CT analysis of the aorta in giant-cell arteritis: a case-control study

Diagnostic accuracy of serum biomarkers to identify giant cell arteritis in patients with polymyalgia rheumatica

INTRODUCTION

Polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) are frequently overlapping conditions. Unlike in GCA, vascular inflammation is absent in PMR. Therefore, serum biomarkers reflecting vascular remodelling could be used to identify GCA in cases of apparently isolated PMR.

MATERIALS AND METHODS

45 patients with isolated PMR and 29 patients with PMR/GCA overlap were included. Blood samples were collected before starting glucocorticoids for all patients. Serum biomarkers reflecting systemic inflammation (interleukin-6 (IL-6), CXCL9), vascular remodelling (MMP-2, MMP-3, MMP-9) and endothelial function (sCD141, sCD146, ICAM-1, VCAM-1, vWFA2) were measured by Luminex assays.

RESULTS

Patients with GCA had higher serum levels of sCD141 (p=0.002) and CXCL9 (p=0.002) than isolated PMR. By contrast, serum levels of MMP-3 (p=0.01) and IL-6 (p=0.004) were lower in GCA than isolated PMR. The area under the curve (AUC) was calculated for sCD141, CXCL9, IL-6 and MMP-3. Separately, none of them were >0.7, but combinations revealed higher diagnostic accuracy. The CXCL9/IL-6 ratio was significantly increased in patients with GCA (p=0.0001; cut-off >32.8, AUC 0.76), while the MMP-3/sCD141 ratio was significantly lower in patients with GCA (p<0.0001; cut-off <5.3, AUC 0.79). In patients with subclinical GCA, which is the most difficult to diagnose, sCD141 and MMP-3/sCD141 ratio demonstrated high diagnostic accuracy with AUC of 0.81 and 0.77, respectively.

CONCLUSION

Combined serum biomarkers such as CXCL9/IL-6 and MMP-3/sCD141 could help identify GCA in patients with isolated PMR. It could allow to select patients with PMR in whom complementary examinations are needed.

[Aortitis]

Aortitis is a rare disease entity of unknown prevalence. Primary aortitis mainly affects the thoracic aorta. They are most often diagnosed on imaging by grade III 18-FDG uptake of the aortic wall on PET, or by circumferential thickening>2.2mm on CT or MRI with late-stage contrast. More rarely, aortitis is histologically proven, as in some cases of clinically isolated aortitis discovered after planned aortic aneurysm surgery or during aortic dissection surgery. The most common histological types are granulomatous/giant cell or lymphoplasmacytic. Clinical signs associated with aortitis are often non-specific: asthenia, fever, dry cough, chest, back, lumbar or abdominal pain. Aortitis can be divided into different etiological categories: primary aortitis, which includes vasculitis with a preferential or exclusive tropism for the aortic wall, aortitis secondary to systemic or iatrogenic diseases, and infectious aortitis. The main etiologies of primary aortitis are giant cell arteritis (GCA), Takayasu arteritis (TA) or clinically isolated aortitis. Aortitis secondary to systemic diseases is seen in atrophying polychondritis, systemic lupus and inflammatory rheumatic diseases such as spondyloarthropathy and rheumatoid arthritis. In both ACG and AT, aortitis is a negative factor, characterized by a higher risk of relapse, cardiovascular complications and increased mortality. The management of aortitis is insufficiently codified, and relies on the control of cardiovascular risk factors, with particular monitoring of blood pressure and LDL cholesterol, and on corticosteroid therapy and immunosuppressive drugs, the use of which will depend on the disease associated with the aortitis, the initial severity and comorbidities.

Diagnosing vasculitis with ultrasound: findings and pitfalls

Rheumatologists are increasingly utilizing ultrasound for suspected giant cell arteritis (GCA) or Takayasu arteritis (TAK). This enables direct confirmation of a suspected diagnosis within the examination room without further referrals. Rheumatologists can ask additional questions and explain findings to their patients while performing ultrasound, preferably in fast-track clinics to prevent vision loss. Vascular ultrasound for suspected vasculitis was recently integrated into rheumatology training in Germany. New European Alliance of Associations for Rheumatology recommendations prioritize ultrasound as the first imaging tool for suspected GCA and recommend it as an imaging option for suspected TAK alongside magnetic resonance imaging, positron emission tomography and computed tomography. Ultrasound is integral to the new classification criteria for GCA and TAK. Diagnosis is based on consistent clinical and ultrasound findings. Inconclusive cases require histology or additional imaging tests. Robust evidence establishes high sensitivities and specificities for ultrasound. Reliability is good among experts. Ultrasound reveals a characteristic non-compressible 'halo sign' indicating intima-media thickening (IMT) and, in acute disease, artery wall oedema. Ultrasound can further identify stenoses, occlusions and aneurysms, and IMT can be measured. In suspected GCA, ultrasound should include at least the temporal and axillary arteries bilaterally. Nearly all other arteries are accessible except the descending thoracic aorta. TAK mostly involves the common carotid and subclavian arteries. Ultrasound detects subclinical GCA in over 20% of polymyalgia rheumatica (PMR) patients without GCA symptoms. Patients with silent GCA should be treated as GCA because they experience more relapses and require higher glucocorticoid doses than PMR patients without GCA. Scores based on intima-thickness (IMT) of temporal and axillary arteries aid follow-up of GCA, particularly in trials. The IMT decreases more rapidly in temporal than in axillary arteries. Ascending aorta ultrasound helps monitor patients with extracranial GCA for the development of aneurysms. Experienced sonologists can easily identify pitfalls, which will be addressed in this article.

