Drug-eluting stents for coronary bifurcations: insights into the crush technique.

Sirolimus-eluting stents appear to reduce substantially restenosis following percutaneous coronary bifurcation intervention. The crush technique was devised to reduce restenosis further by improving stent and drug application to the side-branch ostium. We aimed to investigate the performance of drug-eluting stent (DES) platforms with the crush technique, to identify deployment pitfalls, and to clarify the best deployment strategies. Each stage of the crush technique was photographed in a bifurcation phantom. Simultaneous side- and main-branch dilatation (kissing balloons) fully expanded the stent in the side-branch ostium, widened the gaps between stent struts covering the side branch, and eliminated main-branch distortion. With side branches angled at > 70 degrees , sequential (side- then main-branch) inflations may be needed to achieve best results. Postdilatation of the main branch with a balloon of narrower diameter than the deploying balloon caused main-branch stent distortion. These principles applied to all the bifurcation strategies and stent designs tested.     

A unique pitfall in percutaneous coronary angioplasty of in-stent restenosis: guidewire passage out of the stent.

Three cases of in-stent restenosis are narrated, wherein, during balloon angioplasty of the lesion, the guidewire inadvertently exited out of the stent. The forward balloon progress was halted in this region. In the first case, the situation could only be realized when dilatation of a forcefully pushed small balloon avulsed the well-embedded stent. The mishap was averted in the subsequent two cases by reintroduction of a new guidewire. Some suggestions to avoid this eventuality are offered. Though the cases pertain to in-stent restenosis, the observations may be applicable to the procedures in general that entail passage of a guidewire through a stented area.     

Sirolimus- and paclitaxel-eluting stents in comparison with balloon angioplasty for treatment of in-stent restenosis.

This study evaluated the acute and follow-up effectiveness of sirolimus-eluting stents (SESs) and nonpolymer-based paclitaxel-eluting stents (PESs) in comparison will balloon angioplasty for treatment of complex in-stent restenosis (ISR) lesions. Drug-eluting stents have been demonstrated to be highly effective for treatment of de novo lesions. The use of drug-eluting stents for treatment of complex ISR is less well defined. Eighty one lesions with in-stent restenosis (lesion length < 30 mm in a native coronary artery) were treated with either PTCA alone (n = 26 lesions in 25 patients), PES (n = 27 lesions in 24 patients; Achieve, Cook; 3,1 mug paclitaxel/mm(2) nonpolymer-based coating), SES (n = 28 lesions in 28 patients; Cypher, Cordis; 140 mug sirolimus/cm(2) metal surface area). Nine-month MACE rates were 32%, 8%, and 14% (all due to repeated revascularization procedures, except one death in the SES group) in the PTCA, PES, and SES group, respectively. Postintervention minimal lumen diameter in stent was significantly greater in the SES and the PES group in comparison with the PTCA group (2.37 +/- 0.26, 2.54 +/- 0.42, 1.78 +/- 0.23 mm; P < 0.001). At 6-month angiographic follow-up, late loss in stent was 0.77 +/- 0.45, 0.43 +/- 0.53, and 0.29 +/- 0.52 mm for the PTCA, PES, and SES group, respectively (P = 0.005). In-lesion restenosis rate was 61% for the PTCA group, 20% for the PES group, and 13% for the SES group (P = 0.042). The implantation of SES as well as nonpolymer PES proved to be effective for treatment of ISR. The combination of improved acute gain and reduced late loss results in a significantly improved angiographic follow-up result in comparison with PTCA.     

