.

Results

In the low-risk and moderate-risk APE groups, AOPPs and PAB levels were significantly higher and FRAP levels were significantly lower than those in the control group. AOPPs and IMA levels in the patients with high-risk PE were significantly higher than those in both the low-risk and moderate-risk APE patients. There was a significant correlation between levels of AOPPs and the levels of both IMA (r: 0.462, p < 0.001) and PAB (r:0.378, p < 0.005). Serum FRAP levels were negatively correlated with PAB (r:− 0.683, p < 0.001) and AOPPs levels (r:− 0,384, p < 0.001). There was also a significant positive correlation between the serum IMA and PAB levels.

Conclusions

We clearly demonstrated that reactive oxygen species formation is significantly enhanced in APE. IMA and AOPPs may be used as clinical markers in the evaluation of APE severity in clinical practice. However, further studies with larger patient populations and longer follow-up periods are required to confirm the mechanisms underlying these findings.

Yield of chest computed tomography angiogram in cystic fibrosis patients with suspected pulmonary embolism

Introduction

Individuals with cystic fibrosis (CF) may be at increased risk of pulmonary embolism (PE). Symptoms of PE overlap substantially with those of CF respiratory exacerbations. CF patients commonly undergo chest computed tomography (CT) angiograms (CTPA) to evaluate for PE, but little is known about the clinical presentation and diagnosis of PE in this population.

Objectives

The objectives of this study are to determine the diagnostic yield of CTPA for PE in adult patients with CF and assess the utility of the Revised Geneva Score (RGS) in this population.

Methods

Retrospective review of all CTPA results was performed on CF patients with suspected PE at a large CF center from 1 January 2011 through 31 March 2017. Patient demographics, medical history, and presenting signs and symptoms were abstracted by chart review.

Results

A total of 103 unique CTPA studies were performed in 68 patients. Most were hospitalized at the time of CTPA, predominantly for respiratory manifestations of CF. CTPA identified four patients with PE. The small number of positive studies precluded analysis of predictors of PE. Fewer PE were diagnosed than predicted by the Revised Geneva Score, which was intermediate probability in 77/103 (75%) patients.

Conclusion

The prevalence of PE in CF patients undergoing CTPA for suspected PE was 4%, which is lower than predicted by the Revised Geneva Score. This may be due to a large overlap in the signs and symptoms of PE and exacerbations of CF lung disease.

Safety and Efficiency of Diagnostic Strategies for Ruling Out Pulmonary Embolism in Clinically Relevant Patient Subgroups : A Systematic Review and Individual-Patient Data Meta-analysis

BACKGROUND

How diagnostic strategies for suspected pulmonary embolism (PE) perform in relevant patient subgroups defined by sex, age, cancer, and previous venous thromboembolism (VTE) is unknown.

PURPOSE

To evaluate the safety and efficiency of the Wells and revised Geneva scores combined with fixed and adapted D-dimer thresholds, as well as the YEARS algorithm, for ruling out acute PE in these subgroups.

DATA SOURCES

MEDLINE from 1 January 1995 until 1 January 2021.

STUDY SELECTION

16 studies assessing at least 1 diagnostic strategy.

DATA EXTRACTION

Individual-patient data from 20 553 patients.

DATA SYNTHESIS

Safety was defined as the diagnostic failure rate (the predicted 3-month VTE incidence after exclusion of PE without imaging at baseline). Efficiency was defined as the proportion of individuals classified by the strategy as "PE considered excluded" without imaging tests. Across all strategies, efficiency was highest in patients younger than 40 years (47% to 68%) and lowest in patients aged 80 years or older (6.0% to 23%) or patients with cancer (9.6% to 26%). However, efficiency improved considerably in these subgroups when pretest probability-dependent D-dimer thresholds were applied. Predicted failure rates were highest for strategies with adapted D-dimer thresholds, with failure rates varying between 2% and 4% in the predefined patient subgroups.

LIMITATIONS

Between-study differences in scoring predictor items and D-dimer assays, as well as the presence of differential verification bias, in particular for classifying fatal events and subsegmental PE cases, all of which may have led to an overestimation of the predicted failure rates of adapted D-dimer thresholds.

CONCLUSION

Overall, all strategies showed acceptable safety, with pretest probability-dependent D-dimer thresholds having not only the highest efficiency but also the highest predicted failure rate. From an efficiency perspective, this individual-patient data meta-analysis supports application of adapted D-dimer thresholds.

PRIMARY FUNDING SOURCE

Dutch Research Council. (PROSPERO: CRD42018089366).

