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Abstract
Background Cardiac involvement is more common in Ankylosing Spondylitis (AS) patients with HLA-B27 genotype, especially aortic valvular regurgitation (AVR). AVR in AS is caused by aortic root dilatation and fibrotic thickening of the aortic cusps, both linked to inflammation. Inflammation of the aortic root might lead to a weakening in aortic wall strength and dilatation with AVR. Severe AVR can result in heart failure and is an indication for valve replacement or repair. The prevalence of AVR in AS is estimated at 14–18%, which is significantly higher compared to the general population. Therefore, some advocate regular echocardiographic screening of AS patients [1]. However, the cost-benefit of echocardiographic screening in AS is currently unknown and the precise effect of AS specific cardiac pathology on clinically overt cardiovascular morbidity and mortality remains to be elucidated. Hence, we should aim to identify a specific “at risk” AS population that might benefit from routine echocardiographic monitoring.
Objectives Primary: To assess the association between the aortic root diameter in HLA-B27 positive versus HLA-B27 negative patients.
Secondary: To assess the association between the aortic root diameter with disease duration and inflammation biomarkers.
Methods We performed a cross-sectional study in AS patients between 50–75 years who were recruited from a large rheumatology outpatient clinic. Patients underwent echocardiography, with 2D, spectral and colour flow Doppler. The aortic root was measured at sinuses of Valsalva during diastole. The aortic root diameter was corrected for body surface area (BSA). Correlation between aortic root diameter/BSA and disease duration and inflammation biomarkers were assessed.
Results 132 Consecutive AS patients were included with a mean age of 60.5 years, of whom 110 (83%) were HLA-B27 positive. The median aortic root diameter/BSA ratio was significantly higher in HLA-B27 positive patients compared to HLA-B27 negative patients: 1.75±0.22 mm vs. 1.61±0.14 mm (p=0.001). Eight AS patients (6%) had aortic root dilatation (>2.1mm corrected for BSA), who were all HLA-B27 positive. Patients with and without aortic root dilatation did not significantly differ in age or disease duration. The median aortic root diameter/BSA ratio was correlated with disease duration (r=0.229, p=0.012), but not with inflammatory biomarkers.
Conclusions HLA-B27 positive AS patients with a long disease duration have an increased aortic root diameter and a higher risk for aortic root dilatation compared to HLA-B27 negative AS patients. The risk of developing aortic root dilatation in AS patients is comparable to patients with essential hypertension (6%)[2].
Future prospective studies should assess which AS patients phenotype are at the highest risk of this AS specific cardiac disease, thus candidates for regular echocardiographic screening.
References
Klingberg et al. Aortic Regurgitation Is Common in AS: Time for Routine Echocardiography Evaluation? Am J Med 2015Nov;128(11)1244–1250.
Cuspidi C et al. Prevalence and correlates of aortic root dilatation in patients with essential hypertension. J Hypertens 2006 Mar;24(3)573–80.
References
Disclosure of Interest None declared