The First Balloon-Expandable Coronary Stent: An Expedition That Changed Cardiovascular Medicine

By Gary S. Roubin

The premise of this intriguing book is technical innovation and scientific development. It is about coronary and vascular stenting, a technique that has improved the plight of patients who have unfortunately succumbed to the most devastating epidemic facing modern man—coronary and vascular atherosclerosis. It is also about a lifetime and a career devoted to finding safer, effective, and less invasive solutions to these clinical problems. Gary S. Roubin, MD, PhD, writes of the pioneering work done by Andreas Gruentzig on balloon angioplasty for peripheral and coronary arteries. After Gruentzig’s untimely death, Roubin was determined that Gruentzig’s method would indeed work. He writes of the work involved to get the balloon-expandable coronary stent to the point where it was deployed in man:  September 3, 1987, and follows its development to the current day. This is an account of the expedition that began with the Model T Ford of cardiovascular intervention—an endeavor that evolved into the Ferrari that we know today. This personal story tells of the collaboration of inventors, physician scientists, engineers, and the cardiovascular device industry that has changed the practice of cardiovascular medicine forever.

• Language: English
• Publisher: University of Queensland Press
• Release date: Jan 1, 2015
• ISBN: 9780702255793

Book preview

Contents

Title Page

Preface

Contents

Author Biography

Introduction

Chapter 1

Andreas Gruentzig and Balloon Angioplasty

Chapter 2

The Problems of Abrupt Closure and Restenosis from Arterial Recoil

Chapter 3

Alternative Technologies to Make PTCA Safe and Effective: The Genesis of the Term PCI

Chapter 4

Peripheral Vascular Intervention and the Beginnings of the Stent

Chapter 5

Basic Science and In Vivo Animal Work in the United States

Chapter 6

The First Balloon-Expandable Coronary Stent in Man

Chapter 7

Solving the Problem of Abrupt Closure and the Race for FDA Clinical Approval

Chapter 8

Perfecting the Technology and its Application

Chapter 9

The Value of Coronary Revascularization and Stenting

Endnotes

Pioneers in Angioplasty and Vascular Intervention

Acronyms

Glossary

Index

Acknowledgments

Pictures Section

Imprint Page

Preface

In May 2011, a fresh-faced, enthusiastic device sales representative sat across my desk to explain why we should be using his company’s newest, greatest coronary stent in our cardiovascular interventional suites. A coronary stent is a tiny, tubular device that is compressed around an equally tiny coronary balloon. Using a steerable, fine guide wire as a ‘track’ and percutaneous techniques, skilled interventional cardiologists can accurately position the stent in the coronary arteries to safely treat blockages. As the sales representative pulled the device from his kit, he explained that this was the lowest profile, most trackable device on the market. The stent was able to conform to tortuosity of the coronaries with superb deliverability, radial strength, and visibility. The stent was laser cut from a new metallic compound, with a design that minimized stent thickness without compromising wall coverage or radial strength.

This device was truly the Ferrari of coronary stents and the list of functional features resonated and brought back vivid memories of a forgotten era. The list of features read almost exactly as we had defined the attributes of the ‘ideal coronary stent’ some 25 years earlier. I reached behind my desk and pulled from the shelf a dusty, black-bound dissertation of my MD thesis that contained references and publications from the late 1980s and early 1990s. This was a time when coronary stenting as practiced today was only a wish and a dream. Really though, it was an imperative, if we were to allow Andreas Gruentzig’s balloon angioplasty method of percutaneous revascularization to evolve into a safe and effective alternative to coronary bypass surgery. There was the list of design features that we had defined so many years earlier!

This young salesman had no idea of the challenges, trials, and tribulations faced by those of us who pioneered this work. If balloon dilatation of the coronary arteries was considered—as it was—as still an experimental and unproven therapy, then the thought of implanting metallic devices into the constantly beating and twisting coronary arteries was considered outrageous. Nor, I realized, did the majority of practicing stent operators have any concept of the ‘road traveled’: A path that led to the largely simple and routine procedure practiced today—a procedure that arguably represents one of the most effective percutaneous therapies practiced in medicine. As I pondered the opportunity to record this small part of medical history, I heard a news report that England’s Prince Philip was making a good recovery from heart surgery. At the age of 90, he had a threatened heart attack treated with the placement of a coronary stent. Like millions of other patients, the Prince has benefited from a tiny device placed into the artery supplying blood to the heart. As completion of this book progressed, former President George W. Bush notably received a coronary stent for a ‘threatening’ heart blockage and former Vice President Cheney was to be interviewed regaling how the heart stent (among a long list of other procedures) had saved his own life.

