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.

CT pulmonary angiography appropriateness in a single emergency department: does the use of revised Geneva score matter?

Purpose To assess the percentage of computed tomography pulmonary angiography (CTPA) procedures that could have been avoided by methodical application of the Revised Geneva Score (RGS) coupled with age-adjusted D-dimer cut-offs rather than only clinical judgment in Emergency Department patients with suspected pulmonary embolism (PE). Material and methods Between November 2019 and May 2020, 437 patients with suspected PE based on symptoms and D-dimer test were included in this study. All patients underwent to CTPA. For each patient, we retrospectively calculated the age-adjusted D-dimer cut-offs and the RGS in the original version. Finally, CT images were retrospectively reviewed, and the presence of PE was recorded. Results In total, 43 (9.84%) CTPA could have been avoided by use of RGS coupled with age-adjusted D-dimer cut-offs. Prevalence of PE was 14.87%. From the analysis of 43 inappropriate CTPA, 24 (55.81%) of patients did not show any thoracic signs, two (4.65%) of patients had PE, and the remaining patients had alternative thoracic findings. Conclusion The study showed good prevalence of PE diagnoses in our department using only physician assessment, although 9.84% CTPA could have been avoided by methodical application of RGS coupled with age-adjusted D-dimer cut-offs.

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

Background 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 analyzed 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 (COPD), 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.

Pulmonary Artery Filling Defects in COVID-19 Patients Revealed Using CT Pulmonary Angiography: A Predictable Complication?

Purpose. This study is aimed at assessing the prevalence of pulmonary artery filling defects (PAFDs) consistent with pulmonary artery embolism (PAE) in patients with SARS-CoV-2 infection and at investigating possible radiological or clinical predictors. Materials and Methods. Computed Tomography Pulmonary Angiographies (CTPAs) from 43 consecutive patients with a confirmed COVID-19 infection were retrospectively reviewed, taking into consideration the revised Geneva score and the D-dimer value for each patient. Filling defects within the pulmonary arteries were recorded along with pleural and parenchymal findings such as ground glass opacities, consolidation, crazy paving, linear consolidation, and pleural effusion. All these variables were compared between patients with and without PAFD. The predictive performance of statistically different parameters was investigated using the receiver operating characteristics (ROC). Results. Pulmonary embolism was diagnosed in 15/43 patients (35%), whereas CTPA and parenchymal changes related to pulmonary COVID-19 disease were evident in 39/43 patients (91%). The revised Geneva score and the mean D-dimer value obtained using two consecutive measurements were significantly higher in patients with PAFD. The ROC analysis demonstrated that a mean D-dimer value is the parameter with the higher predictivity (AUC 0.831) that is a cut ‐ off value > 1800 μ g / l which predicts the probability of PAFD with a sensitivity and specificity of 70% and 78%, respectively. Conclusions. This single centre retrospective report shows a high prevalence of pulmonary artery filling defects revealed using CTPA in COVID-19 patients and demonstrates that the mean value of multiple D-dimer measurements may represent a predicting factor of this complication.

Effectiveness of Clinical Decision Tools in Predicting Pulmonary Embolism

Objective. The Wells criteria and revised Geneva score are two commonly used clinical decision tools (CDTs) developed to assist physicians in determining when computed tomographic angiograms (CTAs) should be performed to evaluate the high index of suspicion for pulmonary embolism (PE). Studies have shown varied accuracy in these CDTs in identifying PE, and we sought to determine their accuracy within our patient population. Methods. Patients admitted to the Emergency Department (ED) who received a CTA for suspected PE from 2019 Jun 1 to 2019 Aug 31 were identified. Two CDTSs, the Wells criteria and revised Geneva score, were calculated based on data available prior to CTA and using the common D-Dimer cutoff of >500 μg/L. We determined the association between confirmed PE and CDT values and determined the association between the D-Dimer result and PE. Results. 392 CTAs were identified with 48 (12.1%) positive PE cases. The Wells criteria and revised Geneva score were significantly associated with PE but failed to identify 12.5% and 70.4% of positive PE cases, respectively. Within our cohort, a D-Dimer cutoff of >300 μg/L was significantly associated with PE and captured 95.2% of PE cases. Conclusions. Both CDTs were significantly associated with PE but failed to identify PE in a significant number of cases, particularly the revised Geneva score. Alternative D-Dimer cutoffs may provide better accuracy in identifying PE cases.