The Diagnostic Role of Uric Acid to Creatinine Ratio for the Identification of Patients with Adverse Pulmonary Embolism Outcomes

Background: Uric acid (UA) is the final product of purine metabolism and a marker of oxidative stress that may be involved in the pathophysiology of cardiovascular and thromboembolic disease. The aim of the current study is to investigate the potential value of UA to creatinine ratio (UA/Cr) as a diagnostic tool for the outcome of patients admitted with acute pulmonary embolism (PE) and the correlations with other parameters. Methods: We evaluated 116 patients who were admitted for PE in a respiratory medicine department. PE was confirmed with computed tomography pulmonary angiography. Outcomes evaluated were hospitalization duration, mortality or thrombolysis and a composite endpoint (defined as mortality or thrombolysis). Patients were assessed for PE severity with the PE Severity Index (PESI) and the European Society of Cardiology (ESC) 2019 risk stratification. Results: The median (interquartile range) UA/Cr level was 7.59 (6.3–9.3). UA/Cr was significantly associated with PESI (p < 0.001), simplified PESI (p = 0.019), and ESC 2019 risk stratification (p < 0.001). The area under the curve (AUC) for prediction of 30-day mortality by UA/Cr was 0.793 (95% CI: 0.667–0.918). UA/Cr levels ≥7.64 showed 87% specificity and 94% negative predictive value for mortality. In multivariable analysis UA/Cr was an independent predictor of mortality (HR (95% CI): 1.620 (1.245–2.108), p < 0.001) and composite outcome (HR (95% CI): 1.521 (1.211–1.908), p < 0.001). Patients with elevated UA/Cr levels (≥7.64) had longer hospitalization (median (IQR) 7 (5–11) vs. 6 (5–8) days, p = 0.006)), higher mortality (27.3% vs. 3.2%, p = 0.001) and worse composite endpoint (32.7% vs. 3.4%, p < 0.001). Conclusion: Serum UA/Cr ratio levels at the time of PE diagnosis are associated with disease severity and risk stratification, and may be a useful biomarker for the identification of patients at risk of adverse outcomes.

Predictive scores for the diagnosis of Pulmonary Embolism in COVID-19: A systematic review

Objectives

During the COVID-19 pandemic, several studies described an increased chance of developing pulmonary embolism (PE). Several scores have been used to predict the occurrence of PE. This systematic review summarizes the literature on predicting rules for PE in hospitalized COVID-19 patients (HCPs).

Methods

PUBMED and EMBASE databases were searched to identify articles (1 January 2020-28 April 2021) presenting data pertaining to the use of a prediction rule to assess the risk for PE in adult HCPs. The investigated outcome was the diagnosis of PE. Studies presenting data using a single laboratory assay for PE prediction were excluded. Included studies were appraised for methodological quality using the Newcastle - Ottawa Quality Assessment Scale for Cohort Studies (NOS).

Results

We obtained a refined pool of twelve studies for five scoring systems (Wells score, Geneva score, CHADS2/CHA2DS2VASc/M-CHA2DS2VASc, CHOD score, Padua Prediction Score), and 4,526 patients. Only one score was designed explicitly for HCPs. Three and nine included studies were prospective and retrospective cohort studies, respectively. Among the examined scores, the CHOD score seems promising for predictive ability.

Conclusion

New prediction rules, specifically developed and validated for estimating the risk of PE in HCP, differentiating ICU from non-ICU patients, and taking into account anticoagulation prophylaxis, comorbidities, and the time from COVID-19 diagnosis are needed.

Simple scoring algorithm to identify community-dwelling older adults with limited health literacy: a cross-sectional study in Taiwan

OBJECTIVE

Health literacy (HL) is the degree of individuals' capacity to access, understand, appraise and apply health information and services required to make appropriate health decisions. This study aimed to establish a predictive algorithm for identifying community-dwelling older adults with a high risk of limited HL.

DESIGN

A cross-sectional study.

SETTING

Four communities in northern, central and southern Taiwan.

PARTICIPANTS

A total of 648 older adults were included. Moreover, 85% of the core data set was used to generate the prediction model for the scoring algorithm, and 15% was used to test the fitness of the model.

PRIMARY AND SECONDARY OUTCOME MEASURES

Pearson's χ² test and multiple logistic regression were used to identify the significant factors associated with the HL level. An optimal cut-off point for the scoring algorithm was identified on the basis of the maximum sensitivity and specificity.

RESULTS

A total of 350 (54.6%) patients were classified as having limited HL. We identified 24 variables that could significantly differentiate between sufficient and limited HL. Eight factors that could significantly predict limited HL were identified as follows: a socioenvironmental determinant (ie, dominant spoken dialect), a health service use factor (ie, having family doctors), a health cost factor (ie, self-paid vaccination), a heath behaviour factor (ie, searching online health information), two health outcomes (ie, difficulty in performing activities of daily living and requiring assistance while visiting doctors), a participation factor (ie, attending health classes) and an empowerment factor (ie, self-management during illness). The scoring algorithm yielded an area under the curve of 0.71, and an optimal cut-off value of 5 represented moderate sensitivity (62.0%) and satisfactory specificity (76.2%).

CONCLUSION

This simple scoring algorithm can efficiently and effectively identify community-dwelling older adults with a high risk of limited HL.

PERFORM: Pulmonary embolism risk score for mortality in computed tomographic pulmonary angiography-confirmed patients

BACKGROUND

Current prognostic scores for pulmonary embolism (PE) were partly based on patients without PE confirmation via computed tomographic pulmonary angiography (CTPA), involving subjective parameters and complicated scoring methods. Therefore, we sought to develop an objective, accurate, and simple prognostic model in CTPA-confirmed patients to predict the risk of 30-day mortality.

