A simple and rapid method for identification of lesions at high risk for the no-reflow phenomenon immediately before elective coronary stent implantation

We aimed to design a rapid and reliable method to identify coronary lesions at high risk for the no-reflow phenomenon before elective coronary stent implantation using integrated backscatter intravascular ultrasound (IB-IVUS). The no-reflow phenomenon occurring during elective percutaneous coronary intervention (PCI) worsens patient prognosis, regardless of whether the phenomenon is transient or persistent. We retrospectively studied 353 coronary lesions to identify factors potentially promoting the no-reflow phenomenon, including lesion location and severity. We also performed component analysis by two- and three-dimensional IB-IVUS before elective stent implantation. The cutoff values of the true lipid volume and estimated lipid volume (lipid area at the minimal lumen diameter site × total stent length) for the no-reflow phenomenon were determined by receiver operating curve analysis. Type C lesions, regardless of location and a thrombolysis in myocardial flow grade of 0, were risk factors for the no-reflow phenomenon during PCI. The estimated lipid volume was significantly correlated with the true lipid volume (R ² = 0.778, p < 0.0001). The cutoff value of the estimated lipid volume for the no-reflow phenomenon was 132.6 mm³ (area under the curve = 0.719), and the predictive value was equivalent to that of the true lipid volume. Lesions with an estimated lipid volume of ≥132.6 mm³ had a significantly higher risk of the no-reflow phenomenon during elective stent implantation (odds ratio, 4.35; 95 % confidence interval, 1.67–12.7; p = 0.0024). The simple and rapid measurement of the estimated lipid volume immediately before stenting during PCI constitutes a reliable predictor of lesions at high risk for the no-reflow phenomenon.     

冠状动脉介入术后无再流现象的防治进展

急性心肌梗死患者行经皮冠状动脉介入术(PCI)时,无再流现象的发生严重影响了再通治疗的成功率。因此,改善心肌再灌注,减少无再流现象的发生率成为当今PCI治疗的新热点。本文主要对PCI后无再流现象的预防和治疗进展及存在问题进行综述。     

经皮冠状动脉介入治疗术后的无再流现象

无再流现象 (no reflowphenomenon)是指冠状动脉闭塞 ,血流中断后重新恢复血流 ,却无心肌组织的有效灌注的现象 ,可发生于溶栓治疗及经皮冠状动脉介入治疗 (PCI)术后。本文就PCI术后无再流现象的发生情况、机制、检测、预防和处理等方面的研究进展进行了综述。     

经两种导管注射地尔硫卓处理急诊PCI术中无复流现象的疗效比较

目的:观察急诊经皮冠状动脉介入治疗(PCI)术中出现无复流现象后,经微导管向远端血管床注射地尔硫卓的治疗效果。方法:选择PCI治疗中存在“无复流”现象的患者41例为研究对象,其中20例入选导引导管组,经导引导管冠状动脉内注射地尔硫卓2.0 mg;21例入选微导管组,经微导管注射地尔硫卓2.0 mg至靶病变远端:10 min后复查冠状动脉造影,观察两组患者首次和手术结束前末次造影图像,评定冠状动脉血流心肌梗死溶栓试验(thrombolysis in myocardial infarction,TIMI)分级及TIMI心肌组织灌注分级(TMPG)、1周内住院期间主要心脏不良事件(MACE)事件。结果:2组均可改善PCI治疗后的“无复流”现象。微导管组手术结束前末次造影TIMIⅢ级比例明显高于导引导管组[95%(20/21)vs.40%(8/20),P<0.05],而且手术结束前末次造影TIMI心肌组织灌注分级(TMPG)Ⅲ级亦较高(90%vs.35%,P<0.05),减少1周内住院期间MACE事件(5%vs.30%,P<0.05)。结论:与经导引导管相比,经微导管注射地尔硫卓明显改善急诊PCI术中无复流现象。     

Coronary flow reserve in acute myocardial infarction in a patient treated with primary venous angioplasty. Case report

Residual stenosis, dissection and/or microvascular damage have been proposed as mechanisms of impaired flow after primary angioplasty (PCI) for acute myocardial infarction (MI). In this report we present a patient who underwent PCI for acute anterior MI. Coronary flow reserve (CFR) assessment performed after balloon dilatation suggested possible improvement of coronary flow after stenting. However, we did not observe any improvement in CFR just after stent implantation. We conclude that in patients treated with primary PCI the use of additional pharmacological treatment to prevent microcirculation injury during reperfusion and slow-flow or no-reflow phenomenon should be considered.     

