Over the past twenty years, technical advances in coronary arteriography have contributed to our understanding of the pathophysiologic aspects and natural history of coronary artery disease. Probably more than 700. 000 coronary arterio grams are performed annually throughout the world. Usually, these arteriograms are interpreted visually to determine the morphologic extent and severity of coronary artery disease. These subjective determinations, which are hampered . by relatively large intra- and interobserver variations, are used as a basis for critically important therapeutic decisions: Which arteries are to be revascular ized, which lesions are suitable for coronary bypass surgery or for percutaneous coronary angioplasty? To improve on this clinical decision making, on the treat ment and follow-up of such patients, new, objective and reproducible techniques for the assessment of the extent and severity of coronary artery disease, both in terms of anatomy and functional significance of the lesions, must be made widely available. With such new procedures and technologies the efficacy of new thera peutic procedures, the effects of vasodilating and constricting drugs, and the results of long-term studies on the regression and progression of atherosclerotic plaque can be determined in an objective and cost-effective manner.

From the Foreword by Eric J. Topol In the past five years, interventional cardiology has entered a new era of evaluating percutaneous transcatheter technologies to treat coronary artery disease and prevent restenosis. Cardiologists attempting to follow this new and exciting field may easily be confused by the growth and expansion of new devices, the technical details relevant to each device and enthusiastic claims of success. This monograph is a comprehensive and objective assessment of restenosis from the perspective of these new technologies including stenting, atherectomy, rotational abrasion and lasers, written by innovators and pioneers. The international breadth of experience is reflected in the summary of experiences from both sides of the Atlantic, at times with conflicting observations and results which in itself is valuable, given the diverse experience to date. In addition to the lucid summaries of the early and late results of these new devices, important issues in the methodology of restenosis research are addressed, including limitations of quantitative coronary arteriography in evaluating the new devices and important advances in alternatives to arteriography such as intravascular imaging. As a whole, this monograph is exceptionally worthwhile owing to its complete, up-to-date, balanced and visionary elements. There is no question that the new coronary device era has ushered in some excitement, and some despair. This book serves a pivotal purpose by weaving so many new concepts together, establishing the groundwork for further development of mechanical approaches to limit restenosis. I heartily recommend this text to all interventional cardiologists interested in practical and research aspects of restenosis.

In this fourth book in the series on quantitative coronary arteriography (QCA) with the earlier three volumes published in 1986, 1988 and 1991, the latest developments in this exciting field are covered. Both the methodolog ical and clinical application aspects of these advances are presented in a comprehensive manner in a total of 37 chapters by world renowned experts. The book is subdivided into a total of eight parts, beginning with the more methodological issues, such as QCA and other modalities (3 chapters), cine film versus digital arteriography (3 chapters), quality control in QCA (4 chapters), and coronary blood flow and flow reserve (3 chapters). Since QCA has been well established as the technique for the assessment of regression and progression in atherosclerotic disease, and of restenosis after recanaliz ation procedures, major clinical trials in both groups are described extensively by their principal investigators in a total of 11 chapters. In addition, the QCA results after the application of various recanalization techniques are presented in another eight chapters. In the last part the experiences with various intracoronary prostheses with the emphasis on QCA are discussed in five chapters. This large increase in application oriented chapters means that QCA is well alive and gaining momentum. Although the accuracy and precision of the analytical methods steadily improve with the increasing complexity of the algorithms, there is still always the human factor involved in these processes in terms of frame selection, segment definition, etc.

This is the fifth volume in this series on quantitative coronary arteriography (QCA) published over the last nine years. Research and applications in this exciting, field are covered in a total of 26 chapters by world renowned experts. This book is subdivided into a total of 6 parts, each emphasizing the latest progress in these respective fields. In Part One a comprehensive overview is given of the current knowledge and research in endothelial function, which is of eminent importance for the further understanding of the pathophysiology of coronary artery disease in patients. Fortunately, the use of QCA tools is not limited anymore to leading research institutes; over the last several years these tools have been installed in many cardiology centers world wide. To understand the current possibili ties, limitations and future expectations of QCA, several relevant topics are presented in Part Two. First of all, the questions about why and how QCA systems should be validated both at the development site and at the appli cation sites, and whether data from different vendors and core laboratories can be pooled, are discussed. As the X-ray cardiovascular world steadily moves into the digital imaging era, differences and similarities between the conventional cinefilm and the modern digital approaches are presented. Cur rently. the widespread use of digital imaging is still hindered by the lack of proper archival and exchange media. Requirements and possible solutions for this problem are handled in this section as well.