Abstract 16113: CT Pulmonary Angiography Yield in Patients With an Active Malignancy: Lack of Non-invasive Screening

Patients with an active malignancy are at increased risk of venous thromboembolism due to the production of pro-coagulant factors causing a hypercoagulable state. Providers must keep their index of suspicion high for a pulmonary embolism in these patients because of the high prevalence and often vague symptoms. This is a retrospective study of 2226 patients who underwent CT pulmonary angiography (CTPA) in the emergency department. We compared the diagnosis of PE in patients with and without an active malignancy within the past 6 months. Of those patients without an active cancer, 133/1788 (7.4%) patients were diagnosed with a PE. This is not significantly different from the cohort with cancer where 37/437 (8.5%) patients were diagnosed with a PE (p=0.468). During diagnosis, patients with a history of cancer were less likely to have a chest x-ray, d-dimer or troponin performed prior to the CTPA scan (Table 1). These tests are less invasive and much cheaper than the CTPA and can help identify other pathologies that a patient may be experiencing. Not surprisingly, patients with a malignancy have a higher Wells’ score, revised Geneva score and PERC rule (Table 2), leading providers further down diagnostic algorithms towards CTPA. While many of these high-risk patients should immediately undergo CTPA, patients at low or moderate risk of PE should first be evaluated with less invasive testing such as a chest x-ray or d-dimer. In conclusion, in order to decrease the number of patients unnecessarily undergoing CTPA, patients with an active malignancy should be risk stratified in a similar manner as those patients without a malignancy, including the use of non-invasive testing where appropriate.

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

Background. Pulmonary embolism (PE) diagnosis can sometimes be challenging due to the disease having nonspecific signs and symptoms at the time of presentation. The aim of the present study was to evaluate the validity of the D-dimer in combination with the revised Geneva score (RGS) in prediction of Pulmonary embolism.Methods. This is a retrospective study of 2010 patients with suspected PE who had undergone both D-dimer testing followed by chest CT angiography (CTPA). The predictive accuracy of D-dimer, adjusted D-dimer and the revised Geneva score were calculated. ROC curve was applied to allocate the optimum RGS cutoff for PE prediction.Results. Of all patients, the mean age was 52.2±20.2 years, two-thirds (65.1%) were females, with previous history of; DVT or PE (2%), surgery and/or fracture of lower limb (6.9%), active malignant conditions (14.4%), unilateral lower limb pain (0.6%), and hemoptysis (0.7%).The overall prevalence of PE was 16%. It was 0% in the low, 25.8% in intermediate and 88.9% in high clinical probability categories of RGS. Both conventional and age-adjusted D-dimer thresholds showed significant level of agreement (kappa=0.081, p<0.001), high sensitivity (94% & 92.8%), high NPV (91.2% & 91.4%), low specificity (12.3% & 15.3) and low PPV (17.5% & 17.8%), respectively. Combination of the age-adjusted D-dimer threshold and RGS at a cut-off of 5 points would provide 100% sensitivity and 61.7% specificity 34.1% PPV, 100% NPV and 0.87 AUC. At a RGS cutoff <5 points, PE could be have been excluded in 64.2% of patients with an abnormal age-adjusted D-dimer threshold without further imaging.Conclusion. Conventional and age-adjusted D-dimer tests showed high levels of agreement in prediction of PE, high sensitivity and low specificity. RGS has a good performance in PE prediction. Application of a clinical decision rule, using the revised Geneva score, and age adjusted D-dimer threshold could increase the number of patients in whom PE could be excluded without further imaging.