Angioplasty catheter communication mimicking coronary arterial dissection

We report a case in which a sudden communication between the pressure and balloon inflation lumens of a percutaneous transluminal angioplasty (PTCA) catheter angiographically mimicked dissection of the coronary artery. This case illustrates a previously undescribed catheter artifact that must be differentiated from other complications of PTCA.     

Promising though not yet proven: emerging strategies to promote myocardial salvage.

Remarkable advances in our ability to achieve early and sustained culprit vessel patency in acute myocardial infarction have been satisfying, but our enthusiasm must be tempered by the knowledge that the overall treatment strategy often leaves an inadequate long term clinical result. Early success of percutaneous therapy as judged at angiography does not ensure recovery of normal left ventricular function, the most important determinant of survival in acute myocardial infarction. That congestive heart failure and death still complicate apparently successful percutaneous procedures underscores the need to develop novel therapies which salvage jeopardized myocardium, limit infarct size and preserve left ventricular function. An ever-increasing body of data demonstrates a multifactorial mechanism of myocyte injury and microvascular collapse and also demonstrates that these injuries seem to have a profound impact on long-term outcomes. Given these findings, microvascular protection during the acute event has become the focus of a variety of emerging technologies. The goal of these mechanical and pharmacologic therapies is the restoration of normal metabolic function at the myocyte level. The acute pathologic mechanisms which contribute to sustained left ventricular dysfunction despite angiographically successful revascularization will be reviewed as will be several strategies being developed to counter these pathologic mechanisms.     

Dislocation of the rotating cutter during directional coronary atherectomy: A note of caution

Directional coronary atherectomy (DCA) has received increased attention, especially as a bail-out procedure after failed balloon angioplasty. However, this technique may also be burdened by severe pitfalls. We report a patient with a balloon-resistant left coronary artery lesion subsequently treated with DCA. Despite its over-the-wire guidance, as the rotating cutter was advanced, it deviated from its intra-housing course and intruded into the vascular wall. Dislocation of the rotating blade was due to pressure from hard plaque tissue. After having carefully pulled back the complete catheter system, a severe spasm of the left main stem occurred, which was reversed by intracoronary nitroglycerine. The final angiography showed a left coronary artery without significant, residual stenosis. The case report underscores that DCA passes must be performed under continous fluoroscopic control, especially for balloon-resistant lesions because of the unpredictability of DCA-imminent complication. © 1995 Wiley-Liss, Inc.     

Achieving optimal reperfusion without adjunctive antithrombotic therapy: Novel thrombolytic dosing strategies

There is firm evidence that reperfusion therapy, to be effective must establish and maintain coronary arterial blood flow at a level sufficient to allow myocardial perfusion. However, current thrombolytic regimens have clear limitations, including a relatively low capacity to achieve TIMI Grade 3 blood flow and an unacceptable incidence of coronary reocclusion. Although it has been assumed that the key to achieving optimal reperfusion lies with adjunctive antithrombotic therapy, it may be that novel thrombolytics and dosing strategies can address the problem adequately. This possibility is attractive and requires careful consideration.     

Bleeding after antithrombotic therapy in patients with acute ischemic heart disease

Definitions of bleeding must be considered when evaluating results of clinical trials. Assessments of bleeding impact based on clinical criteria may be more relevant to patient outcomes than those based on simple laboratory measures like an isolated change in hemoglobin, that do not appear to affect patient care. The risk of excessive bleeding in patients who receive antiplatelet and antithrombotic therapy is related to a combination of patient characteristics (older age, female sex, impaired renal function), and delivery factors (excessive dosing, stacking of anticoagulants). Investigators should justify components of bleeding endpoints as being clinically meaningful, sufficiently frequent in the study population, and affected by the intervention.     

Should Percutaneous Coronary Intervention be the Standard Treatment Strategy for Significant Coronary Artery Disease in all Octogenarians?

