Assessment and comparison of probability scores to predict giant cell arteritis

Chadi Sargi1, Stephanie Ducharme-Benard2, Valerie Benard2

  • 1Department of Medicine, Montreal Sacre-Coeur Hospital, University of Montreal, Montreal, QC, Canada.

Clinical Rheumatology
|July 31, 2023
PubMed

Insights

Combining the giant cell arteritis probability score (GCAPS) with ultrasound halo count accurately predicts giant cell arteritis (GCA). This approach offers high sensitivity and specificity, improving diagnostic speed in GCA Fast-Track clinics.

Area of Science:

  • Rheumatology
  • Vascular Medicine
  • Diagnostic Imaging

Background:

  • Giant cell arteritis (GCA) is a systemic vasculitis affecting large arteries, primarily the aorta and its branches.
  • Accurate and timely diagnosis of GCA is crucial to prevent irreversible complications such as vision loss.
  • Clinical assessment and imaging play vital roles in GCA diagnosis, but comparative performance data for various scoring systems are needed.

Purpose of the Study:

  • To compare the diagnostic performance of three clinical prediction scores (GCAPS, Ing score, BK score) and two color Doppler ultrasound (CDUS) metrics (halo count, halo score) for predicting GCA.
  • To evaluate the combined utility of clinical and CDUS scores in GCA diagnosis.

Main Methods:

  • A prospective cohort study included 200 patients with suspected new-onset GCA.
  • Clinical and CDUS data were collected at initial visits to calculate prediction scores.
  • Final GCA diagnosis was confirmed by blinded vasculitis specialists after 6 months, with diagnostic accuracy assessed via ROC curves.

Main Results:

  • The giant cell arteritis probability score (GCAPS) demonstrated the highest sensitivity (0.983) among clinical scores, while the Bhavsar-Khalidi (BK) score showed the highest specificity (0.711).
  • Color Doppler ultrasound (CDUS) halo count of 1 or more exhibited high sensitivity (0.966) and specificity (0.979).
  • Combining concordant clinical and CDUS prediction scores yielded excellent performance in predicting GCA.

Conclusions:

  • A combined approach using a clinical score (e.g., GCAPS) and CDUS halo count provides an accurate and effective method for GCA prediction.
  • This combined strategy is recommended for use in GCA Fast-Track clinics to expedite diagnosis and management.
  • Ultrasound halo count alone is a sensitive and specific indicator for GCA diagnosis.
Abstract