Comparison of the revised Geneva score with the Wells rule for assessing clinical probability of pulmonary embolism

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.

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.

Comparison of international guideline recommendations for the diagnosis of pulmonary embolism

Pulmonary embolism is one of the leading causes of death due to cardiovascular disease. Timely diagnosis is crucial, but challenging, as the clinical presentation of pulmonary embolism is unspecific and easily mistaken for other common medical emergencies. Clinical prediction rules and D-dimer measurement allow stratification of patients into groups of expected prevalence and are key elements in adequate selection of patients for diagnostic imaging; however, the strengths and weaknesses of the multiple proposed prediction rules, when to measure D-dimer, and which cutoff to apply might be elusive to a significant proportion of physicians. 13 international guidelines authored by medical societies or expert author groups provide recommendations on facets of the diagnostic investigations in suspected pulmonary embolism, some of which are hallmarked by pronounced heterogeneity. This Review summarises key recommendations of each guideline, considers the most recent evidence on the topic, compares guideline recommendations on each facet of the diagnosis of pulmonary embolism, and provides a synthesis on the most common recommendations.

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.

Venous Thromboembolism Management in Pregnant Patients

Pulmonary embolism (PE) in pregnancy accounts for 10% of maternal deaths in the United States. As maternal morbidity and mortality continue to increase, it is imperative for all specialties interfacing with pregnant patients to understand the current research and guidelines surrounding risk stratification, diagnosis, and treatments of PE in pregnancy. Given the complexity of high-risk pregnancy-associated PE (PA-PE), that is, which is associated with hemodynamic instability or collapse, and the rising popularity of new technologies to treat high-risk PA-PE in the nonpregnant population, this review aims to emphasize the differences in diagnosis, risk stratification, and management of the pregnant and nonpregnant PE patients. Furthermore, this review will cover treatment paradigms that include anticoagulation versus advanced therapies such as systemic thrombolysis, surgical embolectomy, extracorporeal membrane oxygenation, and inferior vena cava disruption as well as the more novel therapies which fall under the umbrella term of catheter-based treatments. Finally, this review will include a case-based review of 2 patients with PA-PE requiring catheter-based therapies and their ultimate clinical outcomes.

A Clinical Prediction Rule for Thrombosis in Critically Ill COVID-19 Patients: Step 1 Results of the Thromcco Study

The incidence of thrombosis in COVID-19 patients is exceptionally high among intensive care unit (ICU)-admitted individuals. We aimed to develop a clinical prediction rule for thrombosis in hospitalized COVID-19 patients. Data were taken from the Thromcco study (TS) database, which contains information on consecutive adults (aged ≥ 18) admitted to eight Spanish ICUs between March 2020 and October 2021. Diverse logistic regression model analysis, including demographic data, pre-existing conditions, and blood tests collected during the first 24 h of hospitalization, was performed to build a model that predicted thrombosis. Once obtained, the numeric and categorical variables considered were converted to factor variables giving them a score. Out of 2055 patients included in the TS database, 299 subjects with a median age of 62.4 years (IQR 51.5-70) (79% men) were considered in the final model (SE = 83%, SP = 62%, accuracy = 77%). Seven variables with assigned scores were delineated as age 25-40 and ≥70 = 12, age 41-70 = 13, male = 1, D-dimer ≥ 500 ng/mL = 13, leukocytes ≥ 10 × 10³/µL = 1, interleukin-6 ≥ 10 pg/mL = 1, and C-reactive protein (CRP) ≥ 50 mg/L = 1. Score values ≥28 had a sensitivity of 88% and specificity of 29% for thrombosis. This score could be helpful in recognizing patients at higher risk for thrombosis, but further research is needed.

Bedside exclusion of pulmonary embolism in children without radiation (BEEPER): a national study of the Pediatric Emergency Care Applied Research Network-Study protocol

Background

The Pulmonary Embolism Rule Out Criteria (PERC) Peds rule, derived from the PERC rule, was derived to estimate a low pretest probability for pulmonary embolism (PE) in children but has not been prospectively validated.

Objective

The objective of this study was to present a protocol for an ongoing multicenter prospective observational study that evaluates the diagnostic accuracy of the PERC-Peds rule.

Methods

This protocol is identified by the acronym, BEdside Exclusion of Pulmonary Embolism without Radiation in children. The study aims were designed to prospectively validate, or if necessary, refine, the accuracy of PERC-Peds and D-dimer in excluding PE among children with clinical suspicion or testing for PE. Multiple ancillary studies will examine clinical characteristics and epidemiology of the participants. Children aged 4 through 17 years were being enrolled at 21 sites through the Pediatric Emergency Care Applied Research Network (PECARN). Patients taking anticoagulant therapy are excluded. PERC-Peds criteria data, clinical gestalt, and demographic information are collected in real time. The criterion standard outcome is image-confirmed venous thromboembolism within 45 days, determined from independent expert adjudication. We assessed interrater reliability of the PERC-Peds, frequency of PERC-Peds use in routine clinical care, and descriptive characteristics of missed eligible and missed patients with PE.

Results

Enrollment is currently 60% complete with an anticipated data lock in 2025.

Conclusions

This prospective multicenter observational study will not only test whether a set of simple criteria can safely exclude PE without need for imaging but also provide a resource to fill a critical knowledge gap about clinical characteristics of children with suspected and diagnosed PE.

Comparison of VTE risk scores in guidelines for VTE diagnosis in nonsurgical hospitalized patients with suspected VTE

BACKGROUND

The assessment of VTE likelihood with VTE risk scores is essential prior to imaging examinations during VTE diagnostic procedure. Little is known with respect to the disparity of predictive power for VTE diagnosis among VTE risk scores in guidelines for nonsurgical hospitalized patients with clinically suspected VTE.

METHODS

A retrospective study was performed to compare the predictive power for VTE diagnosis among the Wells, Geneva, YEARS, PERC, Padua, and IMPROVE scores in the leading authoritative guidelines in nonsurgical hospitalized patients with suspected VTE.

RESULTS

Among 3168 nonsurgical hospitalized patients with suspected VTE, VTE was finally excluded in 2733(86.3%) ones, whereas confirmed in 435(13.7%) ones. The sensitivity and specificity resulted from the Wells, Geneva, YEARS, PERC, Padua, and IMPROVE scores were (90.3%, 49.8%), (88.7%, 53.6%), (73.8%, 50.2%), (97.7%,16.9%), (80.9%, 44.0%), and (78.2%, 47.0%), respectively. The YI were 0.401, 0.423, 0.240, 0.146, 0.249, and 0.252 for the Wells, Geneva, YEARS, PERC, Padua, and IMPROVE scores, respectively. The C-index were 0.694(0.626-0.762), 0.697(0.623-0.772), 0.602(0.535-0.669), 0.569(0.486-0.652), 0.607(0.533-0.681), and 0.609(0.538-0.680) for the Wells, Geneva, YEARS, PERC, Padua, and IMPROVE scores, respectively. Consistency was significant in the pairwise comparison of Wells vs Geneva(Kappa 0.753, P = 0.565), YEARS vs Padua(Kappa 0.816, P = 0.565), YEARS vs IMPROVE(Kappa 0.771, P = 0.645), and Padua vs IMPROVE(Kappa 0.789, P = 0.812), whereas it did not present in the other pairs. The YI was improved to 0.304, 0.272, and 0.264 for the PERC(AUC 0.631[0.547-0.714], P = 0.006), Padua(AUC 0.613[0.527-0.700], P = 0.017), and IMPROVE(AUC 0.614[0.530-0.698], P = 0.016), with a revised cutoff of 5 or less, 6 or more, and 4 or more denoting the VTE-likely, respectively.

