Limitation
In our patient cohort, there was no patients with significant PDL ≥5 mm,
PDL >3 mm was found in only 2.4% (2/84) patients, which is
likely to limit the strength of ROC analysis. Moreover, the clinical
significance of PDL is still controversial. Long term follow-up results
are controversial now on the relationship between PDL and risk of stroke
and DRT[19]. Our planned upcoming large-scale
clinical follow-up and prospective control study are helpful to answer
this question.