Three-dimensional modeling of double-stent techniques at the left main coronary artery bifurcation using micro-focus X-ray computed tomography.

BACKGROUND: Various double-stent techniques using drug-eluting stents have been proposed to treat the left main coronary artery (LMCA) bifurcation. However, use of these techniques is frequently associated with focal restenosis at the ostium of the left circumflex coronary artery (LCX). OBJECTIVES: To examine the results of double-stent techniques, using a silicon model of the LMCA bifurcation and three-dimensional (3D) reconstruction images created with micro-focus X-ray computed tomography (MFCT). METHODS: Crush, kissing, and modified T stentings were performed with bare metal stents in a LMCA bifurcation model. The stents were then inspected using MFCT at a minimal resolution of 0.06 mm. RESULTS: Gaps in stent apposition to the vessel were observed at the site of stent overlap in the distal LMCA with all stenting techniques. In crush stenting, when the left anterior descending artery stent overlapped the LCX stent, the latter was crushed on the myocardial side of the vessel, and a gap was observed on the nonmyocardial side, at the LCX ostium. When the overlap was reversed, the LCX stent was crushed on the nonmyocardial side and a gap was observed on the myocardial side. In the case of kissing stents, stent overlap created a gap beneath the overlapped portion of the stents. In modified T-stenting, correct positioning of the LCX stent was difficult and MFCT imaging revealed a nonmyocardial gap. CONCLUSIONS: Close apposition of the stent to the vessel at the ostium of the LCX is difficult to achieve at the LMCA bifurcation, regardless of which double-stent technique is employed, due to the site's wide bifurcation angle and complex 3D structure. The distribution of plaque and the bifurcation angle should be considered before double-stent deployment, to avoid leaving a gap over significant plaques.     

Vascular endoscopic and macroscopic observations after crush stenting of coronary artery bifurcations in pigs.

The crush stent technique has recently been proposed to limit the development of restenosis between drug-eluting stents implanted at coronary artery bifurcations. We studied the stent expansion, apposition to the vessel, and aspect of the overlapping stents after in vivo crush stent implantation. Crush stent implantation was performed at coronary bifurcations in anesthetized swines. The treated sites were examined using intravascular ultrasound and a vascular endoscope. The stents removed from the vessel were analyzed macroscopically. After final kissing balloon inflation, an adequate apposition of the stent to the vessel wall was confirmed by vascular endoscopy and visual inspection. However, the side-branch stent was narrowed at the site of stent overlap, and the overlapping stents in the main branch created a metal mass, which could promote the development of thrombosis. The technique of crush stent implantation with additional kissing balloon inflation is feasible and promising. However, it may be limited by thrombosis and restenosis at the carina because of stent overlapping and potential incomplete apposition. Additional studies are needed to confirm the safety and long-term clinical results of this technique.     

Potential risk of provisional stenting in left main coronary artery bifurcation in multivessel‐related acute coronary syndrome

We present a case of an elderly man suffering from an acute coronary syndrome (ACS) with preshock vital signs and remarkable ST–T wave depression in leads V4–V6, and ST elevation in lead aVR. Coronary angiography showed total occlusion of the right coronary artery (RCA) and impending occlusion in the distal left main coronary artery (LMCA) with a tandem lesion in the proximal left anterior descending artery (LAD). After insertion of an intra‐aortic balloon pump both the LAD and left circumflex artery (LCX) were dilated alternatively; and cross‐over stenting in the LMCA bifurcation was subsequently performed. However, total occlusion of the LCX occurred and it caused acute hemodynamic collapse and ventricular fibrillation storm. Immediate installation of percutaneous cardio‐pulmonary support system allowed stent deployment to be performed in the RCA and subsequent reopening of the LCX that led to a return to sinus rhythm. The patient recovered almost normal left ventricular wall motion and previous activity without any neurological deficit within 2 weeks. Provisional stenting in ACS in the LMCA bifurcation with multivessel disease has a potential risk of acute hemodynamic collapse; a planned two‐stent deployment strategy may assure a higher rate of safety in such cases. © 2011 Wiley‐Liss, Inc.     

Simultaneous kissing stent technique to treat left main stem bifurcation disease.

