Early Detection of Pulmonary Embolism in a General Patient Population Immediately Upon Hospital Admission Using Machine Learning to Identify New, Unidentified Risk Factors: Model Development Study.

BACKGROUND: Under- or late identification of pulmonary embolism (PE)-a thrombosis of 1 or more pulmonary arteries that seriously threatens patients' lives-is a major challenge confronting modern medicine. OBJECTIVE: We aimed to establish accurate and informative machine learning (ML) models to identify patients at high risk for PE as they are admitted to the hospital, before their initial clinical checkup, by using only the information in their medical records. METHODS: We collected demographics, comorbidities, and medications data for 2568 patients with PE and 52,598 control patients. We focused on data available prior to emergency department admission, as these are the most universally accessible data. We trained an ML random forest algorithm to detect PE at the earliest possible time during a patient's hospitalization-at the time of his or her admission. We developed and applied 2 ML-based methods specifically to address the data imbalance between PE and non-PE patients, which causes misdiagnosis of PE. RESULTS: The resulting models predicted PE based on age, sex, BMI, past clinical PE events, chronic lung disease, past thrombotic events, and usage of anticoagulants, obtaining an 80% geometric mean value for the PE and non-PE classification accuracies. Although on hospital admission only 4% (1942/46,639) of the patients had a diagnosis of PE, we identified 2 clustering schemes comprising subgroups with more than 61% (705/1120 in clustering scheme 1; 427/701 and 340/549 in clustering scheme 2) positive patients for PE. One subgroup in the first clustering scheme included 36% (705/1942) of all patients with PE who were characterized by a definite past PE diagnosis, a 6-fold higher prevalence of deep vein thrombosis, and a 3-fold higher prevalence of pneumonia, compared with patients of the other subgroups in this scheme. In the second clustering scheme, 2 subgroups (1 of only men and 1 of only women) included patients who all had a past PE diagnosis and a relatively high prevalence of pneumonia, and a third subgroup included only those patients with a past diagnosis of pneumonia. CONCLUSIONS: This study established an ML tool for early diagnosis of PE almost immediately upon hospital admission. Despite the highly imbalanced scenario undermining accurate PE prediction and using information available only from the patient's medical history, our models were both accurate and informative, enabling the identification of patients already at high risk for PE upon hospital admission, even before the initial clinical checkup was performed. The fact that we did not restrict our patients to those at high risk for PE according to previously published scales (eg, Wells or revised Genova scores) enabled us to accurately assess the application of ML on raw medical data and identify new, previously unidentified risk factors for PE, such as previous pulmonary disease, in general populations.

Clinical predictors of pulmonary embolism for inpatients: are computed tomography pulmonary angiograms being requested appropriately?

BACKGROUND: The heterogeneity of inpatient pulmonary embolism (PE) presentations may lead to computed tomography pulmonary angiograms (CTPA) being over-requested. Current clinical predictors for PE, including Wells criteria and Pulmonary Embolism Rule-out Criteria (PERC), have predominantly focussed on outpatient and emergency department populations. AIM: To determine the clinical indicators for ordering inpatient CTPA and the predictors of positive scans for PE. METHODS: Consecutive inpatient CTPA (performed >24 h after admission) from January 2017 to December 2017 were retrospectively reviewed. Variables including baseline characteristics, vital signs and risk factors for PE were extracted. RESULTS: A total of 312 CTPA was reviewed (average patient age 67 years; 46% male) and 36 CTPA were positive for PE (11.5%). The average time to inpatient CTPA request was 7 days. Clinical indicators associated with positive scans were hypoxia (odds ratio (OR) 2.4; 95% confidence interval (CI) 1.1-5.6), tachypnoea (OR 2.5; 95% CI 1.2-6.0), recent surgery or immobilisation (OR 2.7; 95% CI 1.2-6.4), S1Q3T3 pattern on electrocardiogram (ECG; OR 7.2; 95% CI 1.4-35.7) and right bundle branch block pattern on ECG (OR 4.7; 95% CI 1.6-13.1). Hypotension, fever and malignancy were not significant. Both PERC and Wells criteria had poor positive predictive value (12% and 27% respectively), but the negative predictive value for PERC and Wells was 100% and 95.8% respectively. CONCLUSION: Inpatient CTPA appear to be over-requested and can potentially be rationalised based on a combination of clinical predictors and Wells criteria and/or PERC rule. Further prospective studies are needed to develop accurate clinical decision tools targeted towards inpatients.

