Accuracy of a diagnostic strategy combining aortic dissection detection risk score and D-dimer levels in patients with suspected acute aortic syndrome

Acute Aortic Dissection: Observational Lessons Learned From 11 000 Patients

BACKGROUND

Over the past 25 years, diagnosis and therapy for acute aortic dissection (AAD) have evolved. We aimed to study the effects of these iterative changes in care.

METHODS

Patients with nontraumatic AAD enrolled in the International Registry of Acute Aortic Dissection (61 centers; 15 countries) were divided into time-based tertiles (groups) from 1996 to 2022. The impact of changes in diagnostics, therapeutic care, and in-hospital and 3-year mortality was assessed. Cochran-Armitage trend and Jonckheere-Terpstra tests were conducted to test for any temporal trend.

RESULTS

Each group consisted of 3785 patients (mean age, ≈62 years old; ≈65.5% males); nearly two-thirds had type A AAD. Over time, the rates of hypertension increased from 77.8% to 80.4% (P=0.002), while smoking (34.1% to 30.6%, P=0.033) and atherosclerosis decreased (25.6%-16.6%; P<0.001). Across groups, the percentage of surgical repair of type A AAD increased from 89.1% to 92.5% (P<0.001) and was associated with decreased hospital mortality (from 24.1% in group 1 to 16.7% in group 3; P<0.001). There was no difference in 3-year survival (P=0.296). For type B AAD, stent graft therapy (thoracic endovascular aortic repair) was used more frequently (22.3%-35.9%; P<0.001), with a corresponding decrease in open surgery. Endovascular in-hospital mortality decreased from 9.9% to 6.2% (P=0.003). As seen with the type A AAD cohort, overall 3-year mortality for patients with type B AAD was consistent over time (P=0.084).

CONCLUSIONS

Over 25 years, substantial improvements in-hospital survival were associated with a more aggressive surgical approach for patients with type A AAD. Open surgery has been partially supplanted by thoracic endovascular aortic repair for complicated type B AAD, and in-hospital mortality has decreased over the time period studied. Postdischarge survival for up to 3 years was similar over time.

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%).

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.

Acute Aortic Syndromes from Diagnosis to Treatment-A Comprehensive Review

This work aims to provide a comprehensive description of the characteristics of a group of acute aortic diseases that are all potentially life-threatening and are collectively referred to as acute aortic syndromes (AASs). There have been recent developments in the care and diagnostic plan for AAS. A substantial clinical index of suspicion is required to identify AASs before irreversible fatal consequences arise because of their indefinite symptoms and physical indicators. A methodical approach to the diagnosis of AAS is addressed. Timely and suitable therapy should be started immediately after diagnosis. Improving clinical outcomes requires centralising patients with AAS in high-volume centres with high-volume surgeons. Consequently, the management of these patients benefits from the increased use of aortic centres, multidisciplinary teams and an "aorta code". Each acute aortic entity requires a different patient treatment strategy; these are outlined below. Finally, numerous preventive strategies for AAS are discussed. The keys to good results are early diagnosis, understanding the natural history of these disorders and, where necessary, prompt surgical intervention. It is important to keep in mind that chest pain does not necessarily correspond with coronary heart disease and to be alert to the possible existence of aortic diseases because once antiplatelet drugs are administered, a blocked coagulation system can complicate aortic surgery and affect prognosis. The management of AAS in "aortic centres" improves long-term outcomes and decreases mortality rates.

Biomarkers in aortic dissection: Diagnostic and prognostic value from clinical research

ABSTRACT

Aortic dissection is a life-threatening condition for which diagnosis mainly relies on imaging examinations, while reliable biomarkers to detect or monitor are still under investigation. Recent advances in technologies provide an unprecedented opportunity to yield the identification of clinically valuable biomarkers, including proteins, ribonucleic acids (RNAs), and deoxyribonucleic acids (DNAs), for early detection of pathological changes in susceptible patients, rapid diagnosis at the bedside after onset, and a superior therapeutic regimen primarily within the concept of personalized and tailored endovascular therapy for aortic dissection.

The sonographic protocol for the emergent evaluation of aortic dissections (SPEED protocol): A multicenter, prospective, observational study

OBJECTIVES

An aortic dissection (AoD) is a potentially life-threatening emergency with mortality rates exceeding 50%. While computed tomography angiography remains the diagnostic standard, patients may be too unstable to leave the emergency department. Investigators developed a point-of-care ultrasound (POCUS) protocol combining transthoracic echocardiography (TTE) and the abdominal aorta. The study objective was to determine the test characteristics of this protocol.

METHODS

This was an institutional review board-approved, multicenter, prospective, observational, cohort study of a convenience sample of adult patients. Patients suspected of having an AoD received a TTE and abdominal aorta POCUS. Three sonographic signs suggested AoD: a pericardial effusion, an intimal flap, or an aortic outflow track diameter measuring more than 35 mm. Investigators present continuous and categorical data as medians with interquartile ranges or proportions with 95% confidence intervals (CIs) and utilized standard 2 × 2 tables on MedCalc (Version 19.1.6) to calculate test characteristics with 95% CI.

RESULTS

Investigators performed 1314 POCUS examinations, diagnosing 21 Stanford type A and 23 Stanford type B AoD. Forty-one of the 44 cases had at least one of the aforementioned sonographic findings. The protocol has a sensitivity of 93.2% (95% CI 81.3-98.6), specificity of 90.9 (95% CI 89.2-92.5), positive and negative predictive values of 26.3% (95% CI 19.6-33.9) and 99.7% (95% CI 99.2-100), respectively, and an accuracy of 91% (95% CI 89.3-92.5).

CONCLUSIONS

The SPEED protocol has an overall sensitivity of 93.2% for AoD.

