Assessment of the current D-dimer cutoff point in pulmonary embolism workup at a single institution: Retrospective study

Characterizing and quantifying low-value diagnostic imaging internationally: a scoping review

BACKGROUND

Inappropriate and wasteful use of health care resources is a common problem, constituting 10-34% of health services spending in the western world. Even though diagnostic imaging is vital for identifying correct diagnoses and administrating the right treatment, low-value imaging-in which the diagnostic test confers little to no clinical benefit-is common and contributes to inappropriate and wasteful use of health care resources. There is a lack of knowledge on the types and extent of low-value imaging. Accordingly, the objective of this study was to identify, characterize, and quantify the extent of low-value diagnostic imaging examinations for adults and children.

METHODS

A scoping review of the published literature was performed. Medline-Ovid, Embase-Ovid, Scopus, and Cochrane Library were searched for studies published from 2010 to September 2020. The search strategy was built from medical subject headings (Mesh) for Diagnostic imaging/Radiology OR Health service misuse/Medical overuse OR Procedures and Techniques Utilization/Facilities and Services Utilization. Articles in English, German, Dutch, Swedish, Danish, or Norwegian were included.

RESULTS

A total of 39,986 records were identified and, of these, 370 studies were included in the final synthesis. Eighty-four low-value imaging examinations were identified. Imaging of atraumatic pain, routine imaging in minor head injury, trauma, thrombosis, urolithiasis, after thoracic interventions, fracture follow-up and cancer staging/follow-up were the most frequently identified low-value imaging examinations. The proportion of low-value imaging varied between 2 and 100% inappropriate or unnecessary examinations.

CONCLUSIONS

A comprehensive list of identified low-value radiological examinations for both adults and children are presented. Future research should focus on reasons for low-value imaging utilization and interventions to reduce the use of low-value imaging internationally.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42020208072.

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.

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.

Elevated D-Dimers and Right Ventricular Dysfunction on Echocardiography for Diagnosis of Pulmonary Embolism: A Validation Study

Background

There is an increasing need to explore other non-invasive techniques for the diagnosis of pulmonary embolism in resource-limited countries.

Objective

To assess the validity of elevated D-dimer levels and right ventricular (RV) dysfunction on echocardiography in predicting definite massive pulmonary embolism among patients diagnosed with massive pulmonary embolism using computed tomography (CT) pulmonary angiography as the gold standard.

Methods

The patients with acute massive pulmonary embolism on CT pulmonary angiography were included. The participants underwent 12-lead electrocardiography, assessment of D-dimer levels, and bedside echocardiography to determine right ventricular dysfunction. The data were recorded on a proforma and analyzed using IBM SPSS software version 26.0 (IBM Corp., Armonk, NY).

Results

There were 160 patients in the study. The mean age was 49.19 ± 14.89 years. Elevated D-dimer levels were seen in 80.60% of the patients whereas ventricular dysfunction on echocardiography was seen in 90.00% of the patients. The sensitivity and specificity of elevated D dimer levels were 78.99% and 14.60%, respectively. The positive predictive values (PPV) and negative predictive values (NPV) for elevated D-dimer levels were 72.87% and 19.35%, respectively. In contrast, the sensitivity of ventricular dysfunction was 94.96% and specificity 24.39%. PPV was found to be 78.47% and NPV was 62.50%.

Conclusion

Positive D-dimer levels and ventricular dysfunction on echocardiography are sensitive enough to consider the diagnosis of massive pulmonary embolism but lack adequate specificity, thus, necessitating the presence of other noninvasive tests.