Stent Thrombosis after Successful Drug-Eluting Stent Implantation

Background and Objectives：Stent thrombosis (ST) after a successful drug-eluting stent (DES) implantation has been reported in around 1% of clinical trials.However, the incidence of ST with a DES in practice is not well known.Here, we evaluated the possible causes of ST encountered in four Korean hospitals.Subjects and Methods：Between March 2003 and December 2003, 450 patients were treated using a DES in the four study hospitals.We reviewed the clinical and procedural characteristics of 8 patients that experienced ST after a successful DES implantation.Results：Eight patients (1.8%), who were administered antiplatelet medication, experienced ST, with a mortality of 50% at the 2 month follow-up.ST occurred within 7 days in all patients, with the exception of one, with an occurrence 37 days after intervention.Initially, all patients were diagnosed as having acute coronary syndrome.Direct PTCA was performed in 3 patients (38%).Severe calcification or a thrombus was noted in 6 (67%) of 9 lesions.In all cases, no GPIIbIIIa inhibitors were used prior to the DES implantation.Incomplete lesion coverage and incomplete stent expansion appeared in 7 (88%) cases.Conclusion：Our study demonstrated that full expansion of the DES and complete lesion coverage must be accomplished, with high pressure inflation or use of cutting balloon preferably under IVUS guidance, for the prevention of ST.Those patients with acute coronary syndrome might warrant intensive antiplatelet therapy, including GPIIbIIIa inhibitors.(Korean Circulation J 2005;35:163-171) KEY WORDS：Coronary thrombosis；Stents.서 론 2001년 약물 방출 스텐트(drug-eluting stent, DES) 등 장으로 관동맥 중재술 후 재협착에 있어 획기적인 진보가 있 었다. 1) 국내에서도 2003년부터 약물 방출 스텐트를 사용할 수 있게 되었으며 많은 환자에서 시술이 이루어지고 있다.대규모 연구들을 통해 Cypher 스텐트나 Taxus 스텐트 모두 재협착율은 종전의 일반 스텐트보다 75% 이상 감소되어 평 균 4~5% 정도로 보고되었고, 일반 스텐트의 경우 급성 또는 아급성 혈전 생성율은 0.5%에서 1.