Relation between renal function and neointimal tissue characteristics after drug-eluting stent implantation: virtual histology-intravascular ultrasound analysis.

Background: Few data are available about neointimal tissue characteristics after drug-eluting stent (DES) implantation in patients with decreased renal function. We used virtual histology-intravascular ultrasound (VH-IVUS) to assess the neointimal tissue characteristics according to the baseline renal function.

Methods: We compared neointimal tissue components between patients with chronic kidney disease (CKD) [n=19, estimated creatinine clearance (CrCl) <60mL/min] and those without CKD (n=229). The region of interest was placed between the luminal border and the inner border of the stent struts and tissue components were reported as percentages of neointimal volume.

Results: Mean follow-up durations between DES implantation and follow-up VH-IVUS study were 12.0±4.1 months in the CKD group and 11.4±5.6 months in the non-CKD group (p=0.519). At follow-up, neointima volume was significantly greater (72±47mm(3) vs. 47±26 mm(3), p<0.001) and %neointima necrotic core (NC) volume was significantly greater (25.0±11.4% vs. 17.9±10.2%, p=0.012) in the CKD group compared with the non-CKD group. There was negative correlation between CrCl and neointima volume (r=-0.250, p<0.001), however, there was no significant correlation between CrCl and %neointima NC volume (r=-0.034, p=0.591). The only independent predictor of follow-up %neointima NC volume ≥10% was neointima volume (odds ratio 1.025, 95% confidence interval 1.013-1.036, p<0.001).

Conclusions: Renal function was associated with in-stent neointimal growth, but it was not associated with neointima NC formation. Instead, the amount of neointima was associated with more neoatherosclerosis in patients who underwent DES implantation.