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.

Patient-Level, Institutional, and Temporal Variations in Use of Imaging Modalities to Confirm Pulmonary Embolism

Background:

The choice of the imaging modality for diagnosis of pulmonary embolism (PE) could be influenced by provider, patient or hospital characteristics, or over time. However, little is known about the choice of the diagnostic modalities in practice. The aim of this study was to evaluate the variations in the use of imaging modalities for patients with acute PE.

Methods:

Using the data from Registro Informatizado Enfermedad TromboEmbolica (RIETE), a prospective international registry of patients with venous thromboembolism (March 2001–January 2019), we explored the imaging modalities used in patients with acute PE. The imaging modalities included computed tomography pulmonary angiography, ventilation/perfusion scanning, pulmonary angiography, a combination of these tests, or PE signs and symptoms plus imaging-confirmed proximal deep vein thrombosis but no chest imaging.

Results:

Among 38 025 patients with confirmed PE (53.1% female, age: 67.3±17 years), computed tomography pulmonary angiography was the dominant modality of diagnosis in all RIETE enrollees (78.2% [99% CI, 77.6–78.7]); including pregnant patients (58.9% [99% CI, 47.7%–69.4%]) and patients with severe renal insufficiency (62.5% [99% CI, 59.9–65.0]). A greater proportion of patients underwent ventilation/perfusion scanning in larger hospitals compared with smaller hospitals (13.1% versus 7.3%, P <0.001). The use of computed tomography pulmonary angiography varied between 13.3% and 98.3% across the countries, and its use increased over time (46.5% in 2002 to 91.7% in 2018, P <0.001).

Conclusions:

In a large multinational PE registry, variations were observed in the use of imaging modalities according to patient or institutional factors and over time. However, computed tomography pulmonary angiography was the dominant modality of diagnosis, even in pregnancy and severe renal insufficiency. The safety, costs, and downstream effects of these tests on PE-related and non-PE-related outcomes warrant further investigation.

Investigation and diagnostic imaging of suspected pulmonary embolism during pregnancy and the puerperium: A review of the literature

Pulmonary embolism (PE) is a leading cause of maternal mortality with women at increased risk of PE during pregnancy and the early postpartum period. Clinical assessment of suspected PE during pregnancy is challenging as signs and symptoms associated with PE overlap with physiological changes of pregnancy. Clinical tests and rules commonly used to assess pre-test probability of PE were historically not well validated in the pregnant population. The challenges of clinical assessment in the pregnant and postpartum population result in a lowered threshold for diagnostic imaging. Computed tomographic pulmonary angiography (CTPA) and nuclear medicine lung scintigraphy or ventilation/perfusion (V/Q) scans are the main types of diagnostic imaging for suspected PE. Both methods are associated with small levels of ionising radiation exposure to mother and foetus. Accuracy of the diagnostic imaging tests is paramount. Haemodynamic changes of pregnancy, including increased heart rate, increased blood volume and altered flow velocity in the pulmonary arteries, may influence the quality of imaging. This comprehensive review examines the literature and evidence for the investigation and diagnostic imaging of suspected pulmonary embolism during pregnancy with CTPA and V/Q. Clinical decision-making tools, biomarkers and diagnostic imaging during pregnancy and postpartum will be considered with a focus on diagnostic accuracy and yield, radiation dose exposure (maternal-foetal) and protocol modifications. Current practice guideline recommendations and recent literature on diagnostic pathways are also presented.

