Diagnosis Of Giant Cell Arteritis Research Articles

Ultrasonography of the superficial temporal and axillary arteries in giant cell arteritis diagnosis

ObjectivesGiant cell arteritis (GCA) is the main systemic vasculitis in individuals aged ≥ 50 years. Color Doppler ultrasound (CDS) has an established role in GCA diagnosis and management. This study aims to assess the clinical characteristics associated with a positive CDS evaluation and the impact of additional axillary artery examination on diagnostic sensitivity. Material and methodsWe conducted a retrospective analysis of patients undergoing CDS of the superficial temporal arteries, with or without axillary artery assessment, at our hospital, between 2009 and 2023. Patients meeting the new 2022 diagnostic criteria for GCA were included and their characteristics were analyzed according to the presence of the halo sign on CDS. ResultsOf the 135 included patients (54 % female, mean age 75 ± 8 years), the halo sign was observed in 57 %, correlating with higher systemic symptom prevalence (61 % vs 42 %, p = 0.035), lower hemoglobin (p < 0.001), and higher erythrocyte sedimentation rate (p = 0.028). The halo sign inversely related to prior corticosteroid therapy (p = 0.033). Patients with axillary halo sign had fewer external carotid symptoms and a higher vertebral halo sign prevalence. Vertebral halo sign was associated with posterior circulation ischemic stroke (65 %, p < 0.001). Axillary artery studies improved diagnostic sensitivity by 9 %. ConclusionIn our study, the halo sign correlated with higher systemic symptoms and analytical abnormalities. Axillary artery examination enhanced CDS sensitivity, linked to severe outcomes like stroke. Prior corticosteroid therapy reduced CDS sensitivity. The correlation of clinical, laboratory, and ultrasound findings provides a more comprehensive understanding of GCA pathogenesis and evolution.

Histopathology reporting of temporal artery biopsy specimens for giant cell arteritis: results of a modified Delphi study

The temporal artery biopsy (TAB) is regarded as the gold-standard test in the diagnosis of giant cell arteritis (GCA). There is a lack of agreement among experienced pathologists regarding the...

The value of axillary, facial, occipital, subclavian and common carotid arteries ultrasound in the diagnosis of giant cell arteritis

Abstract Objective To assess the diagnostic value for GCA in adding the axillary arteries (AX) to the temporal artery (TA) ultrasound, particularly in patients with a cranial phenotype of the disease; and to investigate the utility of facial (FA), occipital (OC), subclavian (SC) and common carotid (CC) ultrasound in patients with suspected GCA. Methods Patients with new-onset GCA and a positive ultrasound of the TA, AX, FA, OC, SC or CC, followed at the rheumatology departments of two academic centres, were retrospectively included. Results Two hundred and thirty patients were assessed. TA halo sign was identified in 206/230 (89.6%) cases, FA in 40/82 (48.8%), OC in 17/69 (24.6%), AX in 56/230 (24.3%), SC in 31/57 (54.4%) and CC in 14/68 (20.6%). Negative TA ultrasound was found in 24/230 (10.4%) patients: 22 had AX involvement, one exclusive OC involvement and one exclusive SC involvement. Adding AX evaluation to the TA ultrasound increased the diagnostic yield for GCA by 9.6%, whereas adding OC or SCs to the TA and AX ultrasound increased it by 1.4% and 1.8%, respectively. No value was found in adding the FA or CCs. Notably, 13 patients with cranial symptoms and four with exclusively cranial symptoms showed negative TA ultrasound but positive AX ultrasound. Conclusion Adding the evaluation of AXs to the TA ultrasound increased the number of patients diagnosed with GCA, even in cases of predominantly cranial symptoms. In the subset of patients where these arteries were assessed, no substantial benefit was found in adding the FA, OC, SC or CC arteries to the TA and AX ultrasonographic assessment.