Management of 'no-reflow' complicating reperfusion therapy

No-reflow phenomenon, defined as inadequate myocardial perfusion of the adequately dilated target vessel without evidence of angiographic mechanical obstruction. It is a multifactorial, well-recognised, secondary phenomenon following reperfusion therapy such as thrombolysis or percutaneous coronary interventions (PCI). The pathophysiological mechanisms leading to the no-reflow state are incompletely understood. Embolization of the atheromatous material to the distal vasculature and intense arteriole vasospasm caused by microembolization of platelet-rich thrombi that release vasoactive agents resulting in microvascular obstructions are likely mechanisms. Current prophylaxis and management strategies are derived from limited clinical data. Intracoronary verapamil, adenosine and nitroprusside have been most frequently studied and administered for angiographic no-reflow during PCI for acute myocardial infarction or saphenous vein graft (SVG) lesions and have been shown to improve epicardial flow and microvascular perfusion. The use of distal embolic protection devices in SVG interventions also provide microvascular protection and improve clinical outcomes. However, by far the most important measures are prevention and anticipation during PCI as once no-reflow established, complete reversal of the situation may not be possible.     

No reflow phenomenon in percutaneous coronary interventions in ST-segment elevation myocardial infarction

Percutaneous coronary intervention (PCI) is effective in opening the infarct related artery and restoring thrombolysis in myocardial infarction flow 3 (TIMI-flow 3) in large majority of ST-elevation myocardial infarction (STEMI). However there remain a small but significant proportion of patients, who continue to manifest diminished myocardial reperfusion despite successful opening of the obstructed epicardial artery. This phenomenon is called no-reflow. Clinically it manifests with recurrence of chest pain and dyspnea and may progress to cardiogenic shock, cardiac arrest, serious arrhythmias and acute heart failure. No reflow is regarded as independent predictor of death or recurrent myocardial infarction. No reflow is a multi-factorial phenomenon. However micro embolization of atherothrombotic debris during PCI remains the principal mechanism responsible for microvascular obstruction. This review summarizes the pathogenesis, diagnostic methods and the results of various recent randomized trials and studies on the prevention and management of no-reflow.     

Advantages of MGuard coronary stent system

Effectiveness of percutaneous coronary intervention (PCI) within thrombus containing lesions (ST-segment elevation myocardial infarction setting, degenerated saphenous venous grafts) is limited by the risk of occurrence of distal embolization and no-reflow phenomenon. Several pharmacological agents, as well as mechanical devices (i.e. manual aspiration catheters/mechanical thrombectomy, proximal and distal protection devices) were introduced, in the last years, to reduce the risk of angiographic complications during percutaneous coronary intervention and to improve myocardial reperfusion. Recently, the MGuard stent (Inspire MD, Tel Aviv, Israel), a bare-metal stent covered by micron level mesh, which allows to prevent distal embolization by blocking the atherothrombi prolapse through the stent struts during deployment has been introduced. This article discusses the data concerning safety and efficacy of mesh covered stent implantation in a ST-segment elevation myocardial infarction setting, as well as during percutaneous coronary intervention in saphenous venous grafts.     

Prevention of No-flow With Distal Protection Device in Patients Underwent Percutaneous Coronary Intervention

