Bypassing the Evidence

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Screen shot 2012 09 28 at 12.56.25 PM Bypassing the Evidence

In 1999, more than 570,000 coronary artery bypass graft (CABG) surgical procedures were done in the US at an average cost of $45,000. More than 1.3 million diagnostic coronary angiograms are done each year with an average cost of $12,500. This brings the total cost for diagnosis and treatment with these two procedures to approximately $45 billion annually. Scientific evidence now refutes the theoretical basis used to justify these procedures and also suggests that they have little or no impact on either the risk of death from cardiovascular diseases or the risk of death for all causes.

Angiograms are performed to detect major coronary artery blockages. In older Americans, angio-grams usually find one or more coronary arteries that are at least 50% to 70% blocked by atherosclerotic plaque. These are interpreted by cardiologists and cardiac surgeons to be a "ticking time bomb that could go off at any time."


After this warning, many patients are strongly encouraged to undergo bypass surgery. The bypass procedure grafts a blood vessel from some other part of the patient's body to the diseased coronary artery.


The medical rationale for bypass surgery stemmed originally from the belief that blood vessels gradually clog over time kind of like the water pipes in your home. Pipes that are clogged need to be bypassed or replaced. However, in patients who had angiograms, and then later had a heart attack, only about 10 to 15% of those heart attacks occurred in a section of artery that was 70% or more narrowed by atherosclerotic plaque.1, 2, 3, 4


Cardiology textbooks now state that most heart attacks occur in sections of arteries that are less than 50% narrowed. They also point out that even if an artery eventually becomes 100% blocked, it does not cause a heart attack because new, smaller blood vessels grow around this blocked artery.5 Most heart attacks result from the sudden rupture of a cholesterol-rich atherosclerotic plaque. We now know bypass surgery does nothing to prevent atherosclerosis or blood clots.


Of course bypass surgery is dangerous. About 3% who undergo it die during the operation or within a month. Within five years after the surgery, 42% of patients suffer from a significant decline in mental function.6 Bypass surgery invariably damages already diseased blood vessels. This can accelerate the growth of more plaque and possibly increase the risk of dying of a heart attack in the long term. Growing research now suggests that bypass surgery does not improve life expectancy. Although some earlier studies found some benefits in patients with the most severe blockages in the largest coronary arteries, none of the studies were properly controlled. These early studies failed to measure other cardiovascular disease (CVD) risk factors following the bypass surgery. Patients are known to be more likely to quit smoking, exercise and eat a healthier diet after their surgeries. They also are more likely to take medications to lower serum cholesterol levels and reduce the risk of blood clots. All of these changes reduce the risk of another heart attack whether or not the person underwent bypass surgery. If the studies that had suggested fewer heart attacks or deaths following bypass surgery had been corrected for reductions in other risk factors, all or most of the supposed benefit of bypass surgery would be eliminated.7 A 12-year study published in 1960 in the Journal of the American Medical Association, showed that older people who had already had at least one heart attack could greatly reduce their overall chance of dying by adopting a very-low-fat, near vegetarian (VLFNV) diet.8 More recently, Dr. Ornish, a cardiologist, showed that a VLFNV diet actually reversed the atherosclerotic disease process in most subjects and cut the rate of CVD events over a 5-year period by more than 50%.9,10 We have good evidence that a VLFNV diet, coupled with exercise and other lifestyle changes, can dramatically reduce overall mortality primarily by reversing atherosclerosis and preventing heart attacks.

The Bottom Line:


The major benefit of heart surgery appears to be its effect on motivating patients to eat better, quit smoking and exercise more. Another heart procedure becoming increasingly common is called PCTA, a type of angioplasty. It has been shown to be no better than bypass surgery. Both PCTA and bypass surgery do nothing to stop what causes most heart attacks and strokes, namely the growth and eventual rupture of atherosclerotic plaque. These plaques grow in response to a typical American diet and lifestyle.


By James J. Kenney, PhD, RD, FACN.




1. Clin Cardiol 1991;14:868-74


2. J Am Coll Cardiol 1990;218A-22A


3. Am J Coll Cardiol 1988;11:908-16


4. Circulation 1997;96: 1360-62


5. Heart Disease:A Textbook of Cardiovascular Medicine. 5th ed. Philadelphia, PA:WB Saunders Co.;1998:1322


6. N Engl J Med 2001;395:-402




8. JAMA 1960;173:104-8


9. Lancet 1990;336:129-33


10. JAMA 1995;274:894-901

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