Computed Tomography Pulmonary Angiography Research Articles

Single-session catheter-directed lysis using adjunctive clot fragmentation with power pulse spray only is a fast, safe, and effective option for acute pulmonary embolism

ObjectiveSingle-session, catheter-directed thrombolysis (CDT) with adjunctive power pulse spray (PPS) only, without thrombectomy, was evaluated for its safety and effectiveness. We performed a single-center, retrospective analysis of prospectively collected data. MethodsPatients with high-risk or intermediate-risk pulmonary embolism (PE) who met the inclusion criteria and underwent a single session of CDT-PPS were included in the study. The primary outcomes assessed were technical and clinical success and major adverse events. Secondary outcomes included effectiveness based on pre- and postintervention clinical examination, radiographic findings, and reversal of right ventricular dysfunction at 48 hours and 4 weeks after discharge on echocardiography and computed tomography pulmonary angiography. The length of stay in the intensive care unit and overall admission were also analyzed. A return to premorbid exercise tolerance was evaluated at 12 months after the procedure. ResultsBetween May 2016 and January 2023, 104 patients at the Wollongong Hospital were diagnosed with high- or intermediate-risk PE and underwent CDT-PPS. Of the 104 patients, 49 (47%) were considered to have high-risk PE and 55 (53%) intermediate-risk PE. Eleven patients (11%) had absolute contraindications and 49 patients (47%) had relative contraindications to systemic thrombolysis. Technical success was achieved in 102 patients (98%). Survival was 99% at 48 hours, 96% at 4 weeks, and 91% at 12 months. At 4 weeks, echocardiography showed 98% of patients had no evidence of right heart dysfunction, and computed tomography pulmonary angiography showed complete resolution of PE in 72%. There were no major adverse events at 48 hours. The median intensive care unit length of stay was 1 day, and the overall length of stay was 6 days. At 12 months, 96% had returned to their premorbid status. ConclusionsThe CDT-PPS technique is fast, safe, and effective in the treatment of high- and intermediate-risk PE, even in patients with a high bleeding risk, and should be considered as first-line management when the skills and resources are available. Further multicenter prospective studies are needed to corroborate these results.

Can Routine Investigation for Occult Pulmonary Embolism Be Justified in Patients with Deep Vein Thrombosis?

This study aims to investigate whether routine screening for silent pulmonary embolism (PE) can be justified in patients with deep vein thrombosis (DVT). We retrospectively analyzed the medical records of 201 patients with lower-extremity DVT admitted to the vascular surgery department of a single tertiary university center between 2019 and 2023. All patients underwent clinical evaluation, basic laboratory exams, a whole-leg colored duplex ultrasound, and a computed tomography pulmonary angiography (CTPA), to screen for an occult, underlying PE. The overall incidence of silent PE was 48.8%. The median admission D-dimer level was significantly higher in patients with silent PE than in those without PE (9.60 vs. 5.51 mg/L, P=0.001). A D-dimer value ≥5.14 mg/L was discriminant for predicting silent PE, with a sensitivity of 68.2% and a specificity of 59.3%. Silent PE was significantly more common on the right side, with the embolus located at the main pulmonary, lobar, segmental, and subsegmental arteries in 29.6%, 32.7%, 20.4%, and 17.3%, respectively. A higher incidence of occult PE was observed in patients with iliofemoral DVT (P=0.037), particularly when the thrombus extended to the inferior vena cava (P=0.003). Moreover, iliofemoral DVT was associated with a larger size and a more proximal location of the embolus (P=0.041). Multivariate logistic regression showed that male sex (odds ratio [OR]=2.46, 95% confidence interval [CI]: 1.39-3.53; P=0.026), cancer (OR=2.76, 95% CI: 1.45-4.07; P=0.017), previous venous thromboembolism (VTE) history (OR=2.67, 95% CI: 1.33-4.01; P=0.022), D-dimer value ≥5.14 mg/L (OR=2.24, 95% CI: 1.10-3.38; P=0.033), iliofemoral DVT (OR=2.13, 95% CI: 1.19-3.07; P=0.041), and thrombus extension to the IVC (OR=2.95, 95% CI: 1.43-4.47; P=0.009) served as independent predictors for silent PE. A high incidence of silent PE was observed in patients with lower-extremity DVT. Screening of patients with DVT who have the aforementioned predictive risk factors using CTPA for silent PE may be needed and justified for the efficient management of VTE and its long-term complications.

