Clinical practice in giant cell arteritis based on a survey of specialists

Management of giant-cell arteritis in Switzerland: an online national survey

AIMS OF THE STUDY

To assess current practices in diagnosing, treating, and following-up giant-cell arteritis by specialists in Switzerland and to identify the main barriers to using diagnostic tools.

METHODS

We performed a national survey of specialists potentially caring for patients with giant-cell arteritis. The survey was sent by email to all members of the Swiss Societies of Rheumatology and for Allergy and Immunology. A reminder was sent to nonresponders after 4 and 12 weeks. Its questions covered the following dimensions: respondents' main characteristics, diagnosis, treatment, and imaging's role during follow-up. The main study results were summarized using descriptive statistics.

RESULTS

Ninety-one specialists, primarily aged 46-65 years (n = 53/89; 59%), working in academic or nonacademic hospitals or private practice, and treating a median of 7.5 (interquartile range [IQR]: 3-12) patients with giant-cell arteritis per year participated in this survey. Ultrasound of temporal arteries/large vessels (n = 75/90; 83%) and positron-emission-tomography-computed tomography (n = 52/91; 57%) or magnetic resonance imaging (n = 46/90; 51%) of the aorta/extracranial arteries were the most common techniques used to diagnose giant-cell arteritis with cranial or large vessel involvement, respectively. Most participants reported a short time to obtain imaging tests or arterial biopsy. The glucocorticoid tapering scheme, glucocorticoid-sparing agent, and glucocorticoid-sparing treatment duration varied among the participants. Most physicians did not follow a predefined repeat imaging scheme for follow-up and mainly relied on structural changes (vascular thickening, stenosis, or dilatation) to drive treatment choice.

CONCLUSIONS

This survey indicates that imaging and temporal biopsy are rapidly accessible for diagnosing giant-cell arteritis in Switzerland but highlights heterogeneous practice in many disease management areas.

Fever Correlation with Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP) Concentrations in Patients with Isolated Polymyalgia Rheumatica (PMR): A Retrospective Comparison Study between Hospital and Out-of-Hospital Local Registries

Background: Polymyalgia rheumatica (PMR) is the most common systemic inflammatory rheumatic disease affecting the elderly. Giant cell arteritis (GCA) is a granulomatous vasculitis affecting the aorta and its branches associated with PMR in up to 20% of cases. In recent studies based on university hospital registries, fever correlated with the erythrocyte sedimentation rate (ESR) but not with C-reactive protein (CRP) concentrations at the time of diagnosis in patients with isolated PMR. A long delay to a PMR diagnosis was suggested to explain this discrepancy, possibly caused by laboratory alterations (for instance, anemia of chronic disease type) that can influence only ESR. We performed a retrospective comparison study between the university hospital and two out-of-hospital public ambulatory databases, searching for any differences in fever/low-grade fever correlation with ESR and CRP. Methods: We identified all patients with newly diagnosed PMR between 2013 and 2020, only including patients who had a body temperature (BT) measurement at the time of diagnosis and a follow-up of at least two years. We considered BT as normal at <37.2 °C. Routine diagnostic tests for differential diagnostics were performed at the time of diagnosis and during follow-ups, indicating the need for more in-depth investigations if required. The GCA was excluded based on the presence of suggestive signs or symptoms and routine ultrasound examination of temporal, axillary, subclavian, and carotid arteries by experienced ultrasonographers. Patients with malignancies, chronic renal disease, bacterial infections, and body mass index (BMI) > 30 kg/m2 were excluded, as these conditions can increase CRP and/or ESR. Finally, we used the Cumulative Illness Rating Scale (CIRS) for quantifying the burden of comorbidities and excluded patients with a CIRS index > 4 as an additional interfering factor. Results: We evaluated data from 169 (73 from hospital and 96 from territorial registries) patients with newly diagnosed isolated PMR. Among these, 77.7% were female, and 61.5% of patients had normal BT at the time of diagnosis. We divided the 169 patients into two cohorts (hospital and territorial) according to the first diagnostic referral. Age at diagnosis, ESR, CRP, median hemoglobin (HB), and diagnostic delay (days from first manifestations to final diagnosis) were statistically significantly different between the two cohorts. However, when we assessed these data according to BT in the territorial cohort, we found a statistical difference only between ESR and BT (46.39 ± 19.31 vs. 57.50 ± 28.16; p = 0.026). Conclusions: ESR but not CRP correlates with fever/low-grade fever at the time of diagnosis in PMR patients with a short diagnosis delay regardless of HB levels. ESR was the only variable having a statistically significant correlation with BT in a multilevel regression analysis adjusted for cohorts (β = 0.312; p = 0.014).