[Diagnostic and therapeutic management of venous thromboembolic disease in obese patients]

Despite the high proportion of obese patients this population remains understudied in the field of venous thromboembolic disease (VTE). Obesity is a risk factor for pulmonary embolism and/or deep vein thrombosis, especially when it is associated with other risk factors for VTE. Currently there is no validated diagnostic algorithm for VTE in the population of obese patients. Moreover, imaging examinations can be of poor quality and inconclusive. In the prevention of VTE, data concerning obese patients are mainly based on low-level studies. Apart from the context of bariatric surgery, an adjustment of heparin doses according to the weight of the patient is proposed only on a case-by-case basis. According to the current guidelines, therapeutic fixed dose oral anticoagulants should not be prescribed for patients with weights exceeding 120kg or a body mass index>40kg/m². Heparin doses should be weight adjusted and monitored with anti-Xa activity. Anti vitamin K can be prescribed but require INR monitoring. Therefore, new studies specifically dedicated to obese patients are required in the field of VTE for better diagnostic and therapeutic management.

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.

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.

[ESC guidelines 2019 on diagnostics and management of acute pulmonary embolism]

This article on the new European Society of Cardiology (ESC) guidelines for diagnostics and management of acute pulmonary embolism (PE) focusses on new or changed recommendations compared to the previous version of the guidelines from 2014. The current risk-adjusted management algorithm for acute PE includes the clinical severity, aggravating comorbid conditions and right ventricular dysfunction. For low-risk patients early discharge and outpatient treatment are possible, whereas for high-risk patients reperfusion treatment and hemodynamic support have to be considered, depending on the hemodynamic situation and contraindications in the individual patient. Effective therapeutic anticoagulation for at least 3 months is recommended for all patients with PE. Potential indicators for extended anticoagulation are given in the guidelines (class I or class IIa recommendations). New oral anticoagulants (NOAC) are the first choice for anticoagulation in preference to vitamin K antagonists (VKA); however, they are not recommended in patients with severe renal dysfunction, during pregnancy or lactation and in patients with antiphospholipid antibody syndrome. Furthermore, a new algorithm for the follow-up after acute PE is proposed in the guidelines. In cases of symptomatic persistent pulmonary hypertension (PH) the transfer to a specialized center is recommended.

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.

EANM guideline for ventilation/perfusion single-photon emission computed tomography (SPECT) for diagnosis of pulmonary embolism and beyond

These guidelines update the previous EANM 2009 guidelines on the diagnosis of pulmonary embolism (PE). Relevant new aspects are related to (a) quantification of PE and other ventilation/perfusion defects; (b) follow-up of patients with PE; (c) chronic PE; and (d) description of additional pulmonary physiological changes leading to diagnoses of left ventricular heart failure (HF), chronic obstructive pulmonary disease (COPD) and pneumonia. The diagnosis of PE should be reported when a mismatch of one segment or two subsegments is found. For ventilation, Technegas or krypton gas is preferred over diethylene triamine pentaacetic acid (DTPA) in patients with COPD. Tomographic imaging with V/PSPECT has higher sensitivity and specificity for PE compared with planar imaging. Absence of contraindications makes V/PSPECT an essential method for the diagnosis of PE. When V/PSPECT is combined with a low-dose CT, the specificity of the test can be further improved, especially in patients with other lung diseases. Pitfalls in V/PSPECT interpretation are discussed. In conclusion, V/PSPECT is strongly recommended as it accurately establishes the diagnosis of PE even in the presence of diseases like COPD, HF and pneumonia and has no contraindications.

Pulmonary arteries: imaging of pulmonary embolism and beyond

The pulmonary arteries are not just affected by thrombus. Various acquired and congenital conditions can also affect the pulmonary arteries. In this review we discuss cross sectional imaging modalities utilized for the imaging of the pulmonary arteries. Acquired pulmonary artery entities, including pulmonary artery sarcoma (PAS), vasculitis, aneurysm, and arteriovenous malformations, and congenital anomalies in adults, including proximal interruption of the pulmonary artery, pulmonary sling, pulmonary artery stenosis, and idiopathic dilatation of the pulmonary trunk, are also discussed. An awareness of these entities and their imaging findings is important for radiologists interpreting chest imaging.