In June 1989, a third conference concentrating on the progress in quantita tive coronary angiography and related techniques was held in Rotterdam, again very successful as the two preceding events in 1985 and 1987. Tech nical as well as clinical aspects of digital and digitized coronarography, morphometry, parametric imaging and functional quantification of the human coronary circulation were presented and discussed by prominent exponents of those groups who have been active in this particular field for many years. This book contains the chapters representing the lectures held by leading experts during the symposium that update the knowledge currently available, including most recent aspects in angioscopy and intravascular ultrasound imaging. It also includes a historical review on the development of angiogra phic techniques from the very early days on to our times given by one of the pioneers in heart catheterization and angiography, Dr. Kurt Amplatz. Those who had the chance to listen to his talk, will surely remember his impressive, humorous lecture as one of the highlights of this meeting."

Since the introduction of coronary angioplasty in 1977, this procedure has gained a steadily increasing position in the treatment of coronary artery obstmction. From the available evidence it can be estimated, that this thera peutic tool will get even more additional momentum of many ten-thousands of patients to be treated in the next few years, due to a growing fraction of patients who are candidates for this intervention. Information about the indications, benefits and risks of coronary angioplasty is accumulating rapidly in addition to publications about refinements of the technique itself. Recently, a number of investigators have realized that coronary angioplasty is not only a therapeutic tool, but can, during the procedure, be used as a source of diagnostic information. When the catheter is placed in a coronary artery obstruction, inflation of the balloon produces transient myocardial ischemia. Before, during, and after this period of severe ischemia, studies of the perfor mance of the myocardium at risk can be carried out. The fact that therapeutic coronary angioplasty is carried out in a cardiac catheterization laboratory which is by definition optimally equipped for the measurement of hemodynamic parameters, has probably also contributed to the effectuation of these investigations. The combination of hemodynamic and biochemical parameters with morphological information from the coronary angiogram can be utilized for the quantification of myocardial involvement and the success of coronary dilatation with angioplasty. Studies of interactions with pharmacological substances are also feasible and informative."

There are few techniques that have influenced therapeutic strategies in modem cardiology to a similar extent as coronary arteriography. Bypass surgery as well as transluminal coronary angioplasty would not have been possible without coronary angiography serving as a 'midwife' in their evolu tion. Despite the widespread and long-standing use in clinical practice, however, the interpretation of coronary angiograms has not changed very much since the early days. Most angiogr s are still reviewed in a visual and semi-quantitative and thus often very subjective way. In the face of an almost exploding field for interventional catheterization including thrombolysis, balloon dilatation, and other rapidly evolving techniques for transluminal revascularization or recanalization, a more detailed and quantitative analysis of coronary arteriograms is urgently required. In addition to the delineation of coronary morphology, we need dynamic and functional information about flow and perfusion to understand the physiological significance of anatomic abnormalities. Coronary arteriography contains and can provide most of this information. With the application of appropriate techniques, it can be made available in the catheterization laboratory even during the patient's investiga tion, thus facilitating and improving clinical decision making. Objective and reproducible analysis will furthermore enhance our understanding about the pathophysiology of coronary disease."

