## 3 Results
### Clinical Presentation of Patients Referred to the Fast-Track Clinic  
The detailed description of symptoms leading to referral to the FTA are shown in Table 1. Headache was the most frequent symptom, followed by PMR, and systemic symptoms. The following manifestations were the most characteristics to distinguish patients with a final confirmed diagnosis of GCA compared to those who received an  
Figure 1: Flowchart of the fast-track reasons for referral and findings. US: ultrasound; GCA: giant cell arteritis; NOT GCA: diagnosis of GCA not confirmed; pos: positive.  
alternative diagnosis after FTA assessment: jaw claudication, scalp tenderness, bilateral blindness. Systemic symptoms such as fever and weight loss, albeit non-specific, were significantly more frequent in patients with confirmed GCA. Figure 2 (panel A and B) represents the intersection and overlap of presenting symptoms in relation to US findings among patients referred to the FTA who received a confirmed diagnosis of GCA.  
Visual loss occurred in 10.8% of patients with a final diagnosis of GCA. Visual loss not attributable to a final diagnosis of GCA was recorded in 4.5% of patients (\(p\) = 0.041). Bilateral visual loss occurred in 2.7% of patients with GCA.  
PMR had been previously diagnosed and treated prior to the occurrence of a new clinical suspicion leading to the referral to the FTA in 8 (7.2%) patients with GCA. Ongoing new-onset PMR symptoms were recorded for 61 (54.9%) patients receiving a final diagnosis of GCA. On the other hand, 72 (40.9%) referred patients without GCA had a previous diagnosis of PMR and were referred after the occurrence of new symptoms such as headache or systemic symptoms, but these were finally not attributed to a diagnosis of GCA. Peripheral arthritis was found in 4.5% of patients with GCA. Other rarer manifestations such as non-productive cough were recorded in 2.7% of patients.  
\begin{table}
\begin{tabular}{c c c c c} \hline  & **GCA (N= 111)** & **NOT GCA (N = 176)** & **Overall (N = 287)** & \(p\) \\ \hline Headache & 74 (66.6\%) & 65 (36.9\%) & 138 (47.9\%) & \textless{}0.0001 \\ \hline Jaw claudication & 40 (36\%) & 4 (2.3\%) & 50 (17.3\%) & \textless{}0.0001 \\ \hline Tongue claudication & 11 (9.9\%) & 0 & 11 (3.8\%) & \textless{}0.0001 \\ \hline Blurred vision & 6 (5.4\%) & 4 (2.3\%) & 10 (3.5\%) & 0.165 \\ \hline Visual loss & 12 (10.8\%) & 8 (4.5\%) & 20 (6.9\%) & 0.041 \\ \hline Bilateral visual loss & 3 (2.7\%) & 0 & 5 (1.7\%) & 0.029 \\ \hline Scalp tenderness & 25 (22.5\%) & 1 (0.56\%) & 26 (9\%) & \textless{}0.0001 \\ \hline Polymylgia rheumatic & 61 (54.9\%) & 66 (37.5\%) & 127 (44\%) & 0.039 \\ \hline Systemic symptoms & 47 (42.3\%) & 32 (18.1\%) & 79 (27.4\%) & \textless{}0.0001 \\ \hline \(\geq\)2 systemic symptoms & 10 (9\%) & 4 (2.3\%) & 14 (4.9\%) & 0.011 \\ \hline Isolated raised inflammatory markers & 1 (0.9\%) & 9 (5.1\%) & 10 (3.5\%) & 0.058 \\ \hline Normal inflammatory markers & 2 (1.8\%) & 45 (25.6\%) & 47 (16.3\%) & \textless{}0.0001 \\ \hline Fever & 29 (26.1\%) & 13 (7.4\%) & 42 (24.5\%) & \textless{}0.0001 \\ \hline Weight loss & 33 (29.7\%) & 19 (10.7\%) & 52 (18\%) & \textless{}0.0001 \\ \hline Arthritis & 5 (4.5\%) & 7 (3.9\%) & 12 (4.2\%) & 0.804 \\ \hline Non-productive cough & 3 (2.7\%) & 2 (1.1\%) & 5 (1.7\%) & 0.312 \\ \hline Mean ESR value (mm/h) & 59 \(\pm\) 35 & 58 \(\pm\) 35 & 58 \(\pm\) 35 & 0.814 \\ \hline Mean CRP value (mg/L) & 43 \(\pm\) 50 & 42 \(\pm\) 50 & 42 \(\pm\) 50 & 0.869 \\ \hline Mean prednisone-equivalent dose on the day of US scan (mg/day) & 18 \(\pm\) 64 & 17 \(\pm\) 64 & 17 \(\pm\) 64 & 0.897 \\ \hline Not treated with glucocorticoids on the day of US scan & 21 (19\%) & 66 (38\%) & 87 (30\%) & 0.0007 \\ \hline \end{tabular}
\end{table}
Table 1: Clinical presentation of newly referred patients to the fast-track clinic.