Evaluation of the extracranial “multifocal arcuate sign,” a novel MRI finding for the diagnosis of giant cell arteritis, on STIR and contrast-enhanced T1-weighted images

BackgroundWhile early diagnosis of giant cell arteritis (GCA) based on clinical criteria and contrast-enhanced MRI findings can lead to early treatment and prevention of blindness and cerebrovascular accidents, previously reported diagnostic methods which utilize contrast-enhanced whole head images are cumbersome. Diagnostic delay is common as patients may not be aware of initial symptoms and their significance. To improve current diagnostic capabilities, new MRI-based diagnostic criteria need to be established. This study aimed to evaluate the “multifocal arcuate sign” on short tau inversion recovery (STIR) and contrast-enhanced T1-weighted (CE-T1W) images as a novel extracranial finding for the diagnosis of GCA.MethodsA total of 17 consecutive patients (including five with GCA) who underwent CE-T1W and whole-brain axial STIR imaging simultaneously between June 2010 and April 2020 were enrolled. We retrospectively reviewed their MR images. The “multifocal arcuate sign” was defined as “multiple distant arcuate areas with high signal intensity in extracranial soft tissues such as subcutaneous fat, muscles, and tendons.” Extracranial abnormal high-signal-intensity areas were classified as “None,” when no lesions were detected; “Monofocal,” when lesions were detected only in one place; and “Multifocal,” when lesions were detected in multiple places. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of “Multifocal” areas were calculated using cross tabulation. Fisher’s exact test was used to compare “Multifocal” areas in five patients with GCA and those with other diseases. In addition, mean Cohen’s kappa and Fleiss’ kappa statistics were used to compare inter-reader agreement.ResultsThe sensitivity, specificity, PPV, and NPV of the “multifocal arcuate sign” in patients with GCA were 60%, 92–100%, 75–100%, and 85–86%, respectively. Significantly more patients with GCA had “Multifocal” areas compared to those with other diseases (Fisher’s exact test, p = 0.008–0.027). Mean Cohen’s kappa and Fleiss’ kappa for inter-reader agreement with respect to the five GCA patients were 0.52 and 0.49, respectively, for both STIR and CE-T1W sequences.ConclusionsThe new radiologic finding of “multifocal arcuate sign” on STIR and CE-T1W images may be used as a radiologic criterion for the diagnosis of GCA, which can make plain MRI a promising diagnostic modality.

Diagnostic Strategy Using Color Doppler Ultrasound of Temporal Arteries in Patients With High Clinical Suspicion of Giant Cell Arteritis : A Prospective Cohort Study.

Giant cell arteritis (GCA) is the most prevalent systemic vasculitis in people older than 50 years. Any delay in diagnosis impairs patients' quality of life and can lead to permanent damage, particularly vision loss. To evaluate a diagnostic strategy for GCA using color Doppler ultrasound of the temporal artery as a first-line diagnostic test, temporal artery biopsy (TAB) as a secondary test, and physician expertise as the reference method. Prospective multicenter study with a 2-year follow-up. (ClinicalTrials.gov: NCT02703922). Patients were referred by their general practitioner or ophthalmologist to a physician with extensive experience in GCA diagnosis and management in one of the participating centers: 4 general and 2 university hospitals. 165 patients with high clinical suspicion of GCA, aged 79 years (IQR, 73 to 85 years). The diagnostic procedure was ultrasound, performed less than 7 days after initiation of corticosteroid therapy. Only ultrasound-negative patients underwent TAB. Bilateral temporal halo signs seen on ultrasound were considered positive. Ultrasound and TAB results were compared with physician-diagnosed GCA based on clinical findings and other imaging. Diagnosis of GCA was confirmed in 44%, 17%, and 21% of patients by ultrasound, TAB, and clinical expertise and/or other imaging tests, respectively. Their diagnosis remained unchanged at 1 month, and 2 years for those with available follow-up data. An alternative diagnosis was made in 18% of patients. The proportion of ultrasound-positive patients among patients with a clinical GCA diagnosis was 54% (95% CI, 45% to 62%). Small sample size, no blinding of ultrasound and TAB results, lack of an objective gold-standard comparator, and single diagnostic strategy. By using ultrasound of the temporal arteries as a first-line diagnostic tool in patients with high clinical suspicion of GCA, further diagnostic tests for patients with positive ultrasound were avoided. Tender "Recherche CH-CHU Poitou-Charentes 2014."

