Provisional stenting for multivessel PCI

Background: Bare stents reduce acute complications and repeat revascularization following percutaneous coronary intervention (PCI), but are costly and may lead to in‐stent restenosis. It remains unclear whether stents should be universally implanted or whether provisional stenting mainly to suboptimal balloon dilatation results is an acceptable approach for multivessel PCI. Objective: To compare the long‐term clinical restenosis and target lesion revascularization (TLR) of stented and non‐stented coronary artery lesions in patients who had multivessel PCI. Methods: We performed retrospective analysis of matched data from 129 consecutive patients who underwent multivessel PCI (at least optimal balloon angioplasty to one coronary artery segment and balloon angioplasty plus stenting to another coronary artery in the same patient, all lesions are de novo native coronary artery lesions with vessel diameter ?2.5?mm). The study endpoint was restenosis and repeat revascularization at one‐year follow‐up. Results: Baseline characteristics were similar in both groups. Low in‐hospital MACE (3.1%). Acute myocardial infarction, emergency revascularization via either PCI or CABG was detected and angiographic success was achieved in 99.3% of lesions in both groups. The rate of clinically driven angiographic restenosis and TLR at one‐year (follow‐up?100%) was similar (17.1% versus 18.6%, P?=?0.871, and 13.9% versus 16.3%, P?=?0.728, for optimal balloon angioplasty versus provisional stenting. Conclusions: The main findings from this study are that long‐term angiographic restenosis and TLR was comparable for optimal balloon angioplasty and provisional stenting, suggesting that provisional stenting is an acceptable approach for multivessel PCI.     

Interventional Management of Acute Coronary Syndromes

Percutaneous coronary intervention is an effective treatment for a range of coronary syndromes. Although the success rate of the interventions has increased in recent years to more than 90%, percutaneous coronary procedures are still associated with short-term and long-term complications. The most common angiographic short-term complication of balloon angioplasty is acute vessel closure. Clinically, periprocedural non-Q wave myocardial infarctions are common during or immediately following the percutaneous intervention. These complications are associated with adverse clinical prognosis. Formation of platelet-rich thrombi plays a major role in the pathophysiology of acute complications of balloon angioplasty. Potent platelet inhibition with glycoprotein IIb-IIIa inhibitors reduces the incidence of periprocedural death and myocardial infarctions, a benefit that persists at long-term follow-up. The long-term complication of percutaneous interventions is restenosis, which frequently requires repeated revascularization because of ischemic pain. Most pharmacological therapies have proved ineffective for the prevention of restenosis. This may not be surprising, as new evidence shows that the primary mechanism of restenosis may be arterial remodeling. Implantation of coronary stents prevents lumen narrowing due to the remodeling process, and coronary stenting significantly reduces the need for target vessel revascularization. Restenosis is not completely eliminated, however, and new treatment modalities aimed at prevention of in-stent stenosis are actively being sought.     

Drug-Coated Balloons for Coronary and Peripheral Interventional Procedures

Paclitaxel-coated balloon (PCB) angioplasty reduces neointimal proliferation, restenosis, and clinical need for target lesion revascularization (TLR). PCB was superior for coronary restenosis in bare-metal and drug-eluting stents compared with uncoated balloon angioplasty and was noninferior compared with paclitaxel-eluting stents. PCB angioplasty should be considered for treatment of coronary in-stent restenosis. For de novo lesions, PCB plus endothelial progenitor cell capturing stents reduced restenosis and TLR in early reports. Among patients with de novo lesions and diabetes, the combination of PCB plus bare-metal stent revealed similar results in lesions compared with paclitaxel-eluting stents. The early results for PCB in small vessels are also very encouraging. Dual antiplatelet therapy duration may be shorter with PCB angioplasty compared with drug-eluting stents. Nevertheless, the risk for thrombotic vessel occlusion is minimized. Considering peripheral arterial disease, PCB angioplasty for femoropopliteal lesions was superior to uncoated balloon angioplasty. Registries indicate PCB to also be effective in lesions below the knee. Since there is no certain class effect, efficacy and safety have to be demonstrated for different types of PCB for coronary and peripheral interventions.     