A Novel Tool for Distinguishing Type A Acute Aortic Syndrome from Heart Failure and Acute Coronary Syndrome

Type A acute aortic syndrome (urgent AAS, UAAS) has a low incidence and high mortality rate; however, it is often missed or diagnosed late. Our aim was to create a new tool for distinguishing UAAS by using multiple modalities to select patients for CT aortography. This study included 75 patients with UAAS, 77 with acute coronary syndrome (ACS), and 81 with heart failure (HF) who received urgent treatment after propensity matching. Specific symptoms, past medical history, mediastinal width, region of interest (ROI) ratio in the lung base/apex, D-dimers, and troponin I were investigated to differentiate UAAS from ACS and HF. The most significant variables were selected to create a new scoring system. The UAAS score exhibited a performance AUC of 0.982. A simple UAAS score >1, excluding ROI ratios in lung base/apex, showed an AUC of 0.977, a sensitivity of 96%, and specificity of 92.41%. The results were validated using an external data set of 292 patients (simple UAAS score > 1: AUC of 0.966, sensitivity 93.33%, and specificity 95.36%). The simple UAAS score may be a valuable tool for suspecting UAAS and may reduce the likelihood of misdiagnosis or performing unnecessary CT aortography.

Diagnostic biomarkers and aortic dissection: a systematic review and meta-analysis

BACKGROUND

Aortic dissection (AD) is a serious and fatal vascular disease. The earlier the condition of AD patients can be assessed precisely, the more scientifically controlled the patient's condition will be. Therefore, timely and accurate diagnosis is significant for AD. Blood biomarker testing as a method of liquid biopsy can improve the diagnostic efficiency of AD. This study conducted a systematic review of the current blood diagnostic biomarkers of AD.

METHODS

The PubMed, Cochrane Library, Web of Science, and Embase electronic databases were systematically searched from inception to January 1, 2023, using the terms "aortic dissection", "serum", "plasma" and "diagnosis". Stata 12.0 software was used to perform Random effects meta-analysis was performed using Stata 12.0 software to determine the effect sizes and corresponding 95% confidence intervals. Then, a summary receiver operator characteristic (SROC) curve was drawn, and the area under the ROC curve (AUC) was calculated.

RESULTS

D-dimer had the best sensitivity and AUC for AD, with values of 0.96 (95% CI: 0.93-0.98) and 0.95 (95% CI: 0.93-0.97), respectively. The sensitivity and AUC values for D-dimer with a cut-off value of 500 ng/mL were 0.97 (95% CI: 0.95-0.99) and 0.94 (95% CI: 0.92-0.96), respectively. In contrast, microRNA had a better specificity value for AD, at 0.79 (95% CI: 0.73-0.83).

CONCLUSIONS

D-dimer and microRNA have good accuracy in the diagnosis of AD, but the specificity of D-dimer is worse, and studies of microRNA are insufficient. The combination of different biomarkers can improve the diagnostic accuracy. Other blood biomarkers are related to the pathological progression of AD and can be selected according to pathological progress.

Predicting acute aortic syndrome using aortic dissection detection risk score, D-dimer, and X-ray

Objective

Acute aortic syndrome (AAS) is a fatal disease with high mortality. There were previous studies using aortic dissection detection risk score (ADD-RS) and D-dimer (DD) to screen AAS. There were screening failures in previous studies, suggesting the need for a more accurate tool. This study investigated the effect of combining ADD-RS and age adjusted D-dimer (DDage-adj) with abnormal findings on chest radiographs on the diagnosis of AAS in patients admitted to emergency department (ED).

Methods

This single-center retrospective case-control study included 93 patients with AAS and 465 with chest pain (CP), diagnosis other than AAS. We attempted to compare the initial clinical presentation and laboratory examination findings.

Results

Age-adjusted DD (DDage-adj), defined as age x 0.01 mg/L in patients ≥50 years, showed sensitivity of 92.5% and specificity of 76.3% for patients with AAS (p < 0.001). Positive chest radiography findings were significant with AAS group; sensitivity was 89.2% with a specificity of 80.9% (p < 0.001). Multivariate logistic regression analysis was used; widened mediastinum, widening of aortic contour and aortic kinking indicates the probability of AAS in patients with CP (p < 0.05).ADD-RS was used to evaluate the risk of AAS. For low risk group, ADD-RS ≤1, combined use of chest radiography and DDage-adj showed meaningful result. Sensitivity and specificity were 100% and 67.1% with failure rate of 0% (p < 0.001). Multivariate logistic regression analysis were made; widening of the mediastinum (p = 0.035), widening of the aortic contour (p < 0.001) and aortic kinking (p < 0.001) showed significant p-value. Combining DDage-adj and these three chest radiography findings in ADD-RS≤1 patients resulted 0% failure rate with 67.8% specificity (p < 0.001).

Conclusions

The combination of ADD-RS, DDage-adj and chest radiography could lower the failure rate of AAS exclusion strategy. This combination strategy satisfies low failure rate (<3%) and yields relatively high specificity of 67.8%.

Aortic Dissection Detection Risk Score and D-Dimer for Acute Aortic Syndromes in the Chinese Population: Exploration of Optimal Thresholds and Integrated Diagnostic Value

This study aimed to assess the diagnostic performance of the aortic dissection detection risk score (ADD-RS) plus D-dimer for acute aortic syndrome (AAS) in Chinese patients. Two hundred and sixty-two and 200 patients with suspected AAS symptoms were enrolled as exploration cohort and validation cohort, respectively. In exploration cohort, ADD-RS plus D-dimer (AUC = 0.929, 95%CI: 0.887-0.971) presented a better diagnostic value for AAS than ADD-RS or D-dimer alone. Meanwhile, ADD-RS > 1 and D-dimer > 2000 ng/mL were the optimal thresholds. Then, a diagnostic model integrating ADD-RS > 1 plus D-dimer > 2000 ng/mL was established, presenting sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 92.5%, 70.3%, 34.9%, and 98.2%, respectively. In validation cohort, the established diagnostic model exhibited a sensitivity, specificity, PPV, and NPV of 93.1%, 70.2%, 34.6%, and 98.4%, respectively, for diagnosing AAS. Summarily, ADD-RS > 1 and D-dimer > 2000 ng/mL are optimal thresholds for diagnosing AAS in the Chinese population. However, confirmative MSCT results are necessary.

Comparisons of potential values of D-dimer and the neutrophil- to-lymphocyte ratio in patients with suspected acute aortic syndrome

OBJECTIVES

This study aimed to investigate and compare the discriminative performance and clinical utility of D-dimer and the neutrophil-to-lymphocyte ratio (NLR) in the early differential diagnosis of acute aortic syndrome (AAS).

