National survey of emergency physicians on the risk stratification and acceptable miss rate of acute aortic syndrome

Performance and costs of rule-out protocols for acute aortic syndromes: analysis of pooled prospective cohorts

BACKGROUND

Acute aortic syndromes (AAS) are deadly conditions causing unspecific symptoms, such as chest/abdominal/back pain, syncope and neurological deficit. They are diagnosed with computed tomography angiography (CTA), but the patient selection is challenging. To support physicians and standardize management, protocols combining a clinical score with D-dimer (DD) have been developed. However, direct comparison of their diagnostic performance and cost-effectiveness is lacking.

METHODS

We used individual patient data from 3 prospective diagnostic studies of patients with suspected AAS, enrolled in 12 centers from 5 countries. Diagnostic accuracy, failure rate and costs were calculated for 5 protocols, applying 3 scores (aortic dissection detection [ADD], AORTAs and Canadian) and 2 DD thresholds (500 ng/mL [DD500], age-adjusted [DDage]). Costs were estimated using Italian and German reimbursements.

RESULTS

Among 4907 patients, 506 (10.3 %) had an AAS. The sensitivity of the diagnostic protocols ranged from 97.6 % for Canadian/DD500 to 99.4 % for AORTAs/DD500 or DDage (P = 0.022). The specificity was lowest for AORTAs/DD500 (46.8 %; P < 0.001 vs AORTAs/DD500) and highest for ADD/DDage (61.5 %; P < 0.001). The number of potential AAS misses was 4-fold higher with Canadian/DD500 vs AORTAs/DD500 or DDage. The net clinical benefit was highest for ADD/DDage. All protocols reduced CTA exams and costs over a CTA-to-all strategy. Numbers of predicted CTA exams and costs per 100 patients were lowest for ADD/DDage (447 CTAs, 34,366 EUR) and highest (579 CTAs, 43,628 EUR) for AORTAs/DD500.

CONCLUSIONS

Guideline-compliant clinical score/DD based protocols are highly sensitive. Differences in specificity and efficiency are present. Data may guide decision-making based on policies and resources.

Diagnosis of acute aortic syndromes with ultrasound and d-dimer: the PROFUNDUS study

BACKGROUND

In patients complaining common symptoms such as chest/abdominal/back pain or syncope, acute aortic syndromes (AAS) are rare underlying causes. AAS diagnosis requires urgent advanced aortic imaging (AAI), mostly computed tomography angiography. However, patient selection for AAI poses conflicting risks of misdiagnosis and overtesting.

OBJECTIVES

We assessed the safety and efficiency of a diagnostic protocol integrating clinical data with point-of-care ultrasound (POCUS) and d-dimer (single/age-adjusted cutoff), to select patients for AAI.

METHODS

This prospective study involved 12 Emergency Departments from 5 countries. POCUS findings were integrated with a guideline-compliant clinical score, to define the integrated pre-test probability (iPTP) of AAS. If iPTP was high, urgent AAI was requested. If iPTP was low and d-dimer was negative, AAS was ruled out. Patients were followed for 30 days, to adjudicate outcomes.

RESULTS

Within 1979 enrolled patients, 176 (9 %) had an AAS. POCUS led to net reclassification improvement of 20 % (24 %/-4 % for events/non-events, P < 0.001) over clinical score alone. Median time to AAS diagnosis was 60 min if POCUS was positive vs 118 if negative (P = 0.042). Within 941 patients satisfying rule-out criteria, the 30-day incidence of AAS was 0 % (95 % CI, 0-0.41 %); without POCUS, 2 AAS were potentially missed. Protocol rule-out efficiency was 48 % (95 % CI, 46-50 %) and AAI was averted in 41 % of patients. Using age-adjusted d-dimer, rule-out efficiency was 54 % (difference 6 %, 95 % CI, 4-9 %, vs standard cutoff).

CONCLUSIONS

The integrated algorithm allowed rapid triage of high-probability patients, while providing safe and efficient rule-out of AAS. Age-adjusted d-dimer maximized efficiency.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, NCT04430400.