Prevalence of venous thromboembolism in patients undergoing diagnostic venous ultrasound during the first SARS-CoV-2 pandemic.

Background: Venous thromboembolism appears to be associated with severe COVID-19 infection than in those without it. However, this varies considerably depending on the cohort studied. The aims of this single-centre, multi-site retrospective cross-sectional study were to assess the number of all venous scans performed in the first month of pandemic in a large university teaching hospital, to evaluate the incidence of deep venous thrombosis (DVT), and assess the predictive ability of the clinical information available on the electronic patient record in planning work-up for DVT and prioritising ultrasound scans. Patients and methods: All consecutive patients undergoing venous ultrasound for suspected acute DVT between 1st of March and 30th of April 2020 were considered. Primary outcome was the proportion of scans positive for DVT; the secondary outcomes included association of a positive SARS-CoV-2 PCR test, demographic, clinical factors, and Wells scores. Results: 819 ultrasound scans were performed on 762 patients across the Trust in March and April 2020. This number was comparable to the corresponding pre-pandemic cohort from 2019. The overall prevalence of DVT in the studied cohort was 16.1% and was higher than before the pandemic (11.5%, p=.047). Clinical symptoms consistent with COVID-19, irrespective of the SARS-CoV-2 PCR test result (positive_COVID_PCR OR 4.97, 95%CI 2.31-10.62, p<.001; negative_COVID_PCR OR 1.97, 95%CI 1.12-3.39, p=.016), a history of AF (OR 0.20, 95%CI 0.03-0.73, p=.037), and personal history of venous thromboembolism (VTE) (OR 1.95, 95%CI 1.13-3.31, p=.014), were independently associated with the diagnosis of DVT on ultrasound scan. Wells score was not associated with the incidence of DVT. Conclusions: Amongst those referred for the DVT scan, SARS-CoV-2 PCR test was associated with an increased risk of VTE and should be taken into consideration when planning DVT work-up and prioritising diagnostic imaging. We postulate that the threshold for imaging should possibly be lower.

Comparing 'clinical hunch' against clinical decision support systems (PERC rule, wells score, revised Geneva score and YEARS criteria) in the diagnosis of acute pulmonary embolism.

BACKGROUND: Pulmonary embolism (PE) is a common and potentially life-threatening condition. Since it is considered a 'do not miss' diagnosis, PE tends to be over-investigated beyond the evidence-based clinical decision support systems (CDSS), which in turn subjects patients to unnecessary radiation and contrast agent exposure with no apparent benefits in terms of outcome. The purpose of this study was to evaluate the yield of 'clinical hunch' (gestalt) and four CDSS: the PERC Rule, Wells score, revised Geneva score, and Years criteria. METHODS: A review was conducted on the Electronic Medical Records (EMR) of 1566 patients from the Emergency Department at a tertiary teaching hospital who underwent CTPA from the 1st of January 2018 to the 31st of December 2019. The scores for the four CDSS were calculated retrospectively from the EMR data. We considered that a CTPA had been ordered on a clinical hunch when there was no mention of CDSS in the EMR, and no D-dimer test. A bypass of CDSS was confirmed when any step of the diagnostic algorithms was not followed. RESULTS: Of the total 1566 patients who underwent CTPA, 265 (17%) were positive for PE. The diagnosis yield from the five decision groups (clinical hunch and four CDSS) was as follows-clinical hunch, 15%; PERC rule, 18% (6% when bypassed); Wells score, 19% (11% when bypassed); revised Geneva score, 26% (13% when bypassed); and YEARS criteria, 18% (6% when bypassed). CONCLUSION: Clinicians should trust the evidence-based clinical decision support systems in line with the international guidelines to diagnose PE.