METHODS

We retrospectively evaluated 509 patients with objectively confirmed PE by CTPA from 2010 to 2017 in the Minhang Hospital, which is affiliated to Fudan University. Patients were randomly divided into the training and validation cohorts. The primary end point was 30-day mortality. The secondary end points were the time to recovery in 30 days and mortality in 15 days. We compared the predictive performance of Pulmonary Embolism Severity Index (PESI), simplified PESI (sPESI), and the PE risk score we developed, called PERFORM.

FINDINGS

PERFORM (ranging from 0 to 12 score) is based on the patient's age, heart rate, and partial pressure of arterial oxygen. The area under the curve was 0.718 (95% confidence interval [CI], 0.627-0.809) for the training cohort and 0.906 (95% CI, 0.846-0.966) for the validation cohort. PERFORM was as good as PESI and sPESI in predicting mortality. Patients in the low-risk group (PERFORM score < 5) had a shorter time to recovery, whereas those in the high-risk group (PERFORM score ≥ 5) had a high mortality.

INTERPRETATION

PERFORM in CTPA-confirmed patients is an objective, accurate, and simple tool to predict the risk of 30-day mortality.

FUNDING

Research Project of Shanghai Municipal Commission of Health and Family Planning (201740127), Shanghai Medical Key Subject Construction Project (ZK2019B08).

Clinical Significance of Plasma D-Dimer in COVID-19 Mortality

It is not clear whether D-dimer can be an independent predictor of coronavirus disease 2019 (COVID-19) mortality, and the cut-off of D-dimer for clinical use remains to be determined. Therefore, a comprehensive analysis is still necessary to illuminate the clinical significance of plasma D-dimer in COVID-19 mortality. We searched PubMed, Embase, Cochrane Library, and Scopus databases until November 2020. STATA software was used for all the statistical analyses. The identifier of systematic review registration was PROSPERO CRD42020220927. A total of 66 studies involving 40,614 COVID-19 patients were included in our meta-analysis. Pooled data showed that patients in high D-dimer group had poor prognosis than those in low D-dimer group [OR = 4.52, 95% CI = (3.61, 5.67), P < 0.001; HR = 2.81, 95% CI = (1.85, 4.27), P < 0.001]. Sensitivity analysis, pooled data based on different effect models and the Duval and Tweedie trim-and-fill method did not change the conclusions. Subgroup analyses stratified by different countries, cutoffs, sample size, study design, and analysis of OR/HR still keep consistent conclusions. D-dimer was identified as an independent predictor for COVID-19 mortality. A series of values including 0.5 μg/ml, 1 μg/ml, and 2 μg/ml could be determined as cutoff of D-dimer for clinic use. Measurement and monitoring of D-dimer might assist clinicians to take immediate medical actions and predict the prognosis of COVID-19.

Canadian Society of Thoracic Radiology/Canadian Association of Radiologists Best Practice Guidance for Investigation of Acute Pulmonary Embolism, Part 1: Acquisition and Safety Considerations

Acute pulmonary embolism (APE) is a well-recognized cause of circulatory system compromise and even demise which can frequently present a diagnostic challenge for the physician. The diagnostic challenge is primarily due to the frequency of indeterminate presentations as well as several other conditions which can have a similar clinical presentation. This often obliges the physician to establish a firm diagnosis due to the potentially serious outcomes related to this disease. Computed tomography pulmonary angiography (CTPA) has increasingly cemented its role as the primary investigation tool in this clinical context and is widely accepted as the standard of care due to several desired attributes which include great accuracy, accessibility, rapid turn-around time and the ability to suggest an alternate diagnosis when APE is not the culprit. In Part 1 of this guidance document, a series of up-to-date recommendations are provided to the reader pertaining to CTPA protocol optimization (including scan range, radiation and intravenous contrast dose), safety measures including the departure from breast and gonadal shielding, population-specific scenarios (pregnancy and early post-partum) and consideration of alternate diagnostic techniques when clinically deemed appropriate.

The 2019 European guidelines on pulmonary embolism illustrated with the aid of an exemplary case report

Background

The European Society of Cardiology guidelines for the diagnosis and management of acute pulmonary embolism (PE) developed in collaboration with the European Respiratory Society (ERS) has been updated in 2019. Recommendations were added or updated on all stages of the evaluation and management of pulmonary embolism, encompassing diagnosis, early treatment, and long-term management.

Case summary

We illustrate an exemplary case, assembled for the purposes of this review, of a 70-year-old woman who presented at the emergency department with dyspnoea and thoracic pain. She was diagnosed with intermediate–high-risk acute PE and promptly treated with low molecular weight heparin. After 24 h of stay in intensive care unit, she was transferred to the cardiology department and switched to non-vitamin K-dependent oral anticoagulant apixaban 10 mg b.i.d. for 7 days and then 5 mg b.i.d. After discharge from the hospital 8 days later, she received standard-dose apixaban 5 mg b.i.d. for 6 months; the dose was reduced to 2.5 mg b.i.d. for long-term secondary prevention. During follow-up, investigations for PE sequelae were performed due to persisting dyspnoea.

