Thrombose coronaire très tardive par fracture du stent actif. Cas clinique et revue de la littérature

The superiority of drug-eluting stents in reducing the risk of in-stent restenosis compared to bare-metal stents is no longer challenged. Nevertheless, the drug-eluting stents may carry long-term risk of late and very late stent thrombosis. The promoting factors of this complication are usually divided into three chapters depending on the patient, the procedure and the stent. Indeed, the literature has reported several parameters related to the stent itself, such as its length, the malapposition, its diameter, but also more rarely the occurrence of stent fracture. We present the case of a patient admitted for myocardial infarction after a very late thrombosis of Cypher drug-eluting stent four years after its implantation and related to stent fracture.     

Very late stent fracture associated with a sirolimus-eluting stent

Late stent thrombosis (>1 year after implantation) is a recognised complication involving drug-eluting stents. Stent fracture is increasingly being reported as a complication of drug-eluting stent, and in particular sirolimus-eluting stent use. We report the case of very late sirolimus-eluting stent fracture resulting in an acute coronary syndrome. This case report highlights the need for greater awareness and post-marketing surveillance to detect a potential mechanism for late stent thrombosis in the drug-eluting stent era.     

Acute ST-elevation myocardial infarction 6 years following a sirolimus-eluting stent secondary to complete stent fracture

With increasing coronary interventions, coronary stent fracture following implantation of drug-eluting stents is being commonly recognized. Though isolated strut fractures are often only incidental findings, more severe forms of stent fracture with complete transection have adverse clinical outcomes. Most such cases are reported within several months following the index angioplasty. We report an unusual presentation of late stent fracture following a sirolimus-eluting stent, presenting with acute myocardial infarction 6 years after the initial stent implantation. The various mechanisms underlying fracture of drug-eluting stents are reviewed. Because no known mechanisms were noted in our case, unknown factors may also play a role in the genesis of stent fracture. Clinicians need to be aware that such complications may present rarely, extremely late after the index procedure as an acute myocardial infarction.     

Multiple Stent Fractures After Everolimus-Eluting Stent Implantation Causing Acute Myocardial Infarction: A Case Report

Stent fracture is an uncommon complication of drug-eluting stent implantation, but it has a clinical significance because of its potential association with adverse cardiac events such as in-stent restenosis, target lesion revascularization, and stent thrombosis. Multiple stent fractures account for a small proportion, but they may lead to more serious complications. Newer generation drug-eluting stents are designed for improved safety and efficacy compared with early generation drug-eluting stents. Multiple stent fractures after newer generation drug-eluting stent implantation are a rare case.We report a case of 25-year-old male who presented with acute myocardial infarction caused by multiple stent fractures after everolimus-eluting stents implantation and was treated by balloon angioplasty.Physicians should be aware of the possibility of multiple stent fractures even after newer generation drug-eluting stent implantation.     

Late stent fracture – A potential role of left ventricular dilatation

Background

Coronary stent fracture is an under-recognized event but one that has been reported frequently in the drug-eluting stent era. Most reported cases of stent fracture occurred within days to two years after implantation, and are related to stent thrombosis and restenosis.

Case report

Presentation of a 69-year-old male with a history of arterial hypertension and previous percutaneous coronary intervention (PCI), and with implantation of three overlapping drug-eluting stents (DES) on proximal-to-middle left anterior descending artery (LAD). At five-year outpatient evaluation, the patient was found to have a new left bundle branch block associated with mild elevation in Troponin-I value and severe left ventricular dysfunction. The patient recovered as non ST-segment elevation myocardial infarction (NSTEMI) and consequently a new coronary angiography showed total occlusion of proximal LAD with multiple stent fracture. Here we discuss the role of left ventricular dilatation as a contributing factor to late drug-eluting stent fracture.

Conclusion

Different anatomical coronary settings have been described as predisposing factors to stent fracture. Consequently, the remodeling of the left ventricle, together with the rise in diastolic pressure, may have affected the shear stress of LAD stents by increasing mechanical forces produced in the diastolic phase on the epicardial vessel. In addition, left ventricular enlargement could have increased the elongation forces on the stent frames by altering the curvature of the stent. All predisposing factors of stent fracture, including coronary and left ventricular issues, need to be considered before stent implantation to avoid stent fracture and clinical sequelae.     

Drug-eluting stents and stent thrombosis: a cause for concern?