When this saga began in the late 1970s and early 1980s, the burgeoning discipline of Interventional Cardiology was facing many challenges. As we ‘pushed’ the PTCA (percutaneous transluminal coronary angioplasty) method towards more complex lesions and patients with advanced multi-vessel disease, risks abounded. We were challenged by our medical colleagues, our cardiac surgeons, and by the emerging recognition that this procedure, with such potential to benefit our patients with coronary disease, had many shortcomings.

The principal problem was that of ischemic complications and emergency bypass surgery caused by ‘abrupt closure’ after balloon dilatation. The stress of having to request surgical backup and the thought of being called back to hospital for up to one in 10 patients treated was an enormous issue. Thousands of patients suffered from emergency bypass surgery, myocardial damage, and even death, from the potentially simple elective procedure, unpredictably, going wrong.

Now, percutaneous coronary intervention with stenting is a simple procedure with minimal risk: The story of how this remarkable technology came into being is worth telling.

September 3, 2012, was to be the 25th anniversary of the first balloon-expandable stent in man. (Figure 1) This was a day that marked the first deployment of a balloon-expandable metallic prosthesis, a day that would make PTCA a safe and effective procedure for millions of patients for decades to come. This is an account of the expedition that began with the ‘Model T Ford’ of cardiovascular intervention—an endeavor that evolved into the ‘Ferrari’ that we know today. This is a story about the collaboration of inventors, physician scientists, engineers, and the cardiovascular device industry that changed the practice of cardiovascular medicine forever.

DrGary S. Roubin, MD, PhD, is an internationally renowned interventional cardiologist recognized for his groundbreaking work in the development of the first FDA-approved coronary stent, as well as in pioneering the techniques of carotid stenting and embolic protection devices.

He attended medical school at the University of Queensland, undertook his residency in internal medicine at the Royal Prince Alfred Hospital in Sydney, Australia, and his cardiology training at the Hallstrom Institute of Cardiology at the University of Sydney. He enrolled as a PhD candidate in cardiovascular physiology at the University of Sydney, gaining his degree in 1983. Roubin was then awarded a two-year grant by the National Heart Foundation of Australia to undertake postdoctoral research with Andreas Gruentzig at Emory University. In 1987, he developed and placed the first coronary stent in a patient in the United States.

Roubin is a fellow of the American College of Cardiology, the Royal Australian College of Physicians, the Council on Clinical Cardiology of the American Heart Association, the Society for Cardiac Angiography and Intervention, the Society for Vascular Medicine and Biology, the International Society of Endovascular Specialists, the Society of Interventional Radiology, and the International Society for Vascular Surgery.

In 1989, he moved to the University of Alabama at Birmingham as Professor of Medicine and Radiology and Director of the Cardiac Catheterization Laboratories and Interventional Cardiology Section at the University of Alabama Hospital. In 1995 he was awarded a Doctorate in Medicine from the University of Queensland for his basic and clinical research in the development of coronary stenting. During his tenure as Department Chairman and Chief of Service at Lenox Hill Hospital, Roubin took a leadership position, merging the facility into one of the largest and most successful hospital systems in the United States. He is currently the Medical Director of Cardiovascular Associates of the Southeast in Birmingham, Alabama. He lives with his wife, Peta, and his five children between their homes in Jackson Hole, Wyoming, and Birmingham, Alabama, where he maintains an active interventional cardiology practice. This is his first book.

Introduction

The premise of this book is technical innovation and scientific development. It is about coronary and vascular stenting, a technique that has improved the plight of patients unfortunate to have succumbed to the most devastating epidemic of modern man—coronary and vascular atherosclerosis. It is also about a lifetime and a career devoted to finding safer, effective, and less invasive solutions to these clinical problems.

Only with a sense of history and the opportunity to have personally participated in the past 30 years of cardiovascular medicine can this be placed in perspective. The devastating consequences of coronary artery disease including premature sudden death, disability from angina pectoris and heart failure, loss of productive work and lifetime activities, and the devastating cost to society are profound. The economic implications are immense, from death and disability, as well as the cost of hospitalizations and medications and tragic loss of human capital as middle-aged men and women are struck down in the most productive years of their lives.

I have always been struck by the untimely death and loss of the notable newscaster and political commentator, Tim Russert. I have no personal insight into how bad Tim Russert’s heart disease was, nor apparently did anyone else! But, it was bad enough to have suddenly killed him. I personally reflected on how this could have happened, and, of course, from my perspective, on how it could have been prevented. Could the placement of a tiny device called a stent into, for example, a 90% proximal stenosis of one or more of his arteries have made a difference? Could more aggressive testing and treatment have given this man life and the ability to continue his remarkable contribution to society?

There is much to this line of thinking, none of it easy, and the debate and discourse on the subject is vast and has continued for decades. But there are tens of thousands of such personal accounts of lives cut short—valuable, educated, contributing lives—and the unanswered questions deserve much more evaluation, study, and discussion.