Discussion

This exemplary case report puts into context the main novel recommendations from the 2019 ESC Guidelines, including the combination of clinical (pre-test) probability and adjusted D-dimer cut-offs for diagnosis of acute PE, the key role of right ventricular dysfunction in risk stratification, the choice and dosage of oral anticoagulant agents in early and extended anticoagulation, and the identification and management of chronic sequelae in the long-term follow-up.

GPs' familiarity with and use of cardiovascular clinical prediction rules: a UK survey study

BACKGROUND

Clinical prediction rules (CPRs) can help general practitioners (GPs) address challenges in cardiovascular disease. A survey published in 2014 evaluated GPs' awareness and use of CPRs in the UK. However, many new CPRs have been published since and it is unknown which cardiovascular CPRs are currently recognised and used.

AIM

To identify cardiovascular CPRs recognised and used by GPs, and to assess how GPs' familiarity and use have changed over time.

DESIGN & SETTING

An online survey of GPs in the UK was undertaken.

METHOD

Using comparable methods to the 2014 survey, GPs were recruited from a network of doctors in the UK. They were asked how familiar they were with cardiovascular CPRs, how frequently they used them, and why they used them. The results were compared with the 2014 survey.

RESULTS

Most of 401 GPs were familiar with QRISK scores, ABCD scores, CHADS scores, HAS-BLED score, Wells scores for deep vein thrombosis, and Wells scores for pulmonary embolism. The proportions of GPs using these CPRs were 96.3%, 65.1%, 97.3%, 93.0%, 92.5%, and 82.0%, respectively. GPs' use increased by 31.2% for QRISK scores, by 13.5% for ABCD scores, by 54.6% for CHADS scores, by 33.2% for Wells scores for deep vein thrombosis, and by 43.6% for Wells scores for pulmonary embolism; and decreased by 45.9% for the Joint British Societies (JBS) risk calculator, by 38.7% for Framingham risk scores, and by 8.7% for New Zealand tables. GPs most commonly used cardiovascular CPRs to guide therapy and referral.

CONCLUSION

The study found GPs' familiarity and use of cardiovascular CPRs changed substantially. Integrating CPRs into guidelines and practice software might increase familiarity and use.

Comparison of the Wells score and the revised Geneva score as a tool to predict pulmonary embolism in outpatients over age 65

TITLE

Comparison of the Wells score and the revised Geneva score as a tool to predict pulmonary embolism in outpatients over 65 years of age.

INTRODUCTION

The incidence and mortality of pulmonary embolism (PE) is high in the elderly. The Wells score (SW) and the revised Geneva score (RGS) have been validated in patient populations with a large age range. The aim of this study was to compare the predictive accuracy of these two scores in diagnosis of PE in patients over 65 years of age.

METHOD

A prospective multicentre study (nine French and three Belgian centres) was conducted at the same time as the PERCEPIC study. A total of 1757 patients admitted with suspected PE were included and divided into two groups according to age (≥65 years or <65 years). The pre-test probability of PE was assessed prospectively for the RGS. The SW was calculated retrospectively. The predictive accuracy of the two scores was compared by the area under the curve (AUC) of the ROC curves.

RESULTS

The overall prevalence of PE was 11.3%. The prevalence among patients aged ≥65 in the low, moderate and high pre-test probability groups, evaluated using the WS and was respectively 13.5% (CI 95%: CI 9.9-17.3), 28.2% (CI 22.1-34.3), 50% (CI 26-74) and 8.1% (CI 3.2-12.9), 22.3% (CI 18.2-26.3), 43.7% (CI 25.6-61.9) using the RGS. The AUC for the WS and RGS for patients aged ≥65 was 0.632 (CI 0.574-0.691) and 0.610 (CI 0.555-0.666). The difference between the AUCs was not statistically significant (p = .441).

CONCLUSION

In the population for this study, the WS and RGS have the same PE diagnostic accuracy in patients over age 65. This result should be validated in a prospective study that directly compares these scores.

The diagnostic value of D-dimer with simplified Geneva score (SGS) pre-test in the diagnosis of pulmonary embolism (PE)

Background

Pulmonary embolism (PE) is the third most common cardiovascular syndrome with an average annual incidence rate of 77 per 100,000 population in the worldwide. The diagnose algorithms for suspected PE are generally include clinical scoring assessment and plasma D-dimer evaluation, patients with high risk of PE require computed tomographic pulmonary angiogram (CTPA) detection for confirmation.

Methods

In this retrospective analysis, 1035 patients with suspected PE were recruited. All the patients were clinically received simplified Geneva score (SGS) pre-test, determination of plasma D-dimer level, and CTPA detection. All enrolled patients were grouped according to the CTPA results: PE patients and non-PE patients. Then, receiver operating characteristic (ROC) curve were constructed to determine the optimal D-dimer cutoff point value which is based on Yonden’s index (YI).