METHODS

The consecutive patients presenting to Tianjin Chest Hospital for suspected AAS were retrospectively investigated between June 2018 and December 2021. The baseline values of D-dimer and NLR were analyzed and compared in the study population. The discriminative ability of D-dimer and NLR was illustrated and compared using the area under the receiver operating characteristic (ROC) curve (AUC), net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Clinical utility was evaluated by means of decision curve analysis (DCA).

RESULTS

In the study period, a total of 697 participants suspected of having AAS were enrolled and 323 had a final diagnosis of AAS. The baseline level of NLR as well as D-dimer was higher in patients with AAS. The use of NLR showed excellent overall diagnostic performance for AAS with a comparable AUC to that of D-dimer (0.845 vs. 0.822, P > 0.05). The reclassification analyses further confirmed that NLR had better discriminative properties for AAS with a significant NRI of 66.1% and IDI of 12.4% (P < 0.001). Moreover, NLR provided higher net benefit than D-dimer as shown by DCA. Similar results were observed in subgroup analyses according to the different classes of AAS.

CONCLUSIONS

NLR outperformed D-dimer with improved discriminative performance and superior clinical utility in identifying AAS. As a more readily available biomarker, NLR may be a reliable alternative to D-dimer for the screening of suspected AAS in clinical practice.

D-dimer measurement is useful irrespective of time from the onset of acute aortic syndrome symptoms

BACKGROUND

In acute aortic syndrome (AAS) screening, D-dimer is a well-established biomarker whose usefulness has been scarcely studied with respect to its measurement timing. We aimed to evaluate the effectiveness of D-dimer-based AAS screening focused on the time interval between AAS onset and D-dimer measurement.

METHODS

We retrospectively analyzed consecutive patients diagnosed with AAS who visited our hospital between 2011 and 2021. For the primary analysis, we divided patients according to the quartiles of the time interval between AAS symptom onset and D-dimer measurement. D-dimer level ≥ 0.5 μg/mL and age-adjusted D-dimer ≥ [age (years) × 0.01] μg/mL (minimum of 0.5 μg/mL) were defined as positive. The primary endpoint was the comparative ability of D-dimer to detect AAS within and between each time quartile. In an exploratory secondary analysis, we reported patient and AAS characteristics in the subgroup of patients who underwent repeat D-dimer measurement within 48 h of the first D-dimer measure.

RESULTS

The 273 AAS patients were divided into four groups based on quartiles of the time interval (Group 1, ≤1 h; Group 2, 1-2 h; Group 3, 2-5 h; and Group 4, >5 h). There were no significant differences in D-dimer levels or in the proportions with positive D-dimer (Group 1: 97%, Group 2: 96%, Group 3: 99%, Group 4: 99%; P = 0.76) or positive age-adjusted D-dimer (Group 1: 96%, Group 2: 90%, Group 3: 96%, Group 4: 97%; P = 0.32) between the groups. Of the 147 patients who had D-dimer re-measured, nine had negative D-dimer levels on either the primary or secondary measurement. Of these nine patients, eight had AAS with a thrombosed false lumen and one with a patent false lumen had a short length of dissection. In all nine patients, D-dimer levels remained low (maximum of 1.4 μg/mL).

CONCLUSION

D-dimer levels were elevated from the early stages of AAS. The clinical utility of D-dimer is not affected by the time interval from AAS onset to D-dimer measurement, but rather is influenced by AAS characteristics.

Routine Use of a Pocket-Sized Handheld Echoscopic Device Plus a Biomarker by Emergency Medicine Residents with an Early Screening Algorithm for Suspected Type A Acute Aortic Syndrome

(1) Background: The early screening strategy for type A acute aortic syndrome (A-AAS) patients has always been challenging. (2) Methods: From September 2020-31 March 2022, 179 consecutive patients with suspected A-AAS were retrospectively reviewed. We assessed the diagnostic value of the use of handheld echocardiographic devices (PHHEs) by emergency medicine (EM) residents either alone or in combination with serum acidic calponin in this patient group. (3) Results: The direct sign of PHHE had a specificity (SP) of 97.7%. The sign of ascending aortic dilatation showed SE = 77.6%, SP = 68.5%, PPV = 48.1% and NPV = 89%. SE, SP, PPV and NPV of a positive PHHE direct sign were 55.6%, 100%, 100% and 71.4% in 19 hypotension/shock patients with suspected A-AAS, respectively. The area under curve (AUC) of acidic calponin combined with an ascending aorta diameter >40 mm was 0.927, with an SE and SP of 83.7% and 89.2%, respectively. These two combined indicators significantly improved the diagnostic efficiency of A-AAS compared with either of them alone (p = 0.017; standard error 0.016, Z value 2.39; p = 0.001, standard error 0.028, Z value 3.29). (4) Conclusion: EM resident-performed PHHE was highly indicative of A-AAS in patients presenting with shock or hypotension. An ascending aorta diameter > 40 mm combined with acidic calponin demonstrated acceptable diagnostic accuracy as a rapid first-line triage tool to identify patients with suspected A-AAS.

Development and validation of nomogram models to discriminate between acute aortic syndromes and non-ST-elevation myocardial infarction during troponin-blind period

Background

Blood-test-based methods of distinguishing between acute aortic syndromes (AASs) and non-ST-elevation myocardial infarction (NSTEMI) during the troponin-blind period of <2-3 h of symptom onset have not been studied previously. We aimed to explore whether routine biomarkers might facilitate differential diagnosis.

Methods

Data were retrospectively collected from 178 patients with AASs and 460 patients with NSTEMI within 3 h of onset. Differential risk factors related to AASs were identified by univariate and multivariate logistic regression analyses for patients with onset <2 h and onset ≥2 h, respectively, in the cardiac troponin (cTn) cohort. Nomograms were established in the cTn cohort as a training set and validated in the high-sensitivity cTn cohort. To assess the utility of the models in clinical practice, decision curve analyses were performed.