Successful Expansion of an Underexpanded Stent by Rotational Atherectomy

The current routine use of intracoronary stents in percutaneous coronary intervention (PCI) has significantly reduced rates of restenosis, compared with balloon angioplasty alone. On the contrary, small post-stenting luminal dimensions due to undilatable, heavily calcified plaques have repeatedly been shown to significantly increase the rates of in-stent restenosis. Rotational atherectomy of lesions is an alternative method to facilitate PCI and prevent underexpansion of stents, when balloon angioplasty fails to successfully dilate a lesion. Stentablation, using rotational atherectomy to expand underexpanded stents deployed in heavily calcified plaques, has also been reported. We report a case via the transradial approach of rotational-atherectomy–facilitated PCI of in-stent restenosis of a severely underexpanded stent due to a heavily calcified plaque. We review the literature and suggest rotational atherectomy may have a role in treating a refractory, severely underexpanded stent caused by a heavily calcified plaque through various proposed mechanisms.     

Eluting stents: an effective, promising solution?

Recent studies with eluting stents showed encouraging results in preventing in-stent restenosis. We report a case of a patient in whom the implantation of carbon-coated and eluting stents in two different vessels was associated with different angiographic results. A diabetic hypertensive 67-year-old woman with an acute inferior myocardial infarction underwent direct coronary angioplasty on the right coronary artery with the implantation of two carbon-coated stents. In view of the severity of an additional lesion of the left anterior descending coronary artery and diabetes, coronary angioplasty and stenting with an eluting stent was performed in this vessel. Five months later the patient presented with acute pulmonary edema and an increase in troponin I levels. A new coronary angiography showed a long subtotal in-stent restenosis of the right coronary artery, whereas the left anterior descending coronary artery was normal. Our case report suggests that eluting stents should be considered a precious and effective tool in preventing in-stent restenosis.     

Drug-eluting stent: the emerging technique for the prevention of restenosis

Percutaneous coronary interventions (PCI) have surpassed coronary artery bypass grafting as the most common means for treating coronary artery disease, because of materials improvement, the use of stent and pharmacotherapy. However, despite the variety of mechanical techniques such as dilatation, debulking or conventional stent implantation, the incidence of restenosis on short and mid-term follow-up is still representing an important limitation to PCI. Restenosis is mainly due to elastic recoil, negative vessel remodelling and neointimal proliferation, as a response to vessel injury induced by angioplasty devices. The use of conventional stents has provided an efficient method to avoid elastic recoil and negative vessel remodelling, thus partially reducing restenosis as compared to conventional balloon dilatation. However, neointimal proliferation (biological vessel response to injury caused by stent implantation) is not affected by stenting technique. Thus, the extensive use of coronary stent, even in complex lesions, have produced again a "new" disease: the in-stent restenosis especially in some patients' subset (diabetics) or in some lesion subset (bifurcations, long lesions, small vessels, total occlusions, diffuse disease). Therefore, the main target of today's interventional cardiologists is to resolve this problem. The combination between mechanical control of elastic recoil and negative remodelling (stent) and the control of neointimal proliferation - biological response to vessel injury - (antiproliferative drugs) is the emerging approach against restenosis. This emerging approach consists in using the stent as drug carrier to the target site. Local delivery of antiproliferative or immunosuppressive agents using a drug-coated stent is supposed to inhibit in stent restenosis. The first antiproliferative agents being used successfully in clinical trials are sirolimus and paclitaxel and, so far, the data available of these trials demonstrated a marked reduction of restenosis using sirolimus- and paclitaxel-coated stents as compared to conventional stents. However, many questions are still to be answered and several other clinical trials with drug-eluting stents are ongoing, evaluating safety and efficacy of sirolimus and paclitaxel in a larger number of patients and in different subset of coronary lesions type and morphology. Based on the very impressive results available at the present time, we can expect, in the very near future, remarkable changes in our clinical practice and the beginning of a new "era" of interventional cardiology.     

