From the Journals

Imaging reveals different clinico-pathologic patterns in Takayasu’s, giant cell arteritis



While the symptoms of Takayasu’s and giant cell arteritis do not differ greatly, they are associated with different imaging findings of vascular inflammation and luminal damage, a retrospective cohort study has found.

“Clinical symptoms were not sensitive markers of underlying vascular pathology but were specific when present,” Despina Michailidou, MD, PhD, and colleagues wrote in Annals of the Rheumatic Diseases. “Vascular imaging should be considered in the management of these patients since reliance on the presence of clinical symptoms may not be sensitive to detect vascular pathology within an acceptable window to prevent or minimize damage.”

Dr. Michailidou and coauthors in the Systemic Autoimmunity Branch of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) examined the relationships between clinical presentation and imaging findings in 110 patients involved in an ongoing observational cohort study at the National Institutes of Health, including 56 with Takayasu’s arteritis (TAK) and 54 with giant cell arteritis (GCA). The study included data from 270 visits. Dr. Michailidou conducted the study while she was a research fellow at NIAMS, and she is now a rheumatology fellow at the University of Washington, Seattle.

The team looked at 11 symptoms (lightheadedness, positional lightheadedness, carotidynia, arm claudication vertigo, frontotemporal and posterior headache, posterior neck pain, blurred vision, vision loss, and major CNS events, including stroke, transient ischemic attack, or syncope). These were related to findings on MR angiography (MRA) and 18F-fluorodeoxyglucose PET (FDG-PET).

There were no significant between-group differences in six of the symptoms. However, those with TAK had significantly higher rates of carotidynia (21% vs. 0%), lightheadedness (30% vs. 9%), positional lightheadedness (29% vs. 5%), major CNS events (25% vs. 9%), and arm claudication (52% vs. 28%). Arm claudication was the most common symptom in those with TAK (52%), and blurred vision the most common in patients with GCA (37%).

On the day of evaluation, 8% of patients with TAK reported carotidynia; none of the GCA patients reported this. On FDG-PET, carotidynia was more strongly associated with inflammation of the carotid artery than with damage of the carotid artery on MRA.

The sensitivity of this association was low, which indicates “that an absence of carotidynia could still be associated with imaging abnormalities in the carotid artery, particularly on MRA compared with FDG-PET,” the authors wrote. But specificity was high for both FDG-PET and MRA, suggesting that carotidynia was strongly associated with corresponding carotid artery abnormalities on both FDG-PET and MRA.

More of those with GCA than those with TAK reported posterior neck pain (18% vs. 7%). It was significantly associated with vertebral artery inflammation in those with GCA, but not in those with TAK. There was no significant association with vertebral artery damage in either group.

While sensitivity was low for posterior neck pain and imaging abnormalities, specificity was very high in both groups, which indicates “the presence of posterior neck pain was strongly associated with corresponding vertebral artery abnormalities on both FDG-PET and MRA.”

Posterior headache was present in 5% of GCA patients and was significantly associated with vertebral artery damage, but it was not associated with such damage in patients with TAK.

“While posterior headaches in the occipital region are uncommon in patients with GCA, this study emphasizes that presence of a posterior headache should alert the clinician to the likelihood of associated vascular inflammation and damage in the corresponding vertebral artery,” the researchers wrote.

About 6% of patients with TAK and 10% of those with GCA reported frontotemporal headache. The headache was not associated with carotid PET activity or damage in either group of patients.

“While frontotemporal headaches frequently occur in patients with TAK, and are a cardinal feature of GCA, headaches in this region may reflect inflammation in smaller branches of cranial arteries, rather than the corresponding larger arteries of the neck,” the investigators wrote.

Arm claudication was the most commonly reported symptom overall, present in 52% of those with TAK and 28% of those with GCA. It was more strongly associated with subclavian artery damage on MRA than with inflammation on FDG-PET.

The investigators also assessed the association between specific clinical symptoms and the number of affected neck arteries. Patients with large vessel vasculitis and an increased number of damaged neck arteries on MRA were significantly more likely to experience lightheadedness (odds ratio, 2.61), positional lightheadedness (OR, 3.51), or a major CNS event (OR, 3.23). But those with large vessel vasculitis and inflamed neck arteries on FDG-PET were more likely to experience posterior headache (OR, 2.84).

The study isn’t intended to dictate how MRA and FDG-PET should be employed with these patients, the authors noted.

“Rather, these findings may help clinicians predict imaging pathology in specific vascular territories based on patient-reported symptoms and may inform which type of imaging modality would be the most useful to obtain in certain clinical scenarios, recognizing that additional sequences to detect wall morphology may augment the ability of MR-based assessments to detect vascular inflammation in addition to luminal damage.”

The Division of Intramural Research at NIAMS funded the research. The authors had no financial disclosures.

SOURCE: Michailidou D et al. Ann Rheum Dis. 2019 Oct 24. doi: 10.1136/annrheumdis-2019-216145.

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