Optimization of CT pulmonary angiography for pulmonary embolism using task-based image quality assessment and diagnostic reference levels: A multicentric study

PurposeTo establish size-specific diagnostic reference levels (DRLs) for pulmonary embolism (PE) based on patient CT examinations performed on 74 CT devices. To assess task-based image quality (IQ) for each device and to investigate the variability of dose and IQ across different CTs. To propose a dose/IQ optimization. Methods1051 CT pulmonary angiography dose data were collected. DRLs were calculated as the 75th percentile of CT dose index (CTDI) for two patient categories based on the thoracic perimeters. IQ was assessed with two thoracic phantom sizes using local acquisition parameters and three other dose levels. The area under the ROC curve (AUC) of a 2 mm low perfused vessel was assessed with a non-prewhitening with eye-filter model observer. The optimal IQ-dose point was mathematically assessed from the relationship between IQ and dose. ResultsThe DRLs of CTDIvol were 6.4 mGy and 10 mGy for the two patient categories. 75th percentiles of phantom CTDIvol were 6.3 mGy and 10 mGy for the two phantom sizes with inter-quartile AUC values of 0.047 and 0.066, respectively. After the optimization, 75th percentiles of phantom CTDIvol decreased to 5.9 mGy and 7.55 mGy and the interquartile AUC values were reduced to 0.025 and 0.057 for the two phantom sizes. ConclusionDRLs for PE were proposed as a function of patient thoracic perimeters. This study highlights the variability in terms of dose and IQ. An optimization process can be started individually and lead to a harmonization of practice throughout multiple CT sites.

Modern imaging of acute pulmonary embolism

The first-choice imaging test for visualization of thromboemboli in the pulmonary vasculature in patients with suspected acute pulmonary embolism (PE) is multidetector computed tomography pulmonary angiography (CTPA) – a readily available and widely used imaging technique. Through technological advancements over the past years, alternative imaging techniques for the diagnosis of PE have become available, whilst others are still under investigation. In particular, the evolution of artificial intelligence (AI) is expected to enable further innovation in diagnostic management of PE. In this narrative review, current CTPA techniques and the emerging technology photon-counting CT (PCCT), as well as other modern imaging techniques of acute PE are discussed, including CTPA with iodine maps based on subtraction or dual-energy acquisition, single-photon emission CT (SPECT), magnetic resonance angiography (MRA), and magnetic resonance direct thrombus imaging (MRDTI). Furthermore, potential applications of AI are discussed.

Adjusting Atrial Size Parameters for Body Surface Area: Does it Affect the Association With Pulmonary Embolism-related Adverse Events?

Small left atrial (LA) volume was recently reported to be one of the best predictors of acute pulmonary embolism (PE)-related adverse events (AE). There is currently no data available regarding the impact that body surface area (BSA)-indexing of atrial measurements has on the association with PE-related adverse events. Our aim is to assess the impact of indexing atrial measurements to BSA on the association between computed tomography (CT) atrial measurements and AE. Retrospective study (IRB: 2015P000425). A database of hospitalized patients with acute PE diagnosed on CT pulmonary angiography (CTPA) between May 2007 and December 2014 was reviewed. Right and left atrial volume, largest axial area, and axial diameters were measured. Patients undergo both echocardiographies (from which the BSA was extracted) and CTPAs within 48 hours of the procedure. The patient's body weight was measured during each admission. LA measurements were correlated to AE (defined as the need for advanced therapy or PE-related mortality at 30 days) before and after indexing for BSA. The area under the ROC curve was calculated to determine the predictive value of the atrial measurements in predicting AE. The study included 490 acute PE patients; 62 (12.7%) had AE. There was a significant association of reduced BSA-indexed and non-indexed LA volume (both <0.001), area (<0.001 and 0.001, respectively), and short-axis diameters (both <0.001), and their respective RA/LA ratios (all <0.001) with AE. The AUC values were similar for BSA-indexed and non-indexed LA volume, diameters, and area with LA volume measurements being the best predictor of adverse outcomes (BSA-indexed AUC=0.68 and non-indexed AUC=0.66), followed by non-indexed LA short-axis diameter (indexed AUC=0.65, non-indexed AUC=0.64), and LA area (indexed AUC=0.64, non-indexed AUC=0.63). Adjusting for BSA does not substantially affect the predictive ability of atrial measurements on 30-day PE-related adverse events, and therefore, this adjustment is not necessary in clinical practice. While LA volume is the better predictor of AE, LA short-axis diameter has a similar predictive value and is more practical to perform clinically.