Objectives To evaluate the feasibility and safety of distal protection device (PercuSurge) during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome. Methods From October 2004 to August 2007, 40 patients with high risk acute coronary syndrome who received primary coronary intervention were included in this study. Patients were divided into two groups according to whether PercuSurge was attempted during PCI. The basic clinical characteristics, angiographic results, and follow-up data before discharge were compared. Coronary arteries blood flow thrombolysis in myocardial infarction (TIMI) grade, TIMI myocardial perfusion (TMP) grade and the rate of no-reflow were performed in all cases after PCI. Results There was no significant difference between the two groups in basic clinical characteristics and angiography before PCI (P>0.05). All patients underwent PCI successfully in both groups. In the PercuSurge group, PCI with PercuSurge guardwire protection was performed successfully in 18 patients. There was significant difference between the two groups in TIMI 3 flows gained in target vessels after PCI. Better percentage of TMP grade 3 of target vessels was achieved in PercuSurge group. Less no-reflow were found in PercuSurge group. There were lower peak troponin I and serum MB isoenzyme of creatine kinase levels, higher left ventricular ejection fraction and smaller left ventricular end-diastolic dimension in the PercuSurge group after PCI at the date before discharge (P<0.05). There was no major adverse cardiac events in PercuSurge group, only one patient died in the control group. Conclusions This study demonstrates that using the PercuSurge Guardwire system during PCI in high risk acute coronary syndrome patients to prevent no-reflow is feasibility and safety.     

Akutversorgung des akuten Myokardinfarktes

Progress in interventional cardiology and pharmacotherapy has improved the outcome of acute myocardial infarction in recent decades. Nevertheless, acute myocardial infarction is still one of the most common causes of death in Europe. The key to successful treatment is early diagnosis. The treatment of choice for restoration of perfusion of the ischemic myocardium is primary percutaneous coronary intervention (PCI). Due to the large number of catheter laboratories distributed all over the country, this treatment should be available for nearly all patients in Germany. Bivalirudin is recommended for peri-interventional anticoagulation. If sufficient expertise is available a radial artery access is advantageous due to a significant reduction in bleeding complications. For reduction of the no-reflow phenomenon, thrombus aspiration should always be considered before stent implantation. In the absence of contraindications for a prolonged dual antiplatelet therapy, the use of drug-eluting stents is recommended. Dual antiplatelet therapy with acetylsalicylic acid and one of the new adenosine diphosphate (ADP) receptor blockers prasugrel or ticagrelor should be standard.     

Clinical significance of intra-aortic balloon pumping on no-reflow phenomenon of primary percutaneous coronary intervention for acute myocardial infarction

Background Percutaneous coronary intervention(PCI) is used as a treatment for acute myocardial infarction(AMI),and one of its major complications is the angiographic no-reflow phenomenon(NR).Although intra-aortic balloon pumping(IABP) is sometimes used in such patients to increase the diastolic coronary blood flow,there is little available information regarding the effects of IABP on the angiographic no-reflow phenomenon.Method Twenty-two AMI patient with NR were performed primary PCI between January 2006 a...     

An unusual no-reflow phenomenon due to neointimal tissue embolization during drug eluting balloon intervention in stent restenosis: A case report

Acute coronary syndrome is one of the leading causes of death worldwide. Percutaneous coronary intervention (PCI), along with various devices, have been technically developed to dramatically improve mortality risk in patients with acute myocardial infarction. However, no-reflow phenomenon still remains a problematic complication during a PCI, even in the era of drug eluting stents. There are various hypotheses and mechanisms for no-reflow phenomenon, but none have been confirmed. Treatment for no-reflow phenomenon also depends on various underlying conditions, but have not yet shown effective improvement. We presented a case of no-reflow phenomenon caused by an unusual cause.     

Effect of MGuard net protective stent on the release of troponin I in patients with acute coronary syndromes. A randomized controlled trial

This study was designed to determine whether the treatment of patients with unstable angina pectoris or non-Q-wave myocardial infarction with a stent containing a protection net to prevent coronary microembolization affects the severity of biomarker release.The MGuard stent (InspireMD, Tel Aviv, Israel) was designed as a plaque/thrombus-trapping device, using a conventional bare metal stent covered with an ultrathin, flexible mesh net. We hypothesized that this stent would partly eliminate distal embolization and decrease subsequent troponin I (TnI) release.Forty-six acute coronary syndrome patients referred for percutaneous coronary intervention (PCI) were included and randomized in this study. Serum concentrations of TnI were measured prior to, as well as 24 and 48 hours after, the PCI procedure.Technical success was 95% and 100% in the MGuard group and non-MGuard group, respectively. A transient no-reflow phenomenon was observed in one interventional procedure in each group of patients (5% versus 4%; NS). Two patients (one in each group) died during the hospital stay. There was no statistically significant difference in median postprocedural TnI levels in either group.The results suggest that coronary stenting with a stent system containing a protection net to prevent coronary microembolization (eg the MGuard stent) in patients with acute coronary syndromes does not decrease procedural myocardial injury, as measured by TnI release. It seems likely that stenting with the MGuard stent is feasible, however, its safety should be verified in larger studies.     