Large vessel giant cell arteritis

Giant cell arteritis is the principal form of systemic vasculitis affecting people over 50. Large-vessel involvement, termed large vessel giant cell arteritis, mainly affects the aorta and its branches, often occurring alongside cranial giant cell arteritis, but large vessel giant cell arteritis without cranial giant cell arteritis can also occur. Patients mostly present with constitutional symptoms, with localising large vessel giant cell arteritis symptoms present in a minority of patients only. Large vessel giant cell arteritis is usually overlooked until clinicians seek to exclude it with imaging by ultrasonography, magnetic resonance angiography (MRA), computed tomography angiography (CTA), or [18F]fluorodeoxyglucose-PET-CT. Although the role of imaging in treatment monitoring remains uncertain, imaging by MRA or CTA is crucial for identifying aortic aneurysm formation during patient follow up. In this Series paper, we define the large vessel subset of giant cell arteritis and summarise its clinical challenges. Furthermore, we identify areas for future research regarding the management of large vessel giant cell arteritis.

Evolution and outcomes of aortic dilations in giant cell arteritis

OBJECTIVES

To identify factors associated with the progression of giant cell arteritis (GCA)-related or associated aortic dilations.

METHODS

In this retrospective study, 47 GCA patients with aortic dilation were longitudinally analyzed. Each patient underwent ≥2 imaging scans of the aorta during the follow-up. Three progression statuses of aortic dilations were distinguished: fast-progressive (FP) defined by a progression of the aortic diameter ≥5 mm/year or ≥1 cm/2 years, slow progressive (SP) by a progression of the aortic diameter >1 mm during the follow-up, and not progressive (NP) when aortic diameter remained stable.

RESULTS

Among the 47 patients with aortic dilation, the thoracic section was involved in 87 % of patients. Within a total follow-up of 89 [6-272] months, we identified 13 (28 %) patients with FP dilations, and 16 (34 %) and 18 (38 %) patients with SP and NP dilations, respectively. No differences regarding baseline characteristics, cardiovascular risk factors or treatments were observed among the 3 groups. However, FP patients more frequently showed atheromatous disease (p = 0.04), with a more frequent use of statins (p = 0.04) and antiplatelet agents (p = 0.02). Among the 27 (57 %) patients with aortitis, aortic dilation developed on an inflammatory segment in 23 (85 %). Among the FP patients who underwent aortic surgery with available histology (n = 3), all presented active vasculitis.

CONCLUSION

This study suggests that aortic inflammation, as well as atheromatous disease, might participate in the fast progression of aortic dilation in GCA.

Presence of subclinical giant cell arteritis in patients with morning stiffness of duration less than 45 minutes at the time of diagnosis of polymyalgia rheumatica

Introduction

In some patients with polymyalgia rheumatica (PMR), giant cell arteritis (GCA) is subclinical as underlying inflammation of large vessels (LV) is present without evidence of related clinical manifestations. Different factors have been proposed as predictive of subclinical GCA in PMR patients. To date, the literature reports scant data about the association between subclinical GCA and long-lasting morning stiffness (MS) in patients at the time of diagnosis of PMR. Given this background, the aim of this study was to assess the association between subclinical GCA and MS < 45 min in patients with newly diagnosed PMR.

Material and methods

We performed an observational, retrospective, single-centre cohort study of patients consecutively referred to our public out-of-hospital rheumatologic clinic between January 2015 and December 2020, who could be classified as having PMR according to the 2012 EULAR/ACR criteria. Subclinical GCA was investigated through ultrasound examination of a core set of arteries (temporal, axillary, common carotid, and subclavian arteries), in accordance with the EULAR recommendations for the use of imaging in LV vasculitis. Patients who did not have GCA symptoms but showed halo sign in at least one of these arteries were described as having subclinical GCA.

