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

STUDY OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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 YEARS and Adjust-Unlikely D-dimer Testing for Pulmonary Embolism in the Emergency Department.

STUDY OBJECTIVE: We prospectively assessed the diagnostic accuracy of YEARS and a modified age-adjusted clinical decision rule ("Adjust-Unlikely") for pulmonary embolism (PE) testing in the emergency department. METHODS: This study was conducted in tertiary care Canadian emergency departments. When the D-dimer was <500 ng/ml, PE was excluded. Pulmonary imaging for PE was performed when the D-dimer was ≥500 ng/ml. Patients were followed for 30 days, and PE outcomes were independently adjudicated. Physicians systematically recorded the presence or absence of YEARS items (PE most likely, hemoptysis, signs of deep venous thrombosis) prior to D-dimer testing and imaging. We analyzed the diagnostic accuracy of YEARS and the "Adjust-Unlikely" rule. Age adjustment (age x 10 in those >50 years old) was applied in patients where PE was not the most likely diagnosis and 500 ng/ml threshold when PE was most likely. RESULTS: One thousand seven hundred three patients were included, median age 62 (50, 74), 58% female, PE prevalence 8.0%. YEARS sensitivity for PE diagnosis was 92.6% (87.0, 96.0%) and specificity 45.0% (42.5, 47.5%). Adjust-Unlikely sensitivity was 100.0% (97.2, 100.0%) and specificity 32.4% (30.1, 34.8%). Posttest probability of PE in the group of patients with PE excluded by D-dimer between 500 ng/ml and the adjusted limit was 2.8% (1.6, 5.1%) for YEARS and 0.0% (0.0, 2.6%) for the "Adjust-Unlikely" rule. CONCLUSION: The "Adjust-Unlikely" rule would modestly reduce imaging and identify all cases of PE. YEARS would substantially reduce imaging but miss 1 in 14 cases of PE.

Anticoagulation prescription among atrial fibrillation patients managed with and without an anticoagulant initiation pathway: a cohort study.

BACKGROUND AND IMPORTANCE: The Canadian Association of Emergency Physicians atrial fibrillation (AF) checklist advises that emergency physicians initiate anticoagulation therapy for patients with AF or flutter who are CHADS65 positive. OBJECTIVES: The aim was to compare anticoagulation initiation rates between patients treated with and without an anticoagulation assessment pathway (the SAFE pathway). DESIGN: This was a retrospective cohort study. SETTINGS AND PARTICIPANTS: All emergency department patients were discharged home with a diagnosis of AF between June 2018 and May 2020 at two Canadian emergency departments. INTERVENTION: The SAFE pathway is a hard copy form which allows emergency physicians to document contraindications to anticoagulation, the positive components of the CHADS65 score, and details how to prescribe anticoagulation. OUTCOME MEASURES AND ANALYSIS: Trained researchers abstracted data on the use of the SAFE pathway by the presence or absence of the completed, scanned pathway in the electronic medical chart. The exposure of interest was use of this pathway. Patients were followed forward in time for 90 days by electronic medical record review to document stroke, transient ischemic attack, arterial embolism and major bleeding events. All events were independently adjudicated. Adjusted odds ratios were calculated to compare outcomes between those managed with and without the SAFE pathway. RESULTS: In total, 766 patients were included, of whom 264 were already taking anticoagulation, 166 were CHADS65 negative and 65 had a contraindication to anticoagulation, leaving 271 patients eligible for anticoagulation prescription. Among the 271 eligible patients, 137/166 managed with the SAFE pathway were initiated on anticoagulation and 24/105 managed without the SAFE pathway started anticoagulation (adjusted odds ratio 25.9; 13.1-51.2). There was no statistically significant difference in the 90-day rate of stroke or bleeding. CONCLUSION: Use of the SAFE pathway was associated with a higher rate of anticoagulation prescription.

Feasibility of a quality improvement project to increase adherence to evidence-based pulmonary embolism diagnosis in the emergency department.

BACKGROUND: Many evidence-based clinical decision tools are available for the diagnosis of pulmonary embolism (PE). However, these clinical decision tools have had suboptimal uptake in the everyday clinical practice in emergency departments (EDs), despite numerous implementation efforts. We aimed to test the feasibility of a multi-faceted intervention to implement an evidence-based PE diagnosis protocol. METHODS: We conducted an interrupted time series study in three EDs in Ontario, Canada. We enrolled consecutive adult patients accessing the ED with suspected PE from January 1, 2018, to February 28, 2020. Components of the intervention were as follows: clinical leadership endorsement, a new pathway for PE testing, physician education, personalized confidential physician feedback, and collection of patient outcome information. The intervention was implemented in November 2019. We identified six criteria for defining the feasibility outcome: successful implementation of the intervention in at least two of the three sites, capturing data on ≥ 80% of all CTPAs ordered in the EDs, timely access to electronic data, rapid manual data extraction with feedback preparation before the end of the month ≥ 80% of the time, and time required for manual data extraction and feedback preparation ≤ 2 days per week in total. RESULTS: The intervention was successfully implemented in two out of three sites. A total of 5094 and 899 patients were tested for PE in the period before and after the intervention, respectively. We captured data from 90% of CTPAs ordered in the EDs, and we accessed the required electronic data. The manual data extraction and individual emergency physician audit and feedback were consistently finalized before the end of each month. The time required for manual data extraction and feedback preparation was ≤ 2 days per week (14 h). CONCLUSIONS: We proved the feasibility of implementing an evidence-based PE diagnosis protocol in two EDs. We were not successful implementing the protocol in the third ED. REGISTRATION: The study was not registered.