Results

D-dimer, fibrinogen, and age were identified as differential risk factors for AASs with the onset of <2 h. D-dimer at an optimal cutoff level of 281 ng/mL for AASs had a sensitivity of 86.4% and a specificity of 91.3%. A nomogram was developed and validated with areas under the curve (AUC) of 0.934 (95% CI: 0.880-0.988) and 0.952 (95% CI: 0.874-1.000), respectively. D-dimer, neutrophil, bilirubin, and platelet were the differential risk factors for AASs with the onset of ≥2 h. D-dimer at an optimal cutoff level of 385 ng/mL has a sensitivity of 91.8% and a specificity of 91.3%. The AUC of the second nomogram in the training set and the validation set were 0.965 (95% CI: 0.942-0.988) and 0.974 (95% CI: 0.944-1.000), respectively.

Conclusion

Time-dependent quality of D-dimer should be considered for discriminating AASs from NSTEMI. Both nomogram models may have a clinical utility for evaluating the probability of AASs.

Type A Aortic Dissection With Intramural Hematoma: A Challenging Diagnosis

Intramural hematoma (IMH) is considered a part of acute aortic syndromes (AAS), a group of life-threatening aortic diseases with a similar presentation that appears to have different clinical manifestations and pathological and survival characteristics. AAS comprises three major entities, namely, aortic dissection (AD), IMH, and PAU. IMH-like classic AD is classified using Stanford and DeBakey classification systems to indicate the aortic area involved. Early diagnosis and treatment of AAS are crucial for survival; however, diagnosis of IMH may be delayed and challenging due to atypical presentation, investigation findings, and case progression. In this report, we describe a case of delayed and challenging diagnosis of a Stanford type A IMH that was managed surgically with a good outcome.

A Retrospective Analysis of Serum D-Dimer Levels for the Exclusion of Acute Aortic Dissection

Purpose

Acute aortic dissection (AAD) is a highly fatal disorder if not promptly diagnosed. Some international studies have suggested that serum d-dimer levels may be used to exclude AAD, but data are limited. We sought to confirm that d-dimer levels are elevated in American patients with AAD. Additionally, we sought to estimate the test characteristics of the d-dimer for AAD.

Patients and Methods

We performed a retrospective analysis of patients in the Hospital Corporation of America database who arrived at the hospital between 2015 and 2019. We queried the database to find patients who had a diagnosis of AAD or (nonspecific) chest pain, and who also had a d-dimer performed within 24 hours of arrival at the hospital. The median d-dimer was compared in those diagnosed with AAD versus chest pain. We estimated the test characteristics of d-dimer for AAD at the standard cutoff value of 500 ng/mL.

Results

In total, 48,902 patients met the criteria for analysis, including 572 with AAD and 48,330 with chest pain. The median d-dimers were 2455 ng/mL and 385 ng/mL for the AAD and chest pain groups, respectively (p < 0.0001). Using a cutoff of 500 ng/mL, the sensitivity of the d-dimer was 91.1% and the specificity was 71.4%.

Conclusion

Serum d-dimer values are higher in patients with AAD than in those with nonspecific chest pain. At the standard cutoff of 500 ng/mL, the serum d-dimer has a high sensitivity for AAD, but not high enough that d-dimer levels alone can be used in isolation to exclude AAD.

Age-Adjusted D-Dimer in Ruling Out Acute Aortic Syndrome

Background. Recently, D-dimer has been suggested as a biomarker to rule out acute aortic syndrome (AAS). Since it increases with age, this study was conducted to reveal whether an age-adjusted D-dimer can increase diagnostic accuracy in ruling out AAS. Method. A retrospective observational study design was used. Consecutive adult patients who visited an emergency room between January 2015 and September 2020 and who underwent a D-dimer test and computed tomography angiography for suspected AAS were enrolled. We calculated the diagnostic accuracy of both the conventional (0.5 μg/ml) and age-adjusted (age × 0.01 in patients >50 years) D-dimer cut-offs. Result. D-dimer was higher in the AAS group (n = 82) than in the non-AAS group (n = 122) (10.85 (3.61–33.12) vs. 0.40 (0.23–1.07), OR: 1.139 (CI: 1.085 – 1.195), $p<0.001$ ). The D-dimer plasma level had an area under the ROC curve of 0.915 (CI: 0.873–0.956) with AAS. At the age-adjusted cutoff point compared to a 0.5 μg/ml cutoff, the sensitivity of 97.6% and the NLR of 0.04 did not change, but the specificity increased by 5.7% to 65.6%, the PPV increased by 3.6% to 65.6%, and the NPV slightly increased by 0.2% to 97.6%. Conclusion. Compared with a conventional method, the age-adjusted D-dimer cutoff may have higher specificity and PPV while maintaining high sensitivity for ruling out AAS.

Acute aortic syndromes: a review of what we know and future considerations

Acute aortic syndromes represent a spectrum of life-threatening aortic pathologies. Prompt diagnosis and proper management of these syndromes are important in reducing overall mortality and morbidity, which remains high. Acute aortic dissections represent most of these aortic wall pathologies, but intramural haematomas and penetrating atherosclerotic ulcers have been increasingly diagnosed. Type A dissections require prompt surgical treatment, with endovascular options on the horizon. Type B dissections can be complicated or uncomplicated, and treatment is determined based on this designation. Complicated Type B dissections require prompt repair with thoracic endovascular aortic repair (TEVAR) becoming the preferred method. Uncomplicated Type B dissections require medical management, but early TEVAR in the subacute setting is becoming more prominent. Proper surveillance for an uncomplicated Type B dissection is crucial in detecting aortic degeneration and need for intervention. Intramural haematomas and penetrating atherosclerotic ulcers are managed similarly to aortic dissections, but more research is needed to determine the proper management algorithms. Multi-disciplinary aortic programmes have been shown to improve patient outcomes and are necessary in optimizing long-term follow-up.

Potential of unenhanced computed tomography as a screening tool for acute aortic syndromes

AIMS

Contrast-enhanced computed tomography (CE-CT) is the gold standard for diagnosing acute aortic syndromes (AAS). Unenhanced computed tomography (unenhanced-CT) also provides specific findings for AAS; however, its diagnostic ability is not well discussed. This study aims to evaluate the potential of unenhanced-CT as an AAS screening tool.