Results

We included a total of 143 patients (35 men and 108 women). Their median age was of 71.5 years. Thirty-five had MS duration < 45 min at the time of PMR diagnosis. Subclinical GCA was found in 23 PMR patients (16.1%); 18 had a cranial and 5 an extracranial GCA. A univariate analysis highlighted that MS < 45 min was associated with a lower prevalence of GCA (OR = 0.11, 95% CI: 0.04-0.29; p < 0.0001). This association was retained in a multivariable analysis that accounted for 6 different potential covariates (OR = 0.06, 95% CI: 0.01-0.26; p < 0.0001.

Conclusions

In our study MS < 45 min at the time of PMR diagnosis was associated with a significantly lower risk of subclinical GCA, when patients were screened by ultrasound, of approximately 90%. Identification of a more accurate MS cut-off value could improve the accuracy for subclinical GCA in patients with newly diagnosed PMR.

Prognostic factors in giant cell arteritis associated aortitis with PET/CT and CT angiography at diagnosis

BACKGROUND

Prognosis data on giant-cell arteritis (GCA)-associated aortitis are scarce and heterogeneous. The aim of this study was to compare the relapses of patients with GCA-associated aortitis according to the presence of aortitis on CT-angiography (CTA) and/or on FDG-PET/CT.

METHODS

This multicenter study included GCA patients with aortitis at diagnosis; each case underwent both CTA and FDG-PET/CT at diagnosis. A centralized review of image was performed and identified patients with both CTA and FDG-PET/CT positive for aortitis (Ao-CTA+/PET+); patients with positive FDG-PET/CT but negative CTA for aortitis (Ao-CTA-/PET+), and patients solely positive on CTA.

RESULTS

Eighty-two patients were included with 62 (77%) of female sex. Mean age was 67±8 years; 64 patients (78%) were in the Ao-CTA+/PET+ group; 17 (22%) in the Ao-CTA-/PET+ group and 1 had aortitis only on CTA. Overall, 51 (62%) patients had at least one relapse during follow-up: 45/64 (70%) in the Ao-CTA+/PET+ group and 5/17 (29%) in the Ao-CTA-/PET+ group (log rank, p = 0.019). In multivariate analysis, aortitis on CTA (Hazard Ratio 2.90, p = 0.03) was associated with an increased risk of relapse.

CONCLUSION

Positivity of both CTA and FDG-PET/CT for GCA-related aortitis was associated with an increased risk of relapse. Aortic wall thickening on CTA was a risk factor of relapse compared with isolated aortic wall FDG uptake.

Vascular ultrasound in rheumatology practice

Rheumatologists are increasingly using vascular ultrasound. Several guidelines now recommend ultrasound as the first diagnostic modality in giant cell arteritis (GCA). The German curriculum for rheumatology training has recently included ultrasound for the acute diagnosis of vasculitis. Recent studies have shown that ultrasound of temporal, axillary, subclavian, and vertebral arteries has sensitivities and specificities of >90%. Vascular ultrasound detects subclinical GCA in approximately 20% of patients with "pure" polymyalgia rheumatica. GCA fast-track clinics might regularly include these patients. A new score based on the intima-media thickness of the temporal and axillary arteries allows the monitoring of structural changes with treatment. The score decreases faster for the temporal arteries than it does for the axillary arteries. Measuring the diameter of the ascending aorta and the aortic arch might become a fast and cost-effective tool for the long-term monitoring of aortic aneurysms in extracranial GCA. Vascular ultrasound also has a role for Takayasu arteritis, thrombosis, Behçet's syndrome, and Raynaud's phenomenon.

Updates on the diagnosis and monitoring of giant cell arteritis

This mini-review offers a critical appraisal of the currently employed imaging or histopathological tools to diagnose and monitor giant cell arteritis (GCA). An overview of the most updated evidence and current application of color duplex ultrasonography (US), temporal artery biopsy (TAB), 18-fluorodeoxyglucose [18F] FDG-PET/CT, magnetic resonance imaging, and computed tomography angiography is provided. The main limitations of each tool, and the most relevant research developments are discussed. The review highlights the complementary value of the available modalities to ensure a correct diagnosis of GCA, and to provide valuable prognostic information. Novel evidence is accumulating to support the role of imaging, and particularly US, as a monitoring tool for the disease, opening new perspectives for the future management of large vessel vasculitis.