The Common Carotid Artery in the Ultrasound Evaluation of Giant Cell Arteritis.

Vascular ultrasound is commonly used to diagnose giant cell arteritis (GCA). Most protocols include the temporal arteries and axillary arteries, but it is unclear which other arteries should be included. This study investigated whether inclusion of intima media thickness (IMT) of the common carotid artery (CCA) in the ultrasound evaluation of GCA improves the accuracy of the examination. We formed a fast-track clinic to use ultrasound to rapidly evaluate patients with suspected GCA. In this cohort study, patients referred for new concern for GCA received a vascular ultrasound for GCA with the temporal arteries and branches, the axillary artery, and CCA. We compared 57 patients with GCA and 86 patients without GCA. Three patients with GCA had isolated positive CCA between 1 and 1.49 mm, and 21 patients without GCA had isolated positive CCA IMT. At the 1.5-mm CCA cutoff, 4 patients without GCA had positive isolated CCA, and 1 patient with GCA had a positive isolated CCA. The sensitivity of ultrasound when adding carotid arteries to temporal and axillary arteries was 84.21% and specificity 65.12% at an intima media thickness (IMT) cutoff of ≥1 mm and 80.70% and 87.21%, respectively, at a cutoff of ≥1.5 mm. Measurement of the CCA IMT rarely contributed to the diagnosis of GCA and increased the rate of false-positive results. Our data suggest that the CCA should be excluded in the initial vascular artery ultrasound protocol for diagnosing GCA. If included, an IMT cutoff of higher than 1.0 mm should be used.

Transorbital ultrasound in the diagnosis of giant cell arteritis.

The objective of this study was to prospectively evaluate the diagnostic efficacy of transorbital ultrasound (TOS) in patients newly diagnosed with giant cell arteritis (GCA), presenting with visual symptoms. Patients with newly diagnosed, untreated GCA were examined using TOS, assessing central retinal artery flow velocity [peak systolic velocity (PSV), end-diastolic velocity (EDV), resistance index (RI)], and optic nerve diameter (OND). Vascular ultrasound was conducted to evaluate the superficial temporal arteries, their branches, facial, axillary, carotid, and vertebral arteries. We enrolled 54 GCA patients, 27 with visual symptoms, and 27 healthy controls. Eyes of GCA patients with visual symptoms demonstrated significantly lower PSV and EDV (PSV: β = -1.91; P = 0.029; EDV: β = -0.57; P = 0.032) and significantly elevated OND (β = 0.79; P = 0.003) compared with controls. RI did not significantly differ from controls (β = -0.06, P = 0.129). Vascular ultrasound identified an average of 8.7 (SD ± 2.8) pathological vessels per GCA patient. A significant negative association was observed between the number of affected vessels and both PSV (P = 0.048) and EDV (P = 0.040). No association was found with RI (P = 0.249), while a positive significant association was noted with OND (P < 0.001). This study pioneers the application of TOS to assess structural eye changes in newly diagnosed, untreated GCA patients with visual symptoms. Our findings suggest reduced central retinal artery flow and increased optic nerve diameter as potential biomarkers for serious ocular involvement in GCA. The detected association between internal and external carotid artery involvement indicates a common pathophysiological mechanism underlying systemic and ocular manifestations of GCA.

The influence of the cardiac cycle on the halo sign and its impact on the ultrasound diagnosis of giant cell arteritis.