Epicardial and microvascular reperfusion with primary percutaneous coronary intervention.

Restoration of normal flow and tissue-level perfusion are key factors in the reduction of mortality in acute myocardial infarction. The goal of reperfusion during primary percutaneous coronary intervention (PCI) should be to restore not only epicardial patency and flow, but also downstream myocardial tissue perfusion. This review will focus on the techniques able to evaluate and quantify epicardial and microvascular perfusion and on the available therapeutic tools that may be useful in primary PCI. After primary PCI, rates of TIMI flow grade 3 of 80 to 100% have been reported. Furthermore, after stenting during primary PCI more than one third of patients have persistently abnormal corrected TIMI frame counts related to increased downstream resistance. Achievement of TIMI flow grade 3 is no longer sufficient to define an optimal result of primary PCI and restoration of normal tissue-level perfusion is also required. Coronary no/slow reflow and myocardial hypoperfusion after otherwise successful recanalization of infarct-related arteries may involve more than just classical non-reperfusion of the myocardium that is already dead: distal embolization of debris or microparticulate atheromatous material, capillary edema, inflammation, and neurohormonal reflexes and vasoconstriction may play a crucial role. Evolving treatments of the no-reflow phenomenon are directed toward the restoration of microvascular flow abnormalities because these either directly or indirectly contribute to cell death. Promising adjunctive therapies that may reduce microemboli include intensive antiplatelet therapy with aspirin and ticlopidine, platelet glycoprotein IIb/IIIa inhibitors, coronary vasodilators, and embolization protection devices. Therapy targeting microvascular vasospasm also appears promising. Finally a variety of interventional new approaches have been focused on the setting of primary PCI, like atherectomy and thrombectomy devices, distal protection devices, hypothermia and hyperoxemic therapy, that are under investigation in numerous trials before they can be used routinarily.     

急性心肌梗死桥血管病变急诊介入治疗的临床研究

目的评价梗死相关血管为静脉桥血管(SVBG)的急性心肌梗死(AMI)患者,进行急诊直接经皮冠状动脉介入治疗(PCI)的有效性及安全性。方法对≥70岁(213例)与<70岁(96例)两组AMI患者介入治疗的临床效果和不良事件进行比较。分析SVBG有效再通比例、住院期间死亡比例及短期临床预后。结果两组患者PCI的技术成功比例、急性再闭塞比例均未见显著差异。但在≥70岁组,PCI后发生慢血流和无血流现象明显为多、住院期间绝对死亡数为多(20vs4)。死亡病例分析显示,90%的死亡病例出现在发生慢血流无血流现象的病例;多次心肌梗死、SVBG连通优势冠状动脉血管、以及连通惟一剩存的SVBG时,发生无血流慢血流后,死亡危险较高。结论老年AMI患者的SVBG病变急诊介入治疗有明确的效果和高的技术成功率。     

A pilot study with a new, rapid-exchange, thrombus-aspirating device in patients with thrombus-containing lesions: the Diver C.E. study.