CONCLUSIONS

For nonsurgical hospitalized patients with suspected VTE, the Geneva and Wells scores perform best, the PERC scores performs worst despite its significantly high sensitivity, whereas the others perform intermediately, albeit the absolute predictive power of all isolated scores are mediocre. The predictive power of the PERC, Padua, and IMPROVE scores are improved with revised cutoffs.

A new machine learning model for predicting severity prognosis in patients with pulmonary embolism: Study protocol from Wenzhou, China

Introduction

Pulmonary embolism (PE) is a common thrombotic disease and potentially deadly cardiovascular disorder. The ratio of clinical misdiagnosis and missed diagnosis of PE is very large because patients with PE are asymptomatic or non-specific.

Methods

Using the clinical data from the First Affiliated Hospital of Wenzhou Medical University (Wenzhou, China), we proposed a swarm intelligence algorithm-based kernel extreme learning machine model (SSACS-KELM) to recognize and discriminate the severity of the PE by patient's basic information and serum biomarkers. First, an enhanced method (SSACS) is presented by combining the salp swarm algorithm (SSA) with the cuckoo search (CS). Then, the SSACS algorithm is introduced into the KELM classifier to propose the SSACS-KELM model to improve the accuracy and stability of the traditional classifier.

Results

In the experiments, the benchmark optimization performance of SSACS is confirmed by comparing SSACS with five original classical methods and five high-performance improved algorithms through benchmark function experiments. Then, the overall adaptability and accuracy of the SSACS-KELM model are tested using eight public data sets. Further, to highlight the superiority of SSACS-KELM on PE datasets, this paper conducts comparison experiments with other classical classifiers, swarm intelligence algorithms, and feature selection approaches.

Discussion

The experimental results show that high D-dimer concentration, hypoalbuminemia, and other indicators are important for the diagnosis of PE. The classification results showed that the accuracy of the prediction model was 99.33%. It is expected to be a new and accurate method to distinguish the severity of PE.

Role of Physical Therapists in the Management of Individuals at Risk for or Diagnosed With Venous Thromboembolism: Evidence-Based Clinical Practice Guideline 2022

No matter the practice setting, physical therapists work with patients who are at risk for or who have a history of venous thromboembolism (VTE). In 2016, the first clinical practice guideline (CPG) addressing the physical therapist management of VTE was published with support by the American Physical Therapy Association's Academy of Cardiovascular and Pulmonary Physical Therapy and Academy of Acute Care, with a primary focus on lower extremity deep vein thrombosis (DVT). This CPG is an update of the 2016 CPG and contains the most current evidence available for the management of patients with lower extremity DVT and new key action statements (KAS), including guidance on upper extremity DVT, pulmonary embolism, and special populations. This document will guide physical therapist practice in the prevention of and screening for VTE and in the management of patients who are at risk for or who have been diagnosed with VTE. Through a systematic review of published studies and a structured appraisal process, KAS were written to guide the physical therapist. The evidence supporting each action was rated, and the strength of statement was determined. Clinical practice algorithms based on the KAS were developed that can assist with clinical decision-making. Physical therapists, along with other members of the health care team, should implement these KAS to decrease the incidence of VTE, improve the diagnosis and acute management of VTE, and reduce the long-term complications of VTE.

Pulmonary embolism diagnosis: clinical assessment at the front door

This first of two practice reviews addresses pulmonary embolism (PE) diagnosis considering important aspects of PE clinical presentation and comparing evidence-based PE testing strategies. A companion paper addresses the management of PE. Symptoms and signs of PE are varied, and emergency physicians frequently use testing to 'rule out' the diagnosis in people with respiratory or cardiovascular symptoms. The emergency clinician must balance the benefit of reassuring negative PE testing with the risks of iatrogenic harms from over investigation and overdiagnosis.

Age-adjusted D-dimer cut-off levels to rule out venous thromboembolism in patients with non-high pre-test probability: Clinical performance and cost-effectiveness analysis

BACKGROUND

As aging was found to be associated with increased D-dimer levels, the question arose whether D-dimer measurement was useful in the diagnostic strategy of venous thromboembolism (VTE) in elderly patients.

AIM OF THE STUDY

To compare retrospectively the performance of six diagnostic strategies based on the three-level Wells scores and various cut-off levels for D-dimer, evaluated using the HemosIL D-Dimer HS 500 assay, in a derivation cohort of 644 outpatients with non-high pretest probability (PTP) of VTE. The clinical usefulness of the best-performing strategy was then confirmed in a multicenter validation study involving 1255 consecutive outpatients with non-high PTP.

RESULTS

The diagnostic strategy based on the age-adjusted cut-off level calculated by multiplying the patient's age by 10 above 50 years was found to perform the best in the derivation study with a better sensitivity-to-specificity ratio than the conventional strategy based on the fixed cut-off level (500 ng/ml), a higher specificity and a negative predictive value (NPV) above 99%. Such an increase in test specificity was confirmed in the validation cohort, with the NPV remaining above 99%. Taking into account the local reimbursement rates of diagnostic tests, using this strategy led to a 6.9% reduction of diagnostic costs for pulmonary embolism and a 5.1% reduction for deep vein thrombosis, as imaging tests would be avoided in a higher percentage of patients.

CONCLUSION

The diagnostic strategy of VTE based on the age-adjusted cut-off level for D-dimer in patients over 50 years was found to be safe, with NPV above 99%, and cost-effective.

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.

Crucial considerations: Sex differences in the epidemiology, diagnosis, treatment, and outcomes of acute pulmonary embolism in non-pregnant adult patients

Acute pulmonary embolism (PE) affects over 600,000 Americans per year and is a common diagnostic consideration among emergency department patients. Although there are well-documented differences in the diagnosis, treatment, and outcomes of cardiovascular conditions, such as ischemic heart disease and stroke, the influence of sex and gender on PE remains poorly understood. The overall age-adjusted incidence of PE is similar in women and men, but women have higher relative rates of PE during early and mid-adulthood (ages 20-40 years); whereas, men have higher rates of PE after age 60 years. Women are tested for PE at far higher rates than men, yet women who undergo computed tomography pulmonary angiography are ultimately diagnosed with PE 35%-55% less often than men. Among those diagnosed with PE, women are more likely to have severe clinical features, such as hypotension and signs of right ventricular dysfunction. When controlled for PE severity, women are less likely to receive reperfusion therapies, such as thrombolysis. Finally, women have more bleeding complications for all types of anticoagulation. Further investigation of possible sex-specific diagnostic and treatment algorithms is necessary in order to more accurately detect and treat acute PE in non-pregnant adults.

Cost-effectiveness of managing low-risk pulmonary embolism patients without hospitalization. The low-risk pulmonary embolism prospective management study

OBJECTIVE

Evaluate the cost-effectiveness and difference in length-of-stay when patients in the ED diagnosed with low-risk pulmonary embolism (PE) are managed with early discharge or observation.

METHODS

Single cohort prospective management study from January 2013 to October 2016 of patients with PE diagnosed in the ED and evaluated for a primary composite endpoint of mortality, recurrent venous thromboembolism, and/or major bleeding event at 90 days. Low-risk patients had a PE Severity Index score < 86, no evidence of proximal deep vein thrombosis on venous compression ultrasonography of both lower extremities, and no evidence of right heart strain on echocardiography. Patients were managed either in the ED or in the hospital on observation status. Primary outcomes were total length of stay, total encounter costs, and 30-day costs.