Results

294 (28.4%) patients were confirmed with PE and 741(71.6%) individuals were regarded as non-PE cases by CTPA detection. Using the SGS pre-test, 829 (80.1%) patients were classified PE-unlikely (SGS ≤ 2) and 206 (19.9%) patients were PE-likely (SGS ≥ 3). Patients with D-dimer levels above 1.96 mg/L had a significant risk to suffer from PE (area under curve (AUC), 0.707; 95% CI, 0.678–0.735; p < 0.05). Meanwhile, in patients with SGS ≥ 3, the D-dimer cutoff point value moved to 2.2 mg/L (AUC, 0.644; 95% CI, 0.574–0.709; p < 0.05).

Conclusion

D-dimer test in combination with SGS pre-test could improve the accuracy of PE diagnosis. Patients with D-dimer levels over 1.96 mg/L (4 times of the normal level) have a significant risk for PE. In patients with SGS ≥ 3, the D-dimer cutoff point concentration for PE risk moves to the levels of 2.2 mg/L.

Risk Stratification of Pulmonary Embolism

Given the broad treatment options, risk stratification of pulmonary embolism is a highly desirable component of management. The ideal tool identifies patients at risk of death from the original or recurrent pulmonary embolism. Using all-cause death in the first 30-days after pulmonary embolism diagnosis as a surrogate, clinical parameters, biomarkers, and radiologic evidence of right ventricular dysfunction and strain are predictive. However, no study has demonstrated improved mortality rates after implementation of a risk stratification strategy to guide treatment. Further research should use better methodology to study prognosis and test new management strategies in patients at high risk for death.

High-Risk Chief Complaints I: Chest Pain-The Big Three (an Update)

Nontraumatic chest pain is a frequent concern of emergency department patients, with causes that range from benign to immediately life threatening. Identifying those patients who require immediate/urgent intervention remains challenging and is a high-risk area for emergency medicine physicians where incorrect or delayed diagnosis may lead to significant morbidity and mortality. This article focuses on the 3 most prevalent diagnoses associated with adverse outcomes in patients presenting with nontraumatic chest pain, acute coronary syndrome, thoracic aortic dissection, and pulmonary embolism. Important aspects of clinical evaluation, diagnostic testing, treatment, and disposition and other less common causes of lethal chest pain are also discussed.

Predictive value of D-dimer testing for the diagnosis of venous thrombosis in unusual locations: A systematic review

BACKGROUND

The value of D-dimer testing for the diagnosis of thrombosis in unusual sites is not properly established and evidence is scarce. We performed a systematic review of the literature.

METHODS

The search was conducted in MEDLINE and Cochrane Library for papers published in the last 10 years including different presentations of thrombosis in unusual sites. Twenty-three articles were included, from January 1, 2008, to December 31, 2018, comprising 3378 patients with thrombosis in unusual sites (upper extremity deep vein thrombosis, cerebral vein thrombosis and splanchnic vein thrombosis). The Newcastle-Ottawa scale was used to assess the quality of the studies.

RESULTS

Two articles were related to upper extremity thrombosis, showing a high sensitivity and negative predictive value for D-dimer testing. Twelve articles concerned cerebral vein thrombosis, concluding that the timing of D-dimer testing was important, and that patients with a shorter duration of symptoms showed higher D-dimer levels. Sensitivity and specificity in these patients ranged from 58% to 97% and from 77% to 97.5%, respectively. Nine articles were related to splanchnic vein thrombosis. One described a population of patients with mesenteric venous thrombosis, and the rest included patients with portal vein thrombosis. The D-dimer testing methods and the proposed cut-off levels were remarkably different among the included studies.

CONCLUSION

D-dimer testing should not be currently recommended for the diagnosis of thrombosis in unusual sites as a first line diagnostic tool. The development of algorithms combining biomarkers such as D-dimer and clinical decision tools could improve the diagnosis.

Pulmonary Embolism Can Be Nauseous: A Case Report and Review of D-Dimer Use in Pediatric Oncology Patients

BACKGROUND

Pulmonary embolism (PE) is a very common presentation in the emergency department (ED). Despite being life-threatening, PE is preventable if diagnosed and managed early, especially in high-risk patients like pediatric oncology patients. A negative d-dimer has a high negative predictive value and can rule out PE in low-risk patients; however, it does not lower post-test probability enough and should be coupled with further diagnostics in high-risk patients.

CASE REPORT

We describe the case of a 14-year-old girl known to have acute lymphoblastic leukemia and presented to the ED with persistent nausea and vomiting only, which was exacerbated by exertion. She had previously presented to the ED 1 week earlier for the same complaint, with a nonrevealing physical examination. At that time, the patient was worked up for nausea and vomiting and received symptomatic treatment. An electrocardiogram (ECG) during that presentation showed normal sinus rhythm. During this presentation, ECG showed new ST segment depressions from V1 to V6 in addition to an S1Q3T3 pattern. This, coupled with the exacerbation of her initial symptoms, triggered further investigations. Computed tomography angiography (CTA) of the chest was performed and showed a right lower lobe segmental pulmonary artery embolus. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the importance of having a high level of suspicion for PE, especially in pediatric oncology patients and specifically in hematologic malignancies. Although our patient's presentation, examination, and laboratory results were not concerning initially, CTA of the chest showed a PE. We are addressing this particular topic to increase the awareness of emergency physicians of cases like this, as PE can have an unusual presentation and missing such a diagnosis can be fatal.

