Complete disappearance of red thrombi in a drug-eluting stent despite discontinuation of antiplatelet therapy: Angioscopic confirmation.

We present the case of a 48-year-old man with unstable angina who underwent drug-eluting stent (DES) implantation for the left circumflex artery (LCx). Red thrombi within the stent were clearly found by coronary angioscopy. Dual antiplatelet therapy was orally given before the stenting. Twenty-two months after the procedure, the patient visited because of severe chest pain. The patient had stopped taking all prescriptions including antiplatelet drugs for the previous 18 months. The occurrence of late stent thrombosis (LST) derived from previously implanted DES in the LCx was strongly suspected. Unexpectedly, the left coronary angiograms showed neither in-stent restenosis nor thrombotic occlusion. Angioscopic images for the DES segment showed that there were no uncovered stent struts without neointimal coverage. Notably, red thrombi identified immediately after stenting by angioscopy had completely disappeared. Mural red thrombi at the first observation completely disappeared despite premature cessation of dual antiplatelet therapy. Early neointimal coverage may occasionally occur even under the condition of acute coronary syndrome. The leading cause of LST was not only the cessation of dual-antiplatelet therapy and multiple factors contribute to LST of DES. Relatively early and adequate neointimal stent coverage may reduce the risk of thrombus formation including LST even though anti-platelet therapy was discontinued prematurely.