In-stent restenosis characteristics and repeat stenting underexpansion: insights from optical coherence tomography
Dong Yin, Gary S. Mintz, Lei Song, Zhaoyang Chen, Tetsumin Lee, Ajay J. Kirtane, Manish A. Parikh, Jeffrey W. Moses, Khady Fall, Allen Jeremias, Ziad A. Ali, Richard Shlofmitz, Akiko Maehara
Abstract
AIMS: The aim of this study was to use optical coherence tomography (OCT) to predict newly implanted stent expansion for treatment of in-stent restenosis (ISR). METHODS AND RESULTS: With OCT guidance, 143 ISR lesions were treated with a new stent. Stent underexpansion was defined as minimum stent area (MSA) <4.5 mm2 and MSA/average of reference lumen area <70%. New stent underexpansion was found in 33 lesions (23%). These had a smaller old stent MSA (4.13 [3.32-4.62] versus 5.18 [4.01-6.38] mm2, p=0.001), and had a higher prevalence of multiple old stent layers (51.5% versus 10.9%, p<0.001) and neointimal or peri-stent calcium (69.7% versus 37.3%, p=0.001) compared to those without new stent underexpansion. Old stent underexpansion, multiple layers of old stent, maximum calcium angle >180°, and maximum calcium thickness >0.5 mm were independently associated with new stent underexpansion. Patients with new stent underexpansion had a higher prevalence of major adverse cardiac events (35.5% vs 14.3%, p=0.009), mainly driven by a higher rate of myocardial infarction and target vessel revascularisation at two years. CONCLUSIONS: When re-stenting an ISR lesion, old stent underexpansion, the amount of neointimal or peri-stent calcium, and multiple old stent strut layers are important determinants of new stent underexpansion which is then associated with adverse long-term outcomes.