Advances in the diagnosis of acute pulmonary embolism

Venous thromboembolism is a common disease which remains underdiagnosed because of nonspecific presentations which can range from asymptomatic incidental imaging findings to sudden death. Symptoms can overlap with comorbid cardiopulmonary disease, and risk factors that offer clues to the clinician are not always present. The diagnostic approach can vary depending on the specific clinical presentation, but ruling in the diagnosis nearly always depends on lung imaging. Overuse of diagnostic testing is another recognized problem; a cautious, evidence-based approach is required, although physician gestalt must be acknowledged. The following review offers an approach to the diagnosis of acute pulmonary embolism based on the assessment of symptoms, signs, risk factors, laboratory findings, and imaging studies.

Effect of Beta-blockers on Tachycardia in Patients with Pulmonary Embolism

Hypothesis Beta-blockers (BBs) lower the heart rate, which may mask the diagnosis of pulmonary embolism (PE) since one of the main clinical diagnoses of PE is tachycardia. The endpoint of our retrospective study is to determine if the pre-existing use of (BB) significantly affects the utility of these scoring criteria in diagnosing PE. Introduction Diagnosing PE is a challenge because of the non-specificity of its symptoms and signs. The initial step is to assess the patient's likelihood of having a PE. This involves using a scoring system to stratify patients into different levels of risk of having PE (for example, as 'low,' 'moderate,' or 'high' risk). Some of the commonly used criteria are Wells' Score, Geneva Score, and Pulmonary Embolism Rule-out Criteria (PERC) Rule (Charlotte Rule). Methodology This retrospective study was conducted at St. Francis Medical Center. Subjects were taken from a patient population with a new diagnosis of PE (between 2010 and 2017) on the basis of computed tomography angiography (CTA) of the chest. Patients with sepsis or septic shock, heart block, atrioventricular (AV) nodal ablation, pacemaker placement, or taking more than one AV nodal blocker were excluded from the study. Subjects were categorized on the basis of beta-blocker consumption. Result Out of a total of 170 cases, 71 patients were taking beta-blockers and 99 patients were not taking beta-blockers. Among the participants taking BBs, 30.4% had a heart rate <60 and 55.8% had a heart rate between 60 and 100. Conclusion BBs significantly obviate tachycardia in patients with PE. It falsely decreases the Wells' Score and the Geneva Score and results in the inappropriate fulfilling of PERC criteria.

A comparative analysis of the diagnostic performances of four clinical probability models for acute pulmonary embolism in a sub-Saharan African population: a cross-sectional study

Background

The diagnosis of acute pulmonary embolism (PE) is one of the most challenging in emergency settings where prompt and accurate decisions need to be taken for life-saving purposes. Here, the assessment of the clinical probability of PE is a paramount step in its diagnosis. Although clinical probability models (CPM) for PE are routinely used in emergency departments (EDs) of low-resource settings, few studies have cited their diagnostic performances in sub-Saharan Africa (SSA). We aimed to comparatively assess the accuracy of four CPM in the diagnosis of acute PE in sub-Saharan Africans.

Methods

We carried out a cross-sectional study to compare the sensitivity, specificity, positive and negative predictive values and accuracy of four CPM namely; the Wells, simplified Wells, revised Geneva and the simplified revised Geneva (SRG) Scores to computed tomography pulmonary angiography (CTPA) in all adults patients with suspected PE admitted to the EDs of the Gynaeco-obstetric and Paediatric Hospital of Yaoundé and the Yaoundé Central Hospital in Cameroon between January 1, 2017 and April 30, 2018.

Results

In total, we enrolled 30 patients with clinical suspicion of acute PE. PE was confirmed on CTPA in 16 (53.3%) cases. Their mean age was 53.7 ± 15.5 years and 36.7% were males. All four scores had a diagnostic performance superior to 50% in all criteria assessed. The simplified Wells score had the highest sensitivity (62.5%) followed by the Wells score (56.3%). The SRG score had the highest specificity (71.4%). The score with highest PPV was the SRG score (66.7%) and that with the highest NPV was the Wells score (56.3%). Overall the models with the highest accuracies were the Wells and SRG scores (60% for each).

Conclusion

All CPM had a suboptimal diagnostic performance, perhaps highlighting the need of a more optimal CPM for acute PE in SSA. However, the Wells and the SRG scores appeared to be most accurate than the other two scores in the ED. Hence, both or either of them may be used in first intention to predict PE and guide which ED patients should undergo further investigations in an emergency SSA setting.

Prediction Score for persisting perfusion defects after pulmonary embolism

AIMS

Long-term persistence of perfusion defect after pulmonaryembolism (PE) may lead to the development of chronic thromboembolic pulmonary hypertension. Identification of patients at risk of such a complication using a scoring system would be beneficial in clinical practice. Here, we aimed to derive a score for predicting persistence of perfusion defects after PE.

METHODS

83 patients after PE were re-examined 6, 12 and 24 months after the PE episode. Data collected at the time of PE and perfusion status during follow-ups were used for modelling perfusion defects persistence using the Cox proportional hazards model and validated using bootstrap method.

