Giant Cell Arteritis (GCA) causes inflammation and narrowing of blood vessels and can cause
blindness in one third of patients. It is important that a prompt, accurate diagnosis of GCA
is made and treatment given as steroids for two or more years. Currently there is no 100%
accurate test for GCA. Patients usually have new headache and scalp tenderness, typically
with an abnormal blood test. However, it can be difficult to distinguish non-serious forms
of headache from GCA; infection produces similar abnormal blood results. If there is a
suspicion of GCA, treatment with steroids is started straight away. To confirm a diagnosis,
the patient will need a biopsy of a temporal artery (a minor procedure performed under local
anaesthetic to remove a sample of one of the scalp arteries). However, up to 44% of patients
will have a normal biopsy. Therefore it is difficult to know if a patient with a normal
biopsy does or does not have GCA. Withdrawing steroid treatment may increase the risk of
blindness. Continuing treatment in a patient without GCA increases the risk of side effects
(e.g., weight gain, infection risk, osteoporosis and fracture risk, high blood pressure,
diabetes, cataracts). It is important to improve diagnostic tests for GCA. Another test to
help in diagnosing GCA is an ultrasound scan of the arteries in the side of the head and
under the arms. Ultrasound does not involve surgery; it is a simple test which can be
performed as an out patient. Gel is applied to both sides of the head and under each arm. A
sound probe is placed over the artery at each site to produce the scan.
The investigators' study will examine the role of ultrasound in diagnosis of 402 patients
with suspected GCA. All patients will have an ultrasound examination in addition to biopsy
within a week of starting steroids. Patients will be treated according to usual practice.
After six months, the investigators will reassess the diagnosis. The investigators will look
at the accuracy of ultrasound compared with or combined with biopsy. The investigators will
look at how a doctor's knowledge of ultrasound results or biopsy results alone would affect
the diagnosis and recommendation to continue or stop steroid treatment. The investigators
will assess whether knowledge of both results together would alter the diagnosis and
treatment. The investigators will collect information to estimate the costs of different
ways of diagnosing GCA in relation to the impact on quality of life.
OVERALL DESIGN: The overall design consists of a cohort study of 402 participants with
suspected GCA who will be followed up for 6 months; a cost-effectiveness study comparing
ultrasound with temporal artery biopsy; a study of observer agreement in evaluating
ultrasound and temporal artery biopsies; and an expert panel assessing the appropriateness
of alternative strategies for diagnosing and treating patients with suspected GCA.
1. To evaluate the diagnostic accuracy (sensitivity and specificity) of ultrasound as an
alternative to temporal artery biopsy for the diagnosis of GCA in patients referred for
biopsy with suspected GCA.
2. To evaluate the cost-effectiveness (incremental cost per QALY) of ultrasound instead of
biopsy in the diagnosis of GCA.
3. To evaluate inter-observer agreement in the assessment of ultrasound and temporal
4. To elicit expert views on the appropriateness of performing a biopsy following
ultrasound using clinical vignettes.
5. To evaluate the diagnostic accuracy (sensitivity and specificity) of the sequential
diagnostic strategy from 4 as an alternative to temporal artery biopsy alone in the
diagnosis of GCA.
6. To evaluate the cost-effectiveness (incremental cost per QALY) of the diagnostic
strategy from 4 instead of biopsy alone in the diagnosis of GCA.
A prospective cohort study to evaluate the impact of ultrasound or biopsy of temporal
arteries on diagnosis of GCA and treatment decisions . The cohort study will use a paired
design, i.e. all participants will have both US and biopsy, with diagnostic performance
assessed against a composite reference standard diagnosis following final (6 months)
assessment. To evaluate the impact of US/biopsy results on clinical practice and longer term
outcomes, we will derive clinical vignettes based on cases recruited to the study, and
present them to the treating clinician, along with either the ultrasound, or biopsy or both
results, so that they can indicate diagnosis and proposed treatment. The main
cost-effectiveness analyses will evaluate incremental cost per quality adjusted life year
(QALY) on a long term (lifetime) horizon between diagnostic strategies.
Outpatient and inpatient rheumatology and ophthalmology departments in 25 National Health
Service (NHS) trusts in the United Kingdom (UK) (also sites in Europe of required) with
access to high resolution US.
TARGET POPULATION: Patients with suspected GCA who would normally require an urgent temporal
artery biopsy, i.e. referrals from primary care and suspected GCA identified in secondary
care. Recruitment of participants will be restricted to patients for whom US and biopsy can
be performed within 7 days of starting high-dose steroids.
HEALTH TECHNOLOGIES BEING ASSESSED:
Halo, stenosis, or occlusion assessed by high resolution US; presence of giant cells or
granulomatous inflammation on temporal artery biopsy.