METHODS AND RESULTS

We retrospectively examined AAS patients who visited our hospital between 2011 and 2021 to validate the diagnostic value of unenhanced-CT alone and along with the aortic dissection detection risk score (ADD-RS) plus D-dimer. Acute aortic syndrome was assessed as detectable using unenhanced-CT with any of the following findings: pericardial haemorrhage, high-attenuation haematoma, and displacement of intimal calcification or a flap. Of the 316 AAS cases, 292 (92%) were detectable with unenhanced-CT. Twenty-four (8%) cases undetectable with unenhanced-CT involved younger patients [median (interquartile range), 45 (42-51) years vs. 72 (63-80) years, P < 0.001] and patients more frequently complicated with a patent false lumen (79% vs. 42%, P < 0.001). Acute aortic syndrome-detection rate with unenhanced-CT increased with age, reaching 98% (276/282) in those ≥50 years of age and 100% (121/121) in those ≥75 years of age. With the ADD-RS plus D-dimer, there was only one AAS case undetectable with unenhanced-CT among patients ≥50 years of age, except for cases with the ADD-RS ≥1 plus D-dimer levels of ≥0.5 μg/mL.

CONCLUSION

Acute aortic syndromes in younger patients and patients with a patent false lumen could be misdiagnosed with unenhanced-CT alone. The combination of the ADD-RS plus D-dimer and unenhanced-CT could minimize AAS misdiagnosis while avoiding over-testing with CE-CT.

Initiating a New Era of Cardiovascular Diagnosis and Therapy in Acute Aortic Syndromes: The Mainz-Essen Experience (Part I)-Imaging and Biomarkers

Acute aortic syndromes (AAS) encompass a group of life-threatening medical conditions (acute aortic dissection [AAD], intramural hematoma, and penetrating aortic ulcer) with a common pathophysiological pathway. Due to overlapping symptoms and signs with other cardiovascular emergencies, the diagnosis remains challenging resulting in time delays and related increased in-hospital and long-term morbidity and mortality. The Cardiovascular Department of Johannes Gutenberg University in Mainz at West-German Heart Centre in Essen (Germany) first described (in 1984) AAD by transesophageal echocardiography, AAD diagnostic features, and furtherly explored the implementation of "invasive" imaging techniques, namely, intravascular ultrasound and intraluminal phased-array imaging. Furthermore, pioneer studies were undertaken on the biomarker and imaging interplay, namely, D-dimer and F-fluorodeoxyglucose positron emission tomography/computed tomography. We discuss the unique 35-year-long Mainz-Essen experience on the diagnostic and prognostic role of serological and imaging biomarkers in AAS.

Systematic Review of Aortic Dissection Detection Risk Score Plus D-dimer for Diagnostic Rule-out Of Suspected Acute Aortic Syndromes

OBJECTIVES

In patients at low clinical probability of acute aortic syndromes (AASs), decision on advanced aortic imaging is cumbersome. Integration of the aortic dissection detection risk score (ADD-RS) with D-dimer (DD) provides a potential pipeline for standardized diagnostic rule-out. We systematically reviewed and summarized supporting data.

METHODS

Cross-sectional studies assessing integration of ADD-RS with DD for diagnosis of AASs were identified on MEDLINE, EMBASE and Web Of Science databases. Two reviewers independently screened articles, assessed quality, and extracted data. The quality of design and reporting was evaluated with the QUADAS-2 and STARD tools. Individual patient data were obtained, to allow analysis of both conventional (500 ng/mL) and age-adjusted (DD_age-adj ) DD cutoffs. Data were summarized for four diagnostic strategies combining ADD-RS = 0 or ≤ 1, with DD < 500 ng/mL or < DD_age-adj . The statistical heterogeneity of the diagnostic variables was estimated with Higgins' I² . Pooled values were calculated for variables showing nonsignificant heterogeneity.

RESULTS

After screening of 680 studies, four articles (including a total of 3,804 patients) met inclusion criteria. One prospective study provided a low risk of bias/applicability concerns, while methodologic limitations were found in the other three retrospective studies. Statistical heterogeneity was negligible for sensitivity and negative likelihood ratio (LR) values and significant for specificity and positive LR values of all diagnostic strategies. Pooled sensitivity was 99.9% (95% confidence interval [CI] = 99.3% to 100%, I²  = 0) for ADD-RS = 0 and DD < 500 ng/mL or < DD_age-adj , 98.9% (95% CI = 97.9% to 99.9%, I²  = 0) for ADD-RS ≤ 1 and DD < 500 ng/mL, and 97.6% (95% CI = 96.3% to 98.9%, I²  = 0) for ADD-RS ≤ 1 and DD < DD_age-adj .

CONCLUSIONS

Despite methodologic limitations, integration of ADD-RS = 0 or ≤ 1 with DD < 500 ng/mL shows negligible heterogeneity and consistently high sensitivity across studies, thus supporting reliability for diagnostic rule-out of AASs. Data supporting ADD-RS = 0 plus DD_age-adj appear preliminary and require further scrutiny.

Acute type A aortic dissection: Aortic Dissection Detection Risk Score in emergency care – surgical delay because of initial misdiagnosis

Background:

Acute type A aortic dissection requires immediate surgical treatment, but the correct diagnosis is often delayed. This study aimed to analyse how initial misdiagnosis affected the time intervals before surgical treatment, symptoms associated with correct or incorrect initial diagnosis and the potential of the Aortic Dissection Detection Risk Score to improve the sensitivity of initial diagnosis.

Methods:

We conducted a retrospective analysis of 350 patients with acute type A aortic dissection. Patients were divided into two groups: initial misdiagnosis (group 0) and correct initial diagnosis of acute type A aortic dissection (group 1). Symptoms were analysed as predictors for the correct or incorrect initial diagnosis by multivariate analysis. Based on these findings, the Aortic Dissection Detection Risk Score was calculated retrospectively; a result ⩾2 was defined as a positive score.

Results:

The early suspicion of aortic dissection significantly shortened the median time from pain to surgical correction from 8.6 h in patients with an initial misdiagnosis to 5.5 h in patients with the correct initial diagnosis (p&lt;0.001). Of all acute type A aortic dissection patients, 49% had a positive Aortic Dissection Detection Risk Score. Of all initial misdiagnosed patients, 41% had a positive score (⩾2). The presence of lumbar pain (p&lt;0.001), any paresis (p=0.037) and sweating (p=0.042) was more likely to lead to the correct initial diagnosis.

