Very Late Stent Thrombosis due to Neointimal Rupture After Paclitaxel-Eluting Stent Implantation

We report our experience of very late stent thrombosis (VLST) in a young male patient who underwent implantation of two paclitaxel-eluting stents (PES) six years ago. The patient was compliant with standard dual antiplatelet therapy, but he presented with acute myocardial infarction which was associated with VLST. Intravascular ultrasound showed neointimal rupture with thrombus within the PES implanted in the right coronary artery. The lesion was successfully treated with balloon angioplasty without complications, however he was found to be hyporesponsive to clopidogrel when tested for adenosine diphosphate-induced platelet aggregation. The patient was discharged after uneventful recovery with triple anti-platelet therapy using aspirin, clopidogrel and cilostazol. To the best of our knowledge, a time interval of 2,223 days is the longest reported time interval between PES deployment and VLST occurrence. VLST may indeed occur in clinically stable patients, as multiple factors can influence the pathological mechanisms of VLST.

Coronary angioscopy: current topics and future direction

Disruption of vulnerable plaque and following thrombus formation are considered the main cause of acute coronary syndrome (ACS). Intracoronary angioscopy is an endoscopic technology that allows direct visualization of the coronary artery lumen and provides detailed information regarding plaque morphology in patients with coronary artery disease. The color and morphology of coronary plaque under angioscopy observation are proposed to be determinants for plaque stability. Angioscopically yellow plaque represents a thin-cap fibroatheroma, and is associated with a higher incidence of disruption and thrombus formation, and may be associated with future acute coronary syndromes. To circumvent the subjectivity of color interpretation, various quantitative methods have been proposed for identifying vulnerable plaques. Superior to other coronary imaging techniques such as VH IVUS and optical coherence tomography, angioscopy has impressively high sensitivity and specificity in detection of intraluminal thrombus. Angioscopy can also be used as an adjunctive technique during catheter intervention by directly visualizing the thrombus, stent struts and proliferating neointima. The time course and pattern of neointima coverage, as seen by angioscopy, various among different stent systems. Angioscopic assessment of serial changes after stent implantation may have potential benefits on patient's management after coronary stenting.