Drug-eluting stents, most commonly sirolimus-eluting stents and polymer-based paclitaxel-eluting stents, are now widely used during percutaneous coronary interventions, and have largely replaced bare-metal stents to treat a variety of native coronary artery and saphenous vein graft lesions. Stent thrombosis, a complication of both bare-metal and drug-eluting stents, is associated with significant morbidity and mortality including high rates of myocardial infarction and death. Recently, several studies in the literature have raised concern about increased rates of overall stent thrombosis and late stent thrombosis in drug-eluting stents in the so-called 'real world' where off-label uses of drug-eluting stents are common. Hypersensitivity reactions to the polymers used in drug-eluting stents, delayed endothelialization of the stents, and discontinuation of dual antiplatelet therapy have all been implicated in the pathophysiology of drug-eluting stents stent thrombosis. The incidence of total stent thrombosis as well as late stent thrombosis, however, does not seem to be significantly higher in drug-eluting stents than in bare-metal stents. An important risk factor for stent thrombosis in both types of stents appears to be the premature discontinuation of dual antiplatelet therapy, and physicians should educate their patients about the importance of adhering to dual antiplatelet therapy, given the dire clinical consequences of stent thrombosis.     

The conundrum of late and very late stent thrombosis following drug-eluting stent implantation

PURPOSE OF REVIEW: Drug-eluting stents reduce restenosis compared with bare metal stents, but there is growing concern that drug-eluting stents may lead to higher rates of late stent thrombosis, a rare and potentially catastrophic complication following stenting. RECENT FINDINGS: While the data on the risk of late stent thrombosis are not definitive, several general conclusions may be drawn from the available data. Late thrombosis, while associated with high mortality and morbidity, is an uncommon complication of both drug-eluting stents and bare metal stents. Randomized trials of approved drug-eluting stents versus bare metal stents have shown additional cases of late stent thrombosis in drug-eluting stents, but no significant difference in the cumulative incidence of stent thrombosis, myocardial infarction, or cardiac death at 4 years of follow-up. Observational studies suggest higher very late stent thrombosis incidence, but the relative risks of drug-eluting stents versus bare metal stents in specific high-risk groups require further study. Although the etiology of late stent thrombosis is multifactorial, premature discontinuation of clopidogrel appears to be the most important risk factor. SUMMARY: Long-term follow-up of patients after coronary stenting has identified stent thrombosis as a rare but serious event. Ongoing clinical trials in broader patient populations will be helpful to understand the risk of late stent thrombosis with greater certainty.     

A case of early drug-eluting stent fracture

Although stent fracture following femoro-popliteal intervention is well recognized, coronary stent fracture represents an underrecognized entity. Its incidence is low but it represents an important clinical entity as it may complicate with stent thrombosis causing acute coronary syndromes, or may predispose to instent restenosis. Although coronary stent fracture may involve both bare metal stents (BMS) and drug-eluting stents (DES), a recent analysis of the literature indicates that reports of stent fracture have increased since DES was introduced. Furthermore, chronic stretch at specific vessel sites as bends may lead to late occurrence of fracture. We present the case of a patient with a non-ST-segment elevation acute coronary syndrome caused by the early fracture of an everolimus-eluting stent (Xience?) implanted only three days before.     

Coronary pseudoaneurysm in a non-polymer drug-eluting stent: a rare entity

Coronary pseudoaneurysms following implantation of drug-eluting stents, although rare, are not unknown. Nearly all such cases have been reported in patients with sirolimus or paclitaxel polymer-based stents. We describe a case of coronary pseudoaneurysm developing with a non-polymer-based drug-eluting stent in a 50-year-old man who was successfully managed by coronary artery bypass grafting.     

The Problem of Stent Thrombosis Associated With Drug-Eluting Stents and the Optimal Duration of Dual Antiplatelet Therapy

Drug-eluting stents have significantly reduced the problem of restenosis, but there is an association between drug-eluting stents and stent thrombosis that can be a significant clinical problem resulting in myocardial infarction or death. The risk for stent thrombosis increases in certain clinical situations and has been reduced through the use of dual antiplatelet therapy for prolonged periods. Until new therapies are developed, it is essential that patients who have had drug-eluting stents implanted continue with dual-antiplatelet therapy for at least 1 year and possibly for an indefinite period.     