Management of intraoperative acute pulmonary embolism in a patient with subarachnoid haemorrhage undergoing femoral fracture repair

Acute pulmonary embolism (APE) during surgery can be life-threatening. We herein report a case of a 56-year-old man with subarachnoid haemorrhage who underwent surgical repair of a femoral fracture. During surgery with the patient under general anaesthesia, his oxygen saturation and end-tidal carbon dioxide decreased dramatically. An emergency transoesophageal echocardiogram demonstrated mobile echogenic densities in the right pulmonary artery and enlargement of the right atrium, and these findings were suggestive of APE. Considering the patient’s history of subarachnoid haemorrhage, anticoagulation with heparin or thrombolysis therapy for APE was contraindicated. We recommended inferior vena cava filter placement to prevent recurrence of the APE. Unfortunately, the patient and his family members refused the filter implantation, and the patient was discharged.

Clinical presentation and diagnostic work up of suspected pulmonary embolism in a district hospital emergency centre serving a high HIV/TB burden population

Introduction

The diagnosis of pulmonary embolism (PE) is challenging to make and is often missed in the emergency centre. The diagnostic work-up of PE has been improved by the use of clinical decision rules (CDRs) and CT pulmonary angiography (CTPA) in high-income countries. CDRs have not been validated in the South African environment where HIV and tuberculosis (TB) are highly prevalent. Both conditions are known to induce a hyper-coagulable state. The objective of this study was to describe the clinical presentation and diagnostic workup of suspected PE in our setting and to determine the prevalence of HIV and TB in our sample of patients with confirmed PE.

Methods

This study was a retrospective chart review of patients with suspected PE who had CTPAs performed between October 2013 and October 2015 at a district hospital in Cape Town, South Africa. Data were collected on demographics, presenting signs and symptoms, vitals, bedside investigations, HIV and TB status. A Revised Geneva score (RGS) was calculated retrospectively and compared to the CTPA result.

Results

The median age of patients with confirmed PE was 45 years and 68% were female. The CTPA yield for PE in our study population was 32%. The most common presenting complaint was dyspnoea (83%). Deep venous thrombosis (DVT) was present in 29%. No sign or symptom was observed to be markedly different in patients with confirmed PE vs no PE. Among patients with confirmed PE, 37% were HIV positive and 52% had current TB. RGS compared poorly with CTPA results.

Conclusions

PE remains a diagnostic challenge. In our study, the retrospectively calculated CDR was not predictive of PE in a population with a high prevalence of HIV and TB. Emergency physicians should be cautious when making a clinical probability assessment of PE in this setting. However, further studies are needed to develop a predictive CDR for the local environment.

Unenhanced multidetector computed tomography findings in acute central pulmonary embolism

Background

Computed tomography pulmonary angiography (CTPA) is the gold standard for the diagnosis of pulmonary embolism (PE). However, contrast is contraindicated in some patients. The purpose of this study was to determine the diagnostic accuracy of unenhanced multidetector CT (MDCT) for diagnosis of central PE using CTPA as the gold standard.

Methods

The records of patients with suspected PE seen between 2010 and 2013 were retrospectively reviewed. Inclusion criteria were an acute, central PE confirmed by CTPA and non-enhanced MDCT before contrast injection. Patients with a PE ruled out by CTPA served as a control group. MDCT findings studied were high-attenuation emboli in pulmonary artery (PA), main PA dilatation > 33.2 mm, and peripheral wedge-shaped consolidation. Receiver operating characteristic (ROC) analysis was used to determine the sensitivity and specificity of unenhanced MDCT to detect PE. Wells score of all patients were calculated using data extracted from medical records prior to imaging analysis.

