Diagnostic Accuracy of D-Dimer for Acute Aortic Syndromes: Systematic Review and Meta-Analysis

STUDY OBJECTIVE

Acute aortic syndrome is a life-threatening emergency condition. Previous systematic reviews of D-dimer diagnostic accuracy for acute aortic syndrome have been contradictory and based on limited data, but recently published studies offer potential for a more definitive overview. We aimed to perform a systematic review and meta-analysis to determine the diagnostic accuracy of D-dimer for diagnosing acute aortic syndrome.

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 cohort studies (prospective or retrospective) that assessed the use of D-dimer for diagnosing acute aortic syndrome compared with a reference standard test (eg, computed tomographic angiography (CTA), ECG-gated CTA, echocardiography, magnetic resonance angiography, operation, or autopsy) were included. Two independent reviewers completed study selection, data extractions and quality assessment using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Data were synthesized using a bivariate meta-analysis model.

RESULTS

Of 2017 potentially relevant citations, 25 cohort studies met the inclusion criteria, and 18 reporting the 500 ng/mL threshold were included in the primary meta-analysis. Risk of bias domains were mostly unclear due to limited study reporting. The summary sensitivity was 96.5% (95% credible interval [CrI] 94.8% to 98%) and summary specificity was 56.2% (95% CrI, 48.3% to 63.9%). Study specificity varied markedly from 33% to 86%, indicating substantial heterogeneity. Sensitivity analysis including the 7 studies reporting other thresholds showed summary sensitivity of 95.7% (95% CrI, 93.2% to 97.5%) and summary specificity of 57.5% (95% CrI, 50.1% to 64.6%).

CONCLUSION

D-dimer concentration has high sensitivity (96.5%) and moderate specificity (56.2%) for acute aortic syndrome, with some uncertainty around estimates due to risk of bias and heterogeneity. Previous meta-analysis reporting higher specificity may be explained by inclusion of case-control studies that may overestimate accuracy.

A Monte Carlo Sensitivity Analysis for a Dimensionally Reduced-Order Model of the Aortic Dissection

PURPOSE

Aortic dissection is associated with a high mortality rate. Although computational approaches have shed light on many aspects of the disease, a sensitivity analysis is required to determine the significance of different factors. Because of its complex geometry and high computational expense, the three-dimensional (3D) fluid-structure interaction (FSI) simulation is not a suitable approach for sensitivity analysis.

METHODS

We performed a Monte Carlo simulation (MCS) to investigate the sensitivity of hemodynamic quantities to the lumped parameters of our zero-dimensional (0D) model with numerically calculated lumped parameters. We performed local and global analyses on the effect of the model parameters on important hemodynamic quantities.

RESULTS

The MCS showed that a larger lumped resistance value for the false lumen and the tears result in a higher retrograde flow rate in the false lumen (the coefficient of variation,c v , i = 0.0183 , the sensitivityS X i σ = 0.54 , Spearman's coefficient,ρ s = 0.464 ). For the intraluminal pressure, our results show a significant role in the resistance and inertance of the true lumen (the coefficient of variation,c v , i = 0.0640 , the sensitivityS X i σ = 0.85 , and Spearman's coefficient,ρ s = 0.855 for the inertance of the true lumen).

CONCLUSION

This study highlights the necessity of comparing the results of the local and global sensitivity analyses to understand the significance of multiple lumped parameters. Because of the efficiency of the method, our approach is potentially useful to investigate and analyze medical planning.

Mortality and risk factors associated with misdiagnosis of acute aortic syndrome in Ontario, Canada: a population-based study

INTRODUCTION

Acute aortic syndrome (AAS) is a life-threatening aortic emergency. It describes three diagnoses: acute aortic dissection, acute intramural haematoma and penetrating atherosclerotic ulcer. Unfortunately, there are no accurate estimates of the miss rate for AAS, risk factors for missed diagnosis or its effect on outcomes.

METHODS

A population-based retrospective cohort study of anonymously linked data for residents of Ontario, Canada, was carried out. Incident cases of AAS were identified between 2003 and 2018 using a validated algorithm based on ICD codes and death. Before multivariate modelling, all categorical variables were analysed for an association with missed AAS diagnosis using χ2 tests. These preliminary analyses were unadjusted for clustering or any covariates. Finally, we performed multilevel logistic regression analysis using a generalised linear mixed model approach to model the probability of a missed case occurring.