BACKGROUND: While several endovascular techniques have been developed for treating arterial bifurcation lesions, there is, as yet, no single, widely accepted technique for treating left main stem (LMS) bifurcation lesions with stents. The simultaneous kissing stent (SCS) technique seems particularly suited for such lesions. The authors describe a consecutive cohort of patients with LMS bifurcation stenosis treated with this technique and present mechanistic insights from a porcine model. METHODS: Thirty consecutive patients with LMS bifurcation stenosis +/- multivessel disease were treated with SCS technique using paclitaxel-eluting stents. The technique involves simultaneous implantation of two stents (LMS-LAD and LMS-Cx) so that the proximal end of both stents lie at the same level in the body of LMS. Symptom status was recorded and follow-up angiography was performed. In addition, four pigs underwent SCS implantation of the LMS and were studied by direct examination, histology, and scanning electron microscopy. RESULTS: The patients' mean age was 63, 26 were elective and 19 were male. Paclitaxel-eluting stents (Taxus, Boston Scientific) were used. There was one in-hospital death in a highly unstable patient. At 6-month follow-up angiography, two patients required target lesion revascularization. At 13 +/- 3 month follow-up, the remaining patients remain well, with no other major adverse cardiac events. The animals all survived with patent stents. SEM demonstrated full re-endothelialization and histology showed a thin but complete neointima covering the stent struts. CONCLUSION: The SCS technique for treating LMS bifurcation disease with paclitaxel-eluting stents is safe and feasible. Medium term clinical and angiographic results are good. An endothelium and a thin neointima cover the metal struts.     

Elective sirolimus-eluting stent implantation for left main coronary artery disease: six-month angiographic follow-up and 1-year clinical outcome.

The effectiveness of sirolimus-eluting stent (SES) implantation in patients treated electively for left main (LM) stenoses has not been yet ascertained. The present study reports on the clinical and angiographic outcome of 16 consecutive patients treated electively for de novo stenoses in the LM. The impact of SES implantation on major adverse cardiac events was evaluated. Mean age was 65 +/- 11 years. Unprotected LM was present in nine (56%), and eight patients (50%) received stents extending into both the left anterior descending and circumflex arteries for stenoses of the distal left main bifurcation. In-house mortality and reintervention rate was zero. One patient developed a non-Q-wave myocardial infarction related to the index procedure. At 1-year clinical follow-up, there were no deaths or further myocardial infarctions; one (6%) patient required target lesion revascularization. A total of 12 patients (75%) underwent 6-month angiographic follow-up with a late lumen loss of 0.04 +/- 0.65 mm and one focal restenosis (8% of patients). Elective SES implantation for LM disease was associated with zero mortality and a very low incidence of additional major adverse events at 1 year.     

Long-term outcome of simultaneous kissing stenting technique with sirolimus-eluting stent for large bifurcation coronary lesions.

OBJECTIVES: This study was conducted to evaluate the outcomes of simultaneous kissing stenting with sirolimus-eluting stent (SES). BACKGROUND: Percutaneous intervention for bifurcation coronary lesions is still challenging. METHODS: This study was designed to evaluate the long-term outcomes of 36 consecutive patients with large bifurcation coronary lesions who underwent simultaneous kissing stenting with SES. RESULTS: Lesion location was unprotected left main in 29 patients (81%) and anterior descending artery in 7 (19%). The patients received a combination of aspirin and clopidogrel for 6 months and cilostazol for 1 month. Mean proximal reference diameter was 4.05 +/- 0.68 mm. Compared with the side branch (SB), the main vessel (MV) involved longer lesions (25.8 +/- 17.0 mm vs. 10.2 +/- 10.8 mm, P < 0.001) and smaller preprocedural minimal lumen diameters (1.02 +/- 0.53 mm vs. 1.46 +/- 0.78 mm, P = 0.006) and was treated with larger stents (3.1 +/- 0.3 mm vs. 3.0 +/- 0.3 mm, P = 0.006). Angiographic success rate was 100%. Over the follow-up of 26.7 +/- 8.6 months, no deaths, myocardial infarctions or stent thromboses occurred. Target lesion revascularization was performed in five patients (14%). Overall angiographic restenosis occurred in 5/30 patients (17%), consisting of 4 (13%) at MV and 3 (10%) at SB. At follow-up angiography, a membranous diaphragm at the carina was identified in 14 patients (47%), but only one of whom was associated with angiographic restenosis. CONCLUSION: Simultaneous kissing stenting with SES appears a feasible stenting technique in large bifurcation coronary lesions. However, a new angiographic structure of carinal membrane developed in a half of patients at follow-up and its influence needs to be further investigated.     

