Limitations
The number of patients in this cohort was small, and the single-centre,
retrospective, observational design of our study makes the establishment
of causal relationships difficult. Further, our AR cohort was derived
from a single tertiary referral centre in Japan and was thus subject to
selection bias by including a highly selected population of patients
with AR. We did not assess outcomes in this study. Therefore, a larger
scale study with a larger number of patients and a longer period of
follow-up and assessment of prognosis is needed to confirm our findings.