Conclusion:

An early consideration of acute aortic dissection may reduce the delay of surgical care. The suggested Aortic Dissection Detection Risk Score may be a useful tool to improve the preclinical assessment.

Management of acute type B aortic dissection

BACKGROUND

The best management of acute uncomplicated type B aortic dissection is currently a controversial area. Recent advances in endovascular intervention have begun to establish pre-emptive thoracic endovascular aortic repair as a potential strategy. A review about the management for type B aortic dissection has been conducted.

METHODS

A narrative review consisting of 157 original articles, meta-analyses and guidelines was conducted. The findings were synthesized and summarized using 70 articles.

RESULTS

There are clear guidelines directing surgical management of acute complicated type B aortic dissection. However, the best management of acute uncomplicated disease is more ambiguous, which is especially concerning in a condition which is associated with significant morbidity and mortality. Medical management alone is generally favoured. Endovascular intervention is now being considered by some surgeons, but it can be technically difficult, while exposing the patient to potential surgical risks.

CONCLUSIONS

Clinical and anatomical risk factors have been identified to help vascular surgeons make decisions about treatment in acute uncomplicated type B aortic dissection. New endovascular strategies are being developed to reduce surgical risk and address technical challenges. Registry data should be used to support future best management.

Diagnosing Aortic Intramural Hematoma: Current Perspectives

Aortic intramural hematoma (AIH) is an entity within the acute aortic syndrome. Combination of a priori probability, clinical history, laboratory blood test and imaging techniques are the basis for diagnosis of AIH. This review is focused on all aspects related to diagnosis of patients with AIH, from clinical to imaging and analytical.

Characterization and Significance of Monocytes in Acute Stanford Type B Aortic Dissection

Acute aortic dissection (AAD) is one of the most common fatal diseases noted in vascular surgery. Human monocytes circulate in dynamic equilibrium and display a considerable heterogeneity. However, the role of monocytes in AAD remains elusive. In our recent study, we firstly obtained blood samples from 22 patients with Stanford type B AAD and 44 age-, sex-, and comorbidity-matched control subjects. And the monocyte proportions were evaluated by flow cytometry. Results showed that the percentage of total CD14⁺ monocytes in the blood samples of Stanford AAD patients was increased significantly compared with that of normal volunteers (P < 0.0005), and the absolute numbers of CD14^brightCD16⁺ and CD14^brightCD16⁻ monocytes both increased significantly regardless of the percentage of PBMC or CD14⁺ cells, while CD14^dimCD16⁺ monocytes displayed the opposite tendency. However, the percentage of CD14⁺ cells and its three subsets demonstrated no correlation with D-dimer (DD) and C-reactive protein (CRP). Then, blood mononuclear cell (PBMC) samples were collected by Ficoll density gradient centrifugation, followed with CD14⁺ magnetic bead sorting. After the purity of CD14⁺ cells was validated over 90%, AAD-related genes were concentrated in CD14⁺ monocytes. There were no significant differences observed with regard to the mRNA expression levels of MMP1 (P = 0.0946), MMP2 (P = 0.3941), MMP9 (P = 0.2919), IL-6 (P = 0.4223), and IL-10 (P = 0.3375) of the CD14⁺ monocytes in Stanford type B AAD patients compared with those of normal volunteers. The expression levels of IL-17 (P < 0.05) was higher in Stanford type B AAD patients, while the expression levels of TIMP1(P<0.05), TIMP2(P<0.01), TGF-β1 (P < 0.01), SMAD3 (P < 0.01), ACTA2 (P < 0.001), and ADAMTS-1 (P < 0.001) decreased. The data suggested that monocytes might play an important role in the development of Stanford type B AAD. Understanding of the production, differentiation, and function of monocyte subsets might dictate future therapeutic avenues for Stanford type B AAD treatment and can aid the identification of novel biomarkers or potential therapeutic targets for decreasing inflammation in AAD.

Accuracy of aortic dissection detection risk score alone or with D-dimer: A systematic review and meta-analysis

BACKGROUND

To evaluate the diagnostic accuracy and clinical utility of the acute aortic dissection detection risk score (ADD-RS) alone or with D-dimer as a screening test to exclude acute aortic syndrome.

METHODS

We conducted a systematic review and meta-analysis of studies examining the diagnostic accuracy of ADD-RS. We searched MEDLINE, Embase and Cochrane Controlled Register of Trials up to 12 December 2018.

RESULTS

We identified nine studies involving 26,598 patients for ADD-RS alone and 3421 patients with D-dimer. Overall, the methodological quality based on the Quality Assessment of Diagnostic Accuracy Studies 2 was moderate to high. Bivariate meta-analyses showed that the pooled sensitivities were 0.94 (95% confidence interval (CI) 0.90, 0.96) at the threshold of ADD-RS ≥1, 0.46 (95% CI, 0.34, 0.59) at ADD-RS ≥2, 1.00 (95% CI 0.99, 1.00) at ADD-RS ≥1 with D-dimer and 0.99 (95% CI 0.97, 1.00) at ADD-RS ≥2 with D-dimer. For the low prevalence population, failure rate and efficiency were 0.8% and 38.3% at ADD-RS ≥1, 0.03% and 14.5% at ADD-RS ≥1 with D-dimer, and 0.1% and 33.6% at ADD-RS ≥2 with D-dimer, respectively. For the high prevalence population, failure rate and efficiency were 3.8% and 33.3% at ADD-RS ≥1, 0.2% and 12.3% at ADD-RS ≥1 with D-dimer and 0.6% and 28.4% at ADD-RS ≥2 with D-dimer, respectively.

CONCLUSIONS

ADD-RS alone or with D-dimer was a useful screening test with high sensitivity to exclude acute aortic syndrome. However, the optimal threshold of ADD-RS alone or with D-dimer may depend on the clinical setting.

Timely identification of atypical acute aortic dissection in the emergency department:a study from a tertiary hospital

Background/aim

Acute aortic dissection (AAD) is a rare but fatal disease if left untreated. Symptoms are often similar to common conditions; therefore, the diagnostic strategy is important. We aimed to identify the atypical symptoms in a timely manner without putting patients at greater risk for undetected AAD.

