Is the intima-media thickness of temporal and axillary arteries influenced by cardiovascular risk?

Objectives: 1) To measure with ultrasound (US) the intima-media thickness (IMT) of temporal (superficial, parietal and frontal branches) and axillary arteries in subjects without a diagnosis of giant-cell arteritis (GCA) and/or polymyalgia rheumatica (PMR) with different cardiovascular (CV) risk; 2) to assess the performance of previously proposed cut-off values for normal IMT. Methods: Subjects ≥ 50 years without a diagnosis of GCA or PMR were included. Bilateral US of the temporal arteries, including the frontal and parietal branches, and axillary arteries was performed by two sonographers using a 10-22 MHz and 6-18 MHz probe. The following previously proposed cut-off for were considered: Superficial temporal artery: 0.42 mm; Frontal branch: 0.34 mm; Parietal branch: 0.29 mm; Axillary artery: 1.0 mm. Results: A total of 808 arteries in 101 subjects were evaluated; of these, 31 (30.7%) were classified as very high-CV risk, 7 (6.9%) as high, 34 (33.7%) as moderate and 29 (28.7%) as low-risk. Subjects with very high or high-risk showed higher IMT than those with moderate or low-risk in the superficial temporal arteries [0.23 (SD 0.07) vs 0.20 (SD 0.04), p< 0.01] and in the axillary arteries [0.54 (SD 0.17) vs 0.48 (SD 0.10), p: 0.002]. The IMT was higher than the reference cut-off in 13/808 (1.6%) arteries, in ≥ 1 artery in 10/101 subjects (10.1%). Of these 10 subjects, 8 (80%) were classified as having very high or high risk. Conclusion: Our results suggest that CV risk might influence the US-determined IMT of the temporal and axillary arteries in subjects without GCA. Therefore, in patients with suspected GCA, particular attention should be paid when measuring the IMT in those patients with very high/high CV risk.