Serial Intravascular Ultrasound Comparison of the Extent and Distribution of Intimal Hyperplasia Six Months After Stent Implantation for De Novo Versus In-Stent Restenosis Lesions

The aim of this study was to compare intimal hyperplasia (IH) growth at 6 months in patients with de novo lesions treated with stents versus IH regrowth in patients with treated in-stent restenosis. Intravascular ultrasound was performed after intervention and at the 6-month follow-up visit as part of a standardized protocol across several clinical trials. At 6 months, the lumen was larger in the de novo group (mean lumen cross-sectional area [CSA] 6.31 ± 2.2 vs 4.48 ± 1.9 mm2, p = 0.0001; minimum lumen CSA 4.2 ± 1.8 vs 2.59 ± 1.5 mm2, p = 0.0001). However, the total increase in the mean IH CSA volume was the similar in the de novo and ISR groups (2.89 ± 1.6 vs 2.64 ± 1.94 mm2, respectively; p = 0.11). We found that IH regrowth in restented in-stent restenosis lesions was similar to that in de novo stent implantation and that the final lumen CSA was an important component of in-stent restenosis recurrence.