Peter A. Merkel
CHICAGO — Advanced vascular imaging is expected to play an increasingly important role in the diagnosis and management of large-vessel vasculitis, according to a draft of the American College of Rheumatology/EULAR classification criteria for the condition.
“In 1990, the ACR issued classification criteria for seven or eight sets of different forms of vasculitis, including giant cell arteritis and Takayasu arteritis,” Peter A. Merkel, MD, MPH, chief of the division of rheumatology at the University of Pennsylvania, said at the ACR/ARHP 2018 Annual Meeting. “Those classification criteria have had a profound impact on research; almost all of the research since then has depended on that classification criteria to some extent.”
“However, that was approximately 30 years ago, and in that time, several important changes have occurred including a wide adoption of the use of imaging for everything in medicine,” Merkel said. “The availability of MRI, CT scan and ultrasound is incredibly different than it was in 1990, and they have been used regularly.”
Within the proposed draft criteria for giant cell arteritis, investigators recommended that:
- Patients are required to have a diagnosis of vasculitis and aged at least 40 years at diagnosis.
- Patients exhibit at least six points of inclusion criteria, including features such as jaw/tongue claudication, morning stiffness, persistent, severe head pain, rapid visual loss and tenderness of the scalp.
- Imaging criteria include aortic activity detected via fluorodeoxyglucose PET-CT scans, bilateral axillary involvement and ‘halo’ sign at temporal arteries.
Similarly, proposed revisions to the classification criteria for Takayasu arteritis include:
- Patients are required to have a diagnosis of vasculitis, be aged at least 60 years at diagnosis, and exhibit signs of vasculitis via imaging.
- Patients exhibit at least five points of inclusion criteria, including features such as arm/leg claudication, female gender and vasculitis-associated angina or myocardial ischemia.
- Vascular exam findings of arterial bruit, diminished pulse in upper extremity, diminished pulse in the carotid artery, and interarm systolic blood pressure differences of 20 mm Hg.
Merkel noted that these proposed classification criteria will allow clinicians to “sort out among the different types of vasculitis” and differentiate them from conditions that mimic large vessel vasculitis.
“I remind you that this is for classification,” Merkel said. “ACR/EULAR are very careful in their use of that term. ‘Classification’ is to sort out among people who have vasculitis which one it is – this is not to be used diagnostically. However, it is often used inappropriately by people and certainly spreads awareness for the disease.”
Although the draft criteria have not yet been endorsed by ACR/EULAR, Merkel noted that the new set of classification criteria have greater performance than the 1990 criteria, both in general and when the 1990 criteria are applied to current cohorts.
“I think the impact of our new criteria will be substantial, and will likely be widely adopted by researchers as have other criteria released by ACR/EULAR,” Merkel said. “I think it will also highlight some important aspects of the disease that will educate clinicians throughout the world who may not see these diseases that often.”– by Robert Stott
Disclosure: Merkel reports no relevant financial disclosures.
Merkel PA. ACR/EULAR Classification Criteria for Large-Vessel Vasculitis. Presented at ACR/ARHP Annual Meeting, Oct. 20-24, 2018; Chicago.