© JAPI • VOL. 53 • MAY 2005 www.japi.org 483 Case Report Delayed Occurrence of Restenosis in Drug Eluting Stents : An Evidence of Delayed Healing R Sapra*, U Kaul*, RK Gupta*, R Kachru*, T Ghose*, S Sharma**, AK Parida*, MP Samal*, B Singh* Abstract Drug eluting stents have made a significant impact on restenosis. However, there are concerns regarding delayed “catch-up” of restenosis. In this case report we present two such patients with delayed occurrence of restenosis after drug eluting stent implantation. © INTRODUCTION D rug eluting stents (DES) reduce the incidence of restenosis by inhibiting neointimal hyperplasia. However, reduction in neointimal hyperplasia by DES may also delay endothelialization of stent struts. It is feared that inhibition of complete endothelialization in DES may predispose to higher risk of stent thrombosis. It is also postulated that suppression of neointimal hyperplasia by DES may be temporary and as the drug effect wears off, a “catch-up” phenomenon in restenosis may be observed. Upto 2 years follow up of ‘first in man’ implantation of DES is presently available and does not seem to suggest delayed increase in restenosis. 1 Longer follow up in larger studies, however, is needed to clarify the issue. CASE REPORT We have been implanting both sirolimus eluting (Cypher TM , Cordis, Europa, NV) and paclitaxel eluting (Taxus TM , Boston Scientific, Ireland) stents since June, 2002. As a part of our protocol we are performing follow up angiography in all the patients with DES implantation at 6 ± 1 months of follow up or earlier if symptomatically indicated. We have observed delayed occurrence of restenosis in 2 of our cases (one with Cypher and one with Taxus stent). In both the instances patients were asymptomatic at the time of 6 months follow-up angiography with moderate late loss in the stented segment. On subsequent follow up, both of them became symptomatic and repeat angiography revealed significant progression of disease leading to target lesion *Department of Cardiology, Batra Hospital and Medical Research Centre; **Department of Medicine, Northern Central Railway Hospital, New Delhi. Received : 15.6.2004; Accepted : 31.3.2005 revascularization. Case 1 : SKM, a 55 years old male, normotensive, non diabetic, normolipidemic, non smoker presented with unstable angina in September, 2002. His coronary angiography revealed single vessel disease with 90% eccentric stenosis in proximal LAD artery (Fig. 1A). He underwent coronary angioplasty using Taxus 3.0 x 24 mm stent which was postdilated with 3.5 mm balloon. The adequacy of stent expansion was confirmed with intravascular ultrasound (IVUS) evaluation. His final angiogram is shown in Fig. 1B. He was followed up on aspirin, clopidogrel, ramipril and atorvastatin. He underwent follow up angiography 6.2 months after angioplasty which revealed moderate late loss constituting 44% stenosis in the middle of the stent (Fig. 1C). He was asymptomatic at that time and was continued on same medical therapy. He became symptomatic with exertional angina NYHA class II two months later and underwent a treadmill test, which was positive for inducible ischemia. He underwent repeat coronary angiography around 2.5 months after first follow up angiography which revealed marked progression of late loss which now constituted 90% stenosis (Fig. 1D). He was treated with repeat angioplasty and stenting using 3.0 x 28 mm Cypher stent. His symptoms were relieved and he is presently symptom free on 6 months subsequent follow up. Case 2 : MJ a 30 years old diabetic patient who had anterior myocardial infarction in June, 2002. He was thrombolysed elsewhere and was referred to us with recurrent post myocardial infarction angina. His coronary angiography revealed totally occluded LAD artery (Fig. 2A). He underwent angioplasty using Cypher 3.0 x 18 mm stent after administering Inj. Abciximab bolus and infusion. His final coronary angiogram is shown in Fig. 2B. He remained asymptomatic thereafter and was on aspirin, clopidogrel, enalapril, metoprolol