Predictive Factors of Giant Cell Arteritis in Polymyalgia Rheumatica Patients

Polymyalgia rheumatica (PMR) is an inflammatory rheumatism of the shoulder and pelvic girdles. In 16 to 21% of cases, PMR is associated with giant cell arteritis (GCA) that can lead to severe vascular complications. Ruling out GCA in patients with PMR is currently a critical challenge for clinicians. Two GCA phenotypes can be distinguished: cranial GCA (C-GCA) and large vessel GCA (LV-GCA). C-GCA is usually suspected when cranial manifestations (temporal headaches, jaw claudication, scalp tenderness, or visual disturbances) occur. Isolated LV-GCA is more difficult to diagnose, due to the lack of specificity of clinical features which can be limited to constitutional symptoms and/or unexplained fever. Furthermore, many studies have demonstrated the existence-in varying proportions-of subclinical GCA in patients with apparently isolated PMR features. In PMR patients, the occurrence of clinical features of C-GCA (new onset temporal headaches, jaw claudication, or abnormality of temporal arteries) are highly predictive of C-GCA. Additionally, glucocorticoids' resistance occurring during follow-up of PMR patients, the occurrence of constitutional symptoms, or acute phase reactants elevation are suggestive of associated GCA. Research into the predictive biomarkers of GCA in PMR patients is critical for selecting PMR patients for whom imaging and/or temporal artery biopsy is necessary. To date, Angiopoietin-2 and MMP-3 are powerful for predicting GCA in PMR patients, but these results need to be confirmed in further cohorts. In this review, we discuss the diagnostic challenges of subclinical GCA in PMR patients and will review the predictive factors of GCA in PMR patients.

Semi-Quantitative [18F]FDG-PET/CT ROC-Analysis-Based Cut-Offs for Aortitis Definition in Giant Cell Arteritis

[18F]fluorodeoxyglucose-positron emission tomography/computed tomography ([18F]FDG-PET/CT) is used to diagnose large vessel vasculitis in giant cell arteritis (GCA). We aimed to define a semi-quantitative threshold for identifying GCA aortitis from aortic atheroma or the control. Contrast enhanced computed tomography (CECT) was used as the reference imaging for aortic evaluation and to define aortitis, aortic atheroma and control aortas. [18F]FDG-PET/CT was performed on 35 GCA patients and in two different control groups (aortic atheroma (n = 70) and normal control (n = 35)). Aortic semi-quantitative features were compared between the three groups. GCA patients without aortitis on CECT were excluded. Of the GCA patients, 19 (54.3%) were not on glucocorticoids (GC) prior to [18F]FDG-PET/CT. The SUVmax, TBRblood and TBRliver aortic values were significantly higher in the GCA aortitis group than in the aortic atheroma and control groups (p < 0.001). Receiver operating characteristic curve analyses brought to light quantitative cut-off values allowing GCA aortitis diagnosis with optimal sensitivity and specificity versus control or aortic atheroma patients for each PET-based feature analyzed. Considering the overall aorta, a SUVmax threshold of 3.25 and a TBRblood threshold of 1.75 had a specificity of 83% and 75%, respectively, a sensitivity of 81% and 81%, respectively, and the area under the ROC curve (AUC) was 0.86 and 0.83, respectively, for aortitis detection compared to control groups in GCA cases with GC. A SUVmax threshold of 3.45 and a TBRblood threshold of 1.97 had a specificity of 90% and 93%, respectively, a sensitivity of 89% and 89%, respectively, with an AUC of 0.89 and 0.96, respectively, for aortitis detection compared to the control in GC-free GCA cases. Discriminative thresholds of SUVmax and TBRblood for the diagnosis of GCA aortitis were established using CECT as the reference imaging.

Inter and intra-observer agreement of arterial wall contrast-enhanced ultrasonography in giant cell arteritis

Objective

The aim of this study was to analyze inter- and intra-observer agreement for contrast-enhanced ultrasonography (CEUS) for monitoring disease activity in Giant Cell Arteritis (GCA) in the wall of axillary arteries, and common carotid arteries.

Methods

Giant cell arteritis patients have CEUS of axillary arteries and common carotid. These images were rated by seven vascular medicine physicians from four hospitals who were experienced in duplex ultrasonography of GCA patients. Two weeks later, observers again rated the same images. GCA patients were recruited in from December 2019 to February 2021. An analysis of the contrast of the ultrasound images with a gradation in three classes (grade 0, 1, and 2) was performed. Grade 0 corresponds to no contrast, grade 1 to moderate wall contrast and grade 2 to intense contrast. A new analysis in 2 classes: positive or negative wall contrast; was then performed on new series of images.

Results

Sixty arterial segments were evaluated in 30 patients. For the three-class scale, intra-rater agreement was substantial: κ 0.70; inter-rater agreement was fair: κ from 0.22 to 0.27. Thirty-four videos had a wall thickness of less than 2 mm and 26 videos had a wall thickness greater than 2 mm. For walls with a thickness lower than 2 mm: intra-rater agreement was substantial: κ 0.69; inter-rater agreement was fair: κ 0.35. For walls with a thickness of 2 mm or more: intra-rater agreement was substantial: κ 0.53; inter-rater agreement was fair: κ 0.25. For analysis of parietal contrast uptake in two classes: inter-rater agreement was fair to moderate: κ from 0.35 to 0.41; and for walls with a thickness of 2 mm or more: inter-rater agreement was fair to substantial κ from 0.22 to 0.63.