RESULTS

There were 1299 cases of AAS (age mean (SD) 68.03±14.70, woman 500 (38.5%), rural areas (n=111, 8.55%)) over the study period. Missed cases accounted for 163 (12.5%) of the cohort. Mortality (non-missed AAS 59.7% vs missed AAS 54.6%) and surgical intervention (non-missed AAS 31% vs missed AAS 30.7%) were similar in missed and non-missed cases. However, lower acuity (Canadian triage acuity scale >2 (OR 2.45 95% CI 1.71 to 3.52) (the scale is from 1 to 5, with 1 indicating high acuity) had a higher odds of being a missed case and non-ambulatory presentation (OR 0.47 95% CI 0.33 to 0.67) and presenting to a teaching (OR 0.60 95% CI 0.40 to 0.90)) or cardiac centre (OR 0.41 95% CI 0.27 to 0.62) were associated with a lower odds of being a missed case.

CONCLUSIONS

The high rate of misdiagnosis has remained stable for over a decade. Non-teaching and non-cardiac hospitals had a higher incidence of missed cases. Mortality and rates of surgery were not associated with a missed diagnosis of AAS. Educational interventions should be prioritised in non-teaching hospitals and non-cardiac centres.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

Misdiagnosis of aortic dissection: A systematic review of the literature

BACKGROUND

Aortic dissection is a rare but potentially catastrophic condition. Misdiagnosis of aortic dissection is not uncommon as symptoms can overlap with other diagnoses.

OBJECTIVE

We conducted a systematic review to better understand the factors contributing to incorrect diagnosis of this condition.

METHODS

We searched MEDLINE and EMBASE for studies that evaluated the misdiagnosis of aortic dissection. The rate of misdiagnosis was pooled and results were narratively synthesized.

RESULTS

A total of 12 studies with were included with 1663 patients. The overall rate of misdiagnosis of aortic dissection was 33.8%. The proportion of patients presenting with chest pain, back pain and syncope were 67.5%, 24.8% and 6.8% respectively. The proportion of patients with pre-existing hypertension was 55.4%, 30.5% were smokers while the proportion of patients with coronary artery disease, previous cardiovascular surgery or surgical trauma and Marfan syndrome was 14.7%, 5.8%, and 3.7%, respectively. Factors related to misdiagnosis included the presence of symptoms and features associated with other diseases (such as acute coronary syndrome, stroke and pulmonary embolism), the absence of typical features (such as widened mediastinum on chest X-ray) or concurrent conditions such congestive heart failure. Factors associated with more accurate diagnosis included more comprehensive history taking and increased use of imaging.

CONCLUSIONS

Misdiagnosis in patients with an eventual diagnosis of aortic dissection affects 1 in 3 patients. Clinicians should consider aortic dissection as differential diagnosis in patients with chest pain, back pain and syncope. Imaging should be used early to make the diagnosis when aortic dissection is suspected.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

D-Dimer Tests in the Emergency Department: Current Insights

In the Emergency Medicine setting, D-dimer is currently employed in the diagnostic assessment of suspected venous thromboembolism and aortic syndrome. The nonspecific symptoms reported by patients, like chest pain, dyspnea or syncope, uncover a wide range of differential diagnosis, spanning from mild to life-threatening conditions. Therefore, we assumed the perspective of the Emergency Physician and, in this narrative review, we reported a brief presentation of the epidemiology of these symptoms and the characteristics of patients, in whom we could suspect the aforementioned pathologies. We also reported in which patients D-dimer gives useful information. In fact, when the probability of the disease is high, the D-dimer level is futile. On the contrary, given the low specificity of the test, when the probability of the disease is very low, a false-positive value of the D-dimer only increases the risk of overtesting. Patients with low to moderate probability really benefit from the D-dimer testing, in order to prevent the execution of expensive and potentially dangerous imaging tests. In the second part of the review, we focused on the prognostic value of the test in septic patients. The early prognostic stratification of septic patients remains a challenge for the Emergency Physician, in the absence of a definite biomarker or score to rely on. Therefore, we need several parameters for the early identification of patients at risk of an adverse prognosis and the D-dimer may play a role in this demanding task. SARS COVID-19 patients represent an emerging reality, where the role of the D-dimer for prognostic stratification could be relevant. In fact, in patients with severe forms of this disease, the D-dimer reaches very high values, which appear to parallel the course of respiratory failure. Whether the test may add useful information for the management of these patients remains to be determined.

Does implementation of a diagnostic pathway for acute aortic syndrome including D-dimer increase the usage of D-dimer and computed tomography?

INTRODUCTION

The Canadian clinical practice guidelines propose a novel diagnostic pathway incorporating a clinical decision tool and D-dimer to aid in risk stratifying patients for acute aortic syndrome. The objective of this study was to assess if implementation of a diagnostic pathway incorporating D-dimer would increase the usage of D-dimer and computed tomography (CT) in a tertiary care emergency department.

METHODS

Prospective single centre before and after study-recruiting patients over a 6-week period from a tertiary care emergency department.

INTERVENTION

multi model implementation of a diagnostic pathway for acute aortic syndrome incorporating D-dimer.