Materials and methods

We conducted a retrospective observational study of 59 AAD patients with both atypical and typical symptoms from January 2012 to December 2016. Patients with atypical symptoms continuing more than 30 min underwent a D-dimer test and computed tomography (CT) or computed tomographic angiography (CTA).

Results

Of the 59 AAD patients, 22 were atypical. In the atypical group, the median delay time in our hospital was 3.1 h; average delay time after July 2015 was shorter than average delay time before June 2015 (16.59 ± 24.70 vs. 1.90 ± 0.57 h, P = 0.076).

Conclusions

For patients in the emergency department who are suspected of having AAD, incorporating atypical symptoms with high levels of D-dimer into a triage strategy could improve the efficiency of clinical decision making. Furthermore, essential education directed towards the recognition of the atypical symptoms of AAD for front-line physicians may aid in a timely diagnosis, as compared with the usual assessments in the emergency department.

Acute medical management of aortic dissection

Acute aortic dissection is a life-threatening disease. Current therapeutic guidelines recommend medical therapy with aggressive blood pressure lowering for patients with acute aortic dissection, when they are not indicated for emergency surgery. In particular, patients with aortic dissection without ascending aorta involvement (Stanford type B) are treated medically, unless they have fatal complications. Patients with type B aortic dissection who have critical complications have higher early mortality than that in patients without complications. However, recent advances in thoracic endovascular aortic repair can improve the clinical outcomes in such patients. Accordingly, current guidelines recommend thoracic endovascular aortic repair for patients with complicated type B aortic dissection. However, patients with visceral ischemia still have a poor prognosis, even when they are treated with thoracic endovascular aortic repair; an early diagnosis and intervention is crucial to prevent mortality. Understanding the pathophysiological anatomy that can induce organ malperfusion might be important for an early diagnosis and intervention. This review summarizes the current state of acute medical management in patients with acute aortic dissection, based on current evidence and expert consensus, focusing on patients with type B aortic dissection.

Characteristics and Treatment Outcomes of Acute Type A Aortic Dissection With Elevated D-Dimer Concentration

Background

Clinical characteristics and treatment outcomes of acute type A aortic dissection with D‐dimer elevation have not been clarified.

Methods and Results

D‐dimer was measured preoperatively within 24 hours of symptom onset in 262 patients with acute type A aortic dissection. The median (and interquartile range) admission D‐dimer concentration in our total patient group was 26.7 (8.3–85.9) μg/mL. Median (interquartile range) D‐dimer concentrations were 5.0 (2.6–18.0) μg/mL for complete false lumen thrombosis (n=33), 60.9 (19.4–160.4) μg/mL for partial thrombosis (n=81), 26.5 (10.0–70.6) μg/mL for a patent false lumen (n=131), and 8.7 (3.2–26.9) μg/mL for ulcerlike projection (n=17) (P<0.01). With a D‐dimer concentration of ≤8.3 μg/mL representing the lower quartile, we then investigated predictors of a low D‐dimer level. Multivariate analysis showed dissection limited to the ascending aorta (P<0.01; odds ratio, 9.81) or descending aorta (P<0.01; odds ratio, 7.68), a completely thrombosed false lumen (P<0.01; odds ratio, 4.02), and absence of brain ischemia (P=0.013; odds ratio, 4.74) to be predictors of the lower D‐dimer concentration. Compared with patients with a low D‐dimer concentration (≤8.3 μg/mL, n=66), patients with a D‐dimer concentration >8.3 μg/mL (n=196) had a reduced preoperative platelet count and increased operation time and transfusion volume. In‐hospital mortality was elevated in this group (1.5% versus 11.2%; P=0.031), although 7‐year survival did not differ for hospital survivors (lower versus higher, 93.1% versus 79.1%; P=0.21).

Conclusions

D‐dimer concentrations are strongly influenced by the extent of dissection and false lumen status. Operative risks are increased in patients with a relatively high D‐dimer concentration.

[Aortic diseases : Modern diagnostic and therapeutic strategies]

Aortic diseases include not only the thoracic but also the abdominal part of the aorta. In the etiology cardiovascular risk factors, such as hypertension, smoking and hyperlipoproteinemia play a major role, but more and more genetic diseases with familiar predisposition are being identified. Even large aneurysms remain asymptomatic as long as other organs in the neighborhood are not damaged and no acute aortic event occurs including aortic dissection, intramural hematoma, penetrating aortic ulcer, and traumatic aortic injury. Standardized algorithms allow precise and rapid diagnosis for initiating medicinal therapy or operative and/or endovascular interventions (thoracic/endovascular aortic repair, TEVAR/EVAR) in this emergency situation. Specialized aortic centers are recommended to form localized regional networks.

Values of aortic dissection detection risk score combined with ascending aorta diameter >40 mm for the early identification of type A acute aortic dissection

Background

Type A acute aortic dissection (A-AAD), involving the ascending aorta, is a life-threatening disease. To detect A-AAD early and rapidly in patients with acute chest pain, especially in patients with acute myocardial infarction (AMI) secondary to A-AAD, we investigated values of combined use of the risk score and the ascending aorta diameter >40 mm for the early identification of A-AAD.

Methods

Our study retrospectively encompassed 239 patients with acute chest pain on admission to our hospital between July 2010 and December 2016. The risk score was calculated according to the aortic dissection detection (ADD) risk score system, and the ascending aorta diameter was accurately obtained from the transthoracic echocardiography (TTE).

Results

A risk score ≥1 had an excellent sensitivity of 94.9% and a fair negative predictive value (NPV) of 77.8%, with a poor specificity of 8.7% and a positive predictive value (PPV) of 33.5% for the diagnosis of A-AAD. A risk score ≥2 had an excellent specificity of 91.3% and a fair NPV of 73.1%, whereas it had a lower sensitivity of 30.8% and a PPV of 63.2%. A risk score ≥1, combined with an ascending aorta diameter >40 mm, had a sensitivity, a specificity, a PPV, and an NPV of 84.6%, 87.6%, 76.7%, and 92.2% for the diagnosis of A-AAD, respectively. The combined use of a risk score ≥2 and an ascending aorta diameter >40 mm had an excellent specificity of 98.1% and a PPV of 86.4%, a fair NPV of 72.8%, and a poor sensitivity of 24.4% for the detection of A-AAD. Moreover, the omission diagnostic rate for A-AAD was significantly decreased from 33.3% to 7.4% using a risk score ≥1 combined with an ascending aorta diameter >40 mm in patients with AMI secondary to A-AAD.