To investigate whether hypoechoic wall thickness is influenced by the systole or diastole moment in the cardiac cycle and if this can influence ultrasound (US) assessments of giant cell arteritis (GCA). US videos of 100 consecutive patients (50 with GCA, 50 without) performed between January 2021 and June 2023 were reviewed. Intima-media thickness (IMT) of temporal (including common trunk, frontal and parietal branches), axillary and subclavian arteries were measured at two different time points, at systolic peak (SP) and at the end-diastole (ED). Differences between SP IMT and ED IMT, as well as in the halo count (HC) and in the OMERACT GCA Ultrasonography Score (OGUS) between these two times, were analyzed. IMT was significantly higher (4.8-5%) at ED in all arteries, in both GCA and non-GCA groups. HC and OGUS were also higher in ED in both groups. In 4 non-GCA patients (8%), the HC was positive in ED and negative in SP; in all of them the HC in ED was 1. In the GCA group, the timing of the cardiac cycle did not influence the final US diagnosis; however, it did modify the HC in 14 patients (28%). IMT can fluctuate during the cardiac cycle, with higher measurements occurring at ED. This variability could potentially impact the accuracy of US diagnoses and assessments of GCA. If further research corroborates these findings, it may be imperative to revise the guidelines for employing US in diagnosing GCA in order to incorporate these nuanced aspects.

Risk loci involved in giant cell arteritis susceptibility: a genome-wide association study

Giant cell arteritis is an age-related vasculitis that mainly affects the aorta and its branches in individuals aged 50 years and older. Current options for diagnosis and treatment are scarce, highlighting the need to better understand its underlying pathogenesis. Genome-wide association studies (GWAS) have emerged as a powerful tool for unravelling the pathogenic mechanisms involved in complex diseases. We aimed to characterise the genetic basis of giant cell arteritis by performing the largest GWAS of this vasculitis to date and to assess the functional consequences and clinical implications of identified risk loci. We collected and meta-analysed genomic data from patients with giant cell arteritis and healthy controls of European ancestry from ten cohorts across Europe and North America. Eligible patients required confirmation of giant cell arteritis diagnosis by positive temporal artery biopsy, positive temporal artery doppler ultrasonography, or imaging techniques confirming large-vessel vasculitis. We assessed the functional consequences of loci associated with giant cell arteritis using cell enrichment analysis, fine-mapping, and causal gene prioritisation. We also performed a drug repurposing analysis and developed a polygenic risk score to explore the clinical implications of our findings. We included a total of 3498 patients with giant cell arteritis and 15 550 controls. We identified three novel loci associated with risk of giant cell arteritis. Two loci, MFGE8 (rs8029053; p=4·96 × 10-8; OR 1·19 [95% CI 1·12-1·26]) and VTN (rs704; p=2·75 × 10-9; OR 0·84 [0·79-0·89]), were related to angiogenesis pathways and the third locus, CCDC25 (rs11782624; p=1·28 × 10-8; OR 1·18 [1·12-1·25]), was related to neutrophil extracellular traps (NETs). We also found an association between this vasculitis and HLA region and PLG. Variants associated with giant cell arteritis seemed to fulfil a specific regulatory role in crucial immune cell types. Furthermore, we identified several drugs that could represent promising candidates for treatment of this disease. The polygenic risk score model was able to identify individuals at increased risk of developing giant cell arteritis (90th percentile OR 2·87 [95% CI 2·15-3·82]; p=1·73 × 10-13). We have found several additional loci associated with giant cell arteritis, highlighting the crucial role of angiogenesis in disease susceptibility. Our study represents a step forward in the translation of genomic findings to clinical practice in giant cell arteritis, proposing new treatments and a method to measure genetic predisposition to this vasculitis. Institute of Health Carlos III, Spanish Ministry of Science and Innovation, UK Medical Research Council, and National Institute for Health and Care Research.

Development of a diagnostic prediction model for giant cell arteritis by sequential application of Southend Giant Cell Arteritis Probability Score and ultrasonography: a prospective multicentre study