BACKGROUND: In patients with acute coronary syndromes (ACS), distal embolization of thrombotic material is more likely to play a key role in the pathogenesis of myocardial no-reflow during percutaneous coronary intervention (PCI). Thus, interventional techniques able to reduce thrombus burden at the culprit vessel might improve final myocardial reperfusion. OBJECTIVE: To evaluate a new rapid-exchange thrombus-aspirating catheter, the Diver C.E., in patients with thrombotic coronary lesions undergoing PCI. METHODS: Fifty patients with acute myocardial infarction (n = 44) or with non-ST-elevation ACS and angiographic evidence of coronary thrombus (n = 6) undergoing urgent PCI were prospectively enrolled. The Diver C.E. was used to aspirate coronary thrombus from the culprit lesion after placement of the guidewire. Adjunctive balloon inflations and stent implantation were used to achieve good angiographic result. Angiographic coronary flow (by means of TIMI score and corrected TIMI frame count, cTFC), thrombus score (TS), and myocardial perfusion (by means of postintervention myocardial blush grade, MBG) were assessed in all patients. RESULTS: The device could be successfully employed in 96% of the cases (48/50) and yielded significant (P < 0.0001) acute reduction in thrombus burden (TS: predevice 3.5 +/- 0.8, postdevice 2.5 +/- 0.9) and improvement in coronary flow (TIMI grade: predevice 1.0 +/- 0.9, postdevice 2.0 +/- 0.9; CTFC predevice 71 +/- 31, postdevice 39 +/- 26). Final TIMI grade 0-1 was observed in one patient only (2%). A significant (P = 0.02) correlation was found between preintervention TS and efficacy of thrombus aspiration. A more pronounced acute reduction of thrombus burden after thrombus aspiration (TS reduction > or = 2) was associated with a better postintervention angiographic myocardial perfusion (MBG 2.3 +/- 0.9 vs 1.7 +/- 0.8; P = 0.05). CONCLUSIONS: This new, easy-to-use, device is able to reduce thrombus burden and to improve coronary flow in patients with thrombus-containing lesions. The improvement in myocardial perfusion associated to greater thrombus removal highlights the importance of thrombus aspiration in the management of thrombus-burdened coronary lesions.     

Treating Acute “No-Reflow” with Intracoronary Adenosine in 4 Patients during Percutaneous Coronary Intervention

Angiographic evidence of impaired tissue perfusion, known as the “no-reflow” phenomenon, is a serious complication of percutaneous coronary intervention—one that is associated with increased mortality rates. Adenosine is an endogenous nucleoside that attenuates many of the mechanisms that are responsible for no-reflow. Herein, we report the cases of 4 patients who developed the no-reflow phenomenon after elective percutaneous coronary intervention to their native coronary arteries and saphenous vein grafts. In all 4 patients, and without adverse effects, small bolus doses of adenosine through the guiding catheter improved epicardial perfusion—measured by either Thrombolysis In Myocardial Infarction (TIMI) flow grade or corrected TIMI frame count—and tissue-level perfusion, graded according to myocardial blush. In view of adenosine''s extremely short half-life in blood, the continuous administration of adenosine into the distal vascular bed throughout percutaneous coronary intervention may further improve outcomes by reversing or preventing the no-reflow phenomenon.Key words: Adenosine/administration & dosage/physiology/therapeutic use, angioplasty, transluminal, percutaneous coronary/adverse effects/methods, atherosclerosis/complications/therapy, cardiotonic agents/administration & dosage/therapeutic use, coronary vessels/drug effects, creatine kinase/blood, dose-response relationship, drug, graft occlusion, vascular/therapy, myocardial reperfusion/methods, treatment outcome, vasodilator agents/administration & dosage/therapeutic usePercutaneous coronary intervention (PCI) is frequently used to treat atherosclerosis-induced stenosis in native coronary arteries and in degenerated saphenous vein grafts (SVGs). Although PCI has a high initial success rate, enzymatic evidence of myocardial cell necrosis occurs in 22% to 44% of patients after apparently uneventful PCI procedures.^1,2 Microvascular obstruction (due in part to embolization of platelets and atheromatous débris) and intense vasoconstriction of the distal bed (secondary to the release of potent humoral mediators) are responsible for microinfarction after PCI.^3–6 In some patients, vascular compromise manifests itself during the procedure as an abrupt decrease in epicardial blood flow—Thrombolysis In Myocardial Infarction (TIMI) grade 0 to 1—which is known as the “no-reflow” or “slow-reflow” phenomenon. The compromise occurs in the absence of apparent dissection, coronary spasm, thrombus formation, substantial residual stenosis, or distal-vessel cutoff that is suggestive of macroembolization.Adenosine attenuates mechanisms that are responsible for the no-reflow phenomenon.⁷ We describe here the cases of 4 patients in whom intracoronary adenosine reversed no-reflow during PCI of the native coronary vessels and SVGs, as measured by TIMI flow grade, corrected TIMI frame count (CTFC), and myocardial blush grade (MBG).     