Diagnostic accuracy of the aortic dissection detection risk score alone or with D-dimer for acute aortic syndromes: Systematic review and meta-analysis

OBJECTIVES

To evaluate the diagnostic accuracy of the aortic dissection detection risk score (ADD-RS) used alone or in combination with D-dimer for detecting acute aortic syndrome (AAS) in patients presenting with symptoms suggestive of AAS.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Library from inception to February 2024. Additionally, the reference lists of included studies and other systematic reviews were thoroughly searched. All diagnostic accuracy studies that assessed the use of ADD-RS alone or with D-Dimer for diagnosing AAS compared with a reference standard test (e.g. computer tomographic angiography (CTA), ECG-gated CTA, echocardiography, magnetic resonance angiography, operation, or autopsy) were included. Two reviewers independently selected and extracted data. Risk of bias was appraised using QUADAS-2 tool. Data were synthesised using hierarchical meta-analysis models.

RESULTS

We selected 13 studies from the 2017 citations identified, including six studies evaluating combinations of ADD-RS alongside D-dimer>500ng/L. Summary sensitivities and specificities (95% credible interval) were: ADD-RS>0 94.6% (90%, 97.5%) and 34.7% (20.7%, 51.2%), ADD-RS>1 43.4% (31.2%, 57.1%) and 89.3% (80.4%, 94.8%); ADD RS>0 or D-Dimer>500ng/L 99.8% (98.7%, 100%) and 21.8% (12.1%, 32.6%); ADD RS>1 or D-Dimer>500ng/L 98.3% (94.9%, 99.5%) and 51.4% (38.7%, 64.1%); ADD RS>1 or ADD RS = 1 with D-dimer>500ng/L 93.1% (87.1%, 96.3%) and 67.1% (54.4%, 77.7%).

CONCLUSIONS

Combinations of ADD-RS and D-dimer can be used to select patients with suspected AAS for imaging with a range of trade-offs between sensitivity (93.1% to 99.8%) and specificity (21.8% to 67.1%).

Derivation of a clinical decision rule to exclude cerebral venous sinus thrombosis in emergency department patients: A retrospective cohort study

OBJECTIVE

To derive a clinical decision rule to exclude cerebral venous sinus thrombosis (CVST) in the ED. A secondary aim was to derive a rule that incorporated clinical parameters and the non-contrast CT brain.

METHODS

Single-centre, retrospective cohort study. Patients suspected of CVST were identified from the radiology database for CT/MR venograms. Clinical features included in the rule were determined by literature review. The presence of these features in participants was determined by chart review. Variables were tested for univariate association with CVST using logistic regression. Variable selection was accomplished using a forward-stepwise process, calculating the sensitivity/specificity of a rule containing the variable of most significance, then repeating the process after adding the next most significant variable.

RESULTS

Forty-five out of 912 participants had confirmed CVST. The primary clinical rule was answering 'no' to all the following: any prothrombotic risk factor, age ≥54 years, confusion: sensitivity 95.6% (95% confidence interval [CI] 84.9-99.5%), specificity 40.9% (95% CI 37.6-44.2%), negative predictive value 99.4% (95% CI 97.9-99.9%) and positive predictive value 7.7% (95% CI 7.1-8.3%). The rule classified 39.5% of participants as CVST ruled out. The rule incorporating the non-contrast CT brain was answering 'no' to all the following: abnormal non-contrast CT brain, any prothrombotic risk-factor, age ≥54 years, confusion: sensitivity 100.0% (95% CI 91.6-100.0%), specificity 42.0% (95% CI 38.7-45.4%), negative predictive value 100.0% (95% CI not calculated) and positive predictive value 7.8% (95% CI 7.4-8.2%). The rule classified 40.0% of participants as CVST ruled out.

CONCLUSIONS

A clinical decision rule was derived to rule out CVST. These results require validation before adoption into clinical practice.