Giant cell arteritis is a critically ischaemic disease with protean manifestations that require urgent diagnosis and treatment. European Alliance of Associations for Rheumatology (EULAR) recommendations advocate ultrasonography as the first investigation for suspected giant cell arteritis. We developed a prediction tool that sequentially combines clinical assessment, as determined by the Southend Giant Cell Arteritis Probability Score (SGCAPS), with results of quantitative ultrasonography. This prospective, multicentre, inception cohort study included consecutive patients with suspected new onset giant cell arteritis referred to fast-track clinics (seven centres in Italy, the Netherlands, Spain, and UK). Final clinical diagnosis was established at 6 months. SGCAPS and quantitative ultrasonography of temporal and axillary arteries with three scores (ie, halo count, halo score, and OMERACT GCA Score [OGUS]) were performed at diagnosis. We developed prediction models for diagnosis of giant cell arteritis by multivariable logistic regression analysis with SGCAPS and each of the three ultrasonographic scores as predicting variables. We obtained intraclass correlation coefficient for inter-rater and intra-rater reliability in a separate patient-based reliability exercise with five patients and five observers. Between Oct 1, 2019, and June 30, 2022, we recruited and followed up 229 patients (150 [66%] women and 79 [34%] men; mean age 71 years [SD 10]), of whom 84 were diagnosed with giant cell arteritis and 145 with giant cell arteritis mimics (controls) at 6 months. SGCAPS and all three ultrasonographic scores discriminated well between patients with and without giant cell arteritis. A reliability exercise showed that the inter-rater and intra-rater reliability was high for all three ultrasonographic scores. The prediction model combining SGCAPS with the halo count, which was termed HAS-GCA score, was the most accurate model, with an optimism-adjusted C statistic of 0·969 (95% CI 0·952 to 0·990). The HAS-GCA score could classify 169 (74%) of 229 patients into either the low or high probability groups, with misclassification observed in two (2%) of 105 patients in the low probability group and two (3%) of 64 of patients in the high probability group. A nomogram for easy application of the score in daily practice was created. A prediction tool for giant cell arteritis (the HAS-GCA score), combining SGCAPS and the halo count, reliably confirms and excludes giant cell arteritis from giant cell arteritis mimics in fast-track clinics. These findings require confirmation in an independent, multicentre study. Royal College of Physicians of Ireland, FOREUM.

Parietal branch of the superficial temporal artery: An underutilized biopsy site

Purpose: Giant cell arteritis (GCA) is an immune-mediated vasculitis that can lead to significant symptoms and disease sequelae such as headaches, fevers, weight loss, jaw pain, optic neuropathy with permanent vision loss, and stroke. The gold standard for diagnosis of GCA is a temporal artery biopsy (TAB) as it has a high specificity and sensitivity. The TAB is commonly harvested from the frontal branch of the superficial temporal artery, however given its location, there are potentially significant consequences including facial nerve injury and poor cosmetic outcomes. An alternative to this method is biopsy of the parietal branch, as it reduces the risk of facial nerve injury and comfortably hides the scar line within the hair of most patients. Results: We describe in detail our department's TAB technique and experience from pre-procedure preparation to post-procedure care. Conclusion: The parietal branch TAB is a typically underutilised, well tolerated and viable alternative to the frontal branch TAB and it may be considered in the first instance to reduce the risk of complications.

P032 Designing a workshop for a temporal artery biopsy simulation

Abstract Background/Aims A temporal artery biopsy (TAB) is performed to confirm a diagnosis of giant cell arteritis (GCA) and it is recommended by clinical practice guidelines. Historically there have been limited opportunities to perform this procedure and teaching has been largely informal and non standardised. This impacts a trainee’s confidence and competence and potentially patient safety. Simulation is crucial in modern day surgical education and so we designed, organised and delivered a wetlab to teach the steps of TAB to address these issues. Methods The event took place at the Welsh Institute for Minimal Access Therapy (WIMAT) centre in Cardiff. The WIMAT team developed the TAB models to be used. The event covered all of the theoretical aspects of performing a TAB, a demonstration on how to map the temporal artery, how to perform an ultrasound doppler procedure to locate the temporal artery and finally hands on experience performing a TAB with two different complexity models. Participants were asked to complete a 30 item Google Forms Questionnaire to help us to evaluate pre and post session knowledge, understanding and learning experiences pertaining to TAB. Results Participants noted significant improvements in their knowledge and understanding pertaining to all domains covered. A lack of knowledge, a lack of procedures previously performed, concern about damaging the facial nerve and lack of senior support/supervision were all identified as reasons as to why trainees get apprehensive when it comes to performing a TAB. Conclusion This novel formal teaching event provides a blueprint for deaneries to use in their teaching of TAB’s which can benefit trainees and patients. Modern surgical education benefits from wetlabs with expert supervision. Our findings also emphasise the benefits of cross specialty collaborative work. Disclosure S. Rehan: None. P. Watts: None. I. Williams: None. P. Hennessy: None. C. O’Flaherty: None. A. Haridas: None.