Conclusion

The visual analysis of contrast uptake in the wall of the axillary and common carotid arteries showed good intra-rater agreement in GCA patients. The inter-rater agreement was low, especially when contrast was analyzed in three classes. The inter-rater agreement for the analysis in two classes was also low. The inter-rater agreement was higher in two-class analysis for walls of 2 mm thickness or more.

Biopsy negative giant cell arteritis-Revised diagnostic criteria: Giant cell arteritis diagnostic criteria

BACKGROUND

Diagnosis of giant cell arteritis has traditionally relied on demonstration of pathologic changes on temporal artery biopsy.

METHOD

To highlight recent advances in large vessel imaging resulting in revised diagnostic criteria for giant cell arteritis.

CONCLUSION

We call attention to the revised diagnostic criteria imaging evidence of extracranial large vessel thickening as an alternative to temporal artery biopsy in diagnosis of giant cell arteritis in a patient with heralding anterior fornix infarct.

PET/CT of cranial arteries for a sensitive diagnosis of giant cell arteritis

OBJECTIVES

To investigate the performance of cranial PET/CT for the diagnosis of giant cell arteritis (GCA).

METHODS

All patients with a suspected diagnosis of GCA were prospectively enrolled in this study and had a digital PET/CT with evaluation of cranial arteries if they had not started glucocorticoids more than 72 hours previously. The diagnosis of GCA was retained after at least 6 months of follow-up if no other diagnosis was considered by the clinician and the patient went into remission after at least 6 consecutive months of treatment. Cranial PET/CT was considered positive if at least one arterial segment showed hypermetabolism similar to or greater than liver uptake.

RESULTS

For cranial PET/CT, sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) were 73.3%, 97.2%, 91.7% and 89.7%, respectively. For extracranial PET/CT, diagnostic performance was lower (Se = 66.7%, Sp = 80.6%, PPV = 58.8%, NPV = 85.3%). The combination of cranial and extracranial PET/CT improved overall sensitivity (Se = 80%) and NPV (NPV = 90.3%) while decreasing overall specificity (Sp = 77.8%) and PPV (PPV = 60%).

CONCLUSION

Cranial PET/CT can be easily combined with extracranial PET/CT with a limited increase in examination time. Combined cranial and extracranial PET/CT showed very high diagnostic accuracy for the diagnosis of GCA.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT05246540.

Unexplained chest pain in a patient with giant cell arteritis? Think aortic dissection

Giant cell arteritis (GCA) is the commonest of the large-vessel vasculitides. Aortic inflammation in patients with GCA was first described over 80 years ago, but it has only been possible to study this systematically following the development of more sophisticated imaging techniques such as computed tomography angiography, magnetic resonance angiography and positron emission tomography. Both NICE and the European League Against Rheumatism (EULAR) recognise that aortic dissection may complicate GCA but stop short of recommending routine imaging. We report a case that highlights a possible need for large-vessel imaging at the time of diagnosis and during follow-up to enable earlier recognition of aortitis and associated complications including dissection.

ACR Appropriateness Criteria® Noncerebral Vasculitis

Noncerebral vasculitis is a wide-range noninfectious inflammatory disorder affecting the vessels. Vasculitides have been categorized based on the vessel size, such as large-vessel vasculitis, medium-vessel vasculitis, and small-vessel vasculitis. In this document, we cover large-vessel vasculitis and medium-vessel vasculitis. Due to the challenges of vessel biopsy, imaging plays a crucial role in diagnosing this entity. While CTA and MRA can both provide anatomical details of the vessel wall, including wall thickness and enhancement in large-vessel vasculitis, FDG-PET/CT can show functional assessment based on the glycolytic activity of inflammatory cells in the inflamed vessels. Given the size of the vessel in medium-vessel vasculitis, invasive arteriography is still a choice for imaging. However, high-resolution CTA images can depict small-caliber aneurysms, and thus can be utilized in the diagnosis of medium-vessel vasculitis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Giant cell arteritis: A case report and review of literature

Giant cell arteritis, the most common form of vasculitis in the elderly, is characterized by granulomatous inflammation of arteries, which can lead to serious, life-threatening conditions including aortic aneurysms, ruptures, and dissections as well as blindness. Since GCA can be treated by immunosuppressant therapy, such as corticosteroids, early diagnosis and treatment may reduce the risk of serious disability and morbidity. While temporal artery biopsy is considered the gold standard to diagnosis giant cell arteritis, it is intrusive with inherent risks as well as unreliable due to tissue sampling. Imaging studies, such as computerized tomography, are nonintrusive and have been shown to identify vasculitis including giant cell arteritis. We present a case of a 72-year-old male patient who was diagnosed with giant cell arteritis by temporal artery biopsy during surgery for aortic aneurysm and coronary artery bypass graft. Computerized tomography imaging studies, prior to the surgery and biopsy, were suggestive of vasculitis. This case serves to emphasize the beneficial role of imaging studies to assess vasculitis, including giant cell arteritis, that can be done prior to the progressive development of more serious debilitating and potentially fatal pathology.