DIAGNOSIS OF PULMONARY EMBOLISM IN THE EMERGENCY DEPARTMENT.

The aim of this study was to determine the association of clinical presentation, the Wells scoring system and D-dimer values with MSCT pulmonary angiography. A case control study was conducted in the Emergency Department of the Clinical Hospital Sveti Duh throughout 2019. Patients with a referral diagnosis of a pulmonary embolism were included in the study. Patients were divided into two groups. The first group consisted of patients diagnosed with pulmonary embolism by MSCT pulmonary angiography or postmortem, and the second group consisted of patients excluded from pulmonary embolisms. For the Wells score, D-dimers, troponin, respiratory rate and peripheral blood oxygen saturation, statistically significant differences were found between groups of patients with confirmed or excluded pulmonary embolism (p <0.001). For heart rate, chest pain, syncope, and hemoptysis, no statistically significant differences were found between these two groups of patients. Deep venous thrombosis of the lower extremities was found by ultrasound in > 70% of patients with massive a pulmonary embolism. Pulmonary embolism was confirmed in all patients for whom a high risk was calculated according to the Wells score. In conclusion, a low degree of clinical probability (according to the Wells score), along with a normal concentration of D-dimer, are a sure strategy in excluding pulmonary embolism.

Which adults with sickle cell disease need an evaluation for pulmonary embolism?

Individuals living with sickle cell disease (SCD) are at an increased risk of venous thrombo-embolism (VTE) including pulmonary embolisms (PEs). There is a high mortality associated with PE in individuals with SCD. It can be difficult to diagnose PE since presenting symptoms of PE often mimic those of other forms of vaso-occlusive crisis in SCD. Currently, there are no validated models for predicting PEs in patients with sickle cell disease, which often leads to frequent CT scans and exposure to harmful radiation and intravenous contrast. The aim of this study was to evaluate different host variables and potential clinical biomarkers of patients with SCD including those used in the Wells score to assess predictability for PE in order to create a more accurate diagnostic algorithm to predict PE. A retrospective chart review was performed on 349 patients with SCD who underwent testing for a PE with a CT scan of the chest. Forward and backward stepwise model selection was performed to obtain a parsimonious model of the predictors of PEs. The incidence of PE in this population was 9·7%. Of the factors evaluated for this study, the Wells score was the only one with clinical significance. A Wells score greater than 4 had a sensitivity and specificity of 72·5% and 70·1%, respectively, and a score greater than 6 had a sensitivity and specificity of 50% and 87%, respectively. The Wells score is an acceptable clinical tool which may prove useful in individuals with SCD to predict who is most likely to have a PE and therefore should undergo a CT scan. A prospective study is needed to further confirm these findings.

Performance of the Wells score in predicting deep vein thrombosis in medical and surgical hospitalized patients with or without thromboprophylaxis: The R-WITT study.

The Wells score had shown weak performance to determine pre-test probability of deep vein thrombosis (DVT) for inpatients. So, we evaluated the impact of thromboprophylaxis on the utility of the Wells score for risk stratification of inpatients with suspected DVT. This bicentric cross-sectional study from February 1, 2018 to January 31, 2019 included consecutive medical and surgical inpatients who underwent lower limb ultrasound study for suspected DVT. Wells score clinical predictors were assessed by both ordering and vascular physicians within 24 h after clinical suspicion of DVT. Primary outcome was the Wells score's accuracy for pre-test risk stratification of suspected DVT, accounting for anticoagulation (AC) treatment (thromboprophylaxis for ⩾ 72 hours or long-term anticoagulation). We compared prevalence of proximal DVT among the low, moderate and high pre-test probability groups. The discrimination accuracy was defined as area under the receiver operating characteristics (ROC) curve. Of the 415 included patients, 30 (7.2%) had proximal DVT. Prevalence of proximal DVT was lower than expected in all pre-test probability groups. The prevalence in low, moderate and high pre-test probability groups was 0.0%, 3.1% and 8.2% (p = 0.22) and 1.7%, 4.2% and 25.8% (p < 0.001) for inpatients with or without AC, respectively. Area under ROC curves for discriminatory accuracy of the Wells score, for risk of proximal DVT with or without AC, was 0.72 and 0.88, respectively. The Wells score performed poorly for discrimination of risk for proximal DVT in hospitalized patients with AC but performed reasonably well among patients without AC; and showed low inter-rater reliability between physicians. ClinicalTrials.gov Identifier: NCT03784937.