P190 Protocolised ultrasonography led pathway has a high sensitivity for diagnosis of primary large vessel vasculitis

Abstract Background/Aims Ultrasonography (US) for diagnosis of large vessel vasculitis (LVV) is a recommended first line diagnostic procedure. Our county has an annual incidence of 57.5/million for primary LVV (giant cell arteritis (GCA) 48.3/million; Takayasu 2.5/million; unclassified LVV 6.4/million). Our protocolised fast-track US pathway has reduced visual loss from 18.7% to 11.5%. We present the results of our first 1000 unique referrals. Methods Unique requests for US from January 2017 were analysed. Protocolised US examination of the arteries includes superficial temporal artery (STA) and its rami, followed by the entire axillary artery, followed by other arteries as necessary. Halo sign in at least two different arteries was needed for diagnosis of LVV. A temporal artery biopsy (TAB) or positron emission tomography (PET) were requested if the US was negative AND CRP was ≥20mg/L (or missing) AND an alternate explanation for the raised CRP was not immediately apparent. For those where a second test was not requested OR if it was negative, prednisolone was tapered rapidly, and a patient-initiated follow-up allowed rapid re-assessment. If referring physician or patient did not want a second test, GCA was diagnosed on clinical grounds alone and the pathway was considered to have failed. Results Median age was 73 (IQR 13); 11/1000 referrals were for people &amp;lt;50 years of age. The median delay for the procedure was 4 (IQR 4) days. Prednisolone had been started a median of 4 (IQR 5) days previously. 279/1000 (28%) US scans demonstrated vasculitis. Pre-steroid CRP was ≥20mg/L in 283 cases and unavailable in 7. An alternate explanation for the raised CRP was found in 102 cases, 181 were referred for a second test, and 7 received a clinical diagnosis of GCA without a second test. The second test was diagnostic in 31/181 (17%) - 24/139 (17%) TAB, 7/42 (17%) PET. 3/150 cases with a negative second test and 4/431 cases with CRP &amp;lt;20mg/L were diagnosed with GCA on patient-initiated follow-up. The delayed diagnosis did not result in visual loss. 202/279 (72%) US positive cases had bilateral STA involvement. The addition of axillary artery imaging picked up a further 53 (19%) cases; 24/279 (9%) cases needed imaging of other arteries. The sensitivity and negative predictive value of the pathway are 96% (310/324) and 98% (683/690) respectively. Conclusion Our protocolised US led pathway for diagnosis of LVV is highly sensitive and allows disease exclusion with high certainty. Routine US of the superficial temporal artery and its rami, and the entire axillary artery provide diagnosis in 91% of cases but ability to scan more arteries improves yield in a further 9% of cases. Composite testing with US plus second test, stratified by CRP levels, can be recommended as a gold standard diagnostic tool for LVV. Disclosure C.B. Mukhtyar: None. G. Ducker: None. C. Beadsmoore: None. K. Sisson: None. C. Jones: None.

Limb arteries involvement assessed by FDG/PET CT at diagnosis of giant cell arteritis and risk of relapse: An observational study

IntroductionSteroids and anti-IL6 biotherapy are highly effective in obtaining remission in patients with giant cell arteritis (GCA) but the risk of relapses remains high. We aimed to identify predictors of relapse in GCA. MethodsAll consecutive patients admitted with a new diagnosis of GCA – according to the 2022 American College of Rheumatology/EULAR (ACR/EULAR) classification criteria – between May 2011 and May 2022 were eligible for this study. The primary outcome was the GCA relapse rate over the 36-months follow up. Factors associated with the primary outcome and time to first relapse were analyzed. ResultsOne hundred and eight patients (74 [69–81] years, 64.8% women) with a new diagnosis of GCA were studied. GCA was biopsy-proven in 65 (60.2%) cases. Ninety-eight (90.7%) FDG/PET CT scans performed at diagnosis were available for review. All patients received steroids given for 21.0 [18.0–28.5] months, associated with methotrexate (n=1, 0.9%) or tocilizumab (n=2, 1.9%). During a median follow-up of 27.5 [11.4–35.0] months, relapse occurred in 40 (37%) patients. Multivariable Cox regression model, including general signs, gender, aortic wall thickness, FDG uptake in arterial wall and IV steroid pulse as covariates, showed that both general signs (HR 2.0 [1.0–4.0, P<0.05) and FDG uptake in limb arteries (HR 2.7 [1.3–5.5], P<0.01) at diagnosis were associated with GCA relapse. ConclusionFDG uptake in limb arteries at diagnosis is a predictor of relapse in newly diagnosed GCA.