改良Y支架术与reverse crush支架术治疗冠状动脉分叉病变的疗效比较

目的对比改良Y支架术与reverse crush支架术治疗冠状动脉分叉病变的临床疗效。方法将65例冠状动脉分叉病变患者随机分为两组,分别行改良Y支架术（改良组）和reverse crush支架术（对照组）治疗,观察两组疗效和随访1年主要心脏不良事件发生率。结果改良组手术时间、X线曝光时间短于对照组（P均〈0．01）;造影剂和球囊用量少于对照组（P均〈0．01）,最终球囊对吻成功率更高,但无统计学差异（P〉0．05）;6～9个月造影随访,改良组分支血管再狭窄率低于对照组（P〈0．01）。1年随访结束,对照组心脏不良事件发生率高于改良组,但无统计学差异（P〉0．05）。结论改良Y支架术较teverse crash支架术操作简单、费时少,具有更低的分支再狭窄率,有减少随访1年临床心脏不良事件的趋势,推荐临床优先选用。     

Bail-Out stenting for left main coronary artery occlusion following diagnostic angiography

We report a case of acute left main coronary artery occlusion treated with stenting of the left main artery. The patient had a severe ostial left main stenosis and after diagnostic coronary angiography developed a total occlusion of the left main artery with life threatening hemodynamic consequences. Stenting of the unprotected left main coronary artery was successfully performed as a salvage procedure.     

Unprotected left main bifurcation restenosis treated with a 2‐stent technique

The present case report refers to the percutaneous treatment of severe left main stem stenosis as a consequence of proliferative in‐stent restenosis of left circumflex coronary with retrograde involvement. A reverse mini‐crush technique with 2 stents was described. © 2012 Wiley Periodicals, Inc.     

Retrograde left main stenting

Percutaneous transluminal coronary angioplasty of protected left main coronary artery stenosis is usually performed by an antegrade approach. In this case report, we describe left main coronary artery stenting by a retrograde approach through a saphenous venous graft in a patient in whom the antegrade approach was considered less appropriate due to chronic ostial occlusion. © 1996 Wiley-Liss, Inc.     

Comparative long-term efficacy and safety of drug-eluting stent versus coronary artery bypass grafting in ostial left main coronary artery disease: analysis of the MAIN-COMPARE registry

Background : To date, drug‐eluting stent (DES) implantation has not been compared with coronary artery bypass grafting (CABG) for ostial left main coronary artery (LMCA) lesions. Methods : Of the 263 patients in the MAIN‐COMPARE registry with ostial LMCA stenosis, 123 were treated with percutaneous coronary intervention (PCI) with DES and 140 with CABG. We compared their 5‐year overall survival, composite outcomes of death, Q‐wave myocardial infarction (MI) or stroke, and target vessel revascularization (TVR) rates. Results : Unadjusted analysis showed no significant differences between CABG and DES in overall survival rates (95% confidence interval (CI) for hazard ratio (HR): 0.44 to 1.77, P = 0.71), composite outcomes (death, Q‐wave MI, or stroke)‐free survival rates (95% CI for HR: 0.41–1.63, P = 0.56), and TVR‐free survival rates (95% CI for HR: 0.79–5.03, P = 0.14). Multivariate adjusted Cox regression analysis also showed no significant between‐group differences in TVR (95% CI for HR: 0.52–3.79, P = 0.49), death (95% CI for HR: 0.79–2.82, P = 0.22) and the composite of death, Q‐wave MI, or stroke (95% CI for HR: 0.65–2.57, P = 0.46). These results were sustained after propensity score adjustment and propensity score matching analysis. Conclusions : DES implantation for ostial LMCA lesions showed similar 5‐year outcomes of death, major adverse events, and TVR compared with CABG. Although meticulous adjustments decreased baseline difference between the two treatments, the absence of statistical significance could be attributable to the size of the study sample and hidden bias. © 2012 Wiley Periodicals, Inc.     

Management of failed stenting of the unprotected left main coronary artery

Percutaneous coronary intervention (PCI) is increasingly accepted as treatment for unprotected left main coronary artery (ULMCA) disease especially in those patients who are unsuitable for cardiac surgery. Treatment of any stent failure is associated with increased complexity and worse clinical outcomes when compared with de novo lesion revascularization. Intracoronary imaging has provided new insight into mechanisms of stent failure and treatment options have developed considerably over the last decade. There is paucity of evidence on the management strategy for stent failure in the specific setting of ULMCA. Treating any left main with PCI requires careful consideration and consequently treatment of failed stents in ULMCA is complex and provides unique challenges. Consequently, we provide an overview of ULMCA stent failure, proposing a tailored algorithm to guide best management and decision in daily clinical practice, with a special focus on intracoronary imaging characterization of causal mechanisms and specific technical and procedural considerations.     

