Impact of lesion morphology and associated procedures for left main coronary stenting on angiographic outcome after intervention: sub-analysis of Heart Research Group of Kanazawa, HERZ, Study

Impact of stent deformity induced by the kissing balloon technique for bifurcating lesions on in-stent restenosis after coronary intervention

OBJECTIVES

To investigate the impact of stent deformity induced by final kissing balloon technique (KBT) for coronary bifurcation lesions on in-stent restenosis (ISR).

BACKGROUND

In experimental models, the detrimental effects of KBT have been clearly demonstrated, but few data exists regarding the impact of proximal stent deformity induced by KBT on clinical outcomes.

METHODS

We examined 370 coronary lesions where intravascular ultrasound (IVUS)-guided second-generation drug-eluting stent (DES) implantation for coronary bifurcation lesions was performed. Based on IVUS analysis, the stent symmetry index (minimum/maximum stent diameter) and stent overstretch index (the mean of stent diameter/the mean of reference diameter) were calculated in the proximal main vessel.

RESULTS

The stent symmetry index was significantly lower (0.75 ± 0.07 vs 0.88 ± 0.06, P < 0.0001) and the stent overstretch index was significantly higher (1.04 ± 0.08 vs 1.01 ± 0.06, P = 0.0007) in lesions with KBT (n = 174) compared to those without KBT (n = 196). The number of two-stent technique in lesions with KBT was 31 (18%). In multivariate analysis, the degree of stent deformity indices was not associated with ISR in lesions with KBT; however, two-stent technique use was the only independent predictor of ISR at 8 months (hazard ratio: 3.96, 95% confidence interval: 1.25-12.5, P = 0.01).

CONCLUSIONS

Second-generation DES deformity induced by KBT was not associated with mid-term ISR.

Early endothelialization associated with a biolimus A9 bioresorbable polymer stent in a porcine coronary model

Although Nobori^®, with a bioresorbable polymer and biolimus A9 abluminal coating, has unique characteristics, few data exist regarding endothelialization early after implantation. Fifteen Nobori^® and 14 control bare-metal stents (S-stent™) were implanted in 12 pigs. Histopathology of stented segments, inflammation, and intimal fibrin content was evaluated on the 2nd and 14th day after implantation. On the 2nd day, endothelial cells were morphologically and immunohistologically confirmed on the surface of both stents, although some inflammatory cells might be involved. Stent surface endothelialization evaluated with a scanning electron microscope showed partial cellular coverage in both stents. On the 14th day, neointimal thickness and percentage of the neointimal area were significantly lower in Nobori^® than in S-stent™ (51.4 ± 4.5 vs. 76.4 ± 23.6 µm, p < 0.05 and 10.8 ± 2.6 vs. 14.1 ± 4.2%, p < 0.01). No significant differences were found in these parameters on the 2nd day (17.3 ± 14.9 vs. 26.7 ± 13.6 µm and 3.7 ± 3.0 vs. 6.7 ± 3.7%), in inflammatory and intimal fibrin content scores. These results demonstrate that endothelialization could occur early after Nobori^® implantation with similar inflammatory reaction to bare-metal stents, probably contributing to low frequency of in-stent thrombosis and restenosis.