Specific features to differentiate Giant cell arteritis aortitis from aortic atheroma using FDG-PET/CT

Aortic wall ¹⁸F-fluorodeoxyglucose (FDG)-uptake does not allow differentiation of aortitis from atheroma, which is problematic in clinical practice for diagnosing large vessel vasculitis giant-cell arteritis (GCA) in elderly patients. The purpose of this study was to compare the FDG uptake characteristics of GCA aortitis and aortic atheroma using positron emission tomography/FDG computed tomography (FDG-PET/CT). This study compared FDG aortic uptake between patients with GCA aortitis and patients with aortic atheroma; previously defined by contrast enhanced CT. Visual grading according to standardized FDG-PET/CT interpretation criteria and semi-quantitative analyses (maximum standardized uptake value (SUV_max), delta SUV (∆SUV), target to background ratios (TBR)) of FDG aortic uptake were conducted. The aorta was divided into 5 segments for analysis. 29 GCA aortitis and 66 aortic atheroma patients were included. A grade 3 FDG uptake of the aortic wall was identified for 23 (79.3%) GCA aortitis patients and none in the atheroma patient group (p < 0.0001); grade 2 FDG uptake was as common in both populations. Of the 29 aortitis patients, FDG uptake of all 5 aortic segments was positive for 21 of them (72.4%, p < 0.0001). FDG uptake of the supra-aortic trunk was identified for 24 aortitis (82.8%) and no atheromatous cases (p < 0.0001). All semi-quantitative analyses of FDG aortic wall uptake (SUV_max, ∆SUV and TBRs) were significantly higher in the aortitis group. ∆SUV was the feature with the largest differential between aortitis and aortic atheroma. In this study, GCA aortitis could be distinguished from an aortic atheroma by the presence of an aortic wall FDG uptake grade 3, an FDG uptake of the 5 aortic segments, and FDG uptake of the peripheral arteries.

Current advances in giant cell arteritis

PURPOSE OF REVIEW

The aim of this study was to present the latest advances in giant cell arteritis (GCA) care, and recent national and international rheumatology societies guidance which influences clinical practice.

RECENT FINDINGS

Cranial ultrasound reduces diagnostic delay and improves clinical outcomes. Immediate high dose glucocorticoids remain the standard treatment for GCA. Controlled trial evidence using Tocilizumab, an interleukin-6 receptor antagonist, shows good clinical efficacy with steroid-sparing effects.

SUMMARY

Improved patient outcomes require formalizing pathways to diagnosis and closer liaison with rheumatology for long-term management with second-line therapies.

Risk factors for symptomatic vascular events in giant cell arteritis: a study of 254 patients with large-vessel imaging at diagnosis

Aims

To identify factors associated with vascular events in patients with giant cell arteritis (GCA).

Methods

We performed a retrospective study of GCA patients diagnosed over a 20-year-period, who all underwent vascular imaging evaluation at diagnosis. Symptomatic vascular events were defined as the occurrence of any aortic event (aortic dissection or symptomatic aortic aneurysm), stroke, myocardial infarction, limb or mesenteric ischemia and de novo lower limbs arteritis stage 3 or 4. Patients with symptomatic vascular event (VE+) and without were compared, and risk factors were identified in a multivariable analysis.

Results

Thirty-nine (15.4%) of the 254 included patients experienced at least one symptomatic vascular event during follow-up, with a median time of 21.5 months. Arterial hypertension, diabetes, lower limbs arteritis or vascular complication at diagnosis were more frequent in VE+ patients (p < 0.05), as an abnormal computed tomography (CT)-scan at diagnosis (p = 0.04), aortitis (p = 0.01), particularly of the descending thoracic aorta (p = 0.03) and atheroma (p = 0.03). Deaths were more frequent in the VE+ group (37.1 versus 10.3%, p = 0.0003). In multivariable analysis, aortic surgery [hazard ratio (HR): 10.46 (1.41-77.80), p = 0.02], stroke [HR: 22.32 (3.69-135.05), p < 0.001], upper limb ischemia [HR: 20.27 (2.05-200.12), p = 0.01], lower limb ischemia [HR: 76.57 (2.89-2027.69), p = 0.009], aortic atheroma [HR: 3.06 (1.06-8.82), p = 0.04] and aortitis of the descending thoracic aorta on CT-scan at diagnosis [HR: 4.64 (1.56-13.75), p = 0.006] were independent predictive factors of a vascular event.