Coronary artery disease (CAD) remains the leading cause of cardiovascular death in octogenarians. This group of patients represents nearly a fifth of all patients treated with percutaneous coronary intervention (PCI) in real-world practice. Octogenarians have multiple risk factors for CAD and often greater myocardial ischemia than younger counterparts, with a potential of an increased benefit from myocardial revascularization. Despite this, octogenarians are routinely under-treated and belittled in clinical trials. Age does make a difference to PCI outcomes in older people, but it is never the sole arbiter of any clinical decision, whether in relation to the heart or any other aspect of health. The decision when to perform revascularization in elderly patients and especially in octogenarians is complex and should consider the patient on an individual basis, with clarification of the goals of the therapy and the relative risks and benefits of performing the procedure. In ST-segment elevation myocardial infarction (MI), there is no upper age limit regarding urgent reperfusion and primary PCI must be the standard of care. In non-ST-segment elevation acute coronary syndromes, a strict conservative strategy must be avoided; whereas the use of a routine invasive strategy may reduce the occurrence of MI and the need for revascularization at follow-up, with no established benefit in terms of mortality. In stable CAD patients, invasive therapy on top of optimal medical therapy seems better in symptom relief and quality of life. This review summarizes the available data on percutaneous revascularization in the elderly patients and particularly in octogenarians, including practical considerations on PCI risk secondary to ageing physiology. We also analyse technical difficulties met when considering PCI in this cohort and the ongoing need for further studies to ameliorate risk stratification and eventually outcomes in these challenging patients.     

经皮冠状动脉介入治疗术后出血对临床预后的影响与处理对策

经皮冠状动脉介入治疗（PCI）术后出血是PCI相关的常见术后并发症。研究显示PCI术后出血不仅带来额外的医疗负担,同时影响近期及远期的预后。了解PCI术后出血的独立风险预测因素,采用有效措施减少出血事件是改善预后的重要手段。现介绍和PCI术后出血相关的最新研究进展。     

Gestion des charges thrombotiques importantes en angioplastie primaire

A large thrombus burden is not uncommon in primary percutaneous coronary intervention, and is associated with more frequent complications. The role of intracoronary thrombolysis and glycoprotein IIb/IIIa inhibitors in the management of a large thrombus burden is discussed. The use of thromboaspiration must follow a particular logic and used with rigorous manipulations; the capacities of the protective filters are often exceeded. Stents dedicated to thrombus management can be used. Interest and limits of these stents are developed. Direct stenting should be encouraged, and delayed stenting probably considered for the most important thrombotic burden despite “negative” results in studies.     

Routine Coronary Arteriography Following Thrombolytic Therapy for Acute Myocardial Infarction: An Unsettled Controversy

Although coronary artery disease remains the leading cause of death in industrialized countries, the management of patients recovering from acute myocardial infarction varies significantly. The issue of routine arteriography and revascularization following thrombolytic therapy remains controversial despite substantial evidence associating infarct-related artery patency with improved cardiac function and survival. Randomized trials of routine intervention after myocardial infarction have generally failed to demonstrate advantages of this invasive approach but methodological problems limit their application to current practice. High-risk patients should be referred for arteriography. While awaiting definitive trials addressing the influence of routine arteriography on patient survival and its cost effectiveness, the management of other patient groups must be individualized.     

Cardiac markers in the low-risk chest pain patient

With the arrival of point-of-care cardiac marker determination, emergency physicians may be able to arrive at the diagnosis of cardiac ischemia faster than ever before. However, these tests must be used with care, as a lack of understanding about when and how they should be obtained is important both for good patient care and to avoid medicolegal pitfalls. This report reviews risk stratification of patients who present with chest pain, provides an overview of cardiac markers and literature supporting their use, and concludes with a practice guideline for the utilization of cardiac markers in the emergency department.     

