SAT0325 REDUCED STRAIN AND INCREASED STIFFNESS OF COMMON CAROTID ARTERIES IN PATIENTS WITH ANKYLOSING SPONDYLITIS
Authors: Helena Forsblad-d’Elia, Lucy Law, Karin Bengtsson, Stefan Söderberg, Per Lindqvist
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Ankylosing spondylitis (AS) is associated with an increased risk of cardiovascular disease (CVD) which also contributes to the increased mortality observed in AS. It is therefore important to develop non-invasive, accurate methods for early detection of atherosclerotic vascular changes. Studies, in other populations, have demonstrated associations between arterial stiffness and atherosclerotic burden and incident cardiovascular events. The arterial stiffness can be examined by ultrasound providing the β stiffness index that evaluates mechanical deformation properties. Technological advancements in ultrasound have developed a method assessing strain, using speckle tracking technique, which measures deformation mechanics in more dimensions. The speckle tracking method assessing arterial wall motion might permit earlier detection of subclinical CVD. <h3>Objectives:</h3> To study, for the first time, bilateral common carotid arterial (CCA) circumferential strain and β stiffness index in patients with AS and 1) compare the results with age and sex-matched controls and 2) explore relationships between circumferential strain and β stiffness index with disease activity, physical function and traditional risk factors for CVD in patients with AS. <h3>Methods:</h3> A cohort of 149 patients with AS from Northern Sweden (Modif NY, mean age 55.3±11.2 years, 102(68.5%) men, 146(98%) HLAB27) were assessed with spinal radiographs for mSASSS, clinical examination and BASMI, BASFI, ASDAS-CRP and BASDAI. Forty-six patients with AS (50.4±8.7 years, 31(67%) men) and 46 age- and sex-matched controls (49.8±9.2 years, 31(67%) men) with no known hypertension, diabetes or previous CV events were compared. Bilateral CCA ultrasound was carried out on all patients and controls. The circumferential systolic strain was measured and the β stiffness index was calculated. To analyze factors associated with strain and β stiffness index univariate and standard multivariable linear regression analyses were used. Variables with a univariate <i>p-</i>value ≤ 0.1 were considered for the multivariable models. For dichotomous variables, yes was coded 1 and no was coded 0. <h3>Results:</h3> The mean strain was significantly lower in AS patients compared with controls, 7.9±2.6% vs 10.3±1.9%, p&lt;0.001 and the mean β stiffness index was significantly higher in AS compared to controls, 13.1±1.6 mmHg/mm vs 12.3±1.3 mmHg/mm, p=0.018. <h3>Conclusion:</h3> Both CCA strain and β stiffness index differed significantly between AS patients and controls indicating a worse subclinical arterial status in AS. The CCA strain was associated with several AS related variables while the β stiffness index with age and smoking indicating that the methods complement each other in the assessment of distensability of arteries in patients with AS. <h3>Disclosure of Interests:</h3> Helena Forsblad-d'Elia Grant/research support from: Unrestricted grants from Novartis outside the submitted work, Consultant for: Advisory board fees from Sandoz, Novartis and Abbvie, Speakers bureau: Lecturing fees from Novartis, Lucy Law: None declared, Karin Bengtsson: None declared, Stefan Söderberg Consultant for: Advisory board fees from Actelion and MSD, Speakers bureau: Lecturing fees from Actelion, Per Lindqvist: None declared