I will focus on this critical aspect of the stenting story in a later chapter, describing decades of studies that provide evidence that identifying and treating coronary atherosclerosis (deploying the humble coronary stent as appropriate) has made a difference to millions of lives. There is little debate any more about percutaneous intervention (stenting the artery) in cases of acute myocardial infarction or for those cases that involve acute coronary syndromes (ACS). A strong case, though, can also be made for treating even certain stable asymptomatic blockages, but more of that later!

In the United States, the mortality rate from coronary artery disease peaked in the late 1960s. Since this time, there has been a progressive decline in deaths from this disease and the decline continues, despite recent increases in obesity and diabetes in the population. These conditions are potent risk factors for the development of coronary atherosclerosis. So how is it possible that coronary disease mortality continues to fall?

The progressive decline in coronary deaths has been paralleled by a progressive increase in the use of coronary revascularization. We will discuss in detail how the coronary stent facilitated and even enabled this revascularization effort. Clearly, the decline did not begin with the introduction of the coronary stent, but I suggest the ongoing and progressive decline was in no small way related to the availability of this remarkable device. In Nabel and Braunwald’s masterful review, ‘A Tale of Coronary Artery Disease and Myocardial Infarction,’ they note the first description of a CABG revascularization, and the development of coronary angioplasty and coronary stenting as pivotal events associated with the beginning and continued decline in deaths from cardiovascular disease.¹ (Figure 2) I am quick to point out that these two fascinating courses—decreasing mortality and increasing revascularization and stent usage—don’t necessarily imply cause and effect, but the relationship is striking.

Of course, in plotting the contributory factors in decreasing cardiac mortality rates, we must also plot the reduction in cigarette smoking, the increasing awareness of the importance of exercise and diet, the use of potent agents such as beta-blocking drugs to mitigate the effect of ischemia, and the growing realization of the importance of high blood pressure, diabetes, and lipids and cholesterol in the blood. The exponential use of cholesterol-lowering agents and anti-hypertensive drugs are undoubtedly critical to the picture, and their contribution cannot be denied or underestimated. The upswing of these preventative lifestyle and pharmacological strategies also parallel the upswing of the ‘stent curve.’ In addition, we have made tremendous advances in our understanding and treatment of the long-term consequences of coronary atherosclerosis and stenoses. Our treatment of heart failure caused by myocardial damage and cardiac rhythm disturbances are also dramatic success stories.

But to return to the questions and the contribution of the coronary stent, few thoughtful observers could deny the potential contribution. Even if only 20% or 10%, or even 5%, of the overall mortality decline can be attributed to revascularization and stenting, then this represents ongoing success in saving millions of lives.² This is not to deny the remarkable contribution that advances in understanding the biology of atherosclerosis have made, nor to deny the dramatic contribution of risk factor modification, pharmacological, and other therapies.

As the developing economies in the world now grapple with the atherosclerosis epidemic brought about by ‘over-nutrition,’ obesity, diabetes, hypertension, and even unrelenting tobacco consumption, the opportunity for the stent to save lives continues.

Beyond lives cut short in their prime, there was the pain and suffering that was caused by chronic, unrelenting angina pectoris—the symptoms related to coronary stenoses. Practitioners today rarely see this disorder! But when I began my career in cardiovascular medicine some 35 years ago, it was a devastating condition with many patients receiving chronic narcotic therapy for this debilitating disorder. In today’s medical world, it is rare to see a patient totally debilitated by chronic angina pectoris. Sure, the medical therapies available have helped immensely but the vast volumes of rigorous scientific data support the use of stenting for the relief of symptoms that cannot be controlled by medical therapy alone.

So, the first balloon-expandable coronary stent implanted in the world at Emory University Hospital, on September 3, 1987, has made an impact on medicine and human health. What follows is the story of how it came about and the fascinating developmental path that has led to today’s advances.

Gary S. Roubin MD PhD, FRACP, FACC

Chapter 1

Andreas Gruentzig and Balloon Angioplasty

The master was gone. Tragically lost to the world of medicine and specifically to a few of us, his team at the hospital, who assisted him with his pioneering ‘miracle’ work every day. Not only did we lose his clinical and technical brilliance, but also his humanity, his verve for innovation, and the rigorous scientific validation of his method. His teaching and live video mentoring around the world, and his absolute leadership and dominance in the brand new field of medicine that would become known as Interventional Cardiology was legend. (Figure 3)

In editorials throughout the nation, leaders in medicine and commentators lamented the loss of Andreas Gruentzig, the man who promised to change the management of coronary artery disease. For those of us working on his research and clinical trials, the loss was devastating. Not just a personal loss, but real