Results

Thirty-two patients with a PE confirmed by CTPA and 32 with a PE ruled out by CTPA were included. Among the three main MDCT findings, high-attenuation emboli in the PA showed best diagnostic performance (Sensitivity 72.9%; Specificity 100%), followed by main PA dilatation > 33.2 mm (sensitivity 46.9%; specificity 90.6%), and peripheral wedge-shaped consolidation (sensitivity 43.8%; specificity 78.1%). Given any one or more positive findings on unenhanced MDCT, the sensitivity was 96.9% and specificity was 71.9% for a diagnosis of PE in patients. The area under the curve (AUC) of a composite measure of unenhanced MDCT findings (0.909) was significantly higher than that of the Wells score (0.688), indicating unenhanced MDCT was reliable for detecting PE than Wells score.

Conclusions

Unenhanced MDCT is an alternative for the diagnosis of acute central PE when CTPA is not available.

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.

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.

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.

A case series of venous thromboembolic disease in a semi-urban setting in Cameroon

Objective

Our goal was to study the clinical characteristics, risk factors and outcome of patients admitted for venous thromboembolism (VTE) in the medical unit of the Buea Regional Hospital, Cameroon between 1st July 2016 and 30th November 2017.

Results

Twenty-two patients were admitted for VTE. There were 12 (54.4%) men. The mean age was 54.9 ± 13.9 years (range: 31–77 years). The main risk factors were immobilization (40.9%), HIV infection (22.7%), tuberculosis (18.2%), obesity (13.6%) and cancer (13.6%). Nineteen (86.4%) patients had deep venous thrombosis (DVT), 3(13.6%) had pulmonary embolism (PE). One patient had a concomitant DVT and PE. All patients received low molecular weight heparin and 76.2% were discharged on oral vitamin K antagonist while 23.8% were discharged on direct oral anticoagulants. The median length of hospital stay was 9.5 days (range: 4–34). Three deaths (13.6%) were recorded. This study describes VTE in a semi-urban setting in Cameroon and shows that immobility, HIV infection and tuberculosis are common risk factors for VTE in this semi-urban setting.

Surgical embolectomy for acute massive pulmonary embolism: state of the art

Massive pulmonary embolism (PE) is a severe condition that can potentially lead to death caused by right ventricular (RV) failure and the consequent cardiogenic shock. Despite the fact thrombolysis is often administrated to critical patients to increase pulmonary perfusion and to reduce RV afterload, surgical treatment represents another valid option in case of failure or contraindications to thrombolytic therapy. Correct risk stratification and multidisciplinary proactive teams are critical factors to dramatically decrease the mortality of this global health burden. In fact, the worldwide incidence of PE is 60-70 per 100,000, with a mortality ranging from 1% for small PE to 65% for massive PE. This review provides an overview of the diagnosis and management of this highly lethal pathology, with a focus on the surgical approaches at the state of the art.

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.

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.

Imaging of Pulmonary Embolus: Thrombotic, Nonthrombotic, and Mimickers

Pulmonary embolism is a common and potentially fatal pathological condition. Imaging plays a crucial role in the diagnosis and differentiation of the causes of pulmonary embolus. Here we present typical imaging findings associated with both thrombotic and nonthrombotic pulmonary emboli, as well as their potential mimickers.

Venous thromboembolism risk assessments on trauma patients has suboptimal interobserver reliability among inexperienced clinicians (fourth-year medical students)

Background

Venous thromboembolic disease is a major cause of morbidity and mortality in hospitalized patients worldwide. The objective of this study is to compare interobserver reliability for qualitative and quantitative venous thromboembolism (VTE) risk assessments in hospitalized trauma patients.

Methods

We conducted a retrospective medical record review of 40 randomly selected trauma patients admitted to a 448-bed urban level-I trauma center from January 2013 to January 2014. Interclass correlation coefficient (ICC) was calculated based on a two-way mixed model. The sample was equally distributed between patients admitted to the floor and the intensive care unit (ICU). Eight fourth-year medical students performed the risk assessments by the medical record. Two forms for risk assessment were used: a qualitative screening and a quantitative screening. The composite of intraobserver and interobserver variabilities was determined.

Results

The ICC for qualitative VTE risk assessments was 0.845 and for quantitative VTE risk assessment was 0.628.