Sirolimus‐ versus paclitaxel‐eluting stents for coronary bifurcations intervention

Backgrounds : Relative efficacy and safety of sirolimus‐eluting stents (SES) compared with paclitaxel‐eluting stents (PES) remains controversial. It is unknown whether there are different effect and safety in coronary bifurcation treatment between SES and PES. Objectives : The meta‐analysis was performed to compare the clinical outcomes of SES and PES in coronary bifurcation intervention. Methods : Five head‐to‐head clinical trials of SES versus PES in coronary bifurcation intervention were included. A total of 2,567 patients were involved in the meta‐analysis. Mean follow‐up period ranged from 6 to 35 months. The primary end points were the need for target lesion revascularization (TLR) and main‐branch restenosis. Secondary end points were target vessel revascularization (TVR), cardiac death, major adverse cardiac events (MACE), and stent thrombosis. Results : Compared with PES, SES significantly reduced the risk of TLR (5.3% vs. 10.6%, odds ratio (OR) 0.52; 95% confidence interval (CI) = 0.38–0.70, P < 0.001), main‐branch restenosis (4.59% vs. 12.59%, OR 0.31; 95% CI = 0.18–0.55, P < 0.001) and TVR (7.05% vs. 12.57%, OR 0.58; 95% CI = 0.42–0.81, P = 0.001) in coronary bifurcation intervention. In addition, SES group also had a significantly lower incidence of MACE (8.20% vs. 14.13%, OR 0.58; 95% CI = 0.40–0.84, P = 0.004) than PES group. However, there were no statistical difference with respect to the incidence of cardiac death (1.64% vs. 1.09%, P = 0.19) and stent thrombosis (0.84% vs. 1.08%, P = 0.64) between SES and PES groups. Conclusions : Compared with PES, SES reduced the incidence of TLR, main‐branch restenosis and MACE in coronary bifurcation intervention, while the risk of stent thrombosis was similar between SES and PES groups. © 2011 Wiley Periodicals, Inc.     

Reduced incidence of clinical restenosis with newer generation stents, stent oversizing, and high-pressure deployment: single-operator experience

BACKGROUND: Over the last 4 years, several newer generation stents have become available, promising to change the scenery of coronary angioplasty (PTCA) with its attendant restenosis rate. HYPOTHESIS: The aim of this study was to review prospectively the results of a single operator adopting a uniform approach with approximately 0.5 mm stent oversizing and high-pressure (> or = 12-16 bar) deployment and compare them with conventional PTCA in a series of 244 consecutive patients. METHODS: The study included 203 men and 41 women, aged 59 +/- 11 years, who presented with stable angina and/or positive exercise testing (n = 75), unstable angina (n = 161), or acute myocardial infarction (n = 8). Dilated vessels included the left anterior descending artery (n = 139), the right coronary artery (n = 86), the left circumflex artery (n = 47), the ramus branch (n = 4), or venous grafts (n = 2). Stents were implanted for dissection, suboptimal PTCA result, and electively. Two groups were compared: 83 patients who underwent balloon PTCA alone and 161 patients who also received stent(s). RESULTS: The two groups had similar demographics, age (58 +/- 10 vs. 59 +/- 11 years), initial vessel stenosis (92 +/- 7 vs. 93 +/- 6%), and left ventricular ejection fraction (51 +/- 9 vs. 51 +/- 8%). Procedural success was also similar (97.6 vs. 99.4%), but as expected the residual stenosis was much lower in the stent group (< or = 0 vs. 17%). The following stents were employed: J & J (n = 1), NIR (n = 117), ACS (n = 59), AVE (n = 9), Inflow GoldFlex (n = 9), Crossflex (n = 5), Wictor (n = 1), Jostent (n = 16), R stent (n = 9), Seaquence (n = 2) and Wallstent (n = 1). Single stents were used in 118 patients, two stents in 31 patients, three in 6 patients, and four in 6 patients. There was one in-hospital death at 3 days unrelated to the procedure. There were no events of subacute stent thrombosis; all patients in the stent group received combined therapy with aspirin and ticlopidine, the latter for 1 month. During 18 +/- 14 months, the clinical restenosis rate was significantly lower in the stent group (6.9%) than in the PTCA group (28.4%) (p = 0.001). CONCLUSION: In a series of 244 consecutive patients, newer generation stents and a consistent approach of stent oversizing and high-pressure stent deployment by a single operator resulted in high procedural success (99%), lack of stent thrombosis (0%), and a very low clinical restenosis rate (7%).     