RESULTS

213 patients were enrolled. 13 were excluded per the study protocol. Of the remaining 200, 122 were managed with emergency department observation (EDO) and 78 with hospital observation (HO). One patient managed with EDO met the composite outcome due to a major bleeding event on day 61. The mean length of stay for EDO was 793.4 min (SD -169.7, 95% CI:762-823) and for HO was 1170 (SD -211.4, 95% CI:1122-1218) with a difference of 376.8 (95% CI: 430-323, p < 0.0001). Total encounter mean costs for EDO were $1982.95 and $2759.59 for HO, with a difference of $776.64 (95% CI: 972-480, p > 0.0001). 30-day total mean costs for EDO were $2864.14 and $3441.52 for HO, with a difference of $577.38 (95% CI: -1372-217, p = 0.15).

CONCLUSIONS

Patients with low-risk PE managed with ED-based observation have a shorter length of stay and lower total encounter costs than patients managed with Hospital-based observation.

Diagnostic Accuracy of D-Dimer Testing and the Revised Geneva Score in the Prediction of Pulmonary Embolism

BACKGROUND

Pulmonary embolism (PE) diagnosis can sometimes be challenging due to the disease having nonspecific signs and symptoms at the time of presentation. The present study aimed to evaluate the validity of the D-dimer in combination with the revised Geneva score (RGS) in the prediction of pulmonary embolism.

PATIENTS AND METHODS

This is a retrospective study of 2010 patients with suspected PE who had undergone both D-dimer testing followed by chest CT angiography (CTPA), irrespective of the D-dimer test results, at King Abdulaziz Medical City, Riyadh, Saudi Arabia, over 3 years, from Jan. 2016 to Jan. 2019. The predictive accuracy of D-dimer, adjusted D-dimer, and RGS was calculated. The receiver operating characteristic "ROC" curve was applied to allocate the optimum RGS cutoff for PE prediction.

RESULTS

The overall prevalence of PE was 16%. It was 0%, 25.8%, and 88.9% in low, intermediate, and high clinical probability categories of RGS, respectively. Both conventional and age-adjusted D-dimer thresholds showed significant level of agreement (kappa=0.81, p<0.001), high sensitivity (94% and 92.8%), high negative predictive value "NPV" (91.2% and 91.4%), low specificity (12.3% and 15.3%), and low positive predictive value "PPV" (17.5% and 17.8%), respectively. Combination of the age-adjusted D-dimer threshold and RGS at a cut-off of 5 points would provide 100% sensitivity and 61.7% specificity 34.1% PPV, 100% NPV, and 0.87 area under the curve "AUC". At an RGS cutoff <5 points, PE could have been ruled out in more than one-half (1036, 51.5%) of all suspected cases, and would have saved the cost of CTPA.

CONCLUSION

Conventional and age-adjusted D-dimer tests showed high levels of agreement in the prediction of PE, high sensitivity, and low specificity. RGS has a good performance in PE prediction. Using the revised Geneva score alone rules out PE for more than one-half of all suspected without further imaging.

Prevalence of Venous Thromboembolism in Kumasi: A Postmortem-Based Study in a Tertiary Hospital in Ghana

Background

There is a dearth of publications on the prevalence of venous thromboembolism in Ghana. Knowledge of the prevalence of venous thromboembolism, which is often undetected clinically, will help save lives as appropriate interventions can be made as well as provide a general clue to clinicians on detecting venous thromboembolism and pulmonary embolism.

Methods

The study employs a retrospective design with data extracted from the Autopsy Daybook of the Pathology unit, Komfo Anokye Teaching Hospital, 2009 to 2016. Data on patients' demographics were retrieved to establish diagnoses and age and gender distribution. Analysis was made of pulmonary embolism and deep vein thrombosis as a cause of death recorded on death certificates using the criteria of the International Classification of Diseases, version 10.

Results

A total of 150 cases of deep vein thrombosis and/or pulmonary embolism were available for the study period and the results showed an average age of 45.3 years with a standard deviation of 19.96. The ages ranged between 3 years and 96 years with the age group 31 to 40 years being the modal age group. Males recorded the highest number of cases with 92 (59.35%) compared to females with 63 (40.65%). Respiratory disorders, of which pneumonia is the most prevalent, are the leading clinical condition that is often misdiagnosed in place of pulmonary thromboembolism.

Conclusion

VTE is a major health problem especially among the elderly, but unfortunately the clinical diagnosis is usually missed by clinicians hence the need to maintain a high suspicion index.

Prediction of cerebral venous thrombosis with a new clinical score and D-dimer levels

OBJECTIVE

To investigate prediction of cerebral venous thrombosis (CVT) by clinical variables and D-dimer levels.

METHODS

This prospective multicenter study included consecutive patients with clinically possible CVT. On admission, patients underwent clinical examination, blood sampling for D-dimers measuring (ELISA test), and magnetic resonance/CT venography. Predictive value of clinical variables and D-dimers for CVT was calculated. A clinical score to stratify patients into groups with low, moderate, or high CVT risk was established with multivariate logistic regression.

RESULTS

CVT was confirmed in 26.2% (94 of 359) of patients by neuroimaging. The optimal estimate of clinical probability was based on 6 variables: seizure(s) at presentation (4 points), known thrombophilia (4 points), oral contraception (2 points), duration of symptoms >6 days (2 points), worst headache ever (1 point), and focal neurologic deficit at presentation (1 point) (area under the curve [AUC] 0.889). We defined 0 to 2 points as low CVT probability (negative predictive value [NPV] 94.1%). Of the 186 (51.8%) patients who had a low probability score, 11 (5.9%) had CVT. The frequency of CVT was 28.3% (34 of 120) in patients with a moderate (3-5 points) and 92.5% (49 of 53) in patients with a high (6-12 points) probability score. All low CVT probability patients with CVT had D-dimers >500 μg/L. Predictive value of D-dimers for CVT for >675 μg/L (best cutoff) vs >500 μg/L was as follows: sensitivity 77.7%, specificity, 77%, NPV 90.7%, and accuracy 77.2% vs sensitivity 89.4%, specificity 66.4%, NPV 94.6%, and accuracy 72.4%, respectively. Adding the clinical score to D-dimers >500 μg/L resulted in the best CVT prediction score explored (at the cutoff ≥6 points: sensitivity 83%/specificity 86.8%/NPV 93.5%/accuracy 84.4%/AUC 0.937).

CONCLUSION

The proposed new clinical score in combination with D-dimers may be helpful for predicting CVT as a pretest score; none of the patients with CVT showed low clinical probability for CVT and D-dimers <500 μg/L.

CLINICALTRIALSGOV IDENTIFIER

NCT00924859.

Advances in the Diagnosis of Venous Thromboembolism: A Literature Review

The incidence of venous thromboembolism (VTE), including lower extremity deep vein thrombosis (DVT) and pulmonary embolism (PE) is increasing. The increase in suspicion for VTE has lowered the threshold for performing imaging studies to confirm diagnosis of VTE. However, only 20% of suspected cases have a confirmed diagnosis of VTE. Development of pulmonary embolism rule-out criteria (PERC) and update in pre-test probability have changed the paradigm of ruling-out patient with low index of suspicion. The D-dimer test in conjunction to the pre-test probability has been utilized in VTE diagnosis. The age appropriate D-dimer cutoff and inclusion of YEARS algorithm (signs of the DVT, hemoptysis and whether PE is the likely diagnosis) for the D-dimer cutoff have been recent updates in the evaluation of suspected PE. Multi-detector computed tomography pulmonary angiography (CTPA) and compression ultrasound (CUS) are the preferred imaging modality to diagnose PE and DVT respectively. The VTE diagnostic algorithm do differ in pregnant individuals. The prerequisite of avoiding excessive radiation has recruited planar ventilation-perfusion (V/Q) scan as preferred in pregnant patients to evaluate for PE. The modification of CUS protocol with addition of the Valsalva maneuver should be performed while evaluating DVT in pregnant individual.