Fracture of Zotarolimus-Eluting Stent after Implantation

Drug-eluting stents were developed and approved for the reduction of in-stent restenosis. However, restenosis still occurs, and stent fracture is suggested as a cause of restenosis after implantation. Although sirolimus-eluting stents are considered to carry a high risk of fracture, the risk is also present with other drug-eluting stents. Herein, we report the case of a 78-year-old woman who received a zotarolimus-eluting stent for a bifurcation lesion of the left anterior descending coronary artery. Ten months later, she underwent coronary angiography due to angina. The angiogram revealed in-stent restenosis, with a grade IV stent fracture. After percutaneous coronary angioplasty, the patient''s clinical symptoms improved.Key words: Blood vessel prosthesis implantation/instrumentation, coronary restenosis/diagnosis/etiology/prevention & control, drug-eluting stents, drug implants/adverse effects, prosthesis failure, retreatment, stents/adverse effectsAlthough drug-eluting stents (DESs) reduce in-stent restenosis, important complications of coronary DESs are restenosis and thrombosis. Stent fractures have also been reported¹ and are considered to be possible causes of restenosis² within DESs. The sirolimus-eluting stent is reported to be prone to fracture.³ For example, there is the Cypher® stent (Cordis Corporation, a Johnson & Johnson company; Miami Lakes, Fla)—made of balloon-expandable stainless steel, a durable copolymer mixture of polyethylene-covinyl acetate and poly-u-butyl methacrylate, and sirolimus, which is a Gap 1 (G1) cell-cycle inhibitor.⁴ Other DESs are also considered to be at risk of fracture. One, the Endeavor® Sprint Zotarolimus-Eluting Coronary Stent System (Medtronic, Inc.; Minneapolis, Minn), uses a cobalt chromium stent platform; a durable, antithrombotic, phosphorylcholine-encapsulated coating; and another G1 cell-cycle inhibitor, zotarolimus.⁴ Here, we report the case of a woman who was treated with a zotarolimus-eluting stent that subsequently fractured.     

Simultaneous multivessel acute drug-eluting stent thrombosis

Stent thrombosis (ST) in the era of bare metal stents (BMS) using high-pressure stent deployment and combined anti-platelet therapy is an uncommon but feared complication. There is concern for an elevated risk of stent thrombosis (ST) with drug-eluting stents (DES). We describe a case of simultaneous multivessel drug-eluting stent thrombosis 8 h after deployment of paclitaxel-eluting stents in the right coronary (RCA) and left anterior descending (LAD) arteries.     

Recurrent coronary stent thromboses and myocardial infarctions

Although stent thrombosis is a recognized complication of coronary intervention, recurrent stent thrombosis is rarely reported. We present a patient who suffered 3 ST-segment elevation myocardial infarctions associated with repeated stent thromboses within a month and a half. Although a potentially mechanical cause of thrombosis was identified in the only baremetal stent implanted in this case, no predisposing factors were seen for the 2 drug-eluting stents (DES). While recent worrisome data have suggested a slight increase in the incidence of late angiographic stent thrombosis (defined as occurring beyond 30 days) with drug-eluting stents (DES), their risk of subacute thrombosis (from 1 to 30 days) is reported to be equivalent to that of BMS. Therefore, this rare occurrence serves as a sobering reminder of the risks of subacute thrombosis with both BMS and DES. Marked neointimal inhibition, allergic reactions, as well as thienopyridine resistance, may all contribute to the pathophysiology of DES thrombosis. The Food and Drug Administration advisory panel has concluded that when these devices are used for "on-label" indications, the counterbalance of dramatic target lesion revascularization reduction versus rare incidence of late angiographic stent thrombosis results in no overall increase in DES myocardial infarction or mortality risk. Furthermore, a minimum of 1 year of dual antiplatelet therapy is recommended for all recipients of DES at low risk of bleeding.     

Stent thrombosis with drug-eluting stents: a re-examination of the evidence.

The excitement of drug-eluting stents and their promise for reduced restenosis rates have been tempered by recent reports of stent thrombosis. The mechanism of stent thrombosis is multifactorial but appears to be related to delayed endothelialization and healing, late stent malapposition, and antiplatelet resistance. The most important risk factor appears to be the discontinuation of dual antiplatelet therapy. The data from clinical trials suggest that drug-eluting stents are associated with increased incidence of death or myocardial infarction compared with bare metal stents at long-term follow-up, suggesting that the window of thrombotic risk with drug-eluting stents may extend far beyond that for bare metal stents. Measures to possibly decrease the incidence of stent thrombosis include improvements in antiplatelet regimens and newer generation of drug-eluting stents which have biodegradable polymers or are polymer-free. In addition, percutaneous coronary intervention with bare metal stents in patients may be helpful in those known to be intolerant or noncompliant to antiplatelet therapy, have planned procedures or surgeries, or have overwhelming risks which may require discontinuation of dual antiplatelet therapy.     

Drug-eluting stent fracture and acute coronary syndrome

BackgroundCoronary stent fracture is an underrecognized entity but has been reported more frequently in the drug-eluting stent (DES) era. Nevertheless, the clinical implications of coronary stent fracture remain unclear.Methods and MaterialsA literature search for reports of DES fracture was conducted via MEDLINE, and the US Food and Drug Administration Manufacturer and User facility Device Experience (MAUDE) database was accessed via the internet and interrogated for reports of stent fracture between January 1, 2003, and April 30, 2008. Each report was reviewed, and clinical information was extracted for analysis.ResultsThe MEDLINE search identified 202 cases of coronary DES fracture, with 95% of cases involving Cypher sirolimus-eluting stents. Clinical information regarding patient presentation was available in 96 cases. Patients presented with ST-elevation myocardial infarction (STEMI) or stent thrombosis in six cases (6%) and with unstable angina or non-STEMI (NSTEMI) in 40 cases (42%). The MAUDE database search identified 337 stent fracture reports, with 97% of cases involving Cypher stents. Clinical information regarding patient presentation was available 193 cases. Patients presented with STEMI or stent thrombosis in 24 cases (12%) and with unstable angina or NSTEMI in 36 cases (19%).ConclusionsMost reports of drug-eluting stent fracture involve Cypher stents. DES fracture can be associated with stent thrombosis, myocardial infarction and angina. However, whether the incidence of such events reported in the literature and in the MAUDE database is representative of all patients experiencing stent fracture remains unclear.     