MEASUREMENT OF COST AND OUTCOMES:
Data collection at baseline, 2 weeks and 6 months will include clinical and laboratory
markers of disease activity, resource use, health-related quality of life (HRQoL) using the
EuroQol-5D (EQ-5D), and adverse events. Baseline assessment will include retrospective
assessment of symptoms and erythrocyte sedimentation rate/C-reactive protein (ESR/CRP)
results before starting steroids. The reference standard diagnosis will be made using a
composite of American College of Rheumatology classification criteria, GCA-related events,
and alternative diagnoses using data collected at all assessments. Proposed treatment data
will be collected from participating clinicians after each test result is released, and
classified as treatment for GCA (e.g. initiate/continue steroids) or not GCA (e.g.
withdraw/rapid taper of steroids) to compare changes in proposed treatment and evaluate
agreement with the reference diagnosis. Unit costs of resources used will be obtained from
nationally published sources where available. Modelling will estimate the impact of
diagnostic strategies on clinical outcomes (e.g. GCA complications and steroid related
adverse events), their costs and impact on HRQoL beyond study follow-up and within study
follow-up. Probabilities of events, their cost and impact will be obtained from study data,
a systematic literature review, or in the absence of relevant data, by formal elicitation of
expert opinion. Costs and benefits will be discounted at 3.5% (National Institute for Health
and Care Excellence [NICE] guidance) and uncertainty (including modelling assumptions)
subjected to probabilistic sensitivity analysis and scenario analysis.
A sample size of 402 patients provides 90% power at a 5% type I error rate to test the joint
hypothesis that (i) US has greater sensitivity than biopsy (to detect an increase in
sensitivity from 76% for biopsy (assuming a 0.24 false negative fraction based on 9-44%
biopsy-negative GCA) to 87% sensitivity for US; and (ii) to detect specificity of US of no
less than 0.83 based on an expected specificity of 0.96. This sample size will allow
estimation of a one-sided rectangular confidence region for US false and true positive
fractions, assuming 80% prevalence of GCA in patients having a biopsy for suspected GCA,
with the sample size inflated (gamma=0.1) due to uncertainty in the proportion of
cases/controls in a cohort design. We will actually recruit 430 cases to allow for possible
drop-outs from the study. In addition we will recruit 270 individuals for training purposes,
to allow each centre to learn the technique of temporal artery and axillary artery scanning.
Each centre will collect 10 such individuals (training cases), who will be of similar age
and gender as the study cohort, but who will not have temporal arteritis. This is very
important in order to ensure that observers are trained to recognise the appearances seen in
normal (non GCA arteries) especially patients with atherosclerosis. Further ultrasound
training including a video exam (to identify images of both normal and abnormal features of
GCA) and a 'hot' case assessment (scanning a patient with GCA) will be designed into the
ultrasound training programme. In addition, we will provide adequate training days (e.g. 2
separate training days) when all observers will be trained formally by Dr Schmidt and other
ultrasound experts to ensure adequate observer agreement. The first training day will be
held prior to starting the recruitment of patients, and will be repeated after the first
Total: 48 months (UPDATED TO 60 MONTHS SEE BELOW) Month 1-6 Study materials/protocols
prepared; Ethics and research governance approval complete; Centres trained, approved and
ready to recruit.
Month 7-12 Recruitment monitoring report; Quality control report. Month 13-18 Recruitment
monitoring report; Quality control report; Additional centres (if required) trained,
approved and ready to recruit; Month 19-24 Recruitment monitoring report; Quality control
report. Month 25-30 Recruitment monitoring report; Quality control report; Web-based US and
biopsy assessment developed.
Month 31-36 Recruitment completed; Clinical vignettes (web-based) developed. Month 37-42
Follow-up completed; Inter-rater assessment of US and biopsy images analysis competed;
Expert panel review of vignettes completed.
Month 43-48 Database cleaned and locked; Analysis completed; statistical analysis and
economic modelling, report drafting and preparation of papers. Final report completed.
PLEASE NOTE: 12 MONTH EXTENSION WAS GRANTED BY THE FUNDER (NIHR HTA) IN SEPTEMBER 2012 TO
EXTEND THE RECRUITMENT PERIOD FROM THE END OF DECEMBER 2012 TO END OF DECEMBER 2013 (A
FURTHER 12 MONTHS).
TH END OF STUDY WILL NOW BE DECEMBER 2014
The study will be overseen by a Trial Steering Committee (TSC) and an independent Data
Monitoring Committee (DMC)at least 1 meeting per year.
We will develop a biobank of tissue, serum, DNA and ultrasound video imaging of blood
vessels in GCA. An important benefit of the primary protocol is that we can use the
accumulated material for a number of related projects.