Long-term tiapamil treatment of patients with angina pectoris

The effects of a 12-week oral treatment with tiapamil (200 mg t.i.d.) were compared to those of placebo treatment in a group of 20 men with coronary heart disease. There was a slight reduction of anginal symptoms (p < 0.05) and a tendency to less nitroglycerin consumption (p < 0.07). There were no statistically significant differences between the treatments in blood pressure, exercise tolerance during repeated exercise tests, ECG conduction intervals, or routine laboratory tests. No adverse side-effects were encountered. It seems that tiapamil may be beneficial in preventing angina pectoris, but a higher oral dose must be used.     

Biochemical and bioimaging markers for risk assessment and diagnosis in major cardiovascular diseases: a road to integration of complementary diagnostic tools

This report from the first International Course on Integrated Biomarkers, Biochemical and Bioimaging Endpoints in Cardiovascular Diagnosis, Prevention, Therapy and Drug Development provides the basis for optimizing diagnostic, prognostic and therapeutic information in four areas of cardiovascular medicine: primary prevention of cardiovascular diseases, acute coronary syndromes, heart failure and stroke. Risk stratification and treatment strategies can be refined and enhanced through integration of bioimaging and biochemical markers to characterize sub-clinical and clinical atherosclerosis. For the integrative approach to be useful, each of the biomarkers must be validated and cost-effective. Clinical decision is the primary level of integration and is based on clinical evaluation and the use of a combination of bioimaging and biochemical markers. The decision to initiate preventive or therapeutic intervention must take into account the factors affecting the levels of expression of the biomarker and the potential input the biomarker has on metabolic processes or modulation of other biomarkers. The optimal approach to intervention must take into consideration the risk-benefit and cost-effectiveness ratios.     

Radiation exposure: Comparison of rapid exchange and conventional over-the-wire coronary angioplasty systems

The growth of coronary angioplasty has resulted in increased fluoroscopy time to patients, staff, and physicians. Rapid exchange-type catheters have purported to reduce fluoroscopy time and procedure time compared to conventional over-the-wire systems. Of 150 consecutive patients, 54 were treated solely with rapid-exchange catheters and 84 were treated solely with over-the-wire catheters. Excluding 12 cases treated with fixed wire or combination catheters, the following data were found: Overall procedural success was obtained in 98.5% (136/138) of patients, 1.5% (2) requiring emergency coronary artery bypass graft surgery. A significant 35% reduction in fluoroscopy time and 13% reduction in procedure time were found when rapid-exchange catheters were used, with identical success rates, number of balloons used per case, and complication rates compared to over-the-wire catheters. Rapid-exchange catheters should be considered as part of an overall effort to reduce radiation exposure in the interventional cardiology laboratory.     

Some technical considerations in tomographic coronary arteriography

Summary Coronary artery anatomy can be visualized using high-speed, volume scanning x-ray CT. A single scan during a bolus injection of contrast medium provides image data for display of all angles of view of the opacified coronary arterial tree. Due to the tomographic nature of volume image data, the superposition of the vessels on themselves and on other contrast filled coronary arteries, such as would occur in an aortic root injection of contrast agent, can be eliminated.To achieve the goal of coronary arteriography using a single angiographic injection, the tomographic scanner must scan the entire volume encompassing the coronary arteries synchronously and within a brief period of time. The volume must be scanned so that the thickness of the scanned slices is less than the diameter of the smallest vessel desired to be visualized quantitatively. Preliminary results from a fast volume scanning CT scanner (the Dynamic Spatial Reconstructor) used to scan experimental animals are used to indicate the quantitative and qualitative impact of such varibles as scanned slice thickness, scanned slice separation and angle between the vessel and the plane of the scanned slices.This work was supported in part by NIH Grants HL-04664, HL-38042 and RR-02540.     

A novel use of a split sheath to maintain vessel access when guidewire exchange is not possible

After inserting a catheter into a vessel, guidewire exchange technique must be used to maintain vascular access. If the lumen of the catheter is blocked and the guidewire exchange cannot be used, the catheter can only be removed, vascular access is lost, and an alternate vascular approach attempted. We describe a technique to remove the blocked catheter and still maintain vascular access. © 2008 Wiley‐Liss, Inc.     