Prognostic value of 18 FDG-PET at diagnosis and follow-up in giant cell arteritis: An observational restrospective study

ObjectivesTo evaluate the ability of 18FDG PET/CT, at diagnosis of giant cell arteritis (GCA) and during follow-up, to predict occurrence of relapse in large-vessel GCA (LV-GCA). MethodsWe conducted a retrospective study using the French Study Group for Large-Vessel Vasculitis (GEFA) network. Data from patients with LV-GCA diagnosed by PET/CT and who had PET/CT in the following year were collected. For each PET/CT, PET vascular activity score (PETVAS) and total vascular score (TVS) were assessed, and their ability to predict the occurrence of subsequent relapse was assessed. ResultsA total of 65 LV-GCA patients were included, of whom 55 had undergone a follow-up PET/CT 3 to 12 months after the diagnosis of GCA. Patients for whom the second PET/CT (PET2) was performed during active GCA were excluded. PETVAS and TVS decreased between PET1 and PET2 in all patients (p < 0.001). There was no correlation between vascular activity scores in PET2 and time to prednisone taper. For relapse prediction, at PET1, the AUC of the TVS and PETVAS were respectively 51.9 and 41.9 at 6 months, 55.3 and 49.7 at 1 year, 55 and 55.7 at 2 years. For PET2, the AUC were respectively 46.1 and 46.7 at 6 months, 52.1 and 48.9 at 1 year, 58.4 and 52.3 at 2 years. ConclusionPET vascular activity scores at diagnosis and at follow-up PET/CT performed outside a period of GCA activity do not display high performance to predict the occurrence of subsequent relapse in LV-GCA patients.

Ultrasound intima-media thickness cut-off values for the diagnosis of giant cell arteritis using a dual clinical and MRI reference standard and cardiovascular risk stratification.

To derive segmental cut-off values and measures of diagnostic accuracy for the intima-media thickness of compressed temporal artery segments for the diagnosis of giant cell arteritis (GCA) on the patient level. To examine the influence of cardiovascular risk. Retrospectively, patients evaluated for GCA with an ultrasound of the temporal arteries and an MRI of the head, including a T1-fatsat-black blood (T1-BB) sequence, were identified and classified based on cardiovascular risk and a dual reference standard of T1-BB on the segmental level and the clinical diagnosis on the patient level. Intima-media thickness of the common superficial temporal artery (CSTA), frontal and parietal branches (FB, PB) were measured by compression technique. Statistically and clinically optimal (specificity of approx. 90% for the patient level) cut-offs were derived. Diagnostic accuracy was evaluated on the patient level. The population consisted of 144 patients, 74 (51.4%) with and 70 (48.6%) without GCA. The statistically optimal cut-offs were 0.86 mm, 0.68 mm and 0.67 mm for the CSTA, the FB and PB, respectively. On the patient level sensitivity and specificity were 86.5 and 81.4%. Clinically optimal cut-offs were 1.01 mm, 0.82 mm and 0.69 mm and showed a sensitivity of 79.7% and a specificity of 90.0%. For patients without high cardiovascular risk, statistically optimal cut-offs showed a sensitivity of 89.6% and a specificity of 90.5%. Newly derived ultrasound intima-media thickness cut-offs with a dual reference standard show high diagnostic accuracy on the patient level for the diagnosis of GCA, particularly in patients without high cardiovascular risk.