Late stent thrombosis in brachytherapy: the role of long-term antiplatelet therapy

Advances in percutaneous coronary intervention (PCI) have emerged in the past decade. Stenting has improved upon the limitations of angioplasty, acute vessel closure and restenosis by providing mechanical vascular support, resulting in sustained clinical and angiographic benefit. This has led to greater utilization of the technique, although it is associated with a significant incidence of in-stent restenosis. Neointimal hyperplasia is the pathophysiologic process that leads to in-stent restenosis. Brachytherapy can be effective in reducing the occurrence of this process. Unfortunately, brachytherapy trials have identified the phenomenon of late stent thrombosis as a potentially serious complication of this procedure. Late stent thrombosis is thrombosis that occurs > 30 days after PCI. The risk of thrombosis is increased in patients receiving a new stent in addition to brachytherapy. It also appears to be increased when adjunctive antiplatelet therapy with ticlopidine or clopidogrel is discontinued early. Strategies to prevent late stent thrombosis include the prolonged use of combination antiplatelet therapy in addition to limited placement of new stents in patients treated with brachytherapy for in-stent restenosis.     

Coronary stenting: A matter of revascularization

In the last few decades, the recommended treatment for coronary artery disease has been dramatically improved by percutaneous coronary intervention(PCI) and the use of balloon catheters, bare metal stents(BMSs), and drug-eluting stents(DESs). Catheter balloons were burdened by acute vessel occlusion or target-lesion restenosis. BMSs greatly reduced those problems holding up the vessel structure, but showed high rates of instent re-stenosis, which is characterized by neo-intimal hyperplasia and vessel remodeling leading to a renarrowing of the vessel diameter. This challenge was overtaken by first-generation DESs, which reduced restenosis rates to nearly 5%, but demonstrated delayed arterial healing and risk for late in-stent thrombosis, with inflammatory cells playing a pivotal role. Finally, new-generation DESs, characterized by innovations in design, metal composition, surface polymers, and antiproliferative drugs, finally reduced the risk for stent thrombosis and greatly improved revascularization outcomes. New advances include bioresorbable stents potentially changing the future of revascularization techniques as the concept bases upon the degradation of the stent scaffold to inert particles after its function expired, thus theoretically eliminating risks linked with both stent thrombosis and re-stenosis. Talking about DESs also dictates to consider dual antiplatelet therapy(DAPT), which is a fundamental moment in view of the good outcome duration, but also deals with bleeding complications. The better management of patients undergoing PCI should include the use of DESs and a DAPT finely tailored in consideration of the potentially developing bleeding risk in accordance with the indications from last updated guidelines.     

Balloon dilatation and coronary vascular stent implantation

To avoid acute complications and restenosis after percutaneous transluminal coronary angioplasty coronary stents were developed. For the first time three flexible Palmaz-Schatz stents were implanted after application and fixation by balloon inflation in two patients with severe lesions of the left anterior descending coronary artery. The vessels showed larger diameters with smoother surface and smaller gradients compared to balloon angioplasty as related to a blockade of the elastic properties of the vessel and suggested fixation of intima or media dissection. The implantation of the coronary stents was without complications. The control after 24 h showed an open vessel with unchanged diameter. The patients with the proximal lesion of the left anterior descending coronary artery six months later showed no restenosis and no luminal narrowing. The recanalized left anterior descending coronary artery, which was dilated, received two stents and was reoccluded after six months. Meanwhile, up to four stents were implanted successfully in an additional four patients with open vessels as the 24-h-control. Based on this and previous work the implantation of coronary stents seems to open a new dimension for percutaneous transluminal coronary angioplasty because vessel occlusions can be prevented. Whether or not the restenosis rate can be reduced has to be demonstrated in additional studies.     

Prevention of restenosis after coronary angioplasty

PURPOSE OF REVIEW: Despite numerous advances in coronary interventional techniques, the frequent occurrence of restenosis continues to plague interventional cardiology. With the widespread use of drug-eluting stents, there is a need to reexamine critically the roles of the various interventional techniques currently available. RECENT FINDINGS: Drug-eluting stents have dramatically reduced the rates of restenosis and target vessel revascularization in a wide spectrum of patients with varying lesion morphologies. However, when restenosis does occur, it still tends to be dependent on the same factors that predict restenosis with bare metal stenting. The routine use of drug-eluting stents entails high initial costs to the health care system. Debulking as a means to improve outcomes after angioplasty has not lived up to expectations. Gene therapy is rapidly evolving into a viable means to reduce neointimal proliferation after angioplasty. SUMMARY: Careful patient selection and attention to the procedure of stent deployment optimize the results of angioplasty with drug-eluting stents. Because of cost considerations, drug-eluting stents should be used in patients who are expected to have the greatest absolute benefit. In this context, when judiciously used, conventional balloon angioplasty and bare metal stenting still have a definite role in the management of patients with obstructive coronary artery disease.     

