Development of a Computerized, Evidence-Based Decision Support System for Computed Tomography Assessment in Acute Aortic Syndrome in the Emergency Department

Research Article

Austin J Radiol. 2021; 8(10): 1164.

Development of a Computerized, Evidence-Based Decision Support System for Computed Tomography Assessment in Acute Aortic Syndrome in the Emergency Department

Lumbreras-Fernández B1*, Vicente Bártulos A2, Fernandez-Felix BM3, Corres González J4, Zamora J3,5 and Muriel A6

1Radiology Department, Hospital Universitario Ramón y Cajal, Madrid, Spain

2Emergency Radiology Department, Hospital Universitario Ramón y Cajal, Madrid, Spain

3Clinical Biostatistics Unit, Hospital Universitario Ramon y Cajal (IRYCIS), CIBER Epidemiology and Public Health (CIBERESP), Madrid, Spain

4Emergency Department, Hospital Universitario Ramón y Cajal, Madrid, Spain

5Institute of Metabolism and Systems Research, University of Birmingham, England

6Clinical Biostatistic Unit, Hospital Universitario Ramón y Cajal, IRYCIS, CIBER Epidemiology and Public Health (CIBERESP), Nursing Department, Universidad de Alcalá, Madrid, Spain

*Corresponding author: Lumbreras-Fernández B, Radiology Department, Hospital Infanta Sofía, San Sebastián de los Reyes, 28703 Madrid, Spain

Received: August 31, 2021; Accepted: October 06, 2021; Published: October 13, 2021

Abstract

Purpose: To develop a computerized algorithm, or Clinical Decision Support System (CDSS), for managing and requesting imaging in the emergency department, specifically Computerized Tomography Angiography (CTA) of the aorta, when there is suspicion of AAS, and to determine the effect of implementing this system. To determine the factors associated with a positive radiological diagnosis that improve the predictive capacity of CTA findings.

Methods: After developing and implementing an evidence-based algorithm, we studied suspected cases of AAS. Chi-squared test was used to analyze the association between the variables included in the algorithm and radiological diagnosis, with three categories: no relevant findings, positive for AAS, and alternative diagnoses.

Results: 130 requests were identified; 19 (14.6%) had AAS and 34 (26.2%) had a different acute pathology. Of the 19 with AAS, 15 had been stratified as high risk and 4 as intermediate risk. The probability of AAS was 3.4 times higher in patients with known AA (p = 0.021, 95% CI 1.2-9.6) and 5.1 times higher in patients with a new aortic regurgitation murmur (p = 0.019, 95% CI 1.3-20.1). The probability of having an alternative severe acute pathology was 3.2 times higher in patients with hypotension or shock (p = 0.02, 95% CI 1.2-8.5).

Conclusion: The use of a CDSS in the emergency department can help optimize AAS diagnosis. In our hospital it improved AAS management and the diagnostic yield of CTA.

Keywords: Acute aortic syndrome; Chest pain; Thoracic pain; Algorithm; Aortic CT angiography; Clinical decision support system (CDSS)

Abbreviations

AAS: Acute Aortic Syndrome; ACCF/AHA: American College of Cardiology Foundation/American Heart Association; ACR: American College of Radiology; AA: Aortic Aneurysm; CDSS: Clinical Decision Support Systems; CTA-A: Computed Tomography Angiography of the Aorta; ESC: European Society of Cardiology; PTE: Pulmonary Thromboembolism

Introduction

Acute Aortic Syndrome (AAS) has an estimated incidence of 2-3.5/100,000 population/year [1].

The classical presentation is of sudden onset of intense chest, abdominal, or back pain, described as sharp, piercing, tearing, or stabbing. Although pain is the most reported symptom, there is great variety in clinical presentation [2]. There are also several processes that can mimic AAS, including acute coronary syndrome, pleuropulmonary, gastrointestinal, or musculoskeletal pathology, hypotension, and visceral or limb ischemia [3].

This varied presentation along with the lack of specific biomarkers make AAS difficult to diagnose. Due to its rapid progression and high mortality (40% immediate mortality and 1-2% per hour from the onset of symptoms), tools for a rapid, accurate diagnosis are needed [1,4,5].

Due to the prognostic implications of diagnostic error or delay, algorithms or clinical decision support systems (CDSS) are essential to guide the clinician in their diagnostic approach.