Recurrent Vision Loss in a Patient with Giant Cell Arteritis while on High Dose Corticosteroids

Giant cell arteritis (GCA) is a chronic vasculitis that can lead to permanent vision loss. In this case we describe a patient with permanent monocular vision loss from GCA, managed with long-term glucocorticoids, who presented with elevated erythrocyte sedimentation rate and acute visual loss. This patient was promptly given intravenous steroids, with initial improvement, however, she again experienced acute vision loss on the fourth day of treatment. Given the rare nature of this recurrent GCA-related vision loss during treatment, a broader workup was pursued without an alternative cause identified. Temporal biopsy was not performed due to concern of a false-negative in the setting of chronic steroid use. In this report we discuss the long-term monitoring and management of GCA, recurrence in the acute treatment setting, and present evidence related to diagnosis of GCA in the context of long-term steroid use.

Phase-Specific Healthcare Costs Associated With Giant Cell Arteritis in Ontario, Canada.

To estimate the additional healthcare system costs associated with giant cell arteritis (GCA) in the 1-year prediagnosis and postdiagnosis periods and over long-term follow-up compared to individuals with similar demographics and comorbidities without GCA. We performed a population-based study using health administrative data. Newly diagnosed cases of GCA (between 2002 and 2017 and aged ≥ 66 years) were identified using a validated algorithm and matched 1:6 to comparators using propensity scores. Follow-up data were accrued until death, outmigration, or March 31, 2020. The costs associated with care were determined across 3 phases: the year before the diagnosis of GCA, the year after, and ongoing costs thereafter in 2021 Canadian dollars (CAD). The cohort consisted of 6730 cases of GCA and 40,380 matched non-GCA comparators. The average age was 77 (IQR 72-82) years and 68.2% were female. A diagnosis of GCA was associated with an increased cost of CAD $6619.4 (95% CI 5964.9-7274.0) per patient during the 1-year prediagnostic period, $12,150.3 (95% CI 11,233.1-13,067.6) per patient in the 1-year postdiagnostic phase, and $20,886.2 (95% CI 17,195.2-24,577.2) per patient during ongoing care for year 3 onward. Increased costs were driven by inpatient hospitalizations, physician services, hospital outpatient clinic services, and emergency department visits. A diagnosis of GCA was associated with increased healthcare costs during all 3 phases of care. Given the substantial economic burden, strategies to reduce the healthcare utilization and costs associated with GCA are warranted.

Myocardial infarction in a population-based cohort of patients with biopsy-confirmed giant cell arteritis in southern Sweden

ObjectivesTo determine the incidence rate (IR) of myocardial infarction (MI), relative risk of MI, and impact of incident MI on mortality in individuals with biopsy-confirmed giant cell arteritis (GCA).MethodsMIs in...

Performance of a fast-track pathway for giant cell arteritis in Waikato, Aotearoa New Zealand.

Giant cell arteritis (GCA) is the most common primary vasculitis in adults over 50 years of age. To facilitate early diagnosis and reduce harms from corticosteroids and temporal artery biopsies, fast-track pathways have been established. We review the benefits of the fast-track pathway set up in Waikato, Aotearoa New Zealand. Patients were collected prospectively as part of the fast-track pathway from 2014 to 2022. Their records were then reviewed retrospectively to collect data on clinical features, investigations and treatment. There were 648 individual patients over the study period who had a colour Doppler ultrasound (CDUS) of the temporal arteries. There were 17 true positive CDUS, giving a sensitivity of 10.3% (95% confidence interval [CI] 6.3-15.5%) and specificity of 99.8% (95% CI 99.1-100%). Patients with GCA and a positive scan had significantly fewer steroids than those with GCA and a negative scan (p=0.0037). There were 376 patients discharged after a CDUS who did not have a diagnosis of GCA, resulting in reduced corticosteroid and temporal artery biopsy exposure. This is a real-life study that reflects the benefits of fast-track pathways in Aotearoa New Zealand to patients and healthcare systems. It also shows the effect of corticosteroids on positive CDUS, an important consideration when setting up an fast-track pathway.