Transient interruption of contrast on CT pulmonary angiography: effect of mid-inspiratory vs. end-inspiratory respiration command.

To investigate the effects of mid-inspiratory respiration commands and other factors on transient interruption of contrast (TIC) incidence on CT pulmonary angiography. In this retrospective study, 824 patients (mean age, 66.1 ± 15.3 years; 342 males) who had undergone CT pulmonary angiography between January 2021 and February 2023 were included. Among them, 545 and 279 patients were scanned at end- and mid-inspiratory levels, respectively. By placing a circular region of interest, CT attenuation of the main pulmonary artery (CTMPA) was recorded. Associations between several factors, including patient age, body weight, sex, respiratory command vs. TIC and severe TIC incidence (defined as CTMPA < 200 and 150 HU, respectively), were assessed using logistic regression analyses with stepwise regression selection based on Akaike's information criterion. Mid-inspiratory respiration command, in addition to patient age and lighter body weight, had negative association with the incidence of TIC. Only patient age, lighter body weight, female sex, and larger cardiothoracic ratio were negatively associated with severe TIC incidence. Mid-inspiratory respiration commands helped reduce TIC incidence among patients aged < 65 years (p = 0.039) and those with body weight ≥ 75kg (p = 0.005) who were at high TIC risk. Changing the respiratory command from end- to mid-inspiratory levels, as well as patient age and body weight, was significantly associated with TIC incidence.

Risk factors for suspected pulmonary embolism in children: Complication of Mycoplasma pneumoniae pneumonia

PurposePulmonary embolism (PE) is not a rare complication of Mycoplasma pneumoniae pneumonia (MPP) in children. We sought to determine the incidence of PE in children with MPP who underwent clinically indicated CT pulmonary angiography (CTPA) and to evaluate the risk factors for PE. MethodsAll 106 children with MPP who were clinically suspected of having PE and who underwent CTPA were retrospectively enrolled from June 2018 to December 2021. The clinical features, laboratory data, and radiological parameters were recorded (e.g., lung consolidation involved and the Qanadli score). A Cox proportional hazards model and area under the receiver operating characteristic (ROC) curve were used to evaluate the risk factors and prognostic discriminatory capacity for PE. ResultsPE was detected in 26 of 106 (24.5 %) children (mean age, 6.2 years ± 3.3 years; 53 boys). Sixteen of the 26 (61.5 %) children with PE were boys. The mean age of the children with PE was 8.1 ± 2.9 years, and the mean Qanadli score was 15.3 ± 10.2. Children with PE had higher D-dimer levels (9.3 ± 7.1 mg/Lvs. 3.6 ± 3.8 mg/L) and a greater frequency of lung lobe consolidation (25 (96.2 %) vs. 64 (80.0 %)) (all P < 0.05). For children with MPP, age (hazard ratio (HR) = 1.96 (95 % CI1.04, 3.71; P = 0.037), D-dimer level (HR = 1.52, 95 % CI: 1.03, 2.24; P = 0.029), and bilateral lung consolidation (HR = 2.41, 95 % CI: 1.03, 5.58; P = 0.043) were found to be independent predictors of PE. ConclusionClinical and CT radiological predictors could be used to predict PE in children with MPP. The use of risk factor assessment as a tool has the potential to guide more appropriate use of CTPA in children.