The main objectives of this study were:

• To develop a CDSS to improve the appropriateness of Computed Tomography Angiography (CTA) of the aorta when AAS is suspected in the emergency department and to determine the effect of its implementation.

• To identify the risk factors (past medical history, presentation, examination findings) associated with a positive diagnosis of AAS on CTA and that could help in developing a clinical prediction rule.

Materials and Methods

This study forms part of the multicenter project MAPAC-imagen (Mejora de la Adecuación de la Práctica Asistencial y Clínica, meaning Improvement of Appropriateness of Health Care and Clinical Practice) funded by the ISCIII as part of their Acción Estratégica en Salud (Strategic Health Action) between 2013 and 2016. The project was approved by the hospital ethics committee.

The study was conducted in the following phases:

Phase 1: Development of the algorithm for radiological management in cases of suspected AAS

Literature review: The databases Best Practice, Dynamed, Up to Date, Ovid, MEDLINE and EMBASE were consulted, as well as repositories of clinical practice guidelines, ACR guidelines (ACR appropriateness criteria), guidelines from the ACCF/AHA and the ESC, to identify relevant documents on the diagnostic management and risk factors for AAS.

For this systematic search we combined search terms associated with the disease (acute aortic syndrome, aortic dissection, acute intramural hematoma, penetrating aortic ulcer, periaortic hematoma, unstable aneurysm), the reason for attendance (acute chest pain, thoracic pain, chest pain, sudden onset excruciating anterior or interscapular), crossing them with terms for the imaging technique and synonyms (aortic CT angiography, CT angiography, contrast enhanced CT), and the study setting (emergency). To restrict the search we used methodological filters for clinical prediction rules including Haynes Broad Filter (HBF) and Teljeur/Murphy Inclusion Filter 26 items (TMIF-26) and exclusion filter (TMEF).

Development of the algorithm, consensus and implementation: The documents identified in the search were screened, and those considered most relevant as a source of evidence were selected to create the decision support algorithm on the use of CTA for diagnosis of AAS. After analyzing the selected literature we created a narrative synthesis, and the information was used to design an algorithm that took into account the risk factors analyzed in these studies. This algorithm was discussed and consensus opinion sought in an inperson meeting of experts using the Delphi panel technique to assess the appropriateness of the factors included and a second virtual round to reach consensus on factors which had not been agreed upon in the in-person round.

The final algorithm was integrated in the electronic medical record system of our hospital, so that when CTA of the aorta was requested in patients with suspicion of AAS, it generated a pop-up window with questions prompting selection of risk factors. Based on these, it stratified the degree of suspicion of AAS, and the system would then indicate whether or not CTA of the aorta would be appropriate.

Phase 2: Analysis of the outcomes of implementation

Design:

Impact of implementation of the algorithm: This was a beforeand- after study (pre- and post-implementation of the CDSS), of 6 months’ duration for each period, in which all requests for CTA aorta for suspected AAS were collected. We evaluated the number of requests for CTA for suspected AAS and the diagnostic yield of these (normal study, findings of AAS, or other unrelated findings).

Exploration of risk factors associated with radiological findings: All cases of suspected AAS in the 27 successive months after implementation of the algorithm (March 2016 to June 2018) were studied. We evaluated the association between the factors included in the CDSS and the radiological findings on CTA.

Statistical analysis

Univariate multinomial regression models were used to evaluate the association between the risk factors included in the algorithm and the radiological findings, with three categories: normal study or irrelevant/nonpathological findings, study diagnostic of AAS, or study with findings of other acute pathologies different from AAS. No multivariate models were used due to the low frequency of positive findings.

P-values <0.05 were considered indicative of statistical significance.

For statistical analysis the program STATA v.15.1 (StataCorp LLC, 4905 Lakeway Drive, College Station, Texas, USA) was used.

Results

Literature review

The literature search identified 573 studies; 6 of these were excluded as duplicates and 550 as the articles did not meet the criteria (e.g. case series, primary studies, studies not in English or Spanish, or in a pediatric population). Ultimately, the analysis and qualitative synthesis included 17 studies that were used to develop the decision support algorithm. These studies were mainly clinical practice guidelines [1,4], imaging appropriateness guidelines [5-7], systematic reviews [8-14] and metaanalysis [15] and other studies that evaluated risk factors for AAS [16,17]. No clinical prediction rules were identified. The screening and selection process is shown in Figure 1.