Long-term clinical outcome after implantation of medium Palmaz (biliary) stents in very large native coronary arteries.

Intracoronary stenting has been shown to improve acute and long-term clinical results compared with coronary angioplasty. However, clinical outcome after medium Palmaz biliary (PB) stent implantation in very large native coronary arteries (> 4 mm in diameter) is unknown. This study evaluated restenosis and long-term clinical outcome after PB stenting in large native coronary arteries. Between June 1993 and December 1998, 55 patients with 56 lesions were treated with PB stents. Intracoronary stent deployment was successful in all 56 vessels attempted (100%). The mean stenosis was reduced from 65% +/- 10% to 4% +/- 14%. In 48 of the 56 vessels (86%), vessel size was greater than 4.0 mm in diameter and the mean reference vessel diameter was 4.73 +/- 0.7 mm after stenting. Angiographic success was achieved in 100%. Five patients had postprocedural cardiac enzyme elevation. There was no periprocedural death, emergency coronary artery bypass surgery, repeat target lesion revascularization, or acute stent thrombosis. Long-term clinical follow-up at mean of 28 +/- 15 months was obtained in 96% of the patients. Clinical restenosis rate occurred in 18% of ostial (6/34) and 0% of nonostial (0/22) lesions (P < 0.0001) with an overall clinical restenosis rate of 11%. Repeat angioplasty were performed in these six patients. There were three cardiac and three noncardiac deaths. The overall event-free survival at 1 and 3 years was 92% +/- 4% and 80% +/- 6%, respectively. PB stent implantation in very large native coronary arteries can be performed with a high degree of procedural success and low in-hospital complications. The long-term clinical outcome of patients undergoing PB stenting is associated with excellent event-free survival. However, stenting of ostial lesions remains as an important factor for restenosis even in very large coronary artery stenting.     

Coronary artery stents: evaluating new designs for contemporary percutaneous intervention.

Intracoronary stents have markedly improved the short- and long-term safety and efficacy of percutaneous coronary intervention by improving acute gains in luminal dimensions, decreasing abrupt vessel occlusion, and reducing restenosis. At present, nearly 90% of all coronary interventions involve stenting. A variety of advances in stent technology and design have expanded the clinical application of stenting to include complex coronary lesions, multivessel disease, and small-diameter vessels. In addition, the development of stents as drug delivery systems for antithrombotic or antiproliferative agents has the potential to expand the role of coronary stenting, and early clinical experience appears promising. The purpose of this review is to describe recent developments in stent design, examine the results of clinical trials of contemporary stents, and present future directions for investigation of new stent technologies.     

Outcomes of stenting with overlapping drug-eluting stents versus overlapping drug-eluting and bare-metal stents for the treatment of diffuse coronary lesions

Introduction

We investigated the outcomes of stenting with overlapping drug-eluting stents (DES) versus overlapping stenting with a combination of drug-eluting and bare metal stents (BMS) in very long ≥(≥ 25 mm).

Methods and Results

Fifty-two patients treated with either overlapping DES-DES (n = 22) or DES-BMS (n = 30) were selected from a registry of 588 patients with very long coronary lesions. Patients with acute myocardial infarction (MI) within the preceding 48 hours were excluded. The DES-DES combination was more frequently used for longer lesions compared with the DES-BMS group (47.95 ± 9.25 vs 39.98 ± 9.15 mm, p = 0.003). Left anterior descending artery lesions were also more frequently treated with the DES-DES combination (95.5 vs 66.7%, p = 0.02). In four patients in the DES-BMS group, overlapping stents were used for the coverage of dissections. Peri-procedural non-Q-wave MI occurred in one patient in the DES-BMS group. On follow up, only one case of non-fatal MI occurred in a patient with overlapping DES-DES.

Conclusion

Overlapping a BMS in the proximal part of a long DES instead of exclusive deployment of two or more overlapped DES seems to be a safe and feasible therapeutic strategy in our practice.     

