MicroRNA-21 and Venous Neointimal Hyperplasia of Dialysis Vascular Access

BACKGROUND AND OBJECTIVES: There is increasing evidence that microRNAs (miRNAs) play crucial roles in the regulation of neointima formation. However, the translational evidence of the role of miRNAs in dialysis vascular access is limited. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: miRNA expression in tissues was assessed by using venous tissues harvested from ten patients on dialysis who received revision or removal surgery, and ten patients who were predialysis and received creation surgery of arteriovenous fistulas served as controls. To extend these findings, 60 patients who received angioplasty of dialysis access were enrolled and the levels of circulating miRNAs were determined before and 2 days after angioplasty. Clinical follow-up was continued monthly for 6 months. The primary outcome of angioplasty cohort was target lesion restenosis within 6 months after angioplasty. CONCLUSIONS: Certain miRNAs are differentially expressed in the stenotic venous segments of dialysis accesses. An increase in blood miR-21 level with angioplasty is associated with a higher risk of restenosis.