RESULTS

A simple scoring system utilizing two variables (hemoglobin levels and age at the time of PE) was developed. Patients with hemoglobin levels over 140 g/L who were older than 65 years were at the highest risk of perfusion defects; in patients with the same hemoglobin levels and age <65 years, the risk was reduced by 79%, and by 89% in patients with hemoglobin <140 g/L.

CONCLUSION

The proposed scoring system may be useful in clinical practice for identifying patients with high risk of persisting perfusion defects, flagging them for closer follow up, thus improving the effectiveness of long-term treatment of patients after PE.

[Pulmonary embolism mimicking acute coronary syndrome]

Pulmonary embolism is an acute and severe medical condition. Its clinical characteristics are not pathognomonic and can mimick other medico-surgical emergencies. We report the case of a patient admitted with a clinical manifestation of acute coronary syndrome with electrical changes and elevation in cardiac enzymes without abnormal substrate on the coronarography, enabling diagnosis of pulmonary embolism.

Acute Pulmonary Embolism: Contemporary Approach to Diagnosis, Risk-Stratification, and Management

Pulmonary embolism (PE) affects over 300,000 individuals each year in the United States and is associated with substantial morbidity and mortality. Improvements in the diagnostic performance and availability of computed tomographic pulmonary angiography and D-dimer testing have facilitated the evaluation of patients with suspected PE. High clinical suspicion is required in those with risk factors and/or those that manifest signs or symptoms of venous thromboembolic disease, with validated clinical risk scores such as the Wells and modified Wells score or the PE rule-out criteria helpful in estimating the likelihood for PE. For those with confirmed PE, patients should be categorized and triaged according to the presence or absence of shock or hypotension. Normotensive patients can be further risk-stratified using validated prognostic risk scores, as well as by using imaging and cardiac biomarkers, with those having either signs of right ventricular dysfunction on imaging studies and/or abnormal cardiac biomarkers categorized as being at intermediate-risk and requiring close monitoring and hospital admission. Early discharge and/or home therapy are possible in those that do not manifest any high-risk features. The initial treatment for most patients that are stable consists of anticoagulation, with advanced therapies such as thrombolysis, catheter-based therapies, or surgical embolectomy deferred for those at high risk. Given the heterogeneous presentations of PE and various management strategies available, the development of multidisciplinary PE response teams has emerged to help facilitate decision-making in these patients.

Clinical Probability Tools for Deep Venous Thrombosis, Pulmonary Embolism, and Bleeding

Overdiagnosis of venous thromboembolism is associated with increasing numbers of patient complications and health care burden. Multiple clinical tools exist to estimate the probability of pulmonary embolism and deep venous thrombosis. When used with d-dimer testing, these can further stratify venous thromboembolism risk to help inform the use of additional diagnostic testing. Although there are similar tools to estimate bleeding risk, these are not as well-validated and lack reliability.

Diagnosis of pulmonary embolism: Following the evidence from suspicion to certainty

Accurate, timely and cost-effective identification of pulmonary embolism remains a diagnostic challenge. This article reviews the pulmonary embolism diagnostic process with a focus on the best practice advice from the American College of Physicians. Benefits and risks of each diagnostic step are discussed. Emerging diagnostic tools, not included in the algorithm, are briefly reviewed.

Age-dependent diagnostic accuracy of clinical scoring systems and D-dimer levels in the diagnosis of pulmonary embolism with computed tomography pulmonary angiography (CTPA)

OBJECTIVE

The aim of this study was to compare the age-dependent diagnostic performance of clinical scores and D-dimer testing to identify patients with suspected pulmonary embolism (PE).

METHODS

Consecutive patients with suspected PE referred from the emergency department for computed tomography pulmonary angiography (CTPA) were retrospectively evaluated. Diagnostic scores (classic Wells score (WS), modified WS, simplified WS, revised Geneva score (GS), simplified GS, and YEARS score) were calculated from medical records. Results of D-dimer testing were retrieved from the laboratory database. CTPA was the diagnostic reference standard. Four age groups were analyzed (< 50, 50-64, 65-74, and ≥ 75 years). Statistical analysis used receiver operating characteristics as well as uni- and multivariate analyses with calculation of prediction models. The study was IRB approved.

RESULTS

One thousand consecutive patients were included. Areas under the curve (AUC) and accuracies were superior in patients < 50 years. For the classic WS, the AUC decreased by 11% with the optimal cutoff dropping 1.5 points in patients ≥ 75 years; for D-dimer levels, the optimal cutoff was 900 μg/L higher in both ≥ 65 years groups with a max. decrease of the AUC of 9%. In terms of accuracy, the YEARS score performed best across all groups. Classic WS and D-dimer level showed a significant interaction with patient age in prediction models.

CONCLUSION

D-dimer measurement and clinical scores perform best in patients < 50 years. The YEARS score performs best across all age groups and is therefore recommended.

