Aortic root diameter is associated with HLA-B27: identifying the patient with ankylosing spondylitis at risk for aortic valve regurgitation

To assess the association between the aortic root diameter in HLA-B27 positive (+) and HLA-B27 negative (-) ankylosing spondylitis (AS) patients from the CARDAS cohort. The CARDAS study is a cross-sectional study in AS patients between 50 and 75 years who were recruited from a large rheumatology outpatient clinic. Patients underwent cardiovascular screening including echocardiography, with 2D, spectral, and color flow Doppler measurements. The aortic root was measured at sinuses of Valsalva during diastole. The aortic root diameter was adjusted for body surface area (BSA) (aortic root index, cm/m²). 193 Consecutive AS patients were included of whom 158 (82%) were HLA-B27 positive. The aortic root index was significantly higher in HLA-B27 + patients compared to HLA-B27- patients, respectively, 1.76 cm ± 0.21 vs. 1.64 cm ± 0.14, p < 0.001. No difference was seen in the prevalence of aortic valve regurgitation (AVR), p = 0.8. Regression analysis showed a significant association between HLA-B27 and aortic root index corrected for age, sex and cardiovascular risk factors (β 0.091, 95% CI 0.015-0.168, p = 0.02). Especially, male HLA-B27 + patients had a significantly increased aortic root index compared to male HLA-B27- AS patients, respectively, 1.76 cm (1.63-1.88) and 1.59 cm (1.53-1.68), p < 0.001. We found an increased aortic root index in elderly HLA-B27 + AS patients compared to HLA-B27- AS patients, especially in male patients. No difference was seen in the prevalence of AVR. However, as AVR can be progressive, echocardiographic monitoring in elderly male HLA-B27 + AS might be considered.