远程缺血后适应减轻非糖尿病患者冠状动脉支架术中心肌损伤研究

背景：择期冠状动脉介入术中常常会造成心肌损伤,并与远期预后有关。 目的：评价远程缺血后适应在非糖尿病患者冠状动脉支架术中的心肌保护作用。 方法：183例非糖尿病冠心病患者入选并随机分为2组：远程缺血后适应组（N=95）在术后即刻用气压止血带加压至200mmHg阻断一侧上肢血流5分钟后释放压力恢复血流5分钟,共3个循环;对照组（N=88）。主要观察指标是术后16小时心脏超敏肌钙蛋白I。结果：冠状动脉支架术后16小时心脏超敏肌钙蛋白I中位数在远程缺血后适应组显著低于对照组（0.12 比 0.28ng/mL; P< 0.05）。4a型心肌梗死发生率在远程缺血后适应组显著低于对照组（34%比58%,P< 0.05）。 结论：远程缺血后适应在非糖尿病患者冠状动脉支架术中具有心肌保护作用。     

血小板分布宽度对急性心肌梗死冠状动脉介入治疗中无复流的预测价值

目的:研究血小板分布宽度(PDW)对ST段抬高型心肌梗死(STEMI)患者直接经皮冠状动脉介入治疗(PCI)中无复流的预测价值。方法:回顾性分析118例发病12h内接受直接PCI的STEMI连续病例,根据直接PCI术中无复流的发生情况分为无复流组(33例)和正常血流组(85例)。比较2组患者的临床资料、实验室检查结果以及直接PCI结果,应用受试者工作曲线(ROC曲线)分析入院时PDW对无复流发生的预测价值。结果:无复流组患者入院时PDW水平明显高于正常血流组[(16.7±2.3)%∶(15.1±2.2)%,P<0.01]。应用ROC曲线分析PDW对无复流的预测价值,曲线下面积0.726(95%可信区间0.608～0.844,P<0.01)。当截点值为16.45%时,入院时PDW对直接PCI术中无复流进行预测的敏感性和特异性分别为80.0%和72.4%。结论:STEMI患者入院时PDW水平是直接PCI术中发生无复流的预测因素,并具有较好的敏感性和特异性。     

The diagnosis and treatment of the no-reflow phenomenon in patients with myocardial infarction undergoing percutaneous coronary intervention

OBJECTIVE

To review the diagnosis and treatment available for myocardial infarction patients having no-reflow in the setting of percutaneous coronary intervention (PCI).

DATA SOURCES

Data for the present review were obtained from searches in PubMed (1997 to 2007) using the following key terms: “acute myocardial infarction”, “no-reflow phenomenon”, “myocardial contrast echocardiography”, “coronary angiography” and “cardioprotection devices”.

STUDY SELECTION

Mainly original articles and critical reviews written by major research pioneers in interventional cardiology were selected.

RESULTS

Despite a fully patent coronary artery post-PCI for myocardial infarction, patients may experience inadequate myocardial perfusion through a given segment of the coronary circulation without angiographic evidence of mechanical vessel obstruction. This phenomenon is defined as no-reflow and is a growing problem in the field of interventional cardiology. Although voluminous clinical trial data are available, the exact mechanisms involved and which treatment should be administered as first-line therapy are currently unknown. The different techniques used to diagnose no-reflow also have their pros and cons; myocardial contrast echocardiography and coronary angiography are the most reliable techniques. In cases when no-reflow was successfully reversed, patient recovery was associated with favourable left ventricular remodelling and increased left ventricular ejection fraction, even in the absence of significant improvement in regional contractile function.

CONCLUSION

Based on the trials in the literature, myocardial contrast echocardiography is the gold standard for the diagnosis of no-reflow. If no-reflow occurs following PCI, treatment with intracoronary adenosine or verapamil should be administered, because this form of therapy is inexpensive and safe, improves flow in the target vessel and may reduce infarct size.