In recent years there has been an increasing interest in quantitative analysis of coronary cineangiograms and already for a longer time of left ventricular cin- eangiograms. The needfor quantitationofcoronary arterialdimensions has been stimulated by the introduction ofnew therapeutic procedures in the catheteriza- tionlaboratory, suchas the balloon dilatationtechnique (PTCA) and thromboly- tic therapy, by the need to study the vasoactive responses of pharmaceutical agents, and also by the desire to study the progressive nature ofcoronary artery disease with the ultimate goal to find ways to bring a halt to the progression of coronary atherosclerosis or even achieve regression of the disease. Parallel with these clinical developments, rapid technical developments in computerarchitect- ures and semiconductor memories have made it possible to digitize and store cineframesor selected portions thereof in image processors and to analyze these pictorial data quantitatively at affordable prices. More than 15 years of research have been directed by various groups towards the semi- or fully-automated delineation of the left ventricular boundaries on a frame-to-frame basis. Yet not a single system with fully-automated capability is commercially available. In the mean time many different left ventricular wall motion models have been developed, again with little consensuson which model is to be preferred as no golden standard exists.

Obstruction of coronary blood flow and the resultant consequences are the center stage pathophysiologic events in cardiology today. The speculations of Jenner, Burns, Heberdin, McKenzie, Prinzmetal and many others had until now been left to observations of isolated tissue and intact animal experimentation. Only with the advent of Gruentzig's technique, which allowed us to 'work safely inside the coronary arteries' are we able to observe the effects of coronary occlusion in living conscious man. PTCA provides not only a therapeutic modality for non-operatively opening coronary obstructions, but has also provided the best model for studying the effects of acute ischemia on the heart. The procedure also lead the way to all other interventional cardiology developments, including modern thrombolysis in the setting of acute myocardial infarction. In his previous works, Serruys has examined how PTCA can serve as a model for studying acute ischemia. In this book, he and his co-authors discuss the effects of balloon-induced ischemia on the electrocardiographic changes, coronary blood flow dynamics, cardiac muscle metabolism and left ventricular function, as well as measures to counter these effects and provide for reperfusion in unstable angina and acute myocardial infarction. Technology has expanded the 'eyes' of the observer of these events. The authors use many techniques including ECG recording from surface, endocardium, and intracoronary electrodes; angiographic assessment of coronary flow pattern using digital techniques, as well as doppler flow measurements; biochemical assessment of metabolic products stimulated by ischemia; and digital angiographic and echo doppler assessment of left ventricular function.

Quantitative coronary angiography has become an invaluable tool for the interventional cardiologist, providing objective and reproducible measurements of coronary artery dimensions, which can be used to study progression or regression of coronary atherosclerosis, as well as the immediate and long term effects of percutaneous interventions. Until recently, this powerful imaging technology was confined to a small number of so-called high level institutions. Fortunately, with the development of digital cardiac imaging equipment and adaptation of cine-angiographically based computer software for on-line use in the catheterization room, quantitative coronary angiography is now available to all interventionalists. This book is a timely guide for the impending QCA user, providing practical as well as theoretical and scientific information. A comprehensive evaluation of the clinical usefulness of QCA is covered, from the fundamental principles through experimental validation studies, application to clinical trials of a wide range of pharmacological and interventional therapies in the full spectrum of clinical presentation of coronary disease syndromes, evaluation of the therapeutic efficacy of various new devices for coronary intervention, together with extensive presentation of its physiological, functional and anatomical correlations, by comparison with other intracoronary measurement and imaging techniques. In addition, evolving theories and concepts in the ever topical restenosis phenomenon' after percutaneous intervention, based on serial QCA studies, are presented and discussed and a potentially unifying methodological approach to further study of this ubiquitous problem is offered. This book, thanks to the collaboration of many experts in the field of intracoronary imaging and measurement, provides stimulating, interesting and practical information, both for the academic scientist and practising clinician.