Combining lung ultrasound and Wells score for diagnosing pulmonary embolism in critically ill COVID-19 patients.

Subpleural consolidations have been found in lung ultrasound in patients with COVID-19, possibly deriving from pulmonary embolism (PE). The diagnostic utility of impact of lung ultrasound in critical-ill patients with COVID-19 for PE diagnostics however is unclear. We retrospectively evaluated all SARS-CoV2-associated ARDS patients admitted to our ICU between March 8th and May 31th 2020. They were enrolled in this study, when a lung ultrasound and a computed tomography pulmonary angiography (CTPA) were documented. In addition, wells score was calculated to estimate the probability of PE. The CTPA was used as the gold standard for the detection of PE. Twenty out of 25 patients met the inclusion criteria. In 12/20 patients (60%) (sub-) segmental PE were detected by CT-angiography. Lung ultrasound found subpleural consolidations in 90% of patients. PE-typical large supleural consolidations with a size ≥ 1 cm were detectable in 65% of patients and were significant more frequent in patients with PE compared to those without (p = 0.035). Large consolidations predicted PE with a sensitivity of 77% and a specificity of 71%. The Wells score was significantly higher in patients with PE compared to those without (2.7 ± 0.8 and 1.7 ± 0.5, respectively, p = 0.042) and predicted PE with an AUC of 0.81. When combining the two modalities, comparing patients with considered/probable PE using LUS plus a Wells score ≥ 2 to patients with possible/unlikely PE in LUS plus a Wells score < 2, PE could be predicted with a sensitivity of 100% and a specificity of 80%. Large consolidations detected in lung ultrasound were found frequently in COVID-19 ARDS patients with pulmonary embolism. In combination with a Wells score > 2, this might indicate a high-risk for PE in COVID-19.

Comparison of Wells and YEARS clinical decision rules with D-dimer for low-risk pulmonary embolus patients.

BACKGROUND: Assessment of pulmonary embolism (PE) remains a diagnostic and investigative burden to emergency departments. The decision of which D-dimer cut-off to use in low-risk patients remains controversial. AIMS: To compare the sensitivity and specificity of varying D-dimer cut-offs in the diagnosis of PE for Wells low-risk patients. METHODS: Retrospective review of patients presenting to a tertiary emergency department over 42 months who had a D-dimer performed for PE risk stratification. Wells scores were calculated for each patient, those with Wells score of ≤4 ('PE unlikely') were analysed. Four D-dimer thresholds were compared, including traditional threshold (≥0.5 µg/mL), age-adjusted (≥age in years × 0.01 µg/mL), doubled-traditional threshold and YEARS criteria. RESULTS: During the study period, 2291 D-dimers were ordered for suspected PE, of which 2125 were low risk for PE. Of these low-risk patients 46 (2.2%) were found to have a PE. The sensitivity and specificity for each D-dimer threshold were traditional threshold (95.6% and 65.6%), age-adjusted (93.5% and 71.7%), doubled traditional (69.6% and 85.5%) and YEARS criteria (80.4% and 84.0%). Utilising an age-adjusted threshold, YEARS criteria or doubled-traditional threshold would have resulted in 70, 217 and 245 fewer imaging investigations. CONCLUSIONS: The prevalence of PE in this low-risk cohort was very low. Utilising an age-adjusted D-dimer would have reduced imaging tests performed while maintaining good sensitivity. Although The YEARS criteria and doubled-traditional threshold would have reduced scanning considerably both had sensitivities of less than 90%.

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.