Conclusion

To optimize accuracy of VTE risk stratification and appropriate prophylaxis, medical students and first-year residents should be formally trained to perform quantitative assessments.

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.

A one year audit of patients with venous thromboembolism presenting to a tertiary hospital in Johannesburg, South Africa

Introduction

Given the growing burden of venous thromboembolism (VTE) worldwide and the paucity of data from the developing world, the aim of this study was to audit the characteristics, risk factors and length of hospital stay of patients with VTE presenting to a tertiary hospital emergency centre in Johannesburg, South Africa.

Methods

The study was a retrospective record review of all patients who presented with VTE to a tertiary academic emergency centre in Johannesburg, South Africa from 1 April 2012 to 30 March 2013.

Results

Venous thromboembolism was identified in 74 patients; 56 (75.7%) with isolated deep vein thrombosis, 13 (17.6%) with pulmonary embolism and five (6.8%) who had a concurrent deep vein thrombosis with pulmonary embolism. The median age of the patients was 40 years old (range 19–90). The female to male ratio was 2:1. HIV infection, tuberculosis and history of immobilisation were the most common risk factors. The median duration of hospital stay was 14 days (range 4–36). A therapeutic International Normalised Ratio at discharge was only reached in 36.5% of patients.

Conclusion

Venous thromboembolism presentation to the emergency centre is not common, but the risks associated with the morbidity and mortality related to it makes it important despite its relative scarcity. The prevalence of HIV infection amongst patients with VTE is concerning – not only related to the frequency of the pathology but also due to HIV not being factored into the common VTE risk stratification scores.

Are All Intracranial Mass Lesions Always a Contraindication for Thrombolytic Therapy?

Thrombolytic therapy is regarded as the first treatment choice in haemodynamically unstable patients with pulmonary embolism. Intracranial tumors have long been considered as a contraindication to thrombolytic therapy due to the risk of intracerebral haemorrhage. In this report, we presented a 76-year-old female patient with meningioma and massive pulmonary embolism who had received thrombolytic therapy despite a contraindication of intracranial mass. The patient completed the thrombolytic therapy without having complication. (Hong Kong j.emerg.med. 2014;21:98-102)

Age-Adjusted D-Dimer in the Prediction of Pulmonary Embolism: Does a Normal Age-Adjusted D-Dimer Rule Out PE?

Risk assessment for pulmonary embolism (PE) currently relies on physician judgment, clinical decision rules (CDR), and D-dimer testing. There is still controversy regarding the role of D-dimer testing in low or intermediate risk patients. The objective of the study was to define the role of clinical decision rules and D-dimer testing in patients suspected of having a PE. Records of 894 patients referred for computed tomography pulmonary angiography (CTPA) at a University medical center were analyzed. The clinical decision rules overall had an ROC of approximately 0.70, while signs of DVT had the highest ROC (0.80). A low probability CDR coupled with a negative age-adjusted D-dimer largely excluded PE. The negative predictive value (NPV) of an intermediate CDR was 86-89%, while the addition of a negative D-dimer resulted in NPVs of 94%. Thus, in patients suspected of having a PE, a low or intermediate CDR does not exclude PE; however, in patients with an intermediate CDR, a normal age-adjusted D-dimer increases the NPV.

Effects of impaired renal function on levels and performance of D-dimer in patients with suspected pulmonary embolism