急性冠脉综合征危险分层方法的评价

急性冠脉综合征是冠心病病程中的严重事件,往往导致大面积心肌梗死甚至猝死。不同的患者临床表现不尽相同,需要针对患者不同的风险采取相应的临床对策,这就需要对患者进行危险分层。来自于临床试验和专业学会指南的危险分层方法基本思路一致,但都不是呆板的教条,临床应用中需要了解不同危险分层方法的不同特点,根据实际情况灵活掌握,动态评估,选择合适的诊断和治疗方案。最终目的是合理配置有限的医疗资源,获得最佳的治疗效果。     

Computer simulation of the propagation of contrast medium in a coronary artery during one cardiac cycle

In some angiographic methods for measurement of mean coronary flow in ml/min, a threshold is applied to concentration-distance curves obtained from a constant rate injection by computing the intravascular contrast medium concentration along the main coronary branches. If the shape of the velocity profile would remain parabolic throughout the cardiac cycle, the correct threshold value would be 50% of the concentration at the injection site. But, coronary flow being strongly pulsatile, the shape of the velocity profile must be expected to vary appreciably within the cardiac phase. In order to investigate if a single, appropriate threshold value nevertheless exists for a great variety of coronary flow pulses and velocity profiles, the spreading of contrast medium injected continuously in a tube perfused by a time varying flow Q(t) was studied by computer simulation. While the particular time courses of flow and velocity profile appear to be of secondary importance, the ratio injection rate to peak coronary flow has a major impact. If it is equal to or greater than 1, a threshold value of 47% is the best choice. If the ratio is markedly less than 1, no appropriate threshold exists and use of the 47% threshold will result in considerable flow underestimations. This was fully confirmed by measurements of absolute coronary flow performed in patients.     

Coronary Artery Manifestations of Fibromuscular Dysplasia

Fibromuscular dysplasia (FMD) involving the coronary arteries is an uncommon but important condition that can present as acute coronary syndrome, left ventricular dysfunction, or potentially sudden cardiac death. Although the classic angiographic “string of beads” that may be observed in renal artery FMD does not occur in coronary arteries, potential manifestations include spontaneous coronary artery dissection, distal tapering or long, smooth narrowing that may represent dissection, intramural hematoma, spasm, or tortuosity. Importantly, FMD must be identified in at least one other noncoronary arterial territory to attribute any coronary findings to FMD. Although there is limited evidence to guide treatment, many lesions heal spontaneously; thus, a conservative approach is generally preferred. The etiology is poorly understood, but there are ongoing efforts to better characterize FMD and define its genetic and molecular basis. This report reviews the clinical course of FMD involving the coronary arteries and provides guidance for diagnosis and treatment strategies.     

Progression and regression of coronary artery disease in one year

The rate of progression of coronary artery stenoses (CAS) is not clear. Spontaneous regression may also occur.Seventy-one CAS in 25 patients who were enrolled in a study of the effects of chromium on CAS were analysed. Coronary angiography was performed in multiple views and patients randomised to chromium or placebo treatment. Videodensitometric quantitative analysis was performed using a Vanguard XR70 Analyzer. After 1 year all patients were recatheterised. Corresponding frames from identical views were analysed. CAS were assessed with the observers blinded to the initial study results. No differences were found between chromium or placebo and the results have been combined. There was no overall progression of CAS as assessed by % area stenosis (p=0.65), % diameter stenosis (p=0.19), stenotic area (p=0.87), or stenotic diameter (p=0.99). However, 20% of individual lesions progressed, while 10% regressed, and 70% remained the same.These changes must be taken into account in studies of interventions which may modify the course of coronary atherosclerosis, and if coronary by-pass surgery is to be performed with a 1 year delay after angiography.