In the last ten years, volumes have been written about poor quality of care and medical errors. In vascular disease today, only a third of patients with any given risk factor are controlled to goal. The highest risk patients are type 2 diabetics, most of whom have trouble with blood sugar, blood pressure, and cholesterol. Only 7% of type 2 diabetics have all three risk factors controlled simultaneously in spite of the fact that the likelihood of any diabetic complication is reduced by roughly half when blood pressure, blood glucose, and LDL are controlled to goal. The answer to this dilemma, for decades, has been exhortation and education—but very little has changed.
The quality chasm
The Institute of Medicine (IOM) is the medical arm of the National Academy of Sciences. The 1,400 members of the IOM are the best and the brightest of the leaders and thinkers in medicine. The IOM is largely funded by the government and charged by the government with analyzing pressing problems in the medical system.
The IOM’s seminal report from 2001, “Crossing the Quality Chasm” is not, to say the least, very complimentary in its description of American medical care. This report tells us that chronic conditions like diabetes, hypertension, high cholesterol, stroke, coronary artery disease, and congestive heart failure account for most healthcare spending, death, and disability. The IOM tells us that improved care could save lives, prevent disability, and reduce costs. But here is the really striking part:
“The current systems of care cannot do the job. Trying harder will not work. Changing systems of care will.”
The report goes on to recommend focused efforts to address these chronic conditions and spells out the essential elements of improvement.
In no discipline of medicine is the indictment more valid than in the care of patients with arterial disease and vascular risk factors. The current system of care is based on an understanding of arterial disease that is based on focal narrowing of the artery as the cause of heart attack and stroke. The system of care for decades has been based on this outdated understanding of the science. And so, if coronary artery disease is suspected, the patient gets a stress test. If that test is suspicious, the patient goes on to have a cardiac catheterization, and if narrowings are found, they are bypassed surgically or forced open with a stent.
All of this happens very reliably. This is what our current system is designed to produce and it produces it very well. At the same time, it is not designed to control risk factors and so they are not controlled very well. The problem with this is that bypass and stenting do not prevent heart attacks in stable patients.
In “Crossing the Quality Chasm,” the IOM says that it takes 17 years for new data from clinical trials to become part of the practice system. I first thought that was an exaggeration for effect, but, sadly, it understates the case. In 1988, WC Little and others at Wake Forest Medical School compared cardiac catheterization results obtained before and after myocardial infarction. They found that most heart attacks occurred where the arterial obstruction was less than 50%. The authors went on to conclude:
“Because it was difficult to predict the site of the subsequent occlusion in our patients from the initial coronary angiogram, coronary bypass surgery, or angioplasty directed only at the angiographically significant lesions initially present in almost all our patients would not have been effective in preventing the majority of myocardial infarctions. This does not indicate that arteries that do not have obstructive lesions should be bypassed or dilated. Instead, effective therapy to prevent myocardial infarction may need to be directed at the entire coronary tree, not just obstructive lesions…”
This article was reviewed along with three others by Erling Falk in 1995. In that same year, Dr. Peter Libby wrote an article in Circulation on the topic. Dr. Libby is Chief of Cardiology at the Brigham Hospital in the Harvard system. He is co-editor of one of the leading cardiology textbooks and wrote the section on atherosclerosis in Harrison’s Internal Medicine classic.
Dr. Libby wrote:
“Bypass surgery and angioplasty… do not address the nonstenotic but vulnerable plaque. It is of interest in this regard that despite the well-accepted benefit of bypass surgery on anginal symptoms, this treatment aimed at severe stenoses does not prevent myocardial infarction.”
That’s it. Period. Dr. Libby goes on to say that heart attack is caused by unstable cholesterol deposits that rupture and initiate clot formation that acutely obstructs the artery. These events are best prevented by risk factor control, diet, and exercise.
The evidence has become irrefutable since that time. Our current system to deal with arterial disease is based on outdated science and our results—both outcomes and costs—will not improve until we have the courage to address that reality.