Clinical probability and D-dimer measurement play an essential role in the non-invasive diagnostic strategies for pulmonary embolism (PE). PE can be ruled out without further imaging in patients with non-high clinical probability and negative D-dimer. D-dimer level is increased in patients with renal impairment. Whether its diagnostic usefulness is maintained in these patients is not well determined. We aimed to evaluate the effects of renal impairment on diagnostic performances of D-dimer in patients with suspected PE. A retrospective analysis of 1,625 patients with suspected PE included in a multicentre prospective study was performed. D-dimer levels and percentages of patients with a negative D-dimer were compared between three subgroups according to glomerular filtration rate (GFR) estimated by the MDRD formula: ≥90 ml/min (normal renal function), 60–89 ml/min (mild renal impairment), 30–59 ml/min (moderate renal impairment). D-dimer levels increased and the proportion of negative D-dimer decreased significantly according to renal status: 46% negative D-dimer in patients with normal GFR, 31% in patients with mild renal impairment, 11% in those with moderate renal impairment, corresponding to number of patients needed to test to obtain one negative test of 2.2, 3.2 and 9, respectively. In conclusion, the clinical usefulness of D-dimer decreases with renal impairment. However, PE can still be ruled out by negative D-dimer in a substantial proportion of patients with non-high clinical probability, avoiding exposure to contrast media.

Pulmonary embolism and in situ pulmonary artery thrombosis in paediatrics

Data on paediatric pulmonary embolism (PE) are scarce. We sought to systematically review the current literature on childhood PE and conducted a search on paediatric PE via PubMed (1946–2013) and Embase (1980–2013). There was significant heterogeneity in reported data. Two patterns were noted: classic thromboembolic PE (TE-PE) and in situ pulmonary artery thrombosis (ISPAT). Mean age of presentation for TE-PE was 14.86 years, and 51% of cases were males. The commonest method for diagnosis of TE-PE was contrast CT with angiography (74% of patients). The diagnosis of TE-PE was often delayed. Although 85% of children with TE-PE had an elevated D-dimer at presentation, it was non-discriminatory for the diagnosis. In paediatric TE-PE, the prevalence of central venous catheters was 23%, immobilisation 38%, systemic infection 31% and obesity 13%, elevated Factor VIII or von Willebrand factor levels 27%, Protein C deficiency 17%, Factor V Leiden 14% and Protein S deficiency 7%. In patients with TE-PE, pharmacologic thrombolysis was used in 29%; unfractionated heparin was the most common initial anticoagulant treatment in 64% and low-molecular-weight heparins the most common follow-up treatment in 83%. Duration of anticoagulant therapy was variable and death was reported in 26% of TE-PE patients. In contrast to TE-PE, patients with ISPAT were not investigated systematically for presence of thrombophilia, had more surgical interventions as the initial management and were often treated with anti-platelet medications. This review summarises important data and identifies gaps in the knowledge of paediatric PE, which may help to design future studies.

Venous thromboembolism diagnosis: unresolved issues

Recent advances in the management of patients with suspected VTE have both improved diagnostic accuracy and made management algorithms safer, easier to use and well standardised. These diagnostic algorithms are mainly based on the assessment of clinical pretest probability, D-dimer measurement and imaging tests, mainly represented by compression ultrasound (CUS) for suspected DVT and computed tomography pulmonary angiography (CTPA) or lung ventilationperfusion scan for pulmonary embolism. These diagnostic algorithms allow a safe and cost-effective diagnosis for most patients with suspected VTE. In this review, we focus on the challenge of diagnosing VTE in special patient populations, such as elderly patients, pregnant women, or patients with a prior VTE. Some additional challenges are arising that might require adjustments to current diagnostic strategies, such as the reduced clinical suspicion threshold, resulting in a lower proportion of VTE among suspected patients; the overdiagnosis and overtreatment of VTE, especially regarding calf deep-vein thrombosis (DVT) and subsegmental pulmonary embolism (SSPE).

Frequency of use and acceptability of clinical prediction rules for pulmonary embolism among Swiss general internal medicine residents

INTRODUCTION

Whether clinical prediction rules for pulmonary embolism are accepted and used among general internal medicine residents remains uncertain. We therefore evaluated the frequency of use and acceptability of the Revised Geneva Score (RGS) and the Pulmonary Embolism Severity Index (PESI), and explored which factors were associated with rule use.

MATERIALS/METHODS

In an online survey among general internal medicine residents from 10 Swiss hospitals, we assessed rule acceptability using the Ottawa Acceptability of Decision Rules Instrument (OADRI) and explored the association between physician and training-related factors and rule use using mixed logistic regression models.

RESULTS

The response rate was 50.4% (433/859). Overall, 61% and 36% of the residents reported that they always or regularly use the RGS and the PESI, respectively. The mean overall OADRI score was 4.3 (scale 0-6) for the RGS and 4.1 for the PESI, indicating a good acceptability. Rule acceptability (odds ratio [OR] 6.19 per point, 95% confidence interval [CI] 3.64-10.51), prior training in emergency medicine (OR 5.14, CI 2.20-12.01), and availability of internal guidelines recommending RGS use (OR 4.25, CI 2.15-8.43) were associated with RGS use. Rule acceptability (OR 6.43 per point, CI 4.17-9.92) and rule taught at medical school (OR 2.06, CI 1.24-3.43) were associated with PESI use.

CONCLUSIONS

The RGS was more frequently used than the PESI. Both rules were considered acceptable. Rule acceptability, prior training in emergency medicine, availability of internal guidelines, and rule taught at medical school were associated with rule use and represent potential targets for quality improvement interventions.

Assessing clinical probability of pulmonary embolism: prospective validation of the simplified Geneva score

Essentials The simplified Geneva score allows easier pretest probability assessment of pulmonary embolism (PE). We prospectively validated this score in the ADJUST-PE management outcome study. The study shows that it is safe to manage patients with suspected PE according to this score. The simplified Geneva score is now ready for use in routine clinical practice.

SUMMARY

Background Pretest probability assessment by a clinical prediction rule (CPR) is an important step in the management of patients with suspected pulmonary embolism (PE). A limitation to the use of CPRs is that their constitutive variables and corresponding number of points are difficult to memorize. A simplified version of the Geneva score (i.e. attributing one point to each variable) has been proposed but never been prospectively validated. Aims Prospective validation of the simplified Geneva score (SGS) and comparison with the previous version of the Geneva score (GS). Methods In the ADJUST-PE study, which had the primary aim of validating the age-adjusted D-dimer cut-off, the SGS was prospectively used to determine the pretest probability in a subsample of 1621 study patients. Results Overall, PE was confirmed in 294 (18.1%) patients. Using the SGS, 608 (37.5%), 980 (60.5%) and 33 (2%) were classified as having a low, intermediate and high clinical probability. Corresponding prevalences of PE were 9.7%, 22.4% and 45.5%; 490 (30.1%) patients with low or intermediate probability had a D-dimer level below 500 μg L-1 and 653 (41.1%) had a negative D-dimer test according to the age-adjusted cut-off. Using the GS, the figures were 491(30.9%) and 650 (40.9%). None of the patients considered as not having PE based on a low or intermediate SGS and negative D-dimer had a recurrent thromboembolic event during the 3-month follow-up. Conclusions The use of SGS has similar efficiency and safety to the GS in excluding PE in association with the D-dimer test.

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.

Diagnosis of acute pulmonary embolism

Advances in the management of patients with suspected pulmonary embolism (PE) have improved diagnostic accuracy and made management algorithms safer, easier to use, and well standardized. These diagnostic algorithms are mainly based on the assessment of clinical pretest probability, D-dimer measurement, and imaging tests-predominantly computed tomography pulmonary angiography. These diagnostic algorithms allow safe and cost-effective diagnosis for most patients with suspected PE. In this review, we summarize signs and symptoms of PE, current existing evidence for PE diagnosis, and focus on the challenge of diagnosing PE in special patient populations, such as pregnant women, or patients with a prior VTE. We also discuss novel imaging tests for PE diagnosis and highlight some of the additional challenges that might require adjustments to current diagnostic strategies, such as the reduced clinical suspicion threshold, resulting in a lower proportion of PE among suspected patients as well as the overdiagnosis of subsegmental PE.