Treatment of coronary in-stent restenosis with a novel paclitaxel urea coated balloon

Randomized clinical trials investigating the treatment of coronary in-stent restenosis with paclitaxel iopromide coated balloon catheters have shown favorable results. The aim of the present clinical investigation was to assess the efficacy of a novel paclitaxel urea coated angioplasty balloon in the treatment of coronary in-stent restenosis. A total of 26 restenotic bare metal stents in 23 patients with a lesion length of 22.8 ± 11.1 mm and a reference vessel diameter of 2.64 ± 0.31 mm were treated. Up to six months and including the six-month angiographic control, only one target lesion revascularization was necessary; in total, the rate of major adverse cardiovascular events until six-month follow-up was 4.3 %. In-stent late lumen loss was 0.07 ± 0.37 mm, in-segment late lumen loss 0.02 ± 0.50 mm. Binary restenosis was present in one patient (4.3%). The results of this first-in-human series with a paclitaxel urea coated balloon are comparable to paclitaxel iopromide coated balloon catheters. Randomized, controlled clinical trials are warranted to further evaluate this promising approach.     

Revascularization for coronary artery disease in diabetes mellitus: Angioplasty,stents and coronary artery bypass grafting

Patients with diabetes mellitus (DM) are prone to a diffuse and rapidly progressive form of atherosclerosis, which increases their likelihood of requiring revascularization. However, the unique pathophysiology of atherosclerosis in patients with DM modifies the response to arterial injury, with profound clinical consequences for patients undergoing percutaneous coronary intervention (PCI). Multiple studies have shown that DM is a strong risk factor for restenosis following successful balloon angioplasty or coronary stenting, with greater need for repeat revascularization and inferior clinical outcomes. Early data suggest that drug eluting stents reduce restenosis rates and the need for repeat revascularization irrespective of the diabetic state and with no significant reduction in hard clinical endpoints such as myocardial infarction and mortality. For many patients with 1- or 2-vessel coronary artery disease, there is little prognostic benefit from any intervention over optimal medical therapy. PCI with drug-eluting or bare metal stents is appropriate for patients who remain symptomatic with medical therapy. However, selection of the optimal myocardial revascularization strategy for patients with DM and multivessel coronary artery disease is crucial. Randomized trials comparing multivessel PCI with balloon angioplasty or bare metal stents to coronary artery bypass grafting (CABG) consistently demonstrated the superiority of CABG in patients with treated DM. In the setting of diabetes CABG had greater survival, fewer recurrent infarctions or need for re-intervention. Limited data suggests that CABG is superior to multivessel PCI even when drug-eluting stents are used. Several ongoing randomized trials are evaluating the long-term comparative efficacy of PCI with drug-eluting stents and CABG in patients with DM. Only further study will continue to unravel the mechanisms at play and optimal therapy in the face of the profoundly virulent atherosclerotic potential that accompanies diabetes mellitus.     

两种国产西罗莫司洗脱支架治疗ST段抬高型心肌梗死患者的疗效和安全性研究

目的 比较两种国产西罗莫司洗脱支架(Excel与Firebird)对急性ST段抬高型心肌梗死(STEMI)患者行直接经皮冠状动脉介入治疗(PCI)的有效性和安全性.方法 入选我院急性STEMI患者249例,根据植入支架类型,随机分为Excel支架组136例(54.6%)和Firebird支架组113例(45.4%).随访6～24个月,平均12个月行定量冠状动脉造影复查.比较两组患者手术即刻成功率,术后住院及随访过程中主要不良心脏事件(包括心原性死亡、再发心肌梗死和靶病变血运重建)发生率及晚期管腔丢失、支架再狭窄、支架内血栓发生率.结果 两组患者术前临床基线特征及冠状动脉病变情况、直接PCI术后即刻情况差异均无统计学意义(P＞0.05);术后平均12个月随访中,两组患者死亡分别为2例(1.47%)与1例(0.88%),无心原性死亡,非致死心肌梗死分别为1例(0.74% )与1例(0.88%),靶血管再次血运重建分别为2例(1.47%)与2例(1.77%),差异无统计学意义(均P＞0.05).定量冠状动脉造影随访两组支架内最小管腔内径、节段内最小管腔内径、支架内晚期管腔丢失、节段内晚期管腔丢失,差异无统计学意义(均P＞0.05);支架内再狭窄、节段内再狭窄、支架内血栓形成的发生率差异亦无统计学意义(均P＞0.05).结论 STEMI患者直接PCI应用两种国产西罗莫司洗脱支架均有效、安全.