Risk Stratification Model: Lower-Extremity Ultrasonography for Hospitalized Patients with Suspected Deep Vein Thrombosis.

BACKGROUND: The Wells score for deep venous thrombosis (DVT) has a high failure rate and low efficiency among inpatients. OBJECTIVE: To create and validate an inpatient-specific risk stratification model to help assess pre-test probability of DVT in hospitalized patients. DESIGN: Prospective cohort study of hospitalized patients undergoing lower-extremity ultrasonography studies (LEUS) for suspected DVT. Demographics, physical findings, medical history, medications, hospitalization, and laboratory and imaging results were collected. Samples were divided into model derivation (patients undergoing LEUS 11/1/2012-12/31/2013) and validation cohorts (LEUS 1/1/2014-5/31/2015). A DVT prediction rule was derived using the recursive partitioning algorithm (decision tree-type approach) and was then validated. PARTICIPANTS: Adult inpatients undergoing LEUS for suspected DVT from November 2012 to May 2015, excluding those with DVT in the prior 3 months, at a 793-bed, urban academic quaternary-care hospital with ~50,000 admissions annually. MAIN MEASURES: The primary outcome was the presence of proximal DVT, and the secondary outcome was the presence of any DVT (proximal or distal). Model sensitivity and specificity for predicting DVT were calculated. KEY RESULTS: Recursive partitioning yielded four variables (previous DVT, active cancer, hospitalization ≥ 6 days, age ≥ 46 years) that optimized the prediction of proximal DVT and yield in the derivation cohort. From this decision tree, we stratified a scoring system using the validation cohort, categorizing patients into low- and high-risk groups. The incidence rates of proximal DVT were 2.9% and 12.0%, and of any DVT were 5.2% and 21.0%, for the low- and high-risk groups, respectively. The AUC for the discriminatory accuracy of the Center for Evidence-Based Imaging (CEBI) score for risk of proximal DVT identified on LEUS was 0.73. Model sensitivity was 98.1% for proximal and 98.1% for any DVT. CONCLUSIONS: In hospitalized adults, specific factors can help clinicians predict risk of DVT, identifying those with low pre-test probability, in whom ultrasonography can be safely avoided.

[Predictive value of Wells Score, Revised Geneva Score combined with D-dimer for Pulmonary Embolism in patients with acute exacerbation of chronic obstructive pulmonary disease].

Objective: To evaluate the predictive value of Wells score, revised Geneva score combined with D-dimer for the risk of pulmonary embolism in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods: In this study, 234 AECOPD patients underwent CT pulmonary angiography from March 1, 2013 to December 31, 2015 in the First Affiliated Hospital of Zhengzhou University. The basic data of the patients were collected and the patients were classified into AECOPD combined with pulmonary embolism group(pulmonary embolism group) and AECOPD group according to CT pulmonary angiography results. All patients were scored by Wells score and revised Geneva score. The receiver operating characteristic (ROC) curves were generated and the Z test was applied to evaluate the predictive value by comparing the area under the ROC curves (AUC). Results: Totally 32(13.7%) patients had pulmonary embolism out of the 234 AECOPD patients. The AUC by Wells score, revised Geneva score, D-dimer, Wells score + D-dimer, revised Geneva score + D-dimer were 0.869 (95% CI: 0.789-0.949), 0.710 (95% CI: 0.588-0.832), 0.866 (95% CI: 0.790-0.941), 0.926 (95% CI: 0.874-0.977), 0.855 (95% CI: 0.751-0.959). The AUC of Wells score and D-dimer were significantly greater than that of revised Geneva score (Z=2.14, 2.12, both P<0.05); the AUC of Wells score + D-dimer was significantly greater than revised Geneva score + D-dimer (Z=2.73, P<0.05). Conclusion: The predictive value of Wells score + D-dimer for pulmonary embolism in AECOPD patients is higher than revised Geneva score + D-dimer.

Overuse and underuse of pulmonary CT angiography in patients with suspected pulmonary embolism.