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.

Evaluating time to treatment and in-hospital outcomes of pulmonary embolism response teams

BACKGROUND

Pulmonary embolism response teams (PERTs) have become increasingly popular at institutions around the country, although the evidence to support their efficacy is limited. PERTs are mechanisms for rapid involvement of a multidisciplinary team in the management of a time-sensitive condition with many treatment options.

METHODS

We retrospectively reviewed 201 patients with PERT activations since inception, collecting data on demographics, time to treatment, treatment modality, and in-hospital outcomes.

RESULTS

Massive pulmonary embolism accounted for 16 (8.7%) PERT activations. The majority of patients were treated without invasive intervention; 91.4% (95% confidence interval [CI], 87.1%-95.7%) of patients received anticoagulation alone, 4.5% (95% CI, 0%-18.6%) had catheter-directed therapy (CDT), and 3.0% (95% CI, 0%-16.9%) had systemic administration of tissue plasminogen activator (tPA). The average time to intervention was 665 minutes (95% CI, 249-1080 minutes) for CDT and 22 minutes (95% CI, 0-456 minutes) for systemic TPA. The average time to anticoagulation was 2.3 minutes (95% CI, 0-43 minutes). There was a trend toward higher rates of cardiac events (odds ratio [OR], 12.68; 95% CI, 0.62-65.74) and death (OR, 3.19; 95% CI, 0.28-5.18) among patients with massive PE. There was a higher rate of cardiac events (OR, 5.66; 95% CI, 1.34-23.83) among patients who received tPA or an invasive intervention. There was no difference in mortality rates of patients who underwent aggressive management compared with anticoagulation alone.

CONCLUSIONS

A dedicated PERT results in efficient delivery of care and excellent outcomes, in part owing to the rapid (on average, 8 minutes) time to initiation of a multidisciplinary discussion. Patients who ultimately underwent CDT had an interval of >10 hours on average between diagnosis and CDT. This provisional or delayed approach to CDT in selected patients who were not improving with anticoagulation alone (and therefore had potential for higher net benefit from a procedure with its own inherent risks) may have resulted in a lower rate of CDT.

Predictive Model for Pulmonary Embolism in Patients with Deep Vein Thrombosis

BACKGROUND

To develop and verify a risk predictive model/scoring system for pulmonary embolism (PE) among hospitalized patients with deep venous thrombosis of the lower extremities (LDVT).

METHODS

776 patients with LDVT were enrolled in a case-control study between January 2016 and June 2017 from the Vascular Surgery Department of Shanxi Dayi Hospital, China. They were randomly divided into development (543 patients, 70%) and validation (233 patients, 30%) databases. Based on the results of pulmonary computed tomography arteriography, patients were divided into 2 categories; those with PE were designated as the case group, whereas those without comprised the controls. A logistic regression model and scoring system for PE in patients with LDVT was established in the development database and verified in the validation database. Scoring system (Shanxi Dayi Hospital score [SDH score]) was tabulated as follows: right lower extremity or bilateral lower extremities, 1; surgery or immobilization, 1; malignant tumor, 1; history of venous thromboembolism (VTE), 2; D-dimer >1,000 ng/mL, 2; and unprovoked, 2. Calibration and discrimination of the model were assessed by the Hosmer-Lemeshow goodness of fit test and the area under the receiver operating characteristic curve (AUC). Wells score, the Revised Geneva score, and the SDH score for predictive value of PE by AUC in the validation database were compared.

RESULTS

776 patients with LDVT were divided into 2 risk categories based on the scores from the risk model as follows: PE unlikely (score <3) and PE likely (score ≥3). Sensitivity, specificity, and crude agreement of the SDH score in the development database were 76.39%, 55.89%, and 61.33%, respectively. In the validation database, the logistic regression model showed good calibration and discriminative power. The Hosmer-Lemeshow goodness of fit test P value was >0.05, and the AUC was 0.705 (95% CI: 0.634-0.776, P < 0.001). The SDH score also showed good discriminative power, and the AUC was 0.702 (95% CI: 0.631-0.774, P < 0.001). Sensitivity, specificity, and crude agreement of the SDH score in the validation database were 67.61%, 61.73%, and 63.52%, respectively. AUC for the Wells score and the Revised Geneva score was 0.611 (95% CI: 0.533-0.688, P = 0.007) and 0.585 (95% CI: 0.503-0.666, P = 0.040), respectively. Difference of the AUC was not statistically significant between the Wells score and the SDH score (0.611 vs. 0.702, P = 0.059) but was so between the Revised Geneva score and the SDH score (0.585 vs. 0.702, P = 0.016). Sensitivity of the Wells score, Revised Geneva score, and the SDH score (64.79%, 67.61% vs. 67.61%) was not statistically significant. However, the specificity of the Wells score and Revised Geneva score was significantly lower than that of the SDH score (48.77%, 39.51% vs. 61.73%).

CONCLUSIONS

Our logistic regression model and the SDH score based on 7 risk factors as right lower extremity, bilateral lower extremities, unprovoked, surgery or immobilization, malignant tumor, history of VTE, and D-dimer>1,000 ng/mL showed good calibration and discriminative power for the assessment of PE risk in patients with LDVT. The SDH score is more specific for PE prediction in the Chinese population, compared with the Wells score and the Revised Geneva score.

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.

Developing a framework for evidence-based grading and assessment of predictive tools for clinical decision support

BACKGROUND

Clinical predictive tools quantify contributions of relevant patient characteristics to derive likelihood of diseases or predict clinical outcomes. When selecting predictive tools for implementation at clinical practice or for recommendation in clinical guidelines, clinicians are challenged with an overwhelming and ever-growing number of tools, most of which have never been implemented or assessed for comparative effectiveness. To overcome this challenge, we have developed a conceptual framework to Grade and Assess Predictive tools (GRASP) that can provide clinicians with a standardised, evidence-based system to support their search for and selection of efficient tools.

METHODS

A focused review of the literature was conducted to extract criteria along which tools should be evaluated. An initial framework was designed and applied to assess and grade five tools: LACE Index, Centor Score, Well's Criteria, Modified Early Warning Score, and Ottawa knee rule. After peer review, by six expert clinicians and healthcare researchers, the framework and the grading of the tools were updated.

RESULTS

GRASP framework grades predictive tools based on published evidence across three dimensions: 1) Phase of evaluation; 2) Level of evidence; and 3) Direction of evidence. The final grade of a tool is based on the highest phase of evaluation, supported by the highest level of positive evidence, or mixed evidence that supports a positive conclusion. Ottawa knee rule had the highest grade since it has demonstrated positive post-implementation impact on healthcare. LACE Index had the lowest grade, having demonstrated only pre-implementation positive predictive performance.

CONCLUSION

GRASP framework builds on widely accepted concepts to provide standardised assessment and evidence-based grading of predictive tools. Unlike other methods, GRASP is based on the critical appraisal of published evidence reporting the tools' predictive performance before implementation, potential effect and usability during implementation, and their post-implementation impact. Implementing the GRASP framework as an online platform can enable clinicians and guideline developers to access standardised and structured reported evidence of existing predictive tools. However, keeping GRASP reports up-to-date would require updating tools' assessments and grades when new evidence becomes available, which can only be done efficiently by employing semi-automated methods for searching and processing the incoming information.