Observational Model: Cohort, Time Perspective: Prospective
Procedure : Ultrasound of temporal and axillary arteries, Procedure : Temporal artery biopsy
Study Arm Groups : Suspected GCA, Training cohort, Suspected GCA
See Interventions above
- To evaluate the diagnostic accuracy of ultrasound vs temporal artery biopsy for diagnosis of suspected GCA and to evaluate the cost-effectiveness (incremental cost per QALY) of ultrasound instead of biopsy in the diagnosis of GCA.; Six months
- To evaluate inter-observer agreement in the assessment of ultrasound and temporal artery biopsy; Six months; To elicit expert views on the appropriateness of performing a biopsy following ultrasound using clinical vignettes; 3 years; To evaluate the diagnostic accuracy (sensitivity and specificity) of the sequential diagnostic strategy as an alternative to temporal artery biopsy alone in the diagnosis of GCA; 3 years; To evaluate the cost-effectiveness (incremental cost per QALY) of the diagnostic strategy of combined ultrasound and biopsy instead of biopsy alone in the diagnosis of GCA.; 3 years; Specific adverse events measured at each assessment; daily and cumulative steroid dose; steroid side effects; and pain or dysaesthesia at the biopsy site.; Six months; Evolution of an alternative diagnosis; Six months; Negative predictive value of ultrasound in preventing the need for temporal artery biopsies.; Six months; Cost analysis of performing a screening ultrasound examination plus biopsy as part of the diagnostic workup of all patients with suspected GCA; or of performing a screening ultrasound examination instead of biopsy; or of performing a screening ultrasound; Six months; Cost analysis of performing a screening ultrasound examination instead of biopsy in cases with a very low probability of GCA as part of the diagnostic workup of all patients with suspected GCA.; 3 years; Prediction of potential harm done to patients by over diagnosis or under diagnosis of GCA as a result of ultrasound use, either alone or in combination with biopsy; 3 years; Value of axillary artery ultrasound scanning in contributing to the diagnosis of GCA.; Six months; Analysis of proportion of patients with a biopsy positive halo, stenosis, or occlusion assessed by high resolution ultrasound; 3 years; Presence of characteristic features of GCA on temporal artery biopsy in relation to clinical and ultrasound findings; 2 weeks
Sorry, this information is not available
This is available on the Clinicaltrials.gov
18 Years - N/A
Sorry, this information is not available
Sorry, this information is not available
- Inclusion Criteria: for the cohort study
- 1. A clinical suspicion of new diagnosis of GCA e.g. patients with a new onset of
- headache, scalp tenderness, with or without elevated CRP or ESR, jaw or tongue
- claudication with or without visual loss.
- 2. The clinician decides that the patient requires an urgent temporal artery biopsy to
- determine whether or not the diagnosis is GCA.
- 3. The patient agrees and provides NHS consent to undergo a temporal artery biopsy as
- part of standard care.
- 4. Patients have been started on high dose glucocorticoids or will be started on high
- dose glucocorticoids.
- 5. Patients must be willing to attend for an ultrasound scan of their temporal and
- axillary arteries.
- 6. Participants must be willing to give informed written consent or willing to give
- permission for a nominated friend or relative to provide written informed assent if
- they are unable to do so because of physical disabilities e.g. sudden onset of
- blindness/vision loss which can be caused by GCA (this will be made clear in the
- ethics approval application).
- 7. Must be 18 years of age or over.
- For the training cases
- 1. Patients attending hospital outpatient or in patient departments for assessment for
- any condition (apart from giant cell arteritis or polymyalgia rheumatica) or healthy
- staff volunteers.
- 2. Above the age of 50 years.
- 3. Willing to attend for an ultrasound scan of their temporal and axillary arteries.
- 4. Willing and able to give written informed consent.
- Exclusion criteria: for the cohort study
- 1. Previous diagnosis of GCA.
- 2. Use of high dose glucocorticoid (>20mg prednisolone/day) for management of current
- suspected GCA for more than 7 days prior to the dates of the ultrasound and biopsy.
- 3. Long term (>1 month) high dose (>20mg per day at any time) steroids for conditions
- other than PMR, within three months prior to study entry.
- 4. Inability to give informed consent (either written consent or verbal assent from a
- relative or carer)
- 5. Inability to undergo an ultrasound scans of the temporal and axillary arteries.
- 6. Patients with a known cause of headache (not due to GCA), or any condition which
- would preclude the need for a temporal artery biopsy.
- 7. Patients who are unable to undergo an ultrasound scan and a temporal artery biopsy
- within 7 days of starting glucocorticoids.
- For the training cases
- 1. Diagnosis of suspected GCA or a previous history of diagnosed or suspected GCA.
- 2. Inability to give written informed consent.
- 3. Inability to undergo an ultrasound scans of the temporal and axillary arteries
This is in the inclusion criteria above
The Role of Ultrasound Compared to Biopsy of Temporal Arteries in the Diagnosis and Treatment of Giant Cell Arteritis (GCA).
Not available for this trial
- University of Sheffield
- Southend University Hospital
- Nuffield Orthopaedic Centre NHS Trust
- Oxford University Hospitals NHS Trust
- The Leeds Teaching Hospitals NHS Trust
- University of Bristol
- London School of Hygiene and Tropical Medicine
- Medical Center for Rheumatology Berlin-Buch
University of Oxford