A 67-year-old man was hospitalized on April, 2020 for chest pain. The patient had a history of precordial chest pain for 5 years, and aggravation for 1 month. Five years ago, he was diagnosed as acute inferior myocardial infarction. Angiography revealed double vessel disease involving diagonal branch and proximal right coronary artery (RCA) (Fig. A,B). The patient was underwent percutaneous coronary intervention (PCI) with a 3.5mm × 29 mm Partner (sirolimus-eluting stent, Lepu Medical Technology Co., Ltd., Beijing, China) stent) in RCA. The patient’s symptoms relived after PCI, while secondary prevention medications were taken regularly (clopidogrel was stopped after one year, aspirin, statin continued). Unfortunately, two years ago, the patient had another acute inferior wall myocardial infarction. Urgent coronary angiography showed visible stents in the proximal and middle segments of RCA, with in-stent total occlusion(Fig. B). After thrombus was aspirated, one 4.0mm × 33 mm Partner stent was implanted in RCA(Fig. C), considering prior smaller stent maybe related with re-occlusion. Past medical history includes hypertension for 10 years, hyperlipidemia for 5 years, and smoking for 40 years. His brother had coronary heart disease and stent implantation.
After hospitalization, no obvious abnormality in physical examination, and secondary prevention treatment was prescribed. Creatine kinase-MB, troponin and N-terminal pro-brain natriuretic peptide was negative. Echocardiography revealed left ventricular ejection fraction (68%) was in the normal range, and the motion of the basal segment of the posterior wall and the inferior wall of the left ventricle is slightly weakened. Coronary angiography revealed zig-zag shape and visible stents in the proximal segments of RCA; stent fracture could be seen at the first turning point of RCA (Fig. E and F), with coronary blood flow of grade TIMI 3.
Optical coherence tomography (OCT) catheter, (ImageWire, LightLab Imaging, Westford, Massachusetts, USA) was used for further evaluation. We found complete two-layer stent fracture in the proximal part of the RCA with a length of 1.3 mm without stent struts in the middle of the prior stents; the mean diameter of lumen without struts is 4.59 mm (Fig. G). Comprehensive consideration of patients with atypical chest pain, no myocardial ischemia basis, and RCA blood flow unobstructed, we did not carry out interventional. The patient was discharged 2 days later, and no recurrent chest discomfort was reported in the 3 month followed-up.