Background: The aim of the present study was to evaluate the utilization and diagnostic yields of CT pulmonary angiography (CTPA)using the Revised Geneva score and Wells' criteria, in patients with suspected pulmonary embolism (PE). Methods: One hundred and twelve adult patients underwent CTPA for suspected PE were participated in this study. The outcome was positive or negative CTPA for PE. Revised Geneva and Wells' scores were calculated. The relationship between the results obtained rom these two scores and the available risk factors were compared. Descriptive analysis such as frequency and mean as well as analytical statistics including chi-square were done. The data analysis was performed using SPSS (v. 22). Results: In this study, according to the Wells' criteria calculated for the patients, 33.9% of the patients had low clinical, 56.3% intermediate and 9.8% high clinical probability. Among the 11 high clinical patients, 9(81.8%) were CTPA positive. Based on the revised Geneva score, 65 patients (58%) had low clinical, 36 (32.1%) intermediate and 11(9.8%) high clinical probability. Among the 1 high clinical patients, 8 were CTPA positive. Positive predictive value of the low clinical patients based on Wells' criteria and the revised Geneva score was 18.4% and 30.8%, respectively. Also, positive predictive value for high clinical probability of Wells' criteria and the revised Geneva score was 81.8% and 72.8% respectively. Conclusion: Under/overuse of CTPA in diagnosing PTE is a common problem especially in university hospitals. It is possible to avoid unnecessary CTPA requests using scholarly investigations and more accurate clinical risk assessments.

Usefulness of clinical predictors for preoperative screening of deep vein thrombosis in hip fractures.

BACKGROUND: Recent studies showed that preoperative deep vein thrombosis (DVT) was common after hip fracture (HF), and preoperative DVT screening has been recommended for preventing the fatal DVT-related complications, especially in elderly HF patients with high surgical risk. However, to our knowledge, no previous studies have demonstrated the correlation between the clinical risk predictors and preoperative DVT. Therefore, this study aimed to correlate those clinical predictors related to DVT risk assessment with the incidence of preoperative DVT. METHODS: A prospective study was conducted, between July 2015 and June 2016, in 92 HF patients. All patients were evaluated for the DVT-related risk, as patients' characteristics, clinical signs, D-dimer, DVT risk assessment score (Wells score and Caprini score), and then underwent doppler ultrasonography preoperatively. The incidence of preoperative DVT was correlated with each clinical risk predictor, and then significant factors were calculated for diagnostic accuracy. RESULTS: The average patients' age was 78 ± 10 years. Sixty-eight patients (74%) were female. The incidence of preoperative DVT was 16.3% (n = 15). The median time from injury to doppler ultrasonography was 2 days (range 0-150 days). DVT group showed a significantly higher in Wells score and Caprini score compared to the non-DVT group (p < 0.05 all). Sensitivity and specificity of Wells score ≥ 2 and Caprini score ≥12 were 47 and 81, and 93 and 35%, respectively. CONCLUSION: DVT risk assessment may be helpful for stratifying the risk of preoperative DVT in elderly HFs. Those with Caprini score ≥ 12 should be screened with doppler ultrasonography preoperatively. Those with Wells score 0-1 had low risk for preoperative DVT, so the surgery could perform without delay.

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

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

Sparing ultrasound in emergency department patients with suspected deep vein thrombosis by using clinical scores and D-dimer testing.