Influencing factors on the time to CT in suspected pulmonary embolism: an explorative investigation

Pulmonary embolism is a potentially fatal condition with increased mortality if anticoagulation is delayed. This study aimed to find influencing factors on the duration from requesting a computed tomography (CT) pulmonary angiography (CTPA) to performing a CTPA in suspected acute pulmonary embolism. In 1849 cases, automatically generated time data were extracted from the radiological information system. The impact of the distance to the scanner, case-related features (sector of patient care, triage), and workload (demand for CTs, performed CTs, available staff, hospital occupancy) were investigated retrospectively using multiple regression. The time to CTPA was shorter in cases from the emergency room (ER) than in inpatients and outpatients at distances below 160 m and 240 m, respectively. While requests from the ER were also performed faster than cases from regular wards (< 180 m), no difference was found between the ER and intensive care units. Compared to “not urgent” cases, the workflow was shorter in “urgent” (− 17%) and “life-threatening” (− 67%) situations. The process was prolonged with increasing demand (+ 5%/10 CTs). The presented analysis identified relevant in-hospital influences on the CTPA workflow, including the distance to the CT together with the sector of patient care, the case triage, and the demand for imaging.

Beyond pulmonary embolism: Alternative diagnosis and incidental findings on CT pulmonary angiography in sickle cell disease.

Sickle cell disease (SCD) is a genetic hematological disorder associated with severe complications, such as vaso-occlusive crises, acute chest syndrome (ACS), and an increased risk of thromboembolic events, including pulmonary embolism (PE). The diagnosis of PE in SCD patients presents challenges due to the overlapping symptoms with other pulmonary conditions. Our previous study revealed that nearly 96% of computed tomography pulmonary angiography (CTPA) scans in SCD patients were negative for PE, highlighting a gap in understanding the significance of CTPA findings when PE is absent. In this retrospective follow-up study conducted at the Salmaniya Medical Complex in Bahrain, we examined SCD patients with HbSS genotypes who underwent CTPA from January 1, 2018, to December 31, 2021, for suspected PE, but the results were negative. The aim of this study was to identify alternative diagnoses and incidental findings from CTPA scans. Experienced radiologists reviewed the CTPA images and reports to assess potential alternative diagnoses and incidental findings, incorporating an additional analysis of chest X-rays to evaluate the diagnostic value of CTPA. Incidental findings were classified based on their location and clinical significance. Among the 230 evaluated SCD patients (average age 39.7 years; 53% male) who were CTPA negative for PE, 142 (61.7%) had identifiable alternative diagnoses, primarily pneumonia (49.1%). Notably, 88.0% of these alternative diagnoses had been previously suggested by chest radiographs. Furthermore, incidental findings were noted in 164 (71.3%) patients, with 11.0% deemed clinically significant, necessitating immediate action, and 87.8% considered potentially significant, requiring further assessment. Notable incidental findings included thoracic abnormalities such as cardiomegaly (12.2%) and an enlarged pulmonary artery (11.3%), as well as upper abdominal pathologies such as hepatomegaly (19.6%), splenomegaly (20.9%), and gallstones (10.4%). This study underscores the limited additional diagnostic yield of CTPA for identifying alternative diagnoses to PE in SCD patients, with the majority of diagnoses, such as pneumonia, already suggested by chest radiographs. The frequent incidental findings, most of which necessitate further evaluation, highlight the need for a cautious and tailored approach to using CTPA in the SCD population.

Echocardiographic parameters as adjuncts to the Pulmonary Embolism Severity Index in predicting 30-day mortality in acute pulmonary embolism patients.

The Pulmonary Embolism Severity Index (PESI) is a validated tool to predict 30-day all-cause mortality in patients with acute pulmonary embolism (PE) but includes only clinical variables. We aimed to determine the effectiveness of PESI extended with an echocardiographic parameter. This cross-sectional observational study included consecutive patients with acute PE diagnosed with computed tomography pulmonary angiography. Of 117 subjects (57 men, 48.7%), at a median age of 69 (59-80) years, 16 patients died during the 30-day follow-up. Six modified models of PESI with an additional single echocardiographic parameter were created, which increased the predictive value of PESI (area under the curve [AUC] 0.8608): tricuspid annular plane systolic excursion (TAPSE) <18 mm, right ventricular (RV) free wall longitudinal strain (RVFWLS) >-23%, 60/60 sign, RV global longitudinal strain (RVGLS) >-16%, pulmonary ejection acceleration time (AcT) <67 ms, and thrombus in right heart cavities (AUC 0.8657 to 0.8976, respectively, all markers P <0.001). TAPSE, AcT, RVFWLS, and RVGLS showed significant correlations with the PESI score, but not a thrombus in the right heart cavity or the 60/60 sign. As PESI adjuncts, they independently predicted fatal outcomes: thrombus with hazard ratio (HR) 10.04 (95% confidence interval [CI], 2.81-37.12; P <0.001) and the 60/60 sign with HR 4.07 (95% CI, 1.27-12.81; P <0.001). The quantitative echocardiographic parameters of RV systolic function and pulmonary artery blood flow are associated with the PESI score and thus increase its predictive value to a limited extent. PE- specific findings: a thrombus in the right heart cavity and the 60/60 sign are effective adjuncts to the PESI score.

