Ultrasound-Based Vasculitis Diagnosis May Save Vision

Fast-track outpatient clinic for giant cell arteritis also cuts inpatient days

• by Nancy Walsh
  Senior Staff Writer, MedPage Today

Action Points

• The implementation of a "fast-track" clinic with rapid ultrasound assessment for patients with suspected giant cell arteritis led to a dramatic decrease in permanent visual impairment.
• Note that the diagnostic program involved patient evaluation with color Doppler ultrasound within 24 hours of presentation, followed by immediate treatment with corticosteroids for positive findings.

The implementation of a "fast-track" clinic with rapid ultrasound assessment for patients with suspected giant cell arteritis led to a dramatic decrease in permanent visual impairment, a Norwegian study found.
Among 32 patients evaluated conventionally using biopsy of the temporal artery and 43 assessed with the fast-track ultrasound approach, 18 patients -- nine patients in each group -- experienced visual disturbances typical of giant cell arteritis, such as diplopia, blurred vision, and amaurosis fugax, according to Andreas P. Diamantopoulos, MD, PhD, of the Hospital of Southern Norway Trust in Kristiansand, and colleagues.
Yet six patients in the conventional group (21.5%) experienced permanent visual loss compared with only one assessed with the fast track ultrasound approach (2.4%), with what was an 88% lower rate (RR 0.12, 95% CI 0.01 to 0.97, P=0.01), the researchers reported online in Rheumatology.
"Our data indicate that the fast-track clinic including a rapid assessment by ultrasonography may significantly reduce the risk of permanent visual impairment in giant cell arteritis patients," they observed.
Giant cell arteritis is the most common of the primary vasculitides, most often affecting individuals older than 50. One in five patients are thought to experience irreversible vision loss, and high-dose steroids are the treatment of choice.
The gold standard for diagnosing the condition has been biopsy of the temporal artery, with confirmation being provided by a positive response to corticosteroid therapy.
However, the inflammation of the artery typically is segmental and so can be missed if the biopsy needle is inserted in areas unaffected by the vasculitic process.
In addition, delay in obtaining the biopsy is common and clinicians may hesitate to prescribe corticosteroids in high doses to older patients, yet speed is of the utmost importance as vision loss can occur rapidly.
"The fast-track approach has been introduced in several fields in medicine with remarkable success in reducing mortality, morbidity, and inpatient days of care. Rapid initiation of treatment improves outcomes in rheumatoid arthritis through the utilization of the window of opportunity," the researchers noted.
Reports of the successful use of ultrasound for the noninvasive diagnosis of giant cell arteritis have emerged over the past decade, and in 2012 Diamantopoulos and colleagues began implementing a diagnostic program involving patient evaluation with color Doppler ultrasound within 24 hours of presentation, followed by immediate treatment with corticosteroids for positive findings.
The ultrasound assessment included examination of the superficial temporal arteries, the frontal and parietal branches, and the axillary and common carotid arteries, with a hypoechoic ring (halo sign) surrounding a vessel in any of these arteries being considered a positive result.
To compare the results of the fast-track approach and conventional diagnosis, the researchers analyzed outcomes for patients seen in their clinic before and after the implementation date of 2012, including 75 patients seen from April 2010 to October 2014.
Patients' mean age was 74, and twice as many women as men were affected.
The most common visual disturbances were amaurosis fugax in 22%, anterior ischemic optic neuropathy in 22%, blurred vision in 16%, and diplopia in 12%.
The mean number of days spent in the hospital among the conventional care group was 3.6, compared with 0.6 day in the fast-track group, for a mean difference of 3 days (P<0.0005).
The Norwegian Ministry of Finance estimated that the cost of daily inpatient care was 12,433 Norwegian krone ($1,512).
"Thus, implementation of the fast track clinic reduced the cost of inpatient care by ~37,300 Norwegian krone per patient, a total reduction for all the 42 giant cell arteritis patients assessed in the fast-track clinic of 1,566,558 Norwegian krone [$191,138]," the researchers determined.
"The implementation of an innovative technique combined with quick evaluation can lead to a significant decrease of one of the most feared complications of the giant cell arteritis disease. Furthermore, the fast track clinic seems to be more cost effective by reducing the need for inpatient days of care," they wrote.
Limitations of the study included its retrospective design and small number of patients.
"Further observational studies are warranted in order to confirm these encouraging and promising data," Diamantopoulos and colleagues concluded.

Agder Medforsk, a nonprofit scientific organization, supplied the ultrasound equipment (Siemens Acuson S2000).
Diamantopoulos and co-authors disclosed no relevant relationships with industry.

• Reviewed by Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, BSN, RN, Nurse Planner

last updated 08.25.2015