Intravascular ultrasound assessment of minimum lumen area and intimal hyperplasia in in-stent restenosis after drug-eluting or bare-metal stent implantation. The Nordic Intravascular Ultrasound Study (NIVUS) ☆

Abstract Introduction Drug-eluting stents (DES) reduce the risk of restenosis after percutaneous coronary intervention. The aim of the study was to evaluate, by intravascular ultrasound (IVUS), the minimum lumen area site in the stented segment and the distribution of intimal hyperplasia in patients presenting with a DES or bare-metal stent (BMS) in-stent restenosis. Methods The "Nordic Intravascular Ultrasound Study (NIVUS)" study was conducted in Nordic and Baltic countries as a prospective multicenter registry. Two hundred and nine patients (DES n=121 and BMS n=88) with in-stent restenosis were enrolled. Results At the minimum lumen area site in the stented segment, the stent area (5.8±2.2mm 2 vs. 7.6±2.4mm 2 , p 2 vs. 5.0±2.2mm 2 , p 2 (under expansion) was higher in DES (58.7% vs. 37.7%, p=0.008) compared to BMS. Intimal hyperplasia covered 55.4±33.3% of the stent length in the DES compared to 90.7±17.4% in the BMS group, p Conclusion Stent underexpansion was more often seen in DES than BMS in-stent restenosis. DES more often had focal in-stent restenosis with less intimal hyperplasia.