Epidemiology, Etiology, and Pathophysiology of Pulmonary Embolism

AbstractOver the last 20 years, there has been a progressive increase in the incidence of pulmonary embolism (PE) diagnosis in the United States, Europe, and Australia. Increased use of computed tomography pulmonary angiography has likely contributed in part to this rising incidence. However, it is pertinent to note that the burden of comorbidities associated with PE, such as malignancy, obesity, and advanced age, has also increased over the past 20 years. Time-trend analysis in North American, European, and Asian populations suggests that mortality rates associated with PE have been declining. The reported improved survival rates in PE over the past 20 years are likely, at least in part, to be the result of better adherence to guidelines, improved risk stratification, and enhanced treatment. Factors contributing to the development of venous thromboembolism (VTE) include stasis of blood, hypercoagulability, endothelial injury, and inflammation. In 70 to 80% of cases of PE, the thrombi embolizes from the proximal deep veins of the lower extremities and pelvis. Strong risk factors for VTE include lower extremity fractures and surgeries, major trauma, and hospitalization within the previous 3 months for acute myocardial infarction or heart failure with atrial fibrillation. Acute PE causes several pathophysiological responses including hypoxemia and right ventricle (RV) failure. The latter is a result of pulmonary artery occlusion and associated vasoconstriction. Hemodynamic compromise from RV failure is the principal cause of poor outcome in patients with acute PE.

Appropriateness of the use of CTPAs (computed tomographic pulmonary angiograms) in suspected pulmonary embolisms

Appropriateness of the use of CTPAs (computed tomographic pulmonary angiograms) in suspected pulmonary embolisms

Avoidable Overuse of Computed Tomography Pulmonary Angiography (CTPA) in Patients with Suspected Acute Pulmonary Thromboembolism (PTE): The Role of Clinical Prediction Rules and D-Dimer Assay

Background: Computed tomography pulmonary angiography (CTPA) is an imaging technique widely used in the diagnosis of acute pulmonary thromboembolism (PTE). Despite its disadvantages and potential risks, the overuse of CTPA has been a growing concern over the past decades. Objectives: The objective of this study was to investigate the rate of avoidable overuse of CTPA in patients with suspected PTE and to identify factors contributing to this overuse. The study aimed to highlight the importance of proper training for physicians in using validated diagnostic algorithms to minimize the overuse of CTPA and improve patient outcomes. Methods: In a cross-sectional study conducted between April 2016 and March 2019 at Shariati Hospital at Tehran University of Medical Sciences (TUMS), 1058 patients underwent CTPA due to suspected PTE. Wells scores were calculated retrospectively for all patients. The study defined avoidable overuse of CTPA as an imaging request without prior D-dimer testing or ignoring a negative D-dimer result in patients with low clinical pre-test probability. Results: Two hundred and seventy-three patients were excluded from the study due to unavailable documentation or pregnancy. Among the included 785 patients, 139 (17.7%) revealed PTE on CTPA. Based on the Wells scores, 480 patients were identified as the “PTE-unlikely” group. In this group, 299 patients (62.3%) underwent CTPA directly despite recommendations to order a D-dimer test first. Of these patients, 281 (94%) cases showed negative results. Moreover, CTPA was performed inappropriately in 52 “PTE-unlikely” cases despite negative D-dimer serum levels, and only one patient was diagnosed with PTE. Conclusions: The study revealed that 44.7% of the CTPA requests for patients with suspected PTE were avoidable, indicating the need for better adherence to current diagnostic guidelines to reduce unnecessary radiologic investigations and improve patient care.