Abstract：

Objective To compare the efficacy and safety of two kinds of homemade sirolimus-eluting stents (Firebird and Excel) for treatment of acute ST segment elevation myocardial infarction (STEMI) in patients who underwent percutaneous coronary intervention (PCI). Methods The 249 consecutive patients with STEMI who underwent PCI were randomly divided into two groups: Excel group (n=136) and Firebird group (n=113). They were followed up for 6-24 months, and coronary angiography was reviewed average 12 months later. The primary endpoints were major adverse cardiac events, including death, reinfarction and target vessel revascularization. The second endpoints included late luminal loss and restenosis 12 months after treatment. Results There were no significant differences in baseline data, coronary arterial lesion before operation, and immediateness condition after PCI between the two groups (all P＞0.05). Within follow-up, there were 2 (1.47%) death cases and 1 (0.88%) death case, 1 (0.74%) and 1 (0.88%) nonfatal myocardial infarction case, 2 (1.47%) and 2 (1.77%) target vessel revascularization cases in the two groups respectively (all P＞0.05). There were no significant differences in late luminal loss of in-stent and in-segment, the rates of in-stent restenosis, in-segment restenosis and stent thrombosis, the in-stent minimal lumen diameter and in-segment minimal lumen diameter between the two groups (all P＞0.05). Conclusions The two kinds of homemade sirolimus-eluting stents may have similar efficacy and safety in patients with STEMI treated with primary PCI.     

Unintentional extraction of a coronary stent deployed 4 months earlier during cutting-balloon angioplasty for in-stent restenosis

In general, coronary stents, when deployed in a coronary artery by conventional balloon expansion, appear to be tightly forced into the vessel wall, virtually precluding intentional or unintentional removal of the stents. Here, we present a case of unintended coronary stent extraction during cutting balloon angioplasty for high-grade in-stent restenosis of a stent successfully deployed 4 months earlier. The blades of the cutting balloon became stuck in the stent struts. Retrieval of the cutting balloon was only possible in conjunction with the stent using increased traction. Subsequent vessel closure was recanalized and a paclitaxel-eluting stent was implanted, covering the entire region of the previous stent and rendering an excellent angiographic result. Careful inspection of the extracted stent demonstrated complete removal. Retrospective analysis of the stent implantation procedure 4 months prior revealed complete stent expansion and closely matched stent and vessel dimensions as assessed by angiographic criteria.     

Treatment Strategies for In-Stent Restenosis

In-stent restenosis has become a significant clinical problem. It is estimated that in 1997, up to 100,000 patients with in-stent restenosis were treated worldwide. Serial intravascular ultrasound analysis has shown that neointimal hyperplasia represents the most important cause for in-stent restenosis, while late recoil and remodeling are neglectabe. With the recent explosion in the use of coronary stents, clinical investigation on stent restenosis has lagged behind. For example, the true prevalence of in-stent restenosis varies with the lesion and patient subset. It is much higher in the "real world" than in selected patients who are typically controlled in most studies. Diffuse restenosis can be expected in about two-thirds of stented patients, and it is difficult to treat because of unfavorable long-term results. Conventional catheter-based treatment modalities include plain balloon angioplasty (PTCA), rotational atherectomy (RA), excimer laser coronary angioplasty (ELCA), directional coronary atherectomy (DCA), and additional stent implantation. Exact individual recurrence rates for these approaches are not known and show a considerable degree of variability. Recently, brachytherapy has emerged as the most promising way to treat in-stent restenosis.     