Development and Performance of the Pulmonary Embolism Result Forecast Model (PERFORM) for Computed Tomography Clinical Decision Support

IMPORTANCE

Pulmonary embolism (PE) is a life-threatening clinical problem, and computed tomographic imaging is the standard for diagnosis. Clinical decision support rules based on PE risk-scoring models have been developed to compute pretest probability but are underused and tend to underperform in practice, leading to persistent overuse of CT imaging for PE.

OBJECTIVE

To develop a machine learning model to generate a patient-specific risk score for PE by analyzing longitudinal clinical data as clinical decision support for patients referred for CT imaging for PE.

DESIGN, SETTING, AND PARTICIPANTS

In this diagnostic study, the proposed workflow for the machine learning model, the Pulmonary Embolism Result Forecast Model (PERFORM), transforms raw electronic medical record (EMR) data into temporal feature vectors and develops a decision analytical model targeted toward adult patients referred for CT imaging for PE. The model was tested on holdout patient EMR data from 2 large, academic medical practices. A total of 3397 annotated CT imaging examinations for PE from 3214 unique patients seen at Stanford University hospitals and clinics were used for training and validation. The models were externally validated on 240 unique patients seen at Duke University Medical Center. The comparison with clinical scoring systems was done on randomly selected 100 outpatient samples from Stanford University hospitals and clinics and 101 outpatient samples from Duke University Medical Center.

MAIN OUTCOMES AND MEASURES

Prediction performance of diagnosing acute PE was evaluated using ElasticNet, artificial neural networks, and other machine learning approaches on holdout data sets from both institutions, and performance of models was measured by area under the receiver operating characteristic curve (AUROC).

RESULTS

Of the 3214 patients included in the study, 1704 (53.0%) were women from Stanford University hospitals and clinics; mean (SD) age was 60.53 (19.43) years. The 240 patients from Duke University Medical Center used for validation included 132 women (55.0%); mean (SD) age was 70.2 (14.2) years. In the samples for clinical scoring system comparisons, the 100 outpatients from Stanford University hospitals and clinics included 67 women (67.0%); mean (SD) age was 57.74 (19.87) years, and the 101 patients from Duke University Medical Center included 59 women (58.4%); mean (SD) age was 73.06 (15.3) years. The best-performing model achieved an AUROC performance of predicting a positive PE study of 0.90 (95% CI, 0.87-0.91) on intrainstitutional holdout data with an AUROC of 0.71 (95% CI, 0.69-0.72) on an external data set from Duke University Medical Center; superior AUROC performance and cross-institutional generalization of the model of 0.81 (95% CI, 0.77-0.87) and 0.81 (95% CI, 0.73-0.82), respectively, were noted on holdout outpatient populations from both intrainstitutional and extrainstitutional data.

CONCLUSIONS AND RELEVANCE

The machine learning model, PERFORM, may consider multitudes of applicable patient-specific risk factors and dependencies to arrive at a PE risk prediction that generalizes to new population distributions. This approach might be used as an automated clinical decision-support tool for patients referred for CT PE imaging to improve CT use.

Management of Low-Risk Pulmonary Embolism

Pulmonary embolism remains a leading cause of morbidity and mortality in the United States. However, with improved recognition and diagnosis, the risk of death diminishes. The diagnosis depends on the clinician's suspicion. Pulmonary emboli are categorized into low, intermediate, or high risk based on the scoring scales and patients' hemodynamic stability versus instability. Imaging plus biomarkers help stratify patients according to risk. With the advent of the computed tomography multidetector scanners, the improved imaging has increased the detection of subsegmental and incidental pulmonary emboli. Treatment of low-risk as well as subsegmental and incidental pulmonary embolism is evolving.

The problem of under-diagnosis and over-diagnosis of pulmonary embolism

Pulmonary embolism (PE) is an increasingly recognised condition which is associated with significant morbidity and mortality. Despite the better awareness of this serious condition, the diagnosis is still overlooked in many cases with sometimes fatal consequences. Under-diagnosis may be due to several reasons including reliance on non-specific 'classic' symptoms, belief that bedside measurements will likely be abnormal in the setting of acute PE, and confounding factors like co-existent cardiorespiratory diseases or being in an intensive care unit, where the diagnosis may not be considered. At the same time, incidental diagnosis of PE is occurring more often due to frequent use of imaging investigations alongside advancements in CT technology, and dilemma exists as to whether the chance finding of PE requires anticoagulation, especially when identified only at the subsegmental level. This article reviews these two issues of under-diagnosis and over-diagnosis of PE in the current era.

Pentraxin-3 Levels Relate to the Wells Score and Prognosis in Patients with Acute Pulmonary Embolism

Objective

To investigate the value of the PTX-3 test in evaluating the prognosis of acute pulmonary embolism (APE).

Method

117 APE patients were selected and divided into two groups according to plasma PTX-3 levels, including the group in which PTX − 3 ≥ 3.0 ng/mL (n = 42) and the group in which PTX − 3 < 3.0 ng/mL (n = 75). Patients were stratified into high-risk, medium-risk, and low-risk groups according to the Wells scores, and the PTX-3 levels were compared among the groups. Patients had been followed-up as well.

Results

According to the Wells scores, 11 patients were classified as high-risk (9.4%) and 68 were medium-risk (58.1%), while 38 were low-risk (32.5%). The PTX-3 levels in different risk groups were statistically different (all P < 0.05). During the follow-up period, 6 deaths occurred in the group with elevated PTX-3 (≥3.0 ng/mL), while 2 deaths occurred in the group with nonelevated PTX-3 (<3.0 ng/mL). The difference between the two groups was statistically significant (P < 0.01). 13 patients were hospitalized due to recurrent pulmonary embolism, of which 12 were in the group with elevated PTX-3 (≥3.0 ng/mL), while 1 patient was in the group with nonelevated PTX-3 (<3.0 ng/mL). The difference was statistically significant (P < 0.01).

Conclusion

The plasma PTX-3 level in APE patients is correlated with PE risk stratification. There is a significant correlation between PTX-3 levels and PE-related cardiac deaths, as well as the prognosis of recurrent PE. PTX-3 can be used as a clinical indicator of PE prognosis.

The sensitivities and prognostic values of the Wells and revised Geneva scores in diagnosis of pulmonary embolism in the Japanese population

OBJECTIVE

To assess the sensitivities of the Wells score (WS) and the revised Geneva score (RGS) and their prognostic values in the diagnosis of pulmonary embolism (PE) in the Japanese population.

METHODS

We conducted a retrospective chart review of patients with PE aged 16 years or older who were assessed between December 2008 and August 2014. Patients were divided into the PE unlikely and PE likely groups according to the WS and PE unlikely and PE likely groups according to the RGS. We also described the characteristics and three-month mortality of the patients. Univariate predictors with p < 0.05 were included in the multiple regression model. Fisher׳s exact test and Student׳s t-test were used for categorical and continuous variables, respectively.

RESULTS

PE was confirmed in 53 patients, and seven (13%) patients died within 3 months. The mean age was 66.0 ± 14.4 years. There were 32 female patients (60.4%). The RGS had a higher sensitivity than the WS (20.8% vs. 15.1%, P <0.01), although both scores had low yields. Mortality rate was significantly higher in patients with syncope than in those without (33.3% vs. 7.3%, respectively; P = 0.039). After age and sex adjustments, the presence of syncope showed a statistically significant association with mortality. The mortality rate did not significantly differ between the two groups categorized according to the WS (17.4% vs. 0%; P = 0.58) and RGS (21.7% vs. 14.3%; P = 1.00).