A Rare Case of Tuberculous Constrictive Pericarditis Due to Disseminated Tuberculosis with Response to Anti-tuberculosis Chemotherapy and Steroids in a Developed City State

A 27-year-old man presented with a 1-week history of atypical chest pain and sinus tachycardia. His physical examination was unremarkable. His resting ECG showed sinus tachycardia with widespread T-wave inversion. His initial blood tests show mildly raised troponin T and inflammatory markers and marked raised D-dimer. A CT pulmonary angiogram was performed to exclude pulmonary embolism but incidentally revealed an anterior mediastinal mass. A transthoracic echocardiogram and cardiac MRI showed features of constrictive pericarditis. A video-assisted thoracoscopic surgical biopsy of the anterior mediastinal mass showed thymic tissue with necrotising granulomatous inflammation and an acid-fast bacilli culture was positive to tuberculosis infection. The patient was started on anti-tuberculosis chemotherapy and a 6-week tapering course of oral steroids. A repeat cardiac MRI performed after 6 weeks of treatment showed a significant response to treatment with resolution of constrictive physiology.

Anatomically aware dual-hop learning for pulmonary embolism detection in CT pulmonary angiograms

Pulmonary Embolisms (PE) represent a leading cause of cardiovascular death. While medical imaging, through computed tomographic pulmonary angiography (CTPA), represents the gold standard for PE diagnosis, it is still susceptible to misdiagnosis or significant diagnosis delays, which may be fatal for critical cases. Despite the recently demonstrated power of deep learning to bring a significant boost in performance in a wide range of medical imaging tasks, there are still very few published researches on automatic pulmonary embolism detection. Herein we introduce a deep learning based approach, which efficiently combines computer vision and deep neural networks for pulmonary embolism detection in CTPA. Our method brings novel contributions along three orthogonal axes: (1) automatic detection of anatomical structures; (2) anatomical aware pretraining, and (3) a dual-hop deep neural net for PE detection. We obtain state-of-the-art results on the publicly available multicenter large-scale RSNA dataset.

A rare and late complication of lung cancer: bronchial rupture

Abstract Background Tracheobronchial injuries generally occur due to iatrogenic or traumatic causes. Although bronchial rupture due to teratoma and germ cell tumors has been reported in the literature, no cases related to lung cancer have been determined. Our case is presented because of the refusal to be examined for the mass in the lung and the detection of bronchial rupture afterward when he presented with massive hemoptysis. Case presentation A 65-year-old male patient was admitted to the emergency department with the complaint of massive hemoptysis. Six months ago, bronchoscopy was recommended due to the 8 × 7 cm cavitary lesion obliterating the bronchus in the anterior upper lobe of the right lung on chest computed tomography, but the patient refused. The sputum sample, requested 3 times, was negative for acid-resistant bacteria, and no growth was detected in the mycobacterial culture. In the new pulmonary CT angiography, a progressive cavitary lesion invading the right main bronchus, carina, and vena cava superior was observed. Following tranexamic acid treatment and bronchial artery embolization, hemoptysis significantly decreased in the follow-up. In the flexible bronchoscopy performed for diagnostic purposes, the carina was pushed to the left and invaded, and there was damage to the right main bronchus. A biopsy was not performed due to the risk of bleeding, and lavage was performed. Lavage was negative for ARB, there was no growth in the mycobacteria culture, and cytology did not reveal malignant cells. The patient, diagnosed with right main bronchial rupture, was considered inoperable and died 1 month later due to respiratory failure. Conclusions Examinations should be initiated as soon as malignancy is suspected. When diagnosis and treatment are delayed, complications that would be challenging to intervene may develop.