Three‐year outcome of drug‐eluting stent implantation for coronary artery bifurcation lesions

Objectives: To compare the very long‐term clinical outcomes of bifurcation lesions using the crush and the simultaneous kissing stent (SKS) techniques. Background: A variety of two‐stent techniques have been used to treat coronary artery bifurcation lesions in the drug‐eluting stent era, but the long‐term clinical outcome of these approaches is not known. Methods: A total of 74 consecutive patients underwent bifurcation stenting using either the crush or SKS techniques. Mean patient age was 66.91 ± 11.3 years; 26% were diabetic, and the left anterior descending/diagonal bifurcation was the most frequently treated lesion (68%). Results: In‐hospital outcomes were not significantly different between groups. Over a median follow‐up of 3.3 years, 1 patient in the SKS group and 3 patients in the crush group died (P = ns). Probable stent thrombosis leading to death according to the Academic Research Consortium definition occurred in 1 patient in the crush group. Mortality in the remaining 3 patients was noncardiac. Target lesion revascularization (TLR) occurred in 14 patients (40%) in the SKS group and 5 patients (12.8%) in the crush group (P = 0.015). Survival free from major adverse cardiac events (MACE) was significantly less in the SKS group and predominantly driven by TLR (60 vs. 88%, P = 0.001). Conclusions: In conclusion, over a median of 3.3 years of follow‐up, TLR and MACE are significantly lower in bifurcation lesions treated with the crush technique when compared with the SKS technique. Definite or probable stent thrombosis is rare with either technique. © 2009 Wiley‐Liss, Inc.     

Sirolimus-eluting stent implantation for treatment of proximal left anterior descending coronary artery lesions: long-term outcome and predictors of adverse cardiac events.

OBJECTIVES: Acute and long-term results after sirolimus-eluting stent (SES) implantation of proximal left anterior descending coronary artery (LAD) disease were evaluated. BACKGROUND: Although SES has been used increasingly for the treatment of LAD disease, data regarding their safety and efficacy in a real-world population are limited. METHODS: We investigate the short- and long-term results in 966 patients who underwent SES implantation for stenosis of proximal LAD. RESULTS: The procedural success rate was 97.6%, and procedural non-Q-wave myocardial infarction (MI) rate was 14.5%. In-hospital major complications occurred in five patients (0.5%), including three deaths and two Q-wave MIs. During follow-up (20.4 +/- 8.9 months), there were 16 deaths (1.7%; 10 cardiac, 6 noncardiac), 2 Q-wave MIs, and 22 target lesion revascularizations (2.3%). Late stent thrombosis occurred in two patients (0.2%), 14 and 23 months after the procedure. The event-free survival rates for cardiac death/Q-wave MI were 98.6% +/- 0.4% at 1 year and 97.8% +/- 0.6% at 2 years. The cumulative probabilities of survival without major adverse cardiac events (MACE) were 96.7% +/- 0.6% at 1 year and 95.4% +/- 0.8% at 2 years. In multivariate analysis, stented length (HR 1.04, 95%CI 1.01-1.07, P = 0.009) and infarct-related artery (HR 5.18, 95%CI 1.09-24.64, P = 0.039) were independently related to cardiac death/Q-wave MI. In addition, stented length (HR 1.04, 95%CI 1.02-1.06, P < 0.001) and left ventricular dysfunction (HR 2.66, 95%CI 1.07-6.63, P = 0.036) were significant independent predictors of MACE. CONCLUSIONS: SES implantation for proximal LAD disease appears safe and effective in a real-world population, and the independent predictors of MACE included stented length and left ventricular dysfunction.     

Bail-out stenting for left main coronary artery dissection during catheter-based procedure: acute and long-term results

BACKGROUND: The optimal treatment of patients with left main coronary artery (LMCA) dissection during catheter-based procedure remains uncertain. HYPOTHESIS: In cases with significant LMCA dissection occurring during catheter-based procedure, prompt stent implantation may be safe and associated with favorable clinical outcome. METHODS: We evaluated the acute and long-term results of bail-out stenting for LMCA dissection occurring during a catheter-based procedure in 10 patients. RESULTS: Initially, there was no significant stenosis of LMCA segments in these patients. Catheter-induced dissection occurred in eight patients (during diagnostic angiography in three patients and during guiding catheter manipulation in five patients). Two patients suffered dissection in the setting of stent deployment in other vessels. Therefore, bail-out stenting for LMCA dissection was performed in a total of 10 patients. In four patients, hypotension developed and an intra-aortic balloon pump was placed during the procedure. Stents were successfully deployed in all patients; there was no in-hospital mortality. Six-month angiographic follow-up was performed in eight patients. No angiographic restenosis (diameter stenosis > or = 50%) was observed in any patient at follow-up study. During a mean follow-up of 31 +/- 25 months after hospital discharge, there was no major adverse cardiac event (death, myocardial infarction, and target lesion revascularization). CONCLUSIONS: Bail-out LMCA stenting is technically feasible and showed good acute and long-term results in a small series of patients.