Quantitative coronary angiography has become an invaluable tool for the interventional cardiologist, providing objective and reproducible measurements of coronary artery dimensions, which can be used to study progression or regression of coronary atherosclerosis, as well as the immediate and long term effects of percutaneous interventions. Until recently, this powerful imaging technology was confined to a small number of so-called high level institutions. Fortunately, with the development of digital cardiac imaging equipment and adaptation of cine-angiographically based computer software for on-line use in the catheterization room, quantitative coronary angiography is now available to all interventionalists. This book is a timely guide for the impending QCA user, providing practical as well as theoretical and scientific information. A comprehensive evaluation of the clinical usefulness of QCA is covered, from the fundamental principles through experimental validation studies, application to clinical trials of a wide range of pharmacological and interventional therapies in the full spectrum of clinical presentation of coronary disease syndromes, evaluation of the therapeutic efficacy of various new devices for coronary intervention, together with extensive presentation of its physiological, functional and anatomical correlations, by comparison with other intracoronary measurement and imaging techniques. In addition, evolving theories and concepts in the ever topical restenosis phenomenon' after percutaneous intervention, based on serial QCA studies, are presented and discussed and a potentially unifying methodological approach to further study of this ubiquitous problem is offered. Thisbook, thanks to the collaboration of many experts in the field of intracoronary imaging and measurement, provides stimulating, interesting and practical information, both for the academic scientist and practising clinician.

Since the introduction of coronary angioplasty in 1977, this procedure has gained a steadily increasing position in the treatment of coronary artery obstmction. From the available evidence it can be estimated, that this thera peutic tool will get even more additional momentum of many ten-thousands of patients to be treated in the next few years, due to a growing fraction of patients who are candidates for this intervention. Information about the indications, benefits and risks of coronary angioplasty is accumulating rapidly in addition to publications about refinements of the technique itself. Recently, a number of investigators have realized that coronary angioplasty is not only a therapeutic tool, but can, during the procedure, be used as a source of diagnostic information. When the catheter is placed in a coronary artery obstruction, inflation of the balloon produces transient myocardial ischemia. Before, during, and after this period of severe ischemia, studies of the perfor mance of the myocardium at risk can be carried out. The fact that therapeutic coronary angioplasty is carried out in a cardiac catheterization laboratory which is by definition optimally equipped for the measurement of hemodynamic parameters, has probably also contributed to the effectuation of these investigations. The combination of hemodynamic and biochemical parameters with morphological information from the coronary angiogram can be utilized for the quantification of myocardial involvement and the success of coronary dilatation with angioplasty. Studies of interactions with pharmacological substances are also feasible and informative."

In June 1989, a third conference concentrating on the progress in quantita tive coronary angiography and related techniques was held in Rotterdam, again very successful as the two preceding events in 1985 and 1987. Tech nical as well as clinical aspects of digital and digitized coronarography, morphometry, parametric imaging and functional quantification of the human coronary circulation were presented and discussed by prominent exponents of those groups who have been active in this particular field for many years. This book contains the chapters representing the lectures held by leading experts during the symposium that update the knowledge currently available, including most recent aspects in angioscopy and intravascular ultrasound imaging. It also includes a historical review on the development of angiogra phic techniques from the very early days on to our times given by one of the pioneers in heart catheterization and angiography, Dr. Kurt Amplatz. Those who had the chance to listen to his talk, will surely remember his impressive, humorous lecture as one of the highlights of this meeting."

There are few techniques that have influenced therapeutic strategies in modem cardiology to a similar extent as coronary arteriography. Bypass surgery as well as transluminal coronary angioplasty would not have been possible without coronary angiography serving as a 'midwife' in their evolu­ tion. Despite the widespread and long-standing use in clinical practice, however, the interpretation of coronary angiograms has not changed very much since the early days. Most angiogr~s are still reviewed in a visual and semi-quantitative and thus often very subjective way. In the face of an almost exploding field for interventional catheterization including thrombolysis, balloon dilatation, and other rapidly evolving techniques for transluminal revascularization or recanalization, a more detailed and quantitative analysis of coronary arteriograms is urgently required. In addition to the delineation of coronary morphology, we need dynamic and functional information about flow and perfusion to understand the physiological significance of anatomic abnormalities. Coronary arteriography contains and can provide most of this information. With the application of appropriate techniques, it can be made available in the catheterization laboratory even during the patient's investiga­ tion, thus facilitating and improving clinical decision making. Objective and reproducible analysis will furthermore enhance our understanding about the pathophysiology of coronary disease.