Conclusions

The combined use of an ADD risk score ≥1 and an ascending aorta diameter >40 mm was highly indicative of A-AAD in patients presenting with acute chest pain, especially in patients with AMI secondary to A-AAD, which urgently needed computed tomography angiography (CTA) or magnetic resonance imaging (MRI) to confirm the diagnosis of A-AAD.

Biomarkers Investigation for In-Hospital Death in Patients With Stanford Type A Acute Aortic Dissection

This retrospective study aimed to investigate the predictive value of biomarkers for in-hospital mortality of patients with Stanford type A acute aortic dissection (AAD).AAD is a life-threatening disease with an incidence of about 2.6-3.6 cases per 100,000/year.A total of 67 consecutive Stanford type A AAD patients admitted to hospital were divided into a deceased group and survival group. The baseline information of the patients between two groups was systematically compared, followed by examination of the electrocardiograms (ECG). Based on the follow-up during hospitalization, we investigated the simultaneous assessment of indexes like fragmented QRS complex (fQRS), admission systolic blood pressure (SBP), aortic diameter, surgical management, troponin I (TnI), white blood cell (WBC) count, N-terminal pro-brain natriuretic peptide (NT-proBNP), and D-dimer.The levels of TnI and NT-proBNP, WBC counts, and rate of fQRS (+) in patients of the deceased group were significantly higher than those in the survival group. The male sex (hazard ratio, 10.88; P = 0.001), admission SBP (hazard ratio, 0.98; P = 0.012), NT-proBNP (hazard ratio, 1.00; P = 0.001), and WBC count (hazard ratio, 1.10; P = 0.033) were independently related with in-hospital death. As a single marker, WBC count had the highest sensitivity at 84.6% (specificity 65.9%).Admission SBP, NT-proBNP, and WBC count were potential independent risk factors of in-hospital death in Stanford type A AAD patients. WBC count may be a more accurate predictor of type A AAD than either alone.

Diagnostic test accuracy of D-dimer for acute aortic syndrome: systematic review and meta-analysis of 22 studies with 5000 subjects

Diagnostic test accuracy of D-dimer for acute aortic dissection (AAD) has not been evaluated by meta-analysis with the bivariate model methodology. Four databases were electrically searched. We included both case-control and cohort studies that could provide sufficient data concerning both sensitivity and specificity of D-dimer for AAD. Non-English language articles and conference abstract were allowed. Intramural hematoma and penetrating aortic ulcer were regarded as AAD. Based on 22 eligible articles consisting of 1140 AAD subjects and 3860 non-AAD subjects, the diagnostic odds ratio was 28.5 (95% CI 17.6-46.3, I(2) = 17.4%) and the area under curve was 0.946 (95% CI 0.903-0.994). Based on 833 AAD subjects and 1994 non-AAD subjects constituting 12 studies that used the cutoff value of 500 ng/ml, the sensitivity was 0.952 (95% CI 0.901-0.978), the specificity was 0.604 (95% CI 0.485-0.712), positive likelihood ratio was 2.4 (95% CI 1.8-3.3), and negative likelihood ratio was 0.079 (95% CI 0.036-0.172). Sensitivity analysis using data of three high-quality studies almost replicated these results. In conclusion, D-dimer has very good overall accuracy. D-dimer <500 ng/ml largely decreases the possibility of AAD. D-dimer >500 ng/ml moderately increases the possibility of AAD.

Editor's Choice-Biomarkers of acute cardiovascular and pulmonary diseases

Acute cardiothoracic and respiratory diseases frequently remain a challenge to diagnose and differentiate in the emergency setting. The main diseases that manifest with chest pain include ischaemic heart disease, myocarditis, acute pericarditis, aortic dissection/rupture and pulmonary embolism (PE). Diseases that primarily present with dyspnoea include heart failure (HF), acute respiratory distress syndrome (ARDS), pneumonia, asthma exacerbations and chronic obstructive pulmonary disease. Pre-test probabilities of clinical findings play a vital part in diagnostic decisions, and the use of a Bayesian approach to these greatly improves the ability to stratify patients more accurately. However, blood tests (biomarkers) are increasingly used to assist in rapid decision-making in the emergency setting in combination with imaging methods such as chest radiograph, ultrasound and increasingly computed tomography, as well as physiological tests such as the electrocardiogram in addition to physical examination. Specific tests for ischaemic heart disease and myocarditis (cardiac troponins), HF (B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP)), aortic dissection (smooth muscle markers) and PE (D-dimer) have been developed. Surfactant protein-D and interleukin-8 have been developed for ARDS. Additionally, circulating microRNAs have emerged as promising biomarker candidates in cardiovascular disease. With this increasing array of biochemical markers to aid in the diagnosis of chest diseases presenting with chest pain and dyspnoea, we herein review the clinical usefulness of these markers, in particular in differentiating cardiac from pulmonary diseases. A symptom-oriented assessment as necessary for use in the critical setting is described in addition to discussion of individual biomarkers.

Widely Used Types and Clinical Applications of D-Dimer Assay

D-dimers are formed by the breakdown of fibrinogen and fibrin during fibrinolysis. D-dimer analysis is critical for the diagnosis of deep vein thrombosis, pulmonary embolism, and disseminated intravascular coagulation. Modern assays for D-dimer are monoclonal antibody based. The enzyme-linked immunosorbent assay (ELISA) is the reference method for D-dimer analysis in the central clinical laboratory, but is time consuming to perform. Recently, a number of rapid, point-of-care D-dimer assays have been developed for acute care settings that utilize a variety of methodologies. In view of the diversity of D-dimer assays used in central laboratory and point-of-care settings, several caveats must be taken to assure the proper interpretation and clinical application of the results. These include consideration of preanalytical variables and interfering substances, as well as patient drug therapy and underlying disease. D-dimer assays should also be validated in clinical studies, have established cut-off values, and reported according to the reagent manufacturers recommendations.