KEY POINTS

• The probability of pulmonary embolism predicted by fibrin fibrinogen degradation products and clinical scores shows the highest accuracy in patients < 50 years. • The probability of pulmonary embolism predicted by the YEARS score shows the highest accuracy in each age group. • Classic Wells score and fibrin fibrinogen degradation products show a significant interaction with patient age in a logistic regression model.

Generation and characterization of D-dimer specific monoclonal antibodies for use in latex agglutination test

The commercially available D-dimer assays used in the clinical practice often show differences in the results, and their specificity and sensitivity are rather unsatisfactory. Our aim was to develop a new monoclonal antibody against D-dimer with a proper specificity, and estimating its suitability using in a latex agglutination diagnostic test. Monoclonal antibodies were generated using hybridoma technology. Their titer was determined by a self-developed ELISA method. The cross-reactions of the antibodies were tested. Characterization of the epitope specificity of a selected antibody was performed through digestion of D-dimer followed by Western blotting. The amino acid sequences of the active antigen fragments were determined. According to the ELISA results, 38 cell groups were constated as antibody-producing hybridomas, among them 7 gave raised titer of antibody and were cloned. Based on the cross-reaction analysis, none of the antibodies gave cross-reaction with fibrin-E and fibrinogen-E fragments but reacted with fibrin D and fibrinogen D fragments. A low cross-reaction was showed with fibrinogen and fibrin X and Y. Contrary to the others, antibody 2B9 gave no cross-reaction with fibrinogen and reacted weakly with fibrin X and Y fragments. According to the epitope analysis the antibody 2B9 binds to amino acids 94-99 and to amino acids 140-147 on the beta chain and it recognizes the amino acids 23-32 and 93-98 on the gamma chain of D-dimer. Considering the characteristics of the above mentioned monoclonal antibody 2B9, we found that it is suitable to be a basis for a D-dimer diagnostic test with proper specificity.

Multicenter Evaluation of the YEARS Criteria in Emergency Department Patients Evaluated for Pulmonary Embolism

BACKGROUND

It may be possible to safely rule out pulmonary embolism (PE) in patients with low pretest probability (PTP) using a higher than standard D-dimer threshold. The YEARS criteria, which include three questions from the Wells PE score to identify low-PTP patients and a variable D-dimer threshold, was recently shown to decrease the need for imaging to rule out PE by 14% in a multicenter study in the Netherlands. However, the YEARS approach has not been studied in the United States.

METHODS

This study was a prospective, observational study of consecutive adult patients evaluated for PE in 17 U.S. emergency departments. Prior to diagnostic testing, we collected the YEARS criteria: "Does the patient have clinical signs or symptoms of DVT?" "Does the patient have hemoptysis?" "Are alternative diagnoses less likely than PE?" with YEARS (+) being any "yes" response. A negative D-dimer was <1000 mg/dL for YEARS (-) patients and <500 mg/dL for YEARS (+) patients. We calculated test characteristics and used Fisher's exact test to compare proportions of patients who would have been referred for imaging and patients who would have had PE "missed."

RESULTS

Of 1,789 patients, 84 (4%) had PE, 1,134 (63%) were female, 1,038 (58%) were white, and mean (±SD) age was 48 (±16) years. Using the standard D-dimer threshold, 940 (53%) would not have had imaging, with two (0.2%, 95% confidence interval [CI] = 0.02%-0.60%) missed PE. Using YEARS adjustment, 1,204 (67%, 95% CI = 65%-69%) would not have been referred for imaging, with six (0.5%, 95% CI = 0.18%-1.1%) missed PE, and using "alternative diagnoses less likely than PE" adjustment, 1,237 (69%, 95% CI = 67%-71%) would not have had imaging with six (0.49%, 95% CI = 0.18%-1.05%) missed PE. Sensitivity was 97.6% (95% CI = 91.7%-99.7%) for the standard threshold and 92.9% (95% CI = 85%-97%) for both adjusted thresholds. Negative predictive value (NPV) was nearly 100% for all approaches.

CONCLUSIONS

D-dimer adjustment based on PTP may result in a reduced need for imaging to evaluate possible PE, with some additional missed PE but no decrease in NPV.

Patient Assessment: Clinical Presentation, Imaging Diagnosis, Risk Stratification, and the Role of Pulmonary Embolism Response Team

Pulmonary embolism (PE) is currently the third leading cause of death and moreover is likely underdiagnosed. PE remains the most common preventable cause of hospital deaths in the United States, which may be attributable to its diagnostic challenges. Although difficult to diagnose, patient mortality rates are time-dependent, and thus, the suspicion and diagnosis of PE in a timely manner is imperative. Diagnosis based on several criteria which may dictate imaging workup as well as laboratory tests and clinical parameters are discussed. The evolution of treatment guidelines via various clinical trials and recommendations is outlined, setting the stage for the use of fibrinolytics, whether systemic or catheter directed. Treatment, including fibrinolytics, is predicated on patient triage into three large categories-massive, submassive, or low-risk PE. Additionally, a relatively new concept of a multidisciplinary team composed of several subspecialty experts known as the PE response team (PERT) is discussed. PERT's timely and unified recommendations have been shown to optimize care and decrease mortality while tailoring treatment to each individual afflicted by PE.