CONCLUSION

WS and RGS had low sensitivity in the diagnosis of PE and had limited prognostic values in a Japanese community hospital setting. Promoting awareness about the risk of mortality in patients with PE, especially those with syncope, is necessary.

The DAGMAR Score: D-dimer assay-guided moderation of adjusted risk. Improving specificity of the D-dimer for pulmonary embolism

We generated a novel scoring system to improve the test characteristics of D-dimer in patients with suspected PE (pulmonary emboli). Electronic Medical Record data were retrospectively reviewed on Emergency Department (ED) patients 18 years or older for whom a D-dimer and imaging were ordered between June 4, 2012 and March 30, 2016. Symptoms (dyspnea, unilateral leg swelling, hemoptysis), age, vital signs, medical history (cancer, recent surgery, medications, history of deep vein thrombosis or PE, COPD, smoking), laboratory values (quantitative D-dimer, platelets, and mean platelet volume (MPV)), and imaging results (CT, VQ) were collected. Points were designated to factors that were significant in two multiple regression analyses, for PE or positive D-dimer. Points predictive of PE were designated positive values and points predictive of positive D-dimer, irrespective of presence of PE, were designated negative values. The DAGMAR (D-dimer Assay-Guided Moderation of Adjusted Risk) score was developed using age and platelet adjustment and points for factors associated with PE and elevated D-dimer. Of 8486 visits reviewed, 3523 were unique visits with imaging, yielding 2253 (26.5%) positive D-dimers. 3501 CT scans and 156 VQ scans were completed, detecting 198 PE. In our cohort, a DAGMAR Score < 2 equated to overall PE risk < 1.2%. Specificity improved (38% to 59%) without compromising sensitivity (94% to 96%). Use of the DAGMAR Score would have reduced CT scans from 2253 to 1556 and lead to fewer false negative results. By considering factors that affect D-dimer and also PE, we improved specificity without compromising sensitivity.

The Prevalence of Concomitant Deep Vein Thrombosis, Symptomatic or Asymptomatic, Proximal or Distal, in Patients With Symptomatic Pulmonary Embolism

Patients with pulmonary embolism (PE) may have symptomatic or asymptomatic concomitant deep vein thrombosis (DVT). The reported prevalence of PE-associated DVT is variable, and thus, the utility of routine testing is controversial. The aim of our study was to analyze the prevalence of DVT and the factors associated with proximal DVT/whole-leg DVT in patients with symptomatic PE. In 428 consecutive patients (mean age: 59 ± 16.4 years; 52.3% men), we performed clinical examination and complete bilateral compression ultrasound and ascertained medical history and risk factors for DVT/PE. χ² and t tests were used. Deep vein thrombosis was found in 70.6%; proximal DVT in 49.5%. Sensitivity/specificity of DVT symptoms was 42.7%/93.7% for whole-leg DVT and 47.6%/83.3% for proximal DVT. Male gender significantly prevailed among those with whole-leg DVT and with proximal DVT (58.9% and 61.8%). Active malignancy was significantly more frequent in the patients with proximal DVT than without proximal DVT (10.4% vs 3.7%). In conclusion, the prevalence of PE-associated DVT is quite high but clinical diagnosis is unreliable. In our group, male gender and active malignancy were significantly associated with the presence of concomitant proximal DVT.

Use of the d-dimer for Detecting Pulmonary Embolism in the Emergency Department

BACKGROUND

Assessment for pulmonary embolism (PE) in the emergency department (ED) remains complex, involving clinical decision tools, blood tests, and imaging.

OBJECTIVE

Our objective was to examine the test characteristics of the high-sensitivity d-dimer for the diagnosis of PE at our institution and evaluate use of the d-dimer and factors associated with a falsely elevated d-dimer.

METHODS

We retrospectively collected data on adult patients evaluated with a d-dimer and computed tomography (CT) pulmonary angiogram or ventilation perfusion scan at two EDs between June 4, 2012 and March 30, 2016. We collected symptoms (dyspnea, unilateral leg swelling, hemoptysis), vital signs, and medical and social history (cancer, recent surgery, medications, history of deep vein thrombosis or PE, chronic obstructive pulmonary disease, smoking). We calculated test characteristics, including sensitivity, specificity, and likelihood ratios for the assay using conventional threshold and with age adjustment, and performed a univariate analysis.

RESULTS

We found 3523 unique visits with d-dimer and imaging, detecting 198 PE. Imaging was pursued on 1270 patients with negative d-dimers, revealing 9 false negatives, and d-dimer was sent on 596 patients for whom negative Pulmonary Embolism Rule-Out Criteria (PERC) were documented with 2% subsequent radiographic detection of PE. The d-dimer showed a sensitivity of 95.7% (95% confidence interval [CI] 91-98%), specificity of 40.0% (95% CI 38-42%), negative likelihood ratio of 0.11 (95% CI 0.06-0.21), and positive likelihood ratio of 1.59 (95% CI 1.53-1.66) for the radiographic detection of PE. With age adjustment, 347 of the 2253 CT scans that were pursued in patients older than 50 years with an elevated d-dimer could have been avoided without missing any additional PE. Many risk factors, such as age, history of PE, recent surgery, shortness of breath, tachycardia and hypoxia, elevated the d-dimer, regardless of the presence of PE.

CONCLUSIONS

Many patients with negative d-dimer and PERC still received imaging. Our data support the use of age adjustment, and perhaps adjustment for other factors seen in patients evaluated for PE.

Doppler ultrasound and D-dimer

The diagnosis of venous thromboembolism has evolved considerably with the development of standardized diagnostic algorithms that include clinical probability assessment, D-dimer measurement and the use of non-invasive imaging modalities such as compression ultrasonography and computed tomography angiography. The implementation of these strategies aims to improve resource allocation and patient outcome. The judicious use of these diagnostic tools requires a thorough knowledge of the appropriate clinical setting in which every test and strategy is efficient and can be used safely. For this purpose, D-dimer measurement and compression ultrasonography are complementary: the former is mainly used to exclude VTE in selected patients, while the latter is used to confirm the presence of an underlying DVT.

This review provides an appraisal of the features and use of D-dimer and compression ultrasonography in the context of suspected venous thromboembolism.

Massive Pulmonary Embolism after Overdose of Oral Benzodiazepine

Overdose of benzodiazepines rarely causes morbidity or mortality. A 58-year-old woman presented to the emergency department in coma after ingestion of 30 tablets of 0.5 mg alprazolam. She recovered after flumazenil was administered. However, massive pulmonary embolism developed during observation in the emergency department. Endotracheal intubation and recombinant tissue plasminogen activator infusion were initiated. This case report highlights that benzodiazepine overdose can contribute to pulmonary embolism which is a life-threatening condition.

Safety of multidetector computed tomography pulmonary angiography to exclude pulmonary embolism in patients with a likely pretest clinical probability

Essentials Safety of computed tomography (CTPA) to exclude pulmonary embolism (PE) in all patients is debated. We analysed the outcome of PE-likely outpatients left untreated after negative CTPA alone. The 3-month venous thromboembolic risk in these patients was very low (0.6%; 95% CI 0.2-2.3). Multidetector CTPA alone safely excludes PE in patients with likely clinical probability.