Drug-eluting stents or balloon angioplasty for drug-eluting stent-associated restenosis: An observational follow-up study of first-time versus repeated restenosis

Background

The treatment of patients with repeated drug-eluting stent–in stent restenosis (DES-ISR) remains a challenge and a burdensome clinical problem.

不同雷帕霉素药物洗脱支架在老年冠心病患者中的应用与研究

目的探讨雷帕霉素药物洗脱支架在老年冠心病经皮冠状动脉介入治疗中应用的安全性和有效性。方法入选320例冠心病患者,分为国产雷帕霉素药物洗脱支架组(Firebird组)160例,进口雷帕霉素药物洗脱支架组(Cypher组)160例。比较两组置入支架后6个月随访时的临床不良事件和再狭窄率。结果Firebird组共置入支架197枚,Cypher组共置入支架204枚。临床6个月随访示Firebird组临床不良事件3例,Cypher组4例,差异无显著性意义。6个月期随访造影显示Firebird组(66例)和Cypher组(77例)支架内再狭窄各出现1例。结论雷帕霉素药物洗脱支架Firebird和Cypher类似,而且Firebird有更高的效价比。     

Micro stent I,initial results,and six months follow-up by quantitative coronary angiography

The Micro stent^TM (MS) is a balloon expandable stent that allows the treatment of stenoses in distal and tortuous coronary arteries. This prospective study was performed to evaluate initial and late results of MS implantations. A total of 127 MS (101 in native coronary arteries and 26 in saphenous vein grafts) were implanted in 85 patients (1.5 stents/pt, 65 male, and 20 female, age 62, ±10 yr) with angina pectoris class II-III: 21 (25%), angina pectoris class IV: 41(48%), and acute myocardial infarction: 23 (27%). Indications per segment treated (n=93): elective: 49 (53%); suboptimal balloon angioplasty (PTCA) result: 33(35%); bailout: 11 (12%). The patients were discharged with 100 mg of aspirin daily unless other indications for oral anticoagulants were present. Procedural success (diameter stenosis of 30% without the occurrence of clinical events within 3 wk) was 85%. Early clinical events (<3 wk included: death:1%; subacute closure: 5%; coronary artery bypass surgery (CABG): 1%; vascular complications: 4%. Late clinical events (3 wk-6 mo) included: acute myocardial infarction:3%, PTCA 5%, CABG 3%, angina class III-IV: 4%. Quantitative angiographic results were: the minimum lumen diameter increased from 0.90 ± 0.72 before to 3.05 ± 0.48 mm (<P0.001) after stent implantation. At follow-up, which was 5.5 mo ± 1.1 mo, 61/79 pts (77%), the loss in diameter was 0.90 ± 0.68 mm. The net gain was 1.26 ± 0.90 mm. The restenosis rate (diameter stenosis > 50% at FU) was 13%. This study demonstrates high procedural and late success rates of Micro stent implantations. Cathet. Cardiovasc. Diagn. 43:19-27, 1998. © 1998 Wiley-Liss, Inc.     

Distortion of Palmaz-Schatz stent geometry following side-branch balloon dilation through the stent in a rabbit model

The compromise of side-branches following coronary angioplasty of the parent vessel remains a limitation of the procedure. Reports of dilation through a Palmaz-Schatz stent to salvage a compromised side-branch covered by the stent have been made. We examined the distortion of stent geometry which occurs following this procedure in a rabbit model. Palmaz-Schatz stents were placed at the aortoiliac bifurcation in 7 rabbits and the contralateral iliac artery was dilated through the stent. Despite good angiographic results, varied degrees of stent distortion were noted on gross pathologic analysis. Most distortion occurred when the arteries were dilated through the ends of the struts or through the “diamonds,” and least distortion occurred during dilation through the mid-articulation site. While good stent deployment is thought to be necessary for improved outcomes, the distortion of stents after balloon dilation through the stent, despite good angiographic results, may have negative implications for both short- and long-term outcomes. Cathet. Cardiovasc. Diagn. 40:422–426, 1997. © 1997 Wiley-Liss, Inc.