Repeated occurrence of slow flow phenomenon during and late after sirolimus-eluting stent implantation Kenji SakataMasanobu NamuraToshimitsu TakagiNaoto Tama • Isao InokiHidenobu TeraiYuki HoritaMasatoshi IkedaMasakazu Yamagishi

A 78-year-old man with unstable angina showed 90 % stenosis in the proximal left anterior descending artery. Pre-procedural intravascular ultrasound revealed ruptured plaque and attenuated plaque in the lesion. Under these conditions, two overlapping sirolimus-eluting stent (SES) implantation in this lesion resulted in slow flow which was recovered by intracoronary nitrates, nicorandil, and nitro- prusside without further complications. When the patient showed up again 5 years later with recurrence of angina pectoris, angiography revealed a hazy ulcerated in-stent restenosis (ISR) at the site of the SES. Pre-procedural optical coherence tomography (OCT) imaging revealed multiple intimal ruptures, cavity formation behind the stent struts, a thin-cap fibroatheroma containing neointima surrounded by signal-poor, lipid-rich area in the proximal SES, suggesting the progression of neoatherosclerosis within SES. Impor- tantly, there occurred slow flow again after balloon angio- plasty for this lesion. We would suggest careful OCT examination is warranted to confirm development of neo- atherosclerosis within the stent, and distal protection device should be considered to prevent slow flow phenomenon even in a patient with very late ISR.