Conclusion

In this study on GCA cases with large vessels imaging at diagnosis, aortic surgery, stroke, upper or lower limb ischemia, aortic atheroma and aortitis of the descending thoracic aorta on CT-scan, at GCA diagnosis, were independent predictive factors of a vascular event.

Plain language summary

Risk factors for symptomatic vascular events in giant cell arteritisThis study was performed to identify the risk factors for developing symptomatic vascular event during giant cell arteritis (GCA) because these are poorly known.We performed a retrospective study of GCA patients diagnosed over a 20-year-period, who all underwent vascular imaging evaluation at diagnosis.Patients with symptomatic vascular event (VE+) and without (VE-) were compared, and risk factors were identified in a multivariable analysis.Thirty-nine patients experienced at least one symptomatic vascular event during follow-up, with a median time of 21.5 months.Arterial hypertension, diabetes, lower limbs arteritis or vascular complication at diagnosis were significantly more frequent in VE+ patients, as an abnormal CT-scan at diagnosis, aortitis, particularly of the descending thoracic aorta and atheroma. Deaths were more frequent in the VE+ group.Among 254 GCA patients, 39 experienced at least one vascular event during follow-up.Aortic surgery, stroke, upper and lower limb ischemia were vascular event risk factors.Aortic atheroma and descending thoracic aorta aortitis on CT-scan were vascular event risk factors.This study on GCA cases with large vessels imaging at diagnosis, showed that aortic surgery, stroke, upper or lower limb ischemia, aortic atheroma and aortitis of the descending thoracic aorta on CT-scan, at GCA diagnosis, were independent predictive factors of a vascular event.

ACR Appropriateness Criteria® Nontraumatic Aortic Disease

Nontraumatic aortic disease can be caused by a wide variety of disorders including congenital, inflammatory, infectious, metabolic, neoplastic, and degenerative processes. Imaging examinations such as radiography, ultrasound, echocardiography, catheter-based angiography, CT, MRI, and nuclear medicine examinations are essential for diagnosis, treatment planning, and assessment of therapeutic response. Depending upon the clinical scenario, each of these modalities has strengths and weaknesses. Whenever possible, the selection of a diagnostic imaging examination should be based upon the best available evidence. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment. The purpose of this document is to assist physicians select the most appropriate diagnostic imaging examination for nontraumatic aortic diseases.

Giant cell arteritis-related aortic dissection: A multicenter retrospective study

PURPOSE

To describe characteristics and outcomes of patients with giant cell arteritis (GCA)-related aortic dissection.

PATIENTS AND METHODS

We retrospectively included, through a nationwide GCA network, all patients who had an aortic dissection either revealing GCA or occurring during follow-up.

RESULTS

A total of 46 patients were included in this study. Aortic dissection was inaugural and led to GCA diagnosis in 21 patients, whereas it occurred during follow-up in the 25 others, at a median of 53 [1-265] months after GCA diagnosis. Large-vessel vasculitis (LVV) was diagnosed through imaging before or at the time of aortic dissection in 31 (67%) patients. In patients who developed an aortic dissection during follow-up, the aortic event occurred 22 [1-143] months post GCA diagnosis in the patients with previous aortitis, whereas it occurred after 72 [19-265] months in patients without previously diagnosed aortitis (p = 0.005). Aortic surgery was performed in 27 (59%) patients and 23 of them survived. A total of 15 (32%) patients died following the aortic dissection, including 11 who were not operated on. In a multivariate analysis, aortic surgery was the single predictor of survival (HR: 4.3; 95% CI: 1.47- 15.7; p = 0.007).

CONCLUSION

Patients with prior LVV are more prone to develop early aortic dissection and require close monitoring of aortic morphology. One third of patients died from the aortic dissection. Surgery remains the best predictive factor for survival.

