Very late stent thrombosis in late stent malapposition after sirolimus-eluting stent implantation

Late stent malapposition (LSM) has been demonstrated to be more common after drug-eluting stent (DES) implantation than after bare-metal stent (BMS) implantation. To date, this unusual intravascular ultrasonic finding after DES implantation, however, has not received enough attention, because previous studies suggested few adverse clinical sequelae from LSM. We present a case of angiographically-confirmed very late stent thrombosis (ST) in LSM after elective implantation of sirolimus-eluting stents. In this 32-year-old male patient, very late ST occurred at 29 months after DES implantation and at 20 months after the identification of LSM. Although this patient had received sufficient dual antiplatelet therapy with aspirin and clopidogrel for more than 1 year, he suffered from ST shortly after the discontinuation of clopidogrel. Thus, patients with LSM may pose a significant risk for very late ST after discontinuation of dual antiplatelet therapy. The findings suggest that dual antiplatelet therapy should be further prolonged in patients with LSM.