Tag Archives: Coronary Artery Bypass Graft

The Joy of Coronary Arteries (The body ain’t that simple)

‘For every complex problem there is an answer that is clear, simple, and wrong.’ H.L Mencken

Of all the things that I find most frustrating about medicine, it is the power of the simple solution. Nothing, probably, does more damage than a fixed belief in a simple idea. The history of medicine is littered with examples. ‘You have a bad headache…..well then, let us relieve it by removing a large section of your skull.’

‘You have recurrent infection of the tonsils. Well, let us remove these two glands, designed to fight infection, and your problems with infection will be solved.’

‘You had a heart attack. Well, you must rest in bed and take all the strain off your heart for six weeks, at least.’ I have calculated that this action caused the premature death of more people than died in the first and second world wars, Stalin’s pogroms, and the holocaust, added together. No, this doesn’t happen anymore.

But many things still do.

One such thing is the obsession of the medical profession with attacking coronary arteries. The arteries that supply blood to the heart. In many people these arteries develop thickenings (plaques), which can gradually narrow the artery and reduce blood supply to the heart muscle.

This can lead to angina, and suchlike. People also believe this means that a sudden blood clot forming over a narrowing can completely block the blood supply and cause a myocardial infarction (heart attack). People think this, but it is not necessarily true. Arteries without narrowings can suddenly block too – and if they do, the outcomes are usually far worse. Oh yes, the counterintuitive world of human physiology.

Anyway. If you think that a narrow coronary artery is the equivalent of having a ticking time-bomb inside your chest, you will probably want to do something about it. In 1967, someone managed to do so:

 ‘In 1967, the Argentine surgeon Dr. René Favaloro, working at the Cleveland Clinic, successfully used a vein graