The History of Diagnosing Venous Thromboembolism

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

A Prediction Rule for Occurrence of Chronic Thromboembolic Disease After Acute Pulmonary Embolism

BACKGROUND

Occurrence of chronic thromboembolic disease (CTED) after 3 or 6 months of standard and effective anticoagulation is not uncommon in patients with acute pulmonary embolism (PE). To date, there has been no scoring model for the prediction of CTED occurrence.

METHODS

A Prediction Rule for CTED (PRC) was established in the establishment cohort (n=1,124) and then validated in the validation cohort (n=211). Both original and simplified versions of the PRC score were provided by using different scoring and cut-offs.

RESULTS

The PRC score included 10 items: active cancer (3.641; 2.338-4.944; p<0.001), autoimmune diseases (2.218; 1.545-2.891; p=0.001), body mass index >30 kg/m2 (2.186; 1.573-2.799; p=0.001), chronic immobility (2.135; 1.741-2.529; p=0.001), D-dimer >2,000 ng/mL (1.618; 1.274-1.962; p=0.005), PE with deep vein thrombosis (3.199; 2.356-4.042; p<0.001), previous venous thromboembolism (VTE) history (5.268; 3.472-7.064; p<0.001), thromboembolism besides VTE (4.954; 3.150-6.758; p<0.001), thrombophilia (3.438; 2.573-4.303; p<0.001), and unprovoked VTE (2.227; 1.471-2.983; p=0.001). In the establishment cohort, the sensitivity, specificity, Youden index (YI), and C-index were 85.5%, 79.7%, 0.652, and 0.821 (0.732-0.909) when using the original PRC score, whereas they were 87.9%, 74.6%, 0.625, and 0.807 (0.718-0.897) when using the simplified one, respectively (Kappa coefficient 0.819, p-value of McNemar's test 0.786). In the validation cohort, the sensitivity, specificity, YI, and C-index were 86.3%, 76.3%, 0.626, and 0.815 (0.707-0.923) when using the original PRC score, whereas they were 85.0%, 78.6%, 0.636, and 0.818 (0.725-0.911) when using the simplified one, respectively (Kappa coefficient 0.912, p-value of McNemar's test 0.937); both were better than that of the DASH score (72.5%, 69.5%, 0.420, and 0.621 [0.532-0.710]).

CONCLUSIONS

A prediction score for CTED occurrence, termed PRC, predicted the likelihood of CTED occurrence after 3 or 6 months of standard anticoagulation in hospitalised patients with a diagnosis of acute PE.

Machine-learning-based models assist the prediction of pulmonary embolism in autoimmune diseases: A retrospective, multicenter study

BACKGROUND

Pulmonary embolism (PE) is a severe and acute cardiovascular syndrome with high mortality among patients with autoimmune inflammatory rheumatic diseases (AIIRDs). Accurate prediction and timely intervention play a pivotal role in enhancing survival rates. However, there is a notable scarcity of practical early prediction and risk assessment systems of PE in patients with AIIRD.

METHODS

In the training cohort, 60 AIIRD with PE cases and 180 age-, gender-, and disease-matched AIIRD non-PE cases were identified from 7254 AIIRD cases in Tongji Hospital from 2014 to 2022. Univariable logistic regression (LR) and least absolute shrinkage and selection operator (LASSO) were used to select the clinical features for further training with machine learning (ML) methods, including random forest (RF), support vector machines (SVM), neural network (NN), logistic regression (LR), gradient boosted decision tree (GBDT), classification and regression trees (CART), and C5.0 models. The performances of these models were subsequently validated using a multicenter validation cohort.

RESULTS

In the training cohort, 24 and 13 clinical features were selected by univariable LR and LASSO strategies, respectively. The five ML models (RF, SVM, NN, LR, and GBDT) showed promising performances, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.962-1.000 in the training cohort and 0.969-0.999 in the validation cohort. CART and C5.0 models achieved AUCs of 0.850 and 0.932, respectively, in the training cohort. Using D-dimer as a pre-screening index, the refined C5.0 model achieved an AUC exceeding 0.948 in the training cohort and an AUC above 0.925 in the validation cohort. These results markedly outperformed the use of D-dimer levels alone.

CONCLUSION

ML-based models are proven to be precise for predicting the onset of PE in patients with AIIRD exhibiting clinical suspicion of PE.

TRIAL REGISTRATION

Chictr.org.cn: ChiCTR2200059599.

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.

Diagnosis of Pulmonary Embolism in Pregnancy

Pulmonary embolism (PE) is a significant cause of obstetric morbidity and mortality. However, overdiagnosis related to excessive use of diagnostic testing is also associated with long-term major health issues, including impact on future pregnancies and subsequent health care. Accurate diagnosis of PE depends on the knowledge of prevalence of PE in the pregnant population, the a priori probability of a PE based on specific findings in a given patient, and understanding of the accuracy of computed tomography pulmonary angiography (CTPA), the dominant diagnostic modality employed for this diagnosis. Venous thromboembolism is widely considered to be more common in pregnancy. However, this term includes both deep venous thrombosis as well as PE. While the former appears to be more common, published data on the prevalence of PE in pregnancy show little or no increase relative to the general population. Given the published data on the sensitivity and specificity of CTPA, a positive reading is more likely to be a false positive unless the probability of a PE in a given patient is at least 5% (a 200-fold increase from baseline). Doubling the probability to 10% (a 400-fold increase) only improves the positive predictive value to approximately 67%. Strategies to refine the a priori probability of a PE in a given patient are detailed, including scoring systems and D-dimer measurements. A careful history and physical examination and thoughtful development of a differential diagnosis are key elements of clinical practice and should include both the likelihood of each possible diagnosis and the accuracy of diagnostic modalities. This approach should precede the application of a given algorithm. Such a structured approach can decrease utilization and limit false positive diagnoses without increasing morbidity or mortality. KEY POINTS: · Incidence of PE is lower than assumed.. · Incidence is critical for assessing predictive value of a test.. · Computed tomography angiography is likely overused in pregnancy.. · Clinical scoring and D-dimer have a role in PE diagnosis..

Pulmonary Embolism: An Update Based on the Revised AWMF-S2k Guideline

Pulmonary embolism (PE) is the third most common acute cardiovascular disease. The risk of PE increases with age and mortality is high. Patients are stratified into hemodynamically stable versus unstable patients, as this has important implications for diagnosis and therapy. Since clinical signs and symptoms of acute PE are nonspecific, the clinical likelihood of PE is estimated to guide diagnostic pathways. D-dimer testing is performed in hemodynamically stable patients with low or intermediate probability of PE and the visualization of thromboembolism and its sequelae is commonly achieved with computed tomography pulmonary angiography (CTPA), supplemented by ultrasound techniques. With confirmed PE, another risk stratification estimates disease severity and defines intensity and setting of the ensuing treatment. The therapeutic spectrum ranges from outpatient treatment with initial oral anticoagulation to thrombolytic or interventional treatment in the intensive care unit or catheterization laboratory. In single cases, even acute surgical thrombectomy is attempted.

A machine learning model for diagnosing acute pulmonary embolism and comparison with Wells score, revised Geneva score, and Years algorithm

BACKGROUND

Acute pulmonary embolism (APE) is a fatal cardiovascular disease, yet missed diagnosis and misdiagnosis often occur due to non-specific symptoms and signs. A simple, objective technique will help clinicians make a quick and precise diagnosis. In population studies, machine learning (ML) plays a critical role in characterizing cardiovascular risks, predicting outcomes, and identifying biomarkers. This work sought to develop an ML model for helping APE diagnosis and compare it against current clinical probability assessment models.

METHODS

This is a single-center retrospective study. Patients with suspected APE were continuously enrolled and randomly divided into two groups including training and testing sets. A total of 8 ML models, including random forest (RF), Naïve Bayes, decision tree, K-nearest neighbors, logistic regression, multi-layer perceptron, support vector machine, and gradient boosting decision tree were developed based on the training set to diagnose APE. Thereafter, the model with the best diagnostic performance was selected and evaluated against the current clinical assessment strategies, including the Wells score, revised Geneva score, and Years algorithm. Eventually, the ML model was internally validated to assess the diagnostic performance using receiver operating characteristic (ROC) analysis.

RESULTS

The ML models were constructed using eight clinical features, including D-dimer, cardiac troponin T (cTNT), arterial oxygen saturation, heart rate, chest pain, lower limb pain, hemoptysis, and chronic heart failure. Among eight ML models, the RF model achieved the best performance with the highest area under the curve (AUC) (AUC = 0.774). Compared to the current clinical assessment strategies, the RF model outperformed the Wells score ( P = 0.030) and was not inferior to any other clinical probability assessment strategy. The AUC of the RF model for diagnosing APE onset in internal validation set was 0.726.

CONCLUSIONS

Based on RF algorithm, a novel prediction model was finally constructed for APE diagnosis. When compared to the current clinical assessment strategies, the RF model achieved better diagnostic efficacy and accuracy. Therefore, the ML algorithm can be a useful tool in assisting with the diagnosis of APE.

How to recognize pulmonary embolism in syncope patients: A simple rule

BACKGROUND

Syncope can be the presenting symptom of Pulmonary Embolism (PE). It is not known wether using a standardized algorithm to rule-out PE in all patients with syncope admitted to the Emergency Departments (ED) is of value or can lead to overdiagnosis and overtreatment.

METHODS

We tested if simple anamnestic and clinical parameters could be used as a rule to identify patients with syncope and PE in a multicenter observational study. The rule's sensitivity was tested on a cohort of patients that presented to the ED for syncopal episodes caused by PE. The clinical impact of the rule was assessed on a population of consecutive patients admitted for syncope in the ED.

RESULTS

Patients were considered rule-positive in the presence of any of the following: hypotension, tachycardia, peripheral oxygen saturation ≤ 93 % (SpO2), chest pain, dyspnea, recent history of prolonged bed rest, clinical signs of deep vein thrombosis, history of previous venous thrombo-embolism and active neoplastic disease. The sensitivity of the rule was 90.3 % (95 % CI: 74.3 % to 98.0 %). The application of the rule to a population of 217 patients with syncope would have led to a 70 % reduction in the number of subjects needing additional diagnostic tests to exclude PE.

CONCLUSIONS

Most patients with syncope due to PE present with anamnestic and clinical features indicative of PE diagnosis. A clinical decision rule can be used to identify patients who would benefit from further diagnostic tests to exclude PE, while reducing unnecessary exams that could lead to over-testing and over-diagnosis.

High and intermediate risk pulmonary embolism in the ICU

Pulmonary embolism (PE) is a common and important medical emergency, encountered by clinicians across all acute care specialties. PE is a relatively uncommon cause of direct admission to the intensive care unit (ICU), but these patients are at high risk of death. More commonly, patients admitted to ICU develop PE as a complication of an unrelated acute illness. This paper reviews the epidemiology, diagnosis, risk stratification, and particularly the management of PE from a critical care perspective. Issues around prevention, anticoagulation, fibrinolysis, catheter-based techniques, surgical embolectomy, and extracorporeal support are discussed.

Obesity as a Predictor for Pulmonary Embolism and Performance of the Age-Adjusted D-Dimer Strategy in Obese Patients with Suspected Pulmonary Embolism

INTRODUCTION

 Obesity is a risk factor for venous thromboembolism, but studies evaluating its association with pulmonary embolism (PE) in patients with suspected PE are lacking.

OBJECTIVES

 To evaluate whether body mass index (BMI) and obesity (i.e., BMI ≥30 kg/m2) are associated with confirmed PE in patients with suspected PE and to assess the efficiency and safety of the age-adjusted D-dimer strategy in obese patients.

METHODS

 We conducted a secondary analysis of a multinational, prospective study, in which patients with suspected PE were managed according to the age-adjusted D-dimer strategy and followed for 3 months. Outcomes were objectively confirmed PE at initial presentation, and efficiency and failure rate of the diagnostic strategy. Associations between BMI and obesity, and PE were examined using a log-binomial model that was adjusted for clinical probability and hypoxia.

RESULTS

 We included 1,593 patients (median age: 59 years; 56% women; 22% obese). BMI and obesity were not associated with confirmed PE. The use of the age-adjusted instead of the conventional D-dimer cut-off increased the proportion of obese patients in whom PE was considered ruled out without imaging from 28 to 38%. The 3-month failure rate in obese patients who were left untreated based on a negative age-adjusted D-dimer cut-off test was 0.0% (95% confidence interval: 0.0-2.9%).

CONCLUSION

 BMI on a continuous linear scale and obesity were not predictors of confirmed PE among patients presenting with a clinical suspicion of PE. The age-adjusted D-dimer strategy appeared safe in ruling out PE in obese patients with suspected PE.

Sickle-Cell Trait as a Risk Factor for an Unprovoked Venous Thromboembolism: A Case Report

In this case report, we examine the increased risk of venous thromboembolism (VTE) in patients with sickle-cell trait (SCT), illustrated by a patient with SCT who developed pulmonary embolism (PE) despite low scores on conventional risk assessment tools. The case prompts both a discussion of risk assessment and management strategies in this population.

The Legend score synthesizes Wells, PERC, Geneva, D-dimer and predicts acute pulmonary embolism prior to imaging tests

INTRODUCTION

The prediction rules of acute pulmonary embolism(PE) before imaging tests recommended by the commonly used guidelines have low diagnostic efficiency if not combined with D-dimer, therefore it is necessary to seek for a prediction rule with higher diagnostic efficiency.

METHODS

We designed a new score named Legend by synthesizing the scores of Wells, PERC, and Geneva, as well as D-dimer with patients in the development group(n = 2112), and then validated it in patients of validation group(n = 388). Diagnostic efficiency was also compared between Legend score and Wells+D-dimer (DD), PERC+DD, Geneva+DD, and YEARS+DD(YEAR algorithm).

RESULTS

The Legend score comprised active cancer, D-dimer≥1000 ng/mL, DVT symptoms and/or signs, previous venous thromboembolism (VTE) history, and surgery, trauma, or immobilization in the past month. The sensitivity, specificity, Youden index, and area under the curve(AUC) were 0.985, 0.744, 0.729, and (0.861[0.796-0.925], P<0.001), respectively, for original Legend score, whereas were 0.982, 0.778, 0.760, and (0.871[0.823-0.920], P<0.001), respectively, for simplified Legend score. The Kappa coefficient and P value of McNemar test were 0.988 and 1.000, respectively, between the original and simplified Legend scores. In the validation group, the sensitivity, specificity, Youden index, and C-index were 0.971, 0.749, 0.720, and (0.838[0.781-0.896], P<0.001), respectively, for the original Legend score, whereas were 0.986, 0.715, 0.701, and (0.816[0.750-0.880], P = 0.001) respectively, for the simplified Legend score. The Kappa coefficient and P value of McNemar test between original Legend score and Wells+DD, PERC+DD, Geneva+DD, and YEARS+DD were (0.563, 0.001), (0.139, <0.001), (0.631, 0.006), and (0.732, 0.029), respectively. The Kappa coefficient and P value of McNemar test between simplified Legend score and aforementioned scores were (0.675, 0.009), (0.172, <0.001), (0.747, 0.001), and (0.883, 0.012), respectively.

DISCUSSION

In view of the fact the Legend score reserves the efficient predictors and eliminates the inefficient ones in Wells, PERC, and revised Geneva scores, and incorporates D-dimer into it, a more efficient, modified, and user-friendly one has replaced the original ones.

CONCLUSIONS

The Legend score yields excellent diagnostic efficiency with good safety in the pretest prediction of acute PE prior to imaging tests. It also avoids more unnecessary imaging tests than Wells+DD, PERC+DD, Geneva+DD, or YEARS+DD.

Prevalence, Risk Factor and Clinical Characteristics of Venous Thrombus Embolism in Patients with Acute Exacerbation of COPD: A Prospective Multicenter Study

Background and Objective

The prevalence of venous thrombus embolism (VTE) in patients with chronic obstructive pulmonary disease (COPD) is higher than in patients without COPD. Owing to the similarity of clinical symptoms between PE and acute exacerbation COPD (AECOPD), PE is likely to be overlooked or underdiagnosed in patients with AECOPD. The aim of the study was to investigate the prevalence, risk factor, clinical characteristics, and prognostic impact of VTE in patients with AECOPD.

Methods

This multicenter, prospective, cohort study was conducted in 11 research centers of China. Data on the baseline characteristics, VTE-related risk factors, clinical symptoms, laboratory examination results, computed tomography pulmonary angiography (CTPA) and lower limb venous ultrasound of AECOPD patients were collected. Patients were followed up for 1 year.

Results

A total of 1580 AECOPD patients were included in the study. The mean (SD) age was 70.4 (9.9) years and 195 (26%) patients were women. The prevalence of VTE was 24.5% (387/1580) and PE was 16.8% (266/1580). VTE patients were older; had higher BMI; and longer course of COPD than non-VTE patients. The history of VTE, cor pulmonale, less purulent sputum, increased respiratory rate, higher D-dimer, and higher NT-proBNP/BNP were independently associated with VTE in hospitalized patients with AECOPD. The mortality at 1-year was higher in patients with VTE than patients without VTE (12.9% vs 4.5%, p<0.01). There was no significant difference in the prognosis of patients with PE in segmental or subsegmental arteries and in main pulmonary arteries or lobar arteries (P>0.05).

Conclusion

VTE is common in COPD patients and is associated with poor prognosis. Patients with PE at different locations had poorer prognosis than patients without PE. It is necessary to perform active screening strategy for VTE in AECOPD patients with risk factors.

Characteristics associated with diagnostic yield of imaging for deep venous thrombosis and pulmonary embolism in the emergency department, hospital, and office settings: An Optum Clinformatics claims database study (2015-2019)

BACKGROUND

Different patient characteristics influence the decision to order diagnostic imaging for deep venous thrombosis (DVT) and pulmonary embolism (PE) in different settings (emergency department (ED), hospital, and office). Diagnostic yield is defined as the proportion of tests that report positive results. We hypothesize different patient characteristics are associated with higher or lower diagnostic yield of imaging for DVT and PE in different settings.

METHODS

We used Optum Clinformatics™ national claims database (2015-2019) to assess the diagnostic yield of imaging for DVT and PE in three settings: (a) ED discharge, (b) Hospitalized, and (c) Office. We studied the patient characteristics associated with diagnostic yield using logistic regression.

RESULTS

Diagnostic imaging for DVT and PE was performed in 1,502,417 and 710,263 visits, respectively. Diagnostic yield for DVT and PE was 9.8 ± 0.1 % and 12.7 ± 0.1 %, respectively in the overall cohort. In the ED discharge, hospitalized, and office settings, diagnostic yield for DVT was 10.4 ± 0.1 %, 16.9 ± 0.1 %, and 6.5 ± 0.1 %, respectively, and that for PE 6.4 ± 0.1 %, 18.7 ± 0.1 %, and 8.8 ± 0.2 %, respectively. Of the patients who underwent imaging for DVT, higher diagnostic yield was more likely with thrombophilia, central venous access, and cancer. Of the patients who underwent imaging for PE, higher diagnostic yield was most likely with thrombophilia, respiratory failure, and heart failure or acute myocardial infarction.

CONCLUSIONS

In each setting, different patient characteristics influence the diagnostic yield of imaging for DVT and PE and can inform clinical practice. Judicious use of imaging for DVT and PE could reduce costs and avoid exposure to radiation and contrast.

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.

Current Diagnosis and Management of Acute Pulmonary Embolism: A Strategy for General Practitioners in Emergency Department

Pulmonary embolism (PE) is a disease with a relatively good prognosis when diagnosed and treated properly. This review aims to analyse available data and combine them into algorithms that physicians can use in the emergency department for quick decision-making in diagnosing and treating PE. The available data show that PE can be excluded through highly sensitive clinical decision rules, i.e. Pulmonary Embolism Rule-Out Criteria (PERC), Wells criteria, and Revised Geneva criteria, combined with D-dimer assessment. In cases where PE could not be excluded through the mentioned strategies, imaging modalities, such as compression ultrasonography (CUS), computed tomographic pulmonary angiography (CTPA), and planar ventilation/perfusion (V/Q) scan, are indicated for a definite diagnosis. Once a diagnosis has been made, treatment of PE depends on its mortality risk as patients are divided into low-, intermediate-, and high-risk cases. High-risk cases are treated for their hemodynamic instability, given parenteral or oral anticoagulant therapy, and are indicated for reperfusion therapy. Intermediate-risk PE is only given parenteral or oral anticoagulants and reperfusion is indicated when anticoagulants fail. Low-risk cases are given oral anticoagulants and based on the Hestia criteria, patients may be discharged and treated as outpatients.

A Tale of Two D-Dimers: Comparison of Two Assay Methods to Evaluate Deep Vein Thrombosis or Pulmonary Embolism

BACKGROUND

D-dimer testing rules out deep vein thrombosis (DVT) and pulmonary embolism (PE) in low-risk emergency department (ED) patients. Most research has measured fibrin-equivalent units (FEUs), however, many laboratories measure D-dimer units (DDUs).

OBJECTIVE

Our aim was to determine whether either DDU measurements or FEU measurements can rule out DVT/PE using traditional or age-related cutoff values.

METHODS

We performed a de-identified multicenter retrospective evaluation of D-dimer in nonpregnant adult ED patients to evaluate for DVT/PE. DDUs were multiplied by 2 to determine equivalent FEUs prior to analysis. Sensitivity measurements for D-dimer were calculated for FEUs, DDUs, combined FEU/DDUs, and multiple age-adjusted values.

RESULTS

We identified 47,088 ED patients with a D-dimer laboratory value (27,307 FEUs/19,781 DDUs) and 1623 DVT/PEs. The median combined FEU/DDU D-dimer was 400 ng/mL FEUs (interquartile range [IQR] 300-900 ng/mL FEUs) for patients without a DVT/PE vs 2530 ng/mL FEU (IQR 1094-6000 ng/mL FEUs) with a DVT/PE (p < 0.001), overall sensitivity of 87.3% (95% confidence interval [CI] 87.0-87.6%) and negative predictive value of 99.3% (95% CI 99.2-99.4%). Individually, FEUs performed better than DDUs, with sensitivities of 88.0% (95% CI 85.8-89.9%) and 86.1% (95% CI 83.1-88.7%), respectively; however, this difference was not statistically significant. Combined age-adjusted performance had a sensitivity of 90.3% (95% CI 88.3-92.0%); however, a new DDU-only age-adjusted criteria had the highest sensitivity of 91.1% (95% CI 87.9-93.6%).

CONCLUSIONS

Our undifferentiated D-dimer measurements had a slightly lower sensitivity to rule out DVT/PE than reported previously. Our data support using either DDU or FEU measurements for all ages or when using various age-adjusted criteria to rule out DVT/PE.

Diagnosis, Diagnostic Tools, and Risk Stratification for Contemporary Treatment of Pulmonary Embolism

Pulmonary embolism (PE) is quite common and is associated with significant morbidity and mortality. It is estimated that it is the cause of approximately 100,000 annual deaths in the United States. With great variability in presenting symptoms of PE, poor recognition of PE can be fatal. As such, many risk scores have been created to identify the sickest patients. Choosing the appropriate imaging modality is also critical. Invasive pulmonary angiography was once the gold standard to establish the diagnosis. With the advent of nuclear imaging, V/Q scans, invasive angiography has been phased out for diagnosing acute PE. At present, the standard for diagnosis of acute PE is computed tomography pulmonary angiography. In select patient cohorts, nuclear studies remain the modality of choice. Once the diagnosis of acute PE is established, there is a broad spectrum of severity in outcome which has led to substantial focus and development of risk stratification prediction models. We will discuss making the proper diagnosis with contemporary diagnostic tools and risk stratifying patients with PE to receive the correct treatment.

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.

Adherence to risk-assessment protocols to guide computed tomography pulmonary angiography in patients with suspected pulmonary embolism

AIMS

The use of computed tomography pulmonary angiography (CTPA) in the detection of pulmonary embolism (PE) has considerably increased due developing technology and better availability of imaging. The underuse of pre-test probability scores and overuse of CTPA has been previously reported. We sought to investigate the indications for CTPA at a University Hospital emergency clinic and seek for factors eliciting the potential overuse of CTPA.

METHODS AND RESULTS

Altogether 1001 patients were retrospectively collected and analysed from the medical records using a structured case report form. PE was diagnosed in 222/1001 (22.2%) of patients. Patients with PE had more often prior PE/deep vein thrombosis, bleeding/thrombotic diathesis and less often asthma, chronic obstructive pulmonary disease, coronary artery disease, or decompensated heart failure. Patients were divided into three groups based on Wells PE risk-stratification score and two groups based on the revised Geneva score. A total of 9/382 (2.4%), 166/527 (31.5%), and 47/92 (52.2%) patients had PE in the CTPA in the low, intermediate, and high pre-test likelihood groups according to Wells score, and 200/955 (20.9%) and 22/46 (47.8%) patients had PE in the CTPA in the low-intermediate and the high pre-test likelihood groups according to the revised Geneva score, respectively. D-dimer was only measured from 568/909 (62.5%) and 597/955 (62.5%) patients who were either in the low or the intermediate-risk group according to Wells score and the revised Geneva score. Noteworthy, 105/1001 (10.5%) and 107/1001 (10.7%) of the CTPAs were inappropriately ordered according to the Wells score and the revised Geneva score. Altogether 168/1001 (16.8%) could theoretically be avoided.

CONCLUSIONS

This study highlights scant utilization of guideline-recommended risk-stratification tools in CTPA use at the emergency department.

Diagnostic imaging for suspected pulmonary embolism during pregnancy and postpartum: A comparative radiation dose study

INTRODUCTION

To compare the radiation dose exposure and diagnostic efficiency of computed tomographic pulmonary angiography (CTPA) and ventilation/perfusion imaging (V/Q) for clinically suspected pulmonary embolism (PE) in pregnant and postpartum women in a tertiary hospital setting.

METHODS

A retrospective cohort study of 473 pregnant and postpartum women referred for CTPA or V/Q for clinically suspected PE between January 2013 and December 2018 at a tertiary hospital. Maternal effective radiation dose, breast-absorbed radiation dose and fetal-absorbed dose estimates were calculated. Diagnostic yield was evaluated from radiological findings.

RESULTS

Computed tomographic pulmonary angiography (CTPA) was more commonly used for the imaging of suspected PE in pregnant and postpartum populations (51.9% vs. 48.1% and 77.1% vs. 22.9%, respectively). CTPA was associated with higher maternal effective and breast-absorbed doses (maternal effective CTPA 4.7 (±2.9) mSv (millisievert), V/Q 1.7(±0.8) mSv (mean difference 2.93 mSv P < 0.001), and breast-absorbed CTPA 8.0 (±5.2) mGy (milligray), V/Q 0.3 (±0.1) (mean difference 7.67 mGy P < 0.001), respectively). Fetal radiation dose exposure was low. The incidence of positive PE was 5.5%. Indeterminate rates of CTPA and V/Q were 3.0% and 5.5% (P = 0.176), respectively.

CONCLUSIONS

Compared to V/Q, CTPA is associated with higher maternal and breast radiation dose; however, modern CT scanners achieve lower radiation doses than historically described. Fetal radiation dose was comparably low. The diagnostic yield of the imaging modalities in pregnant and postpartum women is similar. Revision of guidelines should occur with the advances in CT technology.

Characteristics and outcomes of cancer patients who develop pulmonary embolism: A cross‑sectional study

Pulmonary embolism (PE), along with deep vein thrombosis, are collectively known as venous thromboembolism (VTE). Predisposing factors for PE include post-operative conditions, pregnancy, cancer and an advanced age; of note, a number of genetic mutations have been found to be associated with an increased risk of PE. The association between cancer and VTE is well-established, and cancer patients present a higher risk of a thrombotic event compared to the general population. In addition, PE is a significant cause of morbidity and mortality among cancer patients. The aim of the present study was to illustrate the clinical characteristics, laboratory findings, radiology features and outcomes of cancer patients who developed PE, collected from an anticancer hospital. For this purpose, adult cancer patients diagnosed with PE by imaging with computed tomography pulmonary angiography were enrolled. The following data were recorded: Demographics, comorbidities, type of cancer, time interval between cancer diagnosis and PE occurrence, the type of therapy received and the presence of metastases, clinical signs and symptoms, predisposing factors for PE development, laboratory data, radiological findings, electrocardiography findings, and the type of therapy received for PE and outcomes in a follow-up period of 6 months. In total, 60 cancer patients were enrolled. The majority of the cancer patients were males. The most common type of cancer observed was lung cancer. The majority of cases of PE occurred within the first year from the time of cancer diagnosis, while the majority of patients had already developed metastases. In addition, the majority of cancer patients had received chemotherapy over the past month, while they were not receiving anticoagulants and had central obstruction. A large proportion of patients had asymptomatic PE. The in-hospital mortality rate was 13.3% and no relapse or mortality were observed during the follow-up period. The present study demonstrates that elevated levels of lactic acid and an increased platelet count, as well as low serum levels of carcinoembryonic antigen, albumin and D-dimer, may be potential biomarkers for asymptomatic PE among cancer patients.

Cancer-associated venous thromboembolism

Cancer-associated thrombosis (including venous thromboembolism (VTE) and arterial events) is highly consequential for patients with cancer and is associated with worsened survival. Despite substantial improvements in cancer treatment, the risk of VTE has increased in recent years; VTE rates additionally depend on the type of cancer (with pancreas, stomach and primary brain tumours having the highest risk) as well as on individual patient's and cancer treatment factors. Multiple cancer-specific mechanisms of VTE have been identified and can be classified as mechanisms in which the tumour expresses proteins that alter host systems, such as levels of platelets and leukocytes, and in which the tumour expresses procoagulant proteins released into the circulation that directly activate the coagulation cascade or platelets, such as tissue factor and podoplanin, respectively. As signs and symptoms of VTE may be non-specific, diagnosis requires clinical assessment, evaluation of pre-test probability, and objective diagnostic testing with ultrasonography or CT. Risk assessment tools have been validated to identify patients at risk of VTE. Primary prevention of VTE (thromboprophylaxis) has long been recommended in the inpatient and post-surgical settings, and is now an option in the outpatient setting for individuals with high-risk cancer. Anticoagulant therapy is the cornerstone of therapy, with low molecular weight heparin or newer options such as direct oral anticoagulants. Personalized treatment incorporating risk of bleeding and patient preferences is essential, especially as a diagnosis of VTE is often considered by patients even more distressing than their cancer diagnosis, and can severely affect the quality of life. Future research should focus on current knowledge gaps including optimizing risk assessment tools, biomarker discovery, next-generation anticoagulant development and implementation science.

Utility of Blood Cellular Indices in the Risk Stratification of Patients Presenting with Acute Pulmonary Embolism

Pulmonary embolism (PE) clinical manifestations vary widely, and that scope is not fully captured by current all-cause mortality risk models. PE is associated with inflammatory, coagulation, and hemostatic imbalances so blood cellular indices may be prognostically useful. Complete blood count (CBC) data may improve current risk models like the simplified pulmonary embolism severity index (sPESI) for all-cause mortality, offering greater accuracy and analytic ability. Acute PE patients (n = 228) with confirmatory diagnostic imaging were followed for all-cause mortality. Blood cellular indices were assessed for association to all-cause mortality and were supplemented into sPESI using multivariate logistic regression. Multiple blood cellular indices were found to be significantly associated with all-cause mortality in acute PE. sPESI including red cell distribution width, hematocrit and neutrophil-lymphocyte ratio had better predictive ability as compared to sPESI alone (AUC: 0.852 vs 0.754). Blood cellular indices contribute an inflammatory and hemodynamic perspective not currently included in sPESI. CBC with differential is a widely used, low-cost test that can augment current risk stratification tools for all-cause mortality in acute PE patients.

Pulmonary embolism and computed tomography angiography: Characteristic findings and technical advices

Pulmonary embolism (PE) is a condition due to blood clots obstructing pulmonary arteries, often related to deep venous thrombosis (DVT). PE can be responsible for acute and even life-threatening clinical situations and it may also lead to chronic sequelae such as chronic thromboembolic pulmonary hypertension (CTEPH). Signs and symptoms associated to PE may overlap those of many other diseases (e.g. chest pain, dyspnea, etc.), therefore an accurate clinical evaluation is mandatory before referring the patient to the most appropriate imaging technique. Pulmonary angiography (PA) has been traditionally considered the gold standard regarding the diagnosis of PE and it is also useful regarding the treatment of said condition. However, PA is an invasive technique, implying all the known risks concerning endovascular procedures. Nowadays, computed tomography angiography (CTA) is considered the imaging technique of choice regarding the diagnosis of PE. This technique is readily-available in most centers and it is able to provide high resolution images, although it implies the administration of ionizing radiations and iodinated contrast medium. Conventional CTA has further been improved with the use of ECG-gated protocols, aimed to reduce motion artifacts due to heartbeat and to evaluate other causes of sudden onset chest pain. Moreover, another interesting technique is dual energy computed tomography (DECT), which allows to elaborate iodine maps, allowing to detect areas of hypoperfusion due to the presence of emboli in pulmonary arteries. This review is aimed to describe the main findings related to PE with an emphasis on CTA, also discussing technical aspects concerning image acquisition protocol.

Elderly Population with COVID-19 and the Accuracy of Clinical Scales and D-Dimer for Pulmonary Embolism: The OCTA-COVID Study

BACKGROUND

Elderly COVID-19 patients have a high risk of pulmonary embolism (PE), but factors that predict PE are unknown in this population. This study assessed the Wells and revised Geneva scoring systems as predictors of PE and their relationships with D-dimer (DD) in this population.

METHODS

This was a longitudinal, observational study that included patients ≥75 years old with COVID-19 and suspected PE. The performances of the Wells score, revised Geneva score and DD levels were assessed. The combinations of the DD level and the clinical scales were evaluated using positive rules for higher specificity.

RESULTS

Among 305 patients included in the OCTA-COVID study cohort, 50 had suspected PE based on computed tomography pulmonary arteriography (CTPA), and the prevalence was 5.6%. The frequencies of PE in the low-, intermediate- and high-probability categories were 5.9%, 88.2% and 5.9% for the Geneva model and 35.3%, 58.8% and 5.9% for the Wells model, respectively. The DD median was higher in the PE group (4.33 mg/L; interquartile range (IQR) 2.40-7.17) than in the no PE group (1.39 mg/L; IQR 1.01-2.75) (p < 0.001). The area under the curve (AUC) for DD was 0.789 (0.652-0.927). After changing the cutoff point for DD to 4.33 mg/L, the specificity increased from 42.5% to 93.9%.

CONCLUSIONS

The cutoff point DD > 4.33 mg/L has an increased specificity, which can discriminate false positives. The addition of the DD and the clinical probability scales increases the specificity and negative predictive value, which helps to avoid unnecessary invasive tests in this population.

Prevalence and predictors of pulmonary embolism in patients with acute exacerbation of chronic obstructive pulmonary disease

Background:

The prevalence of pulmonary embolism (PE) in patients of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) varies over a wide range. Early detection and treatment of PE in AECOPD is a key to improve patient outcome. The purpose of the study was to investigate the prevalence and predictors of PE in patients of AECOPD in a high burden region of North India.

Materials and Methods:

This prospective study included patients of AECOPD with no obvious cause of exacerbation on initial evaluation. Apart from routine workup, the participants underwent assessment of D-dimer, compression ultrasound and venous Doppler ultrasound of the lower limbs and pelvic veins, and a multidetector computed tomography pulmonary angiography.

Results:

A total of 100 patients of AECOPD with unknown etiology were included. PE as a possible cause of AE-COPD was observed in 14% of patients. Among the participants with PE, 63% (n = 9) had a concomitant presence of lower extremity deep venous thrombosis. Hemoptysis and chest pain were significantly higher in patients of AECOPD with PE ([35.7% vs. 7%, P = 0.002] and [92.9% vs. 38.4%, P = 0.001]). Likelihood of PE was significantly higher in patients who presented with tachycardia, tachypnea, respiratory alkalosis (PaCO2 <45 mmHg and pH >7.45), and hypotension. No difference was observed between the two groups in terms of in-hospital mortality, age, sex distribution, and risk factors for embolism except for the previous history of venous thromboembolism (35.7% vs. 12.8% P = 0.03).

Conclusion:

PE was probably responsible for AECOPD in 14% of patients with no obvious cause on initial assessment. Patients who present with chest pain, hemoptysis, tachypnea, tachycardia, and respiratory alkalosis should be particularly screened for PE.

Pulmonary embolism in patients with COVID-19 pneumonia on adequate oral anticoagulation

Thrombotic complications are common in patients with severe COVID-19 pneumonia with important consequences on the diagnostic and therapeutic management. We report a consecutive series of five patients on long-term oral anticoagulation therapy who presented to our hospital for severe COVID-19 pneumonia associated with segmental acute pulmonary embolism despite adherence to therapy and with an adequate anticoagulant range at the time of the event. Four patients were receiving a direct oral anticoagulant (two with edoxaban, one with rivaroxaban and one with apixaban) and one patient a vitamin K antagonist. No significant thrombotic risk factors, active cancer, or detectable venous thromboembolism were present. In all cases, elevated d-dimer and fibrinogen levels with a parallel rise in markers of inflammation were documented. The combination of these findings seems to support the hypothesis that considers the local vascular damage determined by severe viral infection as the main trigger of thrombi detected in the lungs, rather than emboli from peripheral veins.

Predictive Value of MPV and Plasma NT-ProBNP Combined with the Simplified Geneva Scale for the Prognosis of Acute Pulmonary Embolism

OBJECTIVE

To explore the predictive value of mean platelet volume (MPV) and plasma N-terminal probrain natriuretic peptide (NT-ProBNP) combined with a simplified Geneva scale for the prognosis of acute pulmonary embolism (APE).

METHODS

The clinical data of 68 patients with APE admitted to our hospital from October 2017 to October 2019 were collected. According to the prognosis, the patients were divided into a good prognosis group (n = 45) and a poor prognosis group (n = 23). The clinical data, laboratory clinical indexes, and simplified Geneva scale scores were recorded for the two groups. The risk factors of poor prognosis were analyzed by binary multivariate logistic regression analysis; the predictive ability of each index on the prognosis of patients with APE was analyzed by the ROC curve.

RESULTS

The incidences of deep vein thrombosis, diabetes, and hyperlipidemia in the poor prognosis group were higher than those in the good prognosis group (P < 0.05). PLT, platelet distribution width (PDW), MPV, and plasma NT-ProBNP in the poor prognosis group were higher than those in the good prognosis group (P < 0.05). The simplified Geneva scale score of the poor prognosis group was higher than that of the good prognosis group (P < 0.05). PDW, MPV, plasma NT-ProBNP, and simplified Geneva scale were all independent risk factors for the poor prognosis of APE patients (P < 0.05). The AUC of MPV in predicting the prognosis of APE patients was 0.818 (95% CI: 0.712-0.925). When the optimal cutoff value was 0.571, the sensitivity was 77.1%, and the specificity was 80.0%. The AUC of plasma NT-ProBNP in predicting the prognosis of APE patients was 0.762 (95% CI: 0.634-0.891). When the optimal cutoff value was 0.475, the sensitivity was 71.5%, and the specificity was 76.0%. The AUC of the simplified Geneva scale in predicting the prognosis of APE patients was 0.749 (95% CI: 0.618-0.879). When the optimal cutoff value was 0.469, the sensitivity was 82.9%, and the specificity was 64.0%. The AUC of MPV and plasma NT-ProBNP combined with the simplified Geneva scale in predicting the prognosis of APE patients was 0.907 (95% CI: 0.826-0.988). When the optimal cutoff value was 0.726, the sensitivity was 88.6%, and the specificity was 84.0%.

CONCLUSION

MPV, plasma NT-ProBNP, and simplified Geneva scale have a certain predictive value for the prognosis of APE. Compared with a single index, the combination of the three indexes has a significant improvement in predicting the prognosis of APE and has better clinical value.

Investigation and management of pulmonary embolism 1: a probability-based approach

Pulmonary embolism remains a common and potentially deadly disease, despite advances in diagnostic imaging, treatment and prevention. Managing pulmonary embolism requires a multifactorial approach involving risk stratification, determining appropriate diagnostics and selecting individualised therapy. This article reviews the pathophysiology, risk factors, clinical presentation, diagnostic evaluation and therapeutic management and early outpatient management of pulmonary embolism. The second part summarises pulmonary embolism in the setting of pregnancy, COVID-19, recurrent disease and chronic thromboembolic pulmonary hypertension.

Venous thromboembolism

Venous thromboembolism, comprising both deep vein thrombosis and pulmonary embolism, is a chronic illness that affects nearly 10 million people every year worldwide. Strong provoking risk factors for venous thromboembolism include major surgery and active cancer, but most events are unprovoked. Diagnosis requires a sequential work-up that combines assessment of clinical pretest probability for venous thromboembolism using a clinical score (eg, Wells score), D-dimer testing, and imaging. Venous thromboembolism can be considered excluded in patients with both a non-high clinical pretest probability and normal D-dimer concentrations. When required, ultrasonography should be done for a suspected deep vein thrombosis and CT or ventilation-perfusion scintigraphy for a suspected pulmonary embolism. Direct oral anticoagulants (DOACs) are the first-line treatment for almost all patients with venous thromboembolism (including those with cancer). After completing 3-6 months of initial treatment, anticoagulation can be discontinued in patients with venous thromboembolism provoked by a major transient risk factor. Patients whose long-term risk of recurrent venous thromboembolism outweighs the long-term risk of major bleeding, such as those with active cancer or men with unprovoked venous thromboembolism, should receive indefinite anticoagulant treatment. Pharmacological venous thromboembolism prophylaxis is generally warranted in patients undergoing major orthopaedic or cancer surgery. Ongoing research is focused on improving diagnostic strategies for suspected deep vein thrombosis, comparing different DOACs, developing safer anticoagulants, and further individualising approaches for the prevention and management of venous thromboembolism.

Pulmonary embolism with aortic saddle embolism: a rare presentation

We present an uncommon case report of simultaneous pulmonary embolism and aortic saddle embolism. This patient had risk factors for thromboembolic events that included recent surgery for tibia fracture and immobilisation. She underwent emergency bilateral pulmonary artery catheter-directed thrombolysis, followed by bilateral transfemoral embolectomy. The potential benefit of thrombolysis was weighed against the risk of haemorrhage during the surgery after thrombolysis. Treatment guidelines are not well established for such a condition. This case report illustrates our experience and challenges faced in treating this condition.

Pathway for the Diagnosis and Management of Pulmonary Embolism

Venous thromboembolism (VTE), the combined syndromes of deep vein thrombosis (DVT) and pulmonary embolism (PE), is currently the third most frequent acute cardiovascular syndrome globally behind myocardial infarction and stroke. PE carries substantial mortality. In the past decade, we have seen a remarkable improvement in new diagnostic tools as well as advances in therapeutic options to manage patients with PE. Still, even with recently updated society guidelines, the management of intermediate and high-risk PE requires clinician expertise and judgment. To aid healthcare providers caring for patients with acute PE, we have developed a novel, comprehensive yet straightforward, pathway for the management of patients with PE. We believe this pathway can be used in many healthcare systems around the globe. Our pathway for the diagnosis and management of PE is divided into 3 steps: the diagnosis of PE, the acute management of patients with PE, and recommendations for chronic management. The pathway requires classification of the PE by the risk of mortality and thus leads to the appropriate intensity of initial care, intervention, and monitoring. The Pulmonary Embolism Response Team (PERT) is a multispecialty team designed to guide the decision-making for the individual patient with intermediate-high or high-risk PE. The PERT team brings together specialists from different disciplines. The team convenes in real time via a platform such as WhatsApp or text messages to communicate clinical data, discuss the options, and provide consensus for a course of management. The success of this pathway to manage PE depends heavily on developing a collaborative group of specialists dedicated to provide care at each stage to patients with PE.

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.

Suspected Acute Pulmonary Embolism: Gestalt, Scoring Systems, and Artificial Intelligence

Pulmonary embolism (PE) remains a diagnostic challenge in 2021. As the pathology is potentially fatal and signs and symptoms are nonspecific, further investigations are classically required. Based on the Bayesian approach, clinical probability became the keystone of the diagnostic strategy to rule out PE in the case of a negative testing. Several clinical probability assessment methods are validated: gestalt, the Wells score, or the revised Geneva score. While the debate persists as to the best way to assess clinical probability, its assessment allows for the good interpretation of the investigation results and therefore directs the correct diagnostic strategy. The wide availability of computed tomography pulmonary angiography (CTPA) resulted in a major increase in investigations with a moderate increase in diagnosis, without any notable improvement in patient outcomes. This leads to a new challenge for PE diagnosis which is the limitation of the number of testing for suspected PE. We review different strategies recently developed to achieve this goal. The last challenge concerns the implementation in clinical practice. Two approaches are developed: simplification of the strategies versus the use of digital support tools allowing more sophisticated strategies. Artificial intelligence with machine-learning algorithms will probably be a future tool to guide the physician in this complex approach concerning acute PE suspicion.

Diagnosis of pulmonary embolism in patients with acute exacerbations of chronic obstructive pulmonary disease: A cross-sectional study

INTRODUCTION

Pulmonary embolism (PE) remains a frequent complication in patients with chronic obstructive pulmonary disease (COPD). It is unclear that the extent to which the traditional risk stratifying scores for PE are accurate in this population.

METHODS

Cross-sectional study of adult patients with COPD and suspected PE included in an Institutional Registry of Thromboembolic Disease at a tertiary teaching hospital in the city of Buenos Aires, Argentina. We estimated the area under the receiver operating characteristic curves (AU-ROC), sensitivity and specificity of the Wells and Geneva scores using a positive computed tomography angiography as the gold standard for PE. We also estimated the sensitivity and specificity for the presence of isolated worsening of dyspnea at presentation, without other cardinal symptoms of acute exacerbation of COPD.

RESULTS

A total of 168 patients were included, of which 22% had confirmed PE. The AUC was 0.66 (95% CI 0.56-0.76) and 0.56 (95% CI 0.45-0.67) for the Wells and Geneva, respectively. Considering the most widely used cutoff points, the sensitivity and specificity were 24% and 90% for the Wells and 59% and 43% for the Geneva score, respectively. Isolated worsening of dyspnea on presentation had a sensitivity of 92% and specificity of 37%.

CONCLUSIONS

Both Wells and Geneva scores exhibit poor diagnostic accuracy for the diagnosis of PE in patients with COPD. The presence of isolated worsening of dyspnea on presentation could be an easy to identify criteria for the initial triage in this population. Further validation of our findings remains warranted.

Association Between Pulmonary Embolism and COVID-19 in Emergency Department Patients Undergoing Computed Tomography Pulmonary Angiogram: The PEPCOV International Retrospective Study

BACKGROUND

There have been reports of procoagulant activity in patients with COVID-19. Whether there is an association between pulmonary embolism (PE) and COVID-19 in the emergency department (ED) is unknown. The aim of this study was to assess whether COVID-19 is associated with PE in ED patients who underwent a computed tomographic pulmonary angiogram (CTPA).

METHODS

A retrospective study in 26 EDs from six countries. ED patients in whom a CTPA was performed for suspected PE during a 2-month period covering the pandemic peak. The primary endpoint was the occurrence of a PE on CTPA. COVID-19 was diagnosed in the ED either on CT or reverse transcriptase-polymerase chain reaction. A multivariable binary logistic regression was built to adjust with other variables known to be associated with PE. A sensitivity analysis was performed in patients included during the pandemic period.

RESULTS

A total of 3,358 patients were included, of whom 105 were excluded because COVID-19 status was unknown, leaving 3,253 for analysis. Among them, 974 (30%) were diagnosed with COVID-19. Mean (±SD) age was 61 (±19) years and 52% were women. A PE was diagnosed on CTPA in 500 patients (15%). The risk of PE was similar between COVID-19 patients and others (15% in both groups). In the multivariable binary logistic regression model, COVID-19 was not associated with higher risk of PE (adjusted odds ratio = 0.98, 95% confidence interval = 0.76 to 1.26). There was no association when limited to patients in the pandemic period.

CONCLUSION

In ED patients who underwent CTPA for suspected PE, COVID-19 was not associated with an increased probability of PE diagnosis. These results were also valid when limited to the pandemic period. However, these results may not apply to patients with suspected COVID-19 in general.

Acute pulmonary embolism multimodality imaging prior to endovascular therapy

The manuscript discusses the application of CT pulmonary angiography, ventilation–perfusion scan, and magnetic resonance angiography to detect acute pulmonary embolism and to plan endovascular therapy. CT pulmonary angiography offers high accuracy, speed of acquisition, and widespread availability when applied to acute pulmonary embolism detection. This imaging modality also aids the planning of endovascular therapy by visualizing the number and distribution of emboli, determining ideal intra-procedural catheter position for treatment, and signs of right heart strain. Ventilation–perfusion scan and magnetic resonance angiography with and without contrast enhancement can also aid in the detection and pre-procedural planning of endovascular therapy in patients who are not candidates for CT pulmonary angiography.

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

Background

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

Methods

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

Results

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

Conclusion

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

Clinical and radiological diagnosis of pulmonary thromboembolism

Pulmonary thromboembolism has poorly specific clinical symptomatology, which increases the diagnostic suspicion, multiplying the number of patients who will need to undergo imaging tests to confirm the diagnosis. In recent years, pulmonary angiography using multidetector scanners (CT angiography) has been the most widely used imaging test due to its availability and accuracy, which exceeds that of lung ventilation-perfusion (V/Q) scintigraphy. However, CT angiography is not without risks and is also expensive. Its use should therefore be restricting without reducing the diagnostic efficacy, given its enormous prognostic importance and implication. We therefore need to base our approach on previously validated strategies that, taking into account the clinical probability and using highly sensitive diagnostic tests such as D-dimer, will enable us to exclude many patients from undergoing this imaging test. In this article, we review the diagnostic techniques and strategies that are applied for diagnosing pulmonary thromboembolism in hemodynamically stable and unstable outpatients, hospitalised patients, patients with a history of venous thromboembolism and pregnant women.

A Simple Scale for Screening Lower-Extremity Arterial Disease as a Possible Cause of Low Back Pain: a Cross-sectional Study Among 542 Subjects

BACKGROUND

Epidemiological, imaging, and anatomical studies suggest an association between proximal arterial atherosclerosis and development of low back pain (LBP).

OBJECTIVES

We aimed to define (1) the frequency and (2) factors associated with exercise-induced proximal ischemia (EIPI) in individuals with LBP and (3) develop a clinical screening scale.

DESIGN

Monocentric cross-sectional study.

PARTICIPANTS

All patients with history of ongoing LBP referred to our exercise investigation laboratory for exercise transcutaneous oximetry (ex-tcPO₂) between January 2011 and December 2017 (n = 542; mean age, 65.4 ± 10.9; 83.9% men).

MAIN MEASURES

EIPI was defined as a decrease from rest of oxygen pressure (DROP) below - 15 mmHg on the lumbar and/or buttock probes. Ex-tcPO₂ is a reliable validated tool for diagnosing EIPI in comparison with arteriography and computed tomography angiography. Ex-tcPO₂ was performed on a treadmill until symptom manifestation or exhaustion. Clinical data were collected using interview questionnaires, medical file review, and clinical examination.

KEY RESULTS

EIPI was diagnosed in 282 patients (52%). Age ≤ 70 years (OR, 2.22; 95% CI, 1.35-3.57; p = 0.002), a history of proximal revascularization (OR, 2.64; 95% CI, 1.50-4.65; p = 0.001), use of antiplatelet medication (OR, 1.71; 95% CI, 0.96-3.06; p = 0.069), a relationship between exercise and LBP (OR, 2.61; 95% CI, 1.49-4.57; p = 0.001), and an abnormal ankle to brachial index (OR, 2.87; 95% CI, 1.77-4.66; p < 0.0001) were identified as EIPI predictors. Using these items, we developed a screening scale that showed an area under the receiver operating characteristics curve of .756. At a score of ≥ 3, the sensitivity, specificity, and accuracy for EIPI were 84%, 55%, and 71%, respectively.

CONCLUSIONS

EIPI was common among our patients with LBP undergoing ex-TcPO₂. Our screening scale could help better select the patients who require angiography.

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.