Very Late Stent Thrombosis 11 Years after Implantation of a Drug-Eluting Stent

Very late stent thrombosis is an infrequent yet potentially fatal complication associated with drug-eluting stents. We report the case of an 88-year-old man who sustained an ST-segment-elevation myocardial infarction 11 years after initial sirolimus-eluting stent implantation. Optical coherence tomograms of the lesion showed that the focal incomplete endothelialization of the stent struts was the likely cause; neointimal formation, neoatherosclerosis, and late stent malapposition might also have contributed.To our knowledge, this is the longest reported intervening period between stent insertion and the development of an acute coronary event secondary to very late stent thrombosis. The associated prognostic and therapeutic implications are considerable, because they illuminate the uncertainties surrounding the optimal duration of antiplatelet therapy in patients who have drug-eluting stents. Clinicians face challenges in treating these patients, particularly when competing medical demands necessitate the discontinuation of antiplatelet therapy. In addition to the patient''s case, we discuss factors that can contribute to very late stent thrombosis.     

Drug-eluting stents: current issues

Early stent thrombosis occurs in about 1% to 1.5% of patients with drug-eluting stents, very similar to the rate with bare-metal stents. Late stent thrombosis is more of a concern with drug-eluting stents, with an incidence of at least 0.35%. I would urge caution if you feel you have to stop antiplatelet therapy in patients with drug-eluting stents. While neointima formation peaks at 6 months and then may actually regress with bare-metal stents, it continues to grow with drug-eluting stents--although this process appears to plateau by 4 years with sirolimus. With the others, we have to wait and see. We still don't know the best drug-eluting stent. Trials are under way to compare stents with surgery, and the future brings the arrival of a number of exciting new devices and approaches that are now entering clinical trials.     

Drug‐eluting stent fracture: Incidence,contributing factors,and clinical implications

Stent fracture has been observed in noncoronary vessels, especially in the superficial femoral and popliteal arteries and with bare metal stents in saphenous vein grafts of coronary arteries. Since the introduction of drug‐eluting stents, stent fractures have also been reported in small studies and case reports. We reviewed these publications to assess what is known regarding the incidence, contributing factors, and clinical implications of drug‐eluting stent fracture in coronary arteries. The reported rate of drug‐eluting stent fracture in coronary arteries ranges from 1 to 8%, although much of the available literature is derived from single‐center studies that are heterogeneous in their study methods. A higher risk of stent fracture may be associated with the right coronary artery location, excessive tortuosity or angulation of the vessel, overlapping stents, and longer stents. The closed‐cell design of the Cypher stent has been associated with increased rigidity that may increase the risk of stent fracture, although these studies did not assess the overall outcomes between the Cypher and Taxus stents in a head‐to‐head comparison. Stent fracture has been shown by most studies to be associated with a statistically increased incidence of focal in‐stent restenosis, and some have shown an increased risk of target lesion revascularization. Other complications observed with stent fracture include stent thrombosis, coronary aneurysms, myocardial infarction, and sudden death. © 2009 Wiley‐Liss, Inc.     

Future Directions of Drug-Eluting Stents

Coronary artery stents have changed the face of interventional cardiology since their introduction in 1986. The commercial release of drug-eluting stents in 2002 promised to abolish in-stent restenosis as the predominant clinical limitation following stent implantation. Concerns raised about increased risks of adverse events with drug-eluting stents now appear unfounded but have heralded a new era of research, where only hard clinical end-points in sufficiently large numbers of patients are considered adequate. In this review, we highlight some of the potential future directions of drug-eluting stents including specialized stent platforms (including dedicated bifurcation stents), fully degradable stents, and the potential use of stents to prevent cardiac events.     

Acute Left Main Coronary Occlusion Caused by Stent Fracture,Peri-Stent Aneurysm Formation,and Very-Late Stent Thrombosis: Revisiting the Dark Side of Drug-Eluting Stents

A patient presented with acute distal left main occlusion as a result of very late stent thrombosis of 2 drug-eluting stents. Intravascular ultrasound imaging confirmed the presence of a peri-stent aneurysm coupled with malapposition at the site of a stent fracture, reflecting an abnormal vascular response to drug-eluting stents.