PURPOSE: To evaluate compliance with a management strategy for use in emergency department (ED) patients with suspected deep vein thrombosis (DVT) based on Wells score (WS), D-dimer concentrations, and sonographic (US) examinations. METHODS: Retrospective and prospective data on risk factors, physical examination findings, D-dimer concentrations, and US results were collected and reviewed. The prevalence of DVT for each WS category and D-dimer level was calculated. RESULTS: In the retrospective part of the study, 475 consecutive patients were included. Patients' risk for DVT was scored as high (n = 129 [27.2%]), moderate (n = 95 [20%]), or low (n = 251 [52.8%]). D-Dimer test results were available for 34 (7.2%) of the patients. DVT was diagnosed in 105 (22.1%) patients: 99 (76.7%) at high, 4 (4.2%) at moderate, and 2 (0.8%) at low risk. The mean D-dimer concentration was 3,071.7 ng/ml in patients with DVT. In the prospective part of the study, 50 patients were enrolled. Their risk levels for DVT were scored as high (n = 23 [46%]), moderate (n = 7 [14%]), and low (n = 20 [40%]). D-Dimer testing was performed in all patients. The mean D-dimer concentration was 2,966.9 ng/ml in patients with DVT. DVT was diagnosed in 13 (26%) of these 50 patients: 12 (52.2%) at high and 1 (14.3%) at moderate risk for DVT. No patients in the low-risk group and with normal D-dimer concentrations had DVT. CONCLUSIONS: We identified significant correlation between WS, D-dimer concentration, and diagnosis of DVT on US examination. DVT can be excluded with certainty in patients admitted to the ED with a low-risk score for DVT and a negative D-dimer concentration, thus avoiding the need for performing US examinations. A low level of compliance with this management strategy was found in our ED.

The unlikely presence of deep vein thrombosis in a patient with low pretest probability and a negative D-dimer: a case report.

BACKGROUND: Deep vein thrombosis (DVT) is commonly encountered in the emergency department. Clinical models, such as the Wells criteria, allow physicians to estimate the probability of DVT in a patient. Current literature suggests a low pretest probability combined with a negative D-dimer laboratory study rules out DVT approximately 99% of the time. CASE REPORT: This case discusses a 37-year-old male patient who had a low pretest probability and a negative D-dimer, but was found to have a DVT on Doppler ultrasound. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The astute emergency physician must not discount clinical suspicion in order to decide when radiographic imaging is warranted for a possible venous thromboembolism. New adjuncts, such as bedside ultrasonography, can also be implemented to further risk stratify patients, potentially decreasing morbidity and mortality associated with DVT.

Prevalence of venous thromboembolic events and diagnostic performance of the wells score and revised geneva scores for pulmonary embolism in patients with interstitial lung disease: a prospective study.

BACKGROUND: To determine the prevalence of venous thromboembolism (VTE) in patients with connective tissue disease-related interstitial lung diseases (CTD-ILD) and idiopathic interstitial pneumonia (IIP) and to further evaluate associated risk factors. To also examine the diagnostic performance of the Wells score and the revised Geneva scores for diagnosing pulmonary embolism (PE) in ILD patients. METHOD: Fifty-seven patients with CTD-ILD and IIP were prospectively enrolled. Plasma D-dimer was measured by ELISA. Deep-vein thrombosis (DVT) was examined by venous ultrasonography and PE by computed tomography pulmonary angiography. PE prevalence was further assessed by the Wells score and the revised Geneva score. RESULTS: VTE was diagnosed in 15 (26.3%, 15/57) patients. Bivariate analysis revealed that dyspnoea (OR 3.750, 95%CI 1.095-12.842, P=0.035), lower extremity oedema (OR 8.667, 95%CI1.814-41.408, P=0.007), palpitations (OR 4.75, 95%CI1.073-21.032, P=0.040), and positive D-dimer (OR 5.087, 95%CI 1.015-25.485, P=0.048) were associated with VTE. Using the Wells Score, 46 (80.70%), eight (14.4%) and three (5.26%) patients had a low, intermediate and high probability of PE, respectively, with seven (15.22%), three (37.5%) and two (66.67%) of the respective cases confirmed. By the revised Geneva score, 23 (40.35%), 32 (56.14%) and two (3.51%) patients had a low, intermediate and high probability of PE, respectively, with two (8.70%), nine (28.13%) and one (50.00%) of the respective cases confirmed. The AUC for the Wells score and the revised Geneva score was 0.720±0.083 (CI 0.586 to 0.831) and 0.704± 0.081 (CI 0.568 to 0.817), respectively. CONCLUSION: VTE can be seen in approximately one fourth of patients with CTD-ILD or IIP and the Wells score and the revised Geneva score can be used for categorising PE risk.

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.