OUTCOME

proportion of patients receiving D-dimer testing/CT in the 2 weeks before and after implementation.

RESULTS

We included 982 patients (Female 55%, Age mean 51.9, N = 492 pre intervention and N = 490 post intervention). The proportion that received a D-dimer test increased from 6.9 to 10.4% (p < 0.051), while the number of CT aortas remained stable (0.6% vs. 0.6%; p = 0.60). Documentation of pretest probability assessment increased from 1 to 3%, (p < 0.009) following the intervention. In the post intervention cohort, the tool was applied correctly in all cases (N = 17).

CONCLUSION

This single centre study found that a diagnostic pathway for acute aortic syndrome including D-dimer could be implemented without a significant increase in test ordering during this first 2 weeks after implementation. This study adds to the argument for use of D-dimer to help risk stratify patients for the diagnosis of acute aortic syndrome. Future studies are needed to confirm the diagnostic accuracy of this pathway and the long-term impact on resource utilization.

Characteristics of the Inter-arm Difference in Blood Pressure in Acute Aortic Dissection

BACKGROUND

An inter-arm difference in blood pressure (IADBP) is characteristic of acute aortic dissection (AAD), but which arm shows lower blood pressure (BP) and the mechanism of IADBP has not been fully elucidatedMethods: We identified consecutive patients with chest and/or back pain and suspected acute cardiovascular disease whose BP had been measured in both arms. We retrospectively compared the characteristics of such patients with AAD (n=93) to those without (non-AAD group, n=122). Additionally, we separately compared patients with type A AAD (TAAD group, n=58) or type B AAD (TBAD group, n=35) to non-AAD group. Characteristics included in these comparisons were patients' backgrounds and IADBP-related factors such as systolic BP (SBP) in the right arm (R) and left arm (L), R-L or L-R as the IADBP. Computed tomography (CT) findings of AD extending to the brachiocephalic artery (BCA) and/or left subclavian artery (LSCA) were examined in patients having IADBP.

RESULTS

In the TAAD group, the prevalence of R<130mmHg (38%-vs.-19%, p=0.009), L-R>15mmHg (19%-vs.-8%, p=0.047), L-R>20mmHg (14%-vs.-4%, p=0.029) was higher than in the non-AAD group. Multivariate analysis showed L-R>15mmHg with R<130mmHg was independently associated with TAAD (OR 25.97, 95% CI 2.45-275.67, p=0.007). However, IADBP-related factors were not associated with TBAD. AAD patients with L-R>20mmHg were all TAAD, and all aortic dissection extended to BCA just before the right common carotid artery on CT.

CONCLUSIONS

IADBP was characterized by R<L with low R in TAAD, but was not associated with TBAD.

Examining the Relationships Between Air Pollutants and the Incidence of Acute Aortic Dissection with Electronic Medical Data in a Moderately Polluted Area of Northwest China

This paper explored whether air pollutants influenced acute aortic dissection (AAD) incidence in a moderately polluted area. A total of 494 AAD patients’ data from 2013 to 2016 were analyzed. The results showed that AAD had the strongest associations with PM10, SO2, NO2, CO, and O3 on the day before an AAD incident (lag1) and with PM2.5 two days before an incident (lag2) in single-pollutant model. In the three-pollutant model, PM10 was associated with the highest risk of adverse effects (RR = 1.37, 95% CI: 1.22, 1.53), whereas PM2.5 was associated with the lowest risk (RR = .83, 95% CI: .79, .88). Both PM2.5 and PM10 were affected by season, and SO2 was significantly different between heating and non-heating seasons as well. This study revealed significant associations between short-term PM2.5, PM10, and SO2 exposure and daily AAD incidence, showing that PM10 and SO2 were strong predictors of AAD incidence in a moderately polluted area.

A simple intervention to reduce your chance of missing an acute aortic dissection

INTRODUCTION

Acute aortic dissection (AAD) is a time sensitive, difficult to diagnose, aortic emergency. We sought to explore the quality of history taking in AAD and assess its impact on misdiagnosis.

METHODS

We studied a retrospective cohort of patients >18 years old who presented to two tertiary care emergency departments from January 1st 2004 - December 31st 2012 and were diagnosed with an acute aortic dissection (AAD) on CT, MRI or TEE. Trained reviewers' extracted data using a standardized data collection form. The definitions of 5 pain characteristics - character, onset, duration, quality, and radiation were defined a priori.

RESULTS

Data were collected for 194 cases of acute aortic dissection with a mean age of 65(SD 14.1) and 66.7% male, 34(17.6%) missed on initial presentation. Only 20(14.8%) patients were asked all 5 questions. The most common initial incorrect diagnosis were acute coronary syndrome (16, 47%), pulmonary embolism (5, 14.7%) and stroke (4, 11.7%). If <2 questions were asked 1 in 5 cases were missed, 4 times greater than if >2 were asked (P < 0.01).