Implementation, Clinical Benefit and Safety of a D-Dimer-Focused Pulmonary Embolism Testing Pathway in the Emergency Department

Computed tomography pulmonary angiogram (CTPA) is overused during pulmonary embolism (PE) testing in the emergency department (ED), whereas prediction rules and D-dimer are underused. We report the adherence, clinical benefit, and safety of a D-dimer-only strategy to guide need for PE imaging in the ED. This was a prospective multicenter implementation study in 2 EDs with historical and external controls. Patients with suspected PE underwent D-dimer testing and imaging (CTPA or ventilation-perfusion scan) when D-dimer levels were 500 ng/mL or more. PE was ruled out if D-dimer was less than 500 ng/mL or with negative imaging. The primary implementation outcome was the proportion of patients tested for PE in adherence with the pathway. The primary clinical benefit outcome was the proportion of patients tested for PE who received pulmonary imaging. The primary safety outcome was diagnosis of PE in the 30 days following negative PE testing postimplementation. Between January 2018 and June 2021, 16,155 patients were tested for PE, including 33.4% postimplementation, 30.7% preimplementation, and 35.9% in an external control site. Adherence with the D-dimer-only pathway was 97.6% (adjusted odds ratio (aOR) post- versus preimplementation 5.26 (95% confidence interval 1.70 to 16.26). There was no effect on the proportion undergoing PE imaging. Imaging yield increased aOR 4.89 (1.17 to 20.53). Two cases of PE (0.04%; 0.01% to 0.16%) were diagnosed within 30 days. In this Canadian ED study, the uptake of a D-dimer-only PE testing strategy was high. Implementation was associated with higher imaging yield and a D-dimer level of less than 500 ng/mL safely excluded PE.

Comparison of the accuracy of four diagnostic prediction rules for pulmonary embolism in patients admitted to the emergency department

Introduction and ObjectivesRuling out pulmonary embolism (PE) through a combination of clinical assessment and D-dimer level can potentially avoid excessive use of computed tomography pulmonary angiography (CTPA). We aimed to compare the diagnostic accuracy of the standard approach based on the Wells and Geneva scores combined with a standard D-dimer cut-off (500 ng/ml), with three alternative strategies (age-adjusted and the YEARS and PEGeD algorithms) in patients admitted to the emergency department (ED) with suspected PE. MethodsConsecutive outpatients admitted to the ED who underwent CTPA due to suspected PE were retrospectively assessed. Sensitivity, specificity, positive and negative predictive values, likelihood ratios and diagnostic odds ratios were calculated and compared between the different diagnostic prediction rules. ResultsWe included 1402 patients (mean age 69±18 years, 54% female), and PE was confirmed in 25%. Compared to the standard approach (p<0.001), an age-adjusted strategy increased specificity with a non-significant decrease in sensitivity only in patients older than 70 years. Compared to the standard and age-adjusted approaches, the YEARS and PEGeD algorithms had the highest specificity across all ages, but were associated with a significant decrease in sensitivity (p<0.001), particularly in patients aged under 60 years (sensitivity of 81% in patients aged between 51 and 60 years). ConclusionCompared to the standard approach, all algorithms were associated with increased specificity. The age-adjusted strategy was the only one not associated with a significant decrease in sensitivity compared to the standard approach, enabling CTPA requests to be reduced safely.

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.

The Relationship Between Pulmonary Artery Diameter Measured by Chest CT and D-Dimer in COVID-19 Patients Admitted to the Emergency Department

Aim: The coronavirus disease 2019 (COVID-19) pandemic has become a global health emergency due to its rapid spread worldwide. Our study evaluated the relationship between pulmonary artery diameter and d-dimer in COVID-19 patients. &#x0D; &#x0D; Material and Methods: Patients aged 18 years and older with International Classification of Diseases 10 diagnosis code U07.3 who were admitted to our emergency department between March 15, 2020, and November 31, 2020, were included in our study. Demographic data (age, sex), laboratory tests (polymerase chain reaction test, d-dimer level), and imaging results (chest computed tomography, computed tomography pulmonary angiography) of the patients were retrospectively analyzed using medical records and the hospital electronic record system. &#x0D; &#x0D; Results: A total of 1654 patients were included in the study. The 30-day mortality rate was 13.7% (n=227). The most effective independent variable on 30-day mortality was 44 years of age or older. Pulmonary artery diameter and d-dimer levels were found to be higher in both the group with typical COVID-19 chest computed tomography findings and in patients who died within 30 days. However, unlike the literature, there was no significant difference in pulmonary artery diameter and d-dimer levels between patients with and without pulmonary embolism. &#x0D; &#x0D; Conclusion: In conclusion, we found a weak positive correlation between d-dimer and pulmonary artery diameter in COVID-19 patients.