The prediction of response to treatment using power Doppler in rheumatoid arthritis: a systematic review.

Objectives: There is no consensus on how musculoskeletal ultrasound (US), especially power Doppler (PD) positivity, should inform treatment decisions in RA. We aimed to summarize the literature on whether PD positivity can predict response to intensification of RA therapies in patients with moderate to high clinical disease activity. Methods: A systematic literature review was performed using a predefined PICO strategy. The titles and abstracts, and subsequently full texts, were independently screened and reviewed by two reviewers and any disagreement was resolved by a third investigator. Studies that investigated the predictive value of PD were included. Results: Among 2580 abstracts/titles, 13 studies were included. Studies were heterogeneous regarding the inclusion criteria, baseline and new treatments, scanned joints and follow-up duration. In eight studies, patients with higher baseline PD activity had a better response to treatment, mostly with higher reductions in clinical indices. In contrast, two studies found that the probability of achieving clinical remission decreased as the baseline PD score increased. There was no association between baseline PD and the achievement of clinical remission at the follow-up in the remaining three studies. Conclusion: The baseline Doppler severity may suggest better improvement with higher reductions in composite scores, but this may not be enough to predict a remission state. How US can be used to predict response in RA management requires a well-designed study that will need to be shaped by the existing observations, most importantly identifying the outcome measure that will also be important for daily practice.