CONCLUSION

Clinicians should ask and document the character, onset, duration, radiation and severity of pain in any patient presenting with chest, abdominal or flank pain. A focused history still remains the keystone to reducing misdiagnosis.

Aortic Dissection with Subsequent Hemorrhagic Tamponade Diagnosed with Point-of-care Ultrasound in a Patient Presenting with STEMI

A 58-year-old male with no past medical history presented to the emergency department with sudden onset left lower extremity weakness and central chest pain with radiation to his back. Electrocardiogram revealed an acute inferior and posterior ST-segment elevation myocardial infarction (STEMI). Point-of-care ultrasound (POCUS) demonstrated right ventricular akinesis consistent with infarction, and an intimal defect consistent with an aortic dissection. We determined that cardiothoracic surgery was indicated rather than left-heart catheterization and anticoagulation. Using POCUS we were able to immediately diagnose a dissection of the aortic arch and considerably alter treatment in a patient presenting with STEMI.

Discriminatory Value of the Ascending Aorta Diameter in Suspected Acute Type A Aortic Dissection

OBJECTIVE

The objective was to determine if ascending aorta (AscAo) diameters measured by noncontrast computed tomography (CT) allow for meaningful discrimination between patients with and without type A aortic dissection (TAAD), ideally with 100% sensitivity.

METHODS

This study was a retrospective analysis of cases of TAAD, as well as controls, undergoing evaluation for TAAD with CT aortography, presenting to 21 emergency departments within an integrated health system between 2007 and 2015. AscAo diameters were determined using axial noncontrast CT images at the level of the right main pulmonary artery by two readers. AscAo diameters were additionally normalized for age, sex, and body surface area (assessed by a Z-score, which is the number of standard deviations between the observed and expected AscAo diameters). Overall model discrimination was assessed using the area under the receiver operating characteristic curve (AUC). Comparative discrimination was assessed using both the change in AUC (∆AUC) and the continuous net reclassification index (NRI).

RESULTS

A total of 230 cases of TAAD and 325 controls were included in the study. The median ages for cases and controls were 65 and 62 years, and the median AscAo diameters were 50 and 35 mm, respectively. The raw and normalized AscAo diameters demonstrated similarly excellent discrimination (AUCs of 0.96 vs. 0.97, respectively; ∆AUC = 0.01, p = 0.09) and an NRI of 0.30 (95% confidence interval [CI] = 0.13-0.47), both indicating small incremental improvements in classification with the use of the normalized AscAo measures. A raw AscAo diameter of 34 mm and a normalized Z-score of 1.84 both yielded 100% sensitivity for TAAD, with respective specificities of 35% (95% CI = 29.6%-40.2%) and 67% (95% CI = 61.7%-72.2%).

CONCLUSIONS

Nearly all patients with TAAD appear to have enlarged AscAo diameters as measured by noncontrast CT, whereas most patients with suspected but absent TAAD have relatively normal AscAo diameters. Both raw and normalized AscAo measures provided relatively comparable discriminatory value. If validated, these data may be useful in adjudicating risk among patients with suspected TAAD in whom a criterion standard test is unavailable, nondiagnostic, or contraindicated.

Bilateral blood pressure differential as a clinical marker for acute aortic dissection in the emergency department

INTRODUCTION

Interarm systolic BP differential is a classic sign of acute aortic dissection (AAD). All previous studies looking at the association of BP differential with AAD combine systolic BP differential >20 mm Hg with pulse deficit. Our aim was to assess the association of systolic BP differential with AAD, and its role in predicting AAD in the context of other signs and symptoms.

METHODS

Historical matched case-control study using patient data collected between 2002 and 2014: participants were adults >18 years old with a bilateral BP measurement presenting to two tertiary care EDs or one regional cardiac referral centre in Canada. Cases were patients with diagnosed AAD; controls were those with a triage diagnosis of truncal pain (<14 days) and an absence of a clear diagnosis on basic investigation. Cases and controls were matched in a 1:1 ratio by sex and age. Bilateral BP differential and pulse deficit were compared between groups.

RESULTS

A total of 222 patients (111 cases and 111 controls) were analysed. On univariate analysis systolic BP differential >20 mm Hg (OR 2.7, 95% CI 1.39 to 5.25) was significantly associated with AAD. Pulse deficit (diagnostic OR (DOR) 28.9) in isolation had better diagnostic accuracy than systolic BP differential >20 mm Hg in isolation (DOR 2.71) or combined with systolic BP differential >20 mm Hg (DOR 4.2).

CONCLUSION

Bilateral systolic BP differentials >20 mm Hg are associated with non-traumatic AAD. However, the poor diagnostic accuracy and potential variability in measurement limits its clinical usefulness.