SUMMARY

Background In patients with suspected pulmonary embolism (PE) classified as having a likely or high pretest clinical probability, the need to perform additional testing after a negative multidetector computed tomography pulmonary angiography (CTPA) finding remains a matter of debate. Objectives To assess the safety of excluding PE by CTPA without additional imaging in patients with a likely pretest probability of PE. Patients/Methods We retrospectively analyzed patients included in two multicenter management outcome studies that assessed diagnostic algorithms for PE diagnosis. Results Two thousand five hundred and twenty-two outpatients with suspected PE were available for analysis. Of these 2522 patients, 845 had a likely clinical probability as assessed by use of the simplified revised Geneva score. Of all of these patients, 314 had the diagnosis of PE excluded by a negative CTPA finding alone without additional testing, and were left without anticoagulant treatment and followed up for 3 months. Two patients presented with a venous thromboembolism (VTE) during follow-up. Therefore, the 3-month VTE risk in likely-probability patients after a negative CTPA finding alone was 2/314 (0.6%; 95% confidence interval [CI] 0.2-2.3%). Conclusions In outpatients with suspected PE and a likely clinical probability as assessed by use of the simplified revised Geneva score, CTPA alone seems to be able to safely exclude PE, with a low 3-month VTE rate, which is similar to the VTE rate following the gold standard, i.e. pulmonary angiography.

Negative D-dimer testing excludes pulmonary embolism in non-high risk patients in the emergency department

PURPOSE

The purpose of this study was to assess the ability of d-dimer testing to obviate the need for cross-sectional imaging for patients at "non-high risk" for pulmonary embolism (PE).

METHODS

This is a retrospective study of emergency department patients at an academic medical center who underwent cross-sectional imaging (MRA or CTA) to evaluate for PE from 2008 to 2013. The primary outcome was the NPV of d-dimer testing when used in conjunction with clinical decision instruments (CDIs = Wells', Revised Geneva, and Simplified Revised Geneva Scores). The reference standard for PE status included image test results and a 6-month chart review follow-up for venous thromboembolism as a proxy for false negative imaging. Secondary analyses included ROC curves for each CDI and calculation of PE prevalence in each risk stratum.

RESULTS

Of 459 patients, 41 (8.9%) had PE. None of the 76 patients (16.6%) with negative d-dimer results had PE. Thus, d-dimer testing had 100% sensitivity and NPV, and there were no differences in CDI performance. Similarly, when evaluated independently of d-dimer results, no CDI outperformed the others (areas under the ROC curves ranged 0.53-0.55). There was a significantly higher PE prevalence in the high versus "non-high risk" groups when stratified by the Wells' Score (p = 0.03).

CONCLUSIONS

Negative d-dimer testing excluded PE in our retrospective cohort. Each CDI had similar NPVs, whether analyzed in conjunction with or independently of d-dimer results. Our results confirm that PE can be safely excluded in patients with "non-high risk" CDI scores and a negative d-dimer.

Improving the diagnostic management of upper extremity deep vein thrombosis

Essentials The Constans score and D-dimer can rule out upper extremity deep vein thrombosis without imaging. We evaluated the performance of an extended Constans score and an age-adjusted D-dimer threshold. The extended Constans score did not increase the efficiency compared to the original score. Age-adjusted D-dimer testing safely increased the efficiency by 4%, but this needs validation.

SUMMARY

Background Among patients with clinically suspected upper extremity deep vein thrombosis (UEDVT), a clinical decision rule based on the Constans score combined with D-dimer testing can safely rule out the diagnosis without imaging in approximately one-fifth of patients. Objectives To evaluate the performance of the original Constans score, an extended Constans score and an age-adjusted D-dimer positivity threshold. Methods Data of 406 patients with suspected UEDVT previously enrolled in a multinational diagnostic management study were used. The discriminatory performance, calibration and diagnostic accuracy of the Constans score were evaluated. The Constans score was extended by selecting clinical variables that may have incremental value in detecting UEDVT, conditional on the original Constans score items. The performance of the Constans rule was evaluated in combination with fixed and age-adjusted D-dimer thresholds. Results The original Constans score showed good discriminatory performance (c-statistic, 0.81; 95% confidence interval [CI], 0.76-0.85). An extended Constans score with five additional clinical items improved discriminatory performance and calibration, but this did not translate into a higher efficiency in avoiding imaging tests. Compared with a fixed threshold, age-adjusted D-dimer testing increased the proportion of patients for whom imaging and anticoagulation could be withheld from 21% to 25% (gain, 3.7%; 95% CI, 2.3-6.0%). Conclusions The Constans score has good discriminatory performance in the diagnosis of UEDVT. Age-adjusted D-dimer testing is likely to safely increase the efficiency of the diagnostic algorithm, but this approach needs prospective validation.

Best Clinical Practice: Controversies in Outpatient Management of Acute Pulmonary Embolism

BACKGROUND

Pulmonary embolism (PE) is a common condition managed in the emergency department (ED), with a wide range of morbidity and mortality. Patients are classically admitted for treatment and monitoring of anticoagulation.

OBJECTIVE

We sought to evaluate the controversy concerning outpatient therapy for patients with acute PE and investigate the feasibility, safety, and efficacy of outpatient management.

DISCUSSION

Patients with venous thromboembolism have historically been admitted for treatment and monitoring for concern of worsening disease or side effects of anticoagulation (bleeding). More than 90% of EDs admit patients with PE in the United States. However, close to 50% of patients may be appropriate for discharge and outpatient therapy. The published literature suggests that outpatient treatment is safe, feasible, and efficacious, with similar rates of recurrent venous thromboembolism and all-cause mortality, especially with novel oral anticoagulants. Multiple scoring criteria can be used, including the Pulmonary Embolism Severity Index (PESI), simplified PESI, Hestia criteria, Geneva Prognostic Score, European Society of Cardiology guidelines, Global Registry of Acute Coronary Events, and Aujesky score. Simplified PESI and the European Society of Cardiology guidelines have high-quality evidence, sufficient sensitivity, and ease of use for the ED. Patients considered for outpatient therapy should possess low hemorrhage risk, adequate social situation, negative biomarkers, ability to comply, and no alternate need for admission.

CONCLUSIONS

Patients with acute PE are often admitted in the United States, but a significant proportion may be appropriate for discharge. Patients with low risk for adverse events according to clinical scoring criteria, adequate follow-up, ability to comply, and no other need for admission can be discharged with novel oral anticoagulant therapy.

The role of computed tomography in the diagnosis of acute and chronic pulmonary embolism

Pulmonary embolism (PE) is a potentially life threatening condition requiring adequate diagnosis and treatment. Computed tomography pulmonary angiography (CTPA) is excellent for including and excluding PE, therefore CT is the first-choice diagnostic imaging technique in patients suspected of having acute PE. Due to its wide availability and low invasiveness, CTPA tends to be overused. Correct implementation of clinical decision rules in diagnostic workup for PE improves adequate use of CT. Also, CT adds prognostic value by evaluating right ventricular (RV) function. CT-assessed RV dysfunction and to lesser extent central emboli location predicts PE-related mortality in normotensive and hypotensive patients, while PE embolic obstruction index has limited prognostic value. Simple RV/left ventricular (LV) diameter ratio measures >1.0 already predict risk for adverse outcome, whereas ratios <1.0 can safely exclude adverse outcome. Consequently, assessing the RV/LV diameter ratio may help identify patients who are potential candidates for treatment at home instead of treatment in the hospital. A minority of patients develop chronic thromboembolic pulmonary hypertension (CTEPH) following acute PE, which is a life-threatening condition that can be diagnosed by CT. In proximal CTEPH, involving the more central pulmonary arteries, thrombectomy usually results in good outcome in terms of both functional status and long-term survival rate. CT is becoming the imaging method of choice for diagnosing CTEPH as it can identify patients who may benefit from thrombectomy. New CT developments such as distensibility measurements and dual-energy or subtraction techniques may further refine diagnosis and prognosis for improved patient care.