[The current place of non-invasive large-vessel imaging in the diagnosis and follow-up of giant cell arteritis]

Large vessel involvement in giant cell arteritis has long been described, although its right frequency and potential prognostic value have only been highlighted for two decades. Large vessel involvement not only is associated with a high incidence of late aortic aneurysms, but also might cause greater resistance to glucocorticoids and longer treatment duration, as well as worse late cardiovascular outcomes. These data were brought to our attention, thanks to substantial progress recently made in large vessel imaging. This relies on four single, often complementary, approaches of varying availability: colour Doppler ultrasound, contrast-enhanced computed tomography with angiography and, magnetic resonance imaging, which all demonstrate homogeneous circumferential wall thickening and describe structural changes; 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET/CT), which depicts wall inflammation and assesses many vascular territories in the same examination. In addition, integrated head-and-neck PET/CT can accurately and reliably diagnose cranial arteritis. All four procedures exhibit high diagnostic performance for a large vessel arteritis diagnosis so that the choice is left to the physician, depending on local practices and accessibility; the most important is to carry out the chosen modality without delay to avoid false or equivocal results, due to early vascular oedema changes as a result of high dose glucocorticoid treatment. Yet, ultrasound study of the superficial cranial and subclavian/axillary arteries remains a first line assessment aimed at strengthening and expediting the clinical diagnosis as well as raising suspicion of large-vessel involvement. In treated patients, vascular imaging results are poorly correlated with clinical-biological controlled disease so that it is strongly recommended not to renew imaging studies unless a large vessel relapse or complication is suspected. On the other hand, a structural monitoring of aorta following giant cell arteritis is mandatory, but uncertainties remain regarding the best procedural approach, timing of first control and spacing between controls. Individuals at greater risk of developing aortic complication, e.g. those with classic risk factors for aneurysm and/or visualised aortitis, should be monitored more closely.

18F-Fluorodeoxyglucose PET/Computed Tomography in the Diagnosis and Monitoring of Giant Cell Arteritis

18F-Fluorodeoxyglucose (FDG) PET/computed tomography (CT) is a highly accurate diagnostic tool for large vessel vasculitis (LVV) and is one of the recommended imaging modalities for confirmation of the diagnosis. This article focuses on the role of FDG-PET/CT in LVV diagnosis and disease monitoring, mainly focusing on giant cell arteritis; in particular, the diagnostic accuracy, diagnostic criteria, the potential pitfalls in the interpretation of large vessel FDG uptake, and the clinical indication compared with other imaging modalities are discussed.

Giant cell arteritis: is the clinical spectrum of the disease changing?

BACKGROUND

Giant cell arteritis is a vasculitis of large and middle-sized arteries that affects patients aged over 50 years. It can show a typical clinical picture consisting of cranial manifestations but sometimes nonspecific symptoms and large-vessel involvement prevail. Prompt diagnosis and treatment is essential to avoid irreversible damage.

DISCUSSION

There has been an increasing knowledge on the occurrence of the disease without the typical cranial symptoms and its close relationship and overlap with polymyalgia rheumatica, and this may contribute to reduce the number of underdiagnosed patients. Although temporal artery biopsy is still the gold-standard and temporal artery ultrasonography is being widely used, newer imaging techniques (FDG-PET/TAC, MRI, CT) can be of valuable help to identify giant cell arteritis, in particular in those cases with a predominance of extracranial large-vessel manifestations.

CONCLUSIONS

Giant cell arteritis is a more heterogeneous condition than previously thought. Awareness of all the potential clinical manifestations and judicious use of diagnostic tests may be an aid to avoid delayed detection and consequently ominous complications.

The impact of temporal artery biopsy for the diagnosis of giant cell arteritis in clinical practice in a tertiary university hospital

Background

Temporal artery biopsy (TAB) is useful in assisting with giant cell arteritis (GCA) diagnosis but lacks sensitivity. The aim of our study was to assess the diagnostic impact of TAB histology in patients with suspected GCA on hospital admission.

Methods

A prospectively maintained database was queried for all TABs performed between 1-1-2000 until 31-12-2017 at the University Hospital of Ioannina. Thus, inclusion criteria were made on the grounds of every patient that underwent a TAB during the above-mentioned period, regardless of demographic, clinical and laboratory data.

Results

Two hundred forty-five TABs were included (149 females and 96 males), with a mean age of 64.5 (±3.5) years. The mean symptoms duration until admission to the hospital was 8.6 (±1.3) weeks and all had elevated acute phase reactants on admission. The reasons of admission were fever of unknown origin (FUO) in 114 (46.5%) patients, symptoms of polymyalgia rheumatica (PMR) in 84 (34.3%), new headache in 33 (13.5%), anemia of chronic disease (ACD) in 8 (3.32%) and eye disturbances in 6 (2.5%) patients. Positive results were found in 49 (20%) TABs. More specifically, in 14% of patients with FUO, 21% in those with PMR, while in patients with a new headache the percentage was 27%. Finally, 5 out of 6 (83.3%) of patients with ocular symptoms and only one (12.5%) of those suffering from ACD. Visual manifestations and FUO are correlated with a positive TAB.

Conclusion

It seems that TAB is useful in assisting with GCA diagnosis, but lacks sensitivity.