Evaluation of the Canadian Clinical Practice Guidelines Risk Prediction Tool for Acute Aortic Syndrome: The RIPP Score

Introduction

Acute aortic syndrome (AAS) is a rare clinical syndrome with a high mortality rate. The Canadian clinical practice guideline for the diagnosis of AAS was developed in order to reduce the frequency of misdiagnoses. As part of the guideline, a clinical decision aid was developed to facilitate clinician decision-making (RIPP score). The aim of this study is to validate the diagnostic accuracy of this tool and assess its performance in comparison to other risk prediction tools that have been developed.

Methods

This was a historical case-control study. Consecutive cases and controls were recruited from three academic emergency departments from 2002-2020. Cases were identified through an admission, discharge, or death certificated diagnosis of acute aortic syndrome. Controls were identified through presenting complaint of chest, abdominal, flank, back pain, and/or perfusion deficit. We compared the clinical decision tools' C statistic and used the DeLong method to test for the significance of these differences and report sensitivity and specificity with 95% confidence intervals.

Results

We collected data on 379 cases of acute aortic syndrome and 1340 potential eligible controls; 379 patients were randomly selected from the final population. The RIPP score had a sensitivity of 99.7% (98.54-99.99). This higher sensitivity resulted in a lower specificity (53%) compared to the other clinical decision aids (63-86%). The DeLong comparison of the C statistics found that the RIPP score had a higher C statistic than the ADDRS (-0.0423 (95% confidence interval -0.07-0.02); P < 0.0009) and the AORTAs score (-0.05 (-0.07 to -0.02); P = 0.0002), no difference compared to the Lovy decision tool (0.02 (95% CI -0.01-0.05 P < 0.25)) and decreased compared to the Von Kodolitsch decision tool (0.04 (95% CI 0.01-0.07 P < 0.008)).

Conclusion

The Canadian clinical practice guideline's AAS clinical decision aid is a highly sensitive tool that uses readily available clinical information. It has the potential to improve diagnosis of AAS in the emergency department.

Current practice for primary headache disorders and perspectives on peripheral nerve blocks among emergency physicians in Canada: A national survey

OBJECTIVE

This national postal survey aimed to examine Canadian emergency physicians' practice patterns with respect to drug treatment and perspectives on peripheral nerve blocks.

BACKGROUND

The treatment of primary headache disorders in the emergency department is variable.

METHODS

We surveyed 500 emergency physicians listed in the Canadian Medical Directory according to a modified Dillman's method: an initial invitation was followed by up to four reminders to nonresponders. Physicians were asked questions regarding their frequency of medication administration and perspectives toward peripheral nerve blocks.

RESULTS

Of 500 mailed surveys, 468 were delivered and 179 physicians responded (response rate = 38.2%). The majority of physicians were men (92/144, 63.9%); 80.6% (116/144) had been in practice for greater than or equal to 10 years with 50.7% (75/148) in a community or district general teaching hospital. Commonly used pharmacotherapies for primary headaches were intravenous dopamine receptor antagonists (69%), co-administration of ketorolac and a dopamine receptor antagonist (54.2%), intravenous fluid boluses (54%), nonsteroidal anti-inflammatory drugs (NSAIDs) alone (53.5%), and acetaminophen (51.4%). Only 80 of 144 physicians (55.6%) reported previous experience with peripheral nerve blocks (95% confidence interval [CI] = 48%-65%). The majority (68/80, 85.0%) agreed peripheral nerve blocks are safe and 55.1% (43/78) agreed they are effective. The vast majority (118/140, 84.3%) would consider peripheral nerve blocks as a first-line treatment option given sufficient evidence from a future trial (95% CI = 78%-90%).

CONCLUSION

NSAIDs alone, as well as dopamine receptor antagonists with or without ketorolac are commonly used for primary headache in Canadian emergency departments. A large proportion of physicians have never used a peripheral nerve block in their practice; among those who have experience with peripheral nerve blocks, the majority find them safe and effective. The majority of respondents would consider peripheral nerve blocks as a first-line treatment option given sufficient evidence from a future trial.