Comparison of the Wells score with the revised Geneva score for assessing suspected pulmonary embolism: a systematic review and meta-analysis

The Wells score and the revised Geneva score are two most commonly used clinical rules for excluding pulmonary embolism (PE). In this study, we aimed to assess the diagnostic accuracy of these two rules; we also compared the diagnostic accuracy between them. We searched PubMed and Web of science up to April 2015. Studies assessed Wells score and revised Geneva score for diagnosis suspected PE were included. The summary area under the curve (AUC) and the 95 % confidence interval (CI) were calculated. Eleven studies were included in this meta-analysis. For Wells score, the sensitivity ranged from 63.8 to 79.3 %, and the specificity ranged from 48.8 to 90.0 %. The overall weighted AUC was 0.778 (95 % CI 0.740-0.818; Z = 9.88, P < 0.001). For revised Geneva score, the sensitivity ranged from 55.3 to 73.6 %. The overall weighted AUC was 0.693 (95 % CI 0.653-0.736; Z = 11.96, P < 0.001). 95 % CIs of two AUCs were not overlapped, which indicated Wells score was more accurate than revised Geneva score for predicting PE in suspected patients. Meta-regression showed diagnostic accuracy of these two rules was not related with PE prevalence. Sensitivity analysis by only included prospective studies showed the results were robust. Our results showed the Wells score was more effective than the revised Geneva score in discriminate PE in suspected patients.

Comparing three clinical prediction rules for primarily predicting the 30-day mortality of patients with pulmonary embolism: The "Simplified Revised Geneva Score," the "Original PESI," and the "Simplified PESI"

Background:

Patients with suspected pulmonary embolism (PE) should be evaluated for the clinical probability of PE using an applicable risk score. The Geneva prognostic score, the PE Severity Index (PESI), and its simplified version (sPESI) are well-known clinical prognostic scores for PE. The purpose of this study was to analyze these clinical scores as prognostic tools.

Materials and Methods:

A historical cohort study was conducted on patients with acute PE in Al-Zahra Teaching Hospital, Isfahan, Iran, from June 2013 to August 2014. To compare survival in the 1-month follow-up and factor-analyze mortality from the survival graph, Kaplan–Meier, and log-rank logistic regression were applied.

Results:

Two hundred and twenty four patients were assigned to two “low risk” and “high risk” groups using the three versions of “Simplified PESI, Original PESI, and Simplified Geneva.” They were followed for a period of 1 month after admission. The overall mortality rate within 1 month from diagnosis was about 24% (95% confidence interval, 21.4–27.2). The mortality rate of low risk PE patients was about 4% in the PESI, 17% in the Geneva, and <1% in the simplified PESI scales (P < 0.005). The mortality rate among high risk patients was 33%, 33.5%, and 27.5%, respectively.

Conclusions:

Among patients with acute PE, the simplified PESI model was able to accurately predict mortality rate for low risk patients. Among high risk patients, however, the difference between the three models in predicting prognosis was not significant.

Clinical Decision Rules for Diagnostic Imaging in the Emergency Department: A Research Agenda

BACKGROUND

Major gaps persist in the development, validation, and implementation of clinical decision rules (CDRs) for diagnostic imaging.

OBJECTIVES

The objective of this working group and article was to generate a consensus-based research agenda for the development and implementation of CDRs for diagnostic imaging in the emergency department (ED).

METHODS

The authors followed consensus methodology, as outlined by the journal Academic Emergency Medicine (AEM), combining literature review, electronic surveys, telephonic communications, and a modified nominal group technique. Final discussions occurred in person at the 2015 AEM consensus conference.

RESULTS

A research agenda was developed, prioritizing the following questions: 1) what are the optimal methods to justify the derivation and validation of diagnostic imaging CDRs, 2) what level of evidence is required before disseminating CDRs for widespread implementation, 3) what defines a successful CDR, 4) how should investigators best compare CDRs to clinical judgment, and 5) what disease states are amenable (and highest priority) to development of CDRs for diagnostic imaging in the ED?

CONCLUSIONS

The concepts discussed herein demonstrate the need for further research on CDR development and implementation regarding diagnostic imaging in the ED. Addressing this research agenda should have direct applicability to patients, clinicians, and health care systems.

Comparison of Wells and Revised Geneva Rule to Assess Pretest Probability of Pulmonary Embolism in High-Risk Hospitalized Elderly Adults

OBJECTIVES

To assess and compare the diagnostic power for pulmonary embolism (PE) of Wells and revised Geneva scores in two independent cohorts (training and validation groups) of elderly adults hospitalized in a non-emergency department.

DESIGN

Prospective clinical study, January 2011 to January 2013.

SETTING

Unit of Internal Medicine inpatients, University of Catania, Italy.

PARTICIPANTS

Elderly adults (mean age 76 ± 12), presenting with dyspnea or chest pain and with high clinical probability of PE or D-dimer values greater than 500 ng/mL (N = 203), were enrolled and consecutively assigned to a training (n = 101) or a validation (n = 102) group. The clinical probability of PE was assessed using Wells and revised Geneva scores.

MEASUREMENTS

Clinical examination, D-dimer test, and multidetector computed angiotomography were performed in all participants. The accuracy of the scores was assessed using receiver operating characteristic analyses.

RESULTS

PE was confirmed in 46 participants (23%) (24 training group, 22 validation group). In the training group, the area under the receiver operating characteristic curve was 0.91 (95% confidence interval (CI) = 0.85-0.98) for the Wells score and 0.69 (95% CI = 0.56-0.82) for the revised Geneva score (P < .001). These results were confirmed in the validation group (P < .05). The positive (LR+) and negative likelihood ratios (LR-) (two indices combining sensitivity and specificity) of the Wells score were superior to those of the revised Geneva score in the training (LR+, 7.90 vs 1.34; LR-, 0.23 vs 0.66) and validation (LR+, 13.5 vs 1.46; LR-, 0.47 vs 0.54) groups.

CONCLUSION

In high-risk elderly hospitalized adults, the Wells score is more accurate than the revised Geneva score for diagnosing PE.

Investigation of Suspected Pulmonary Embolism at Hutt Valley Hospital with CT Pulmonary Angiography: Current Practice and Opportunities for Improvement

Aims. To study the use of CT pulmonary angiography (CTPA) at Hutt Hospital and investigate the use of pretest probability scoring in the assessment of patients with suspected pulmonary embolism (PE). Methods. We studied patients with suspected PE that underwent CTPA between January and May 2012 and collected data on demographics, use of pretest probability scoring, and use of D Dimer and compared our practice with the British Thoracic Society (BTS) guideline. Results. 105 patients underwent CTPA and 15% of patients had PE. 13% of patients had a Wells score prior to their scan. Wells score calculated by researchers revealed 54%, 36%, and 8% patients had low, medium, and high risk pretest probabilities and 8%, 20%, and 50% of these patients had positive scans. D Dimer was performed in 58% of patients and no patients with a negative D Dimer had a PE. Conclusion. The CTPA positive rate was similar to other contemporary studies but lower than previous New Zealand studies and some international guidelines. Risk stratification of suspected PE using Wells score and D Dimer was underutilised. A number of scans could have been safely avoided by using accepted guidelines reducing resources use and improving patient safety.