Imaging Can Mislead in Inflammatory Arthritis

Maureen Salamon

June 17, 2019

MADRID — Too often, imaging tests lead to the overdiagnosis and excess treatment of inflammatory arthritis, leaving patients vulnerable to adverse drug effects with no improvement in outcome, according to a presentation here at the European League Against Rheumatism 2019 Congress.

"Imaging has to be used in context with clinical assessments and be directed toward the question rheumatologists are looking for," said Stefan Siebert, MBBCH, PhD, from the University of Glasgow in the United Kingdom.

"Imaging is an adjunct to being a good doctor in terms of decision-making for diagnosis and treatment," he told Medscape Medical News. "It shouldn't drive you."

Siebert described several pivotal studies to illustrate how readily inflammatory forms of arthritis — such as rheumatoid arthritis and axial spondyloarthritis — are overdiagnosed or treated inappropriately.

"In terms of diagnosis, the imaging we use should be in high-risk populations rather than in those with a low probability of finding what you're looking for," Siebert told the audience of more than 1000 people. "And in RA, in terms of treatment, beyond clinical remission, imaging doesn't add anything further to outcomes."

For example, "there was no difference in clinical outcome" when musculoskeletal ultrasound (MSUS) was used to assess disease activity and guide an intensive treat-to-target strategy of disease-modifying anti-rheumatic drugs (DMARDs) in the randomized TaSER study of 111 patients with early rheumatoid arthritis (Ann Rheum Dis. 2016;75:1043-1050). "Ultrasound didn't add anything," Siebert said.

Similarly, there was no meaningful difference in outcomes over 2 years when structured ultrasound that targeted clinical and imaging remission was compared with a conventional strategy that targeted clinical remission in 238 patients with early rheumatoid arthritis in the ARCTIC study (BMJ. 2016;354:i4205).

And there was no improvement in outcomes when an MRI-guided treat-to-target strategy was compared with a conventional treat-to-target strategy in the IMAGINE-RA trial of 200 patients (JAMA. 2019;321:461-472). "In terms of clinical remission and radiographic progress, there was no difference between the two groups," said Siebert.

In this trio of studies, treatment was escalated and DMARD use was higher in the MSUS and MRI groups, and serious adverse events were also higher.

"Using imaging to guide therapy led to the prescription of potentially harmful medicines," Siebert reported. "It comes at a cost to the patient and society."

Overdiagnosis

In a study of healthy individuals subjected to MSUS on 40 joints, power Doppler results in the wrists of 8% of study participants indicated synovial inflammation marking rheumatoid arthritis, but these people had no symptoms (Rheumatology [Oxford]. 2015;54:458-462).

"In the rheumatology world, we think of inflammation as bad," he explained, "but inflammation is a normal response to insults. That's our immune system doing its job. Just detecting inflammation is not enough to make a diagnosis."

And when rheumatologists rely too heavily on MRI-indicated sacroiliac joint inflammation, it is easy to overdiagnose axial spondyloarthritis, Siebert added.

"It's the intensity of the inflammatory changes that are important on MRI, rather than superficial, normal inflammation," which is often experienced by runners, pregnant women, and people with lower back pain, among others, he said.

In the rheumatology world, we think of inflammation as bad, but inflammation is a normal response to insults.

Enthesitis is another radiographic finding that appears in the vast majority of patients with psoriasis or fibromyalgia, for example, but that doesn't mean they have inflammatory arthritis, Siebert said.

"We have this problem of having diagnoses as binary," he explained, "but inflammation is a normal response and diagnosis is not binary."

"We need to be really careful. Diagnosis is probably a bit more dynamic than that," he added. "The scans just assist us."

In our fervor to optimize treatment from the point of view of a clinician, we cannot forget about the patient, said Jose Antonio Da Silva, MD, PhD, from the University of Coimbra in Portugal.

An early diagnosis "may give the patient the best possible outcome," he told Medscape Medical News, "but we cannot forget that all medications have side effects and may be priming patients to negative results that may not happen if the disease followed its course."

Patient-reported outcomes should be paramount when physicians aim to "measure the success of our interventions and the appropriateness of our diagnosis," Da Silva said.

Siebert reports receiving grant or research support from, being a consultant for, or being a member of the speakers bureau for BMS, AbbVie, Novartis, Pfizer, Janssen, Celgene, UCB, and Boehringer Ingelheim. Da Silva has disclosed no relevant financial relationships.

European League Against Rheumatism (EULAR) 2019 Congress: Abstract SP0141. Presented June 14, 2019.

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