Treatment Strategies for Bifurcation Lesions

Percutaneous transluminal angioplasty of coronary artery bifurcations represents a still evolving field of interventional cardiology. The dilatation of stenoses located at the site of coronary bifurcations has been limited by the risk of side branch occlusion with subsequent myocardial infarction and high rates of late restenosis. The initial success rates of conventional balloon dilatation were improved by the introduction of side branch protection using two guidewires as well as the "kissing balloon" technique. The potential advantage of atherectomy techniques, however, was associated with a high incidence of acute complications. While bifurcation stenting promises to allow optimal geometric reconstruction of bifurcation lesions using multiple or single component bifurcation stents, late intimal hyperplasia remains a potential limitation of this interventional approach.     

紫杉醇微孔载药支架与进口雷帕霉素药物洗脱支架治疗冠心病的临床效果比较

目的:比较紫杉醇微孔载药支架和进口雷帕霉素药物洗脱支架在经皮冠状动脉介入治疗中的临床疗效。方法: 筛选73例行经皮冠状动脉介入治疗术的冠心病患者,随机分为两组,紫杉醇微孔载药支架组（紫杉醇组,35例）和进口雷帕霉素药物洗脱支架组（雷帕霉素组,38例）。支架植入术后6个月复查冠状动脉造影（CAG）。随访6个月,对比两组支架内血栓形成、主要心血管不良事件（包括心源性死亡、非致死性心肌梗死、靶病变血运重建）和支架内再狭窄发生率。结果: 随访6个月,两组均未出现急性、亚急性和晚期支架内血栓形成、非致死性心肌梗死和心源性死亡。心绞痛、支架内再狭窄和靶病变血运重建发生率均无统计学差异。结论: 紫杉醇微孔载药支架与进口雷帕霉素药物洗脱支架在治疗冠状动脉简单病变时具有相同的近、中期临床疗效和安全性。     

Bare-Metal Stents Versus Drug-Eluting Stents for Primary Angioplasty: Long-Term Outcome

Percutaneous transluminal coronary intervention (PCI) is the most used myocardial revascularization technique for patients with coronary artery disease. Primary PCI with stent implantation is widely considered the gold standard for the treatment of ST-elevation myocardial infarction patients. Coronary stents, compared with balloon angioplasty, have reduced focal lesion restenosis. To reduce in-stent restenosis, drug-eluting stents (DES) were designed to locally release drugs inhibiting neointimal growth. Recent concerns have emerged on the potential higher risk of stent thrombosis with DES that might be even more pronounced among myocardial infarction patients. For these reasons, DES for primary PCI remains an “off-label” use. In the last several years, a number of randomized trials and registries have tested the safety and efficacy of DES in primary PCI. Data from these studies were analyzed in several meta-analyses, reasonably consistently demonstrating that the use of DES significantly decreased the need for revascularization without an increase in the incidence of death, recurrent infarction, or stent thrombosis at long-term follow-up.     

普通球囊与切割球囊成形术对冠状动脉支架内再狭窄的近远期疗效

目的　对切割球囊成形术 (CBA)与普通球囊成形术 (POBA)支架内再狭窄病变的近远期血管造影结果比较 ,评价 CBA对支架内再狭窄病变的有效性。方法　 37例 ,共 39处病变 ,2 3处进入 CBA组 ,16处进入 POBA组。分别比较术后即刻及远期定量冠状动脉造影最小血管径 (ML D)、狭窄度 (DS)、再狭窄率、即刻管腔获得 (AL G)、即刻血管弹性回缩 (AR)及弹性回缩率 (ARR)。结果　术后即刻 ML D、DS、AL G两组差异无显著性。 CBA组最大扩张压、AR及 ARR均较 POBA组低 (P<0 .0 5或 P<0 .0 0 1)。随访造影结果 ,CBA组 ML D明显大于 POBA组 (P<0 .0 5 ) ;DS及再狭窄率均小于 POBA组 (P<0 .0 1)。结论　 CBA组的低压扩张治疗支架内再狭窄病变是有效的 ,对血管损伤小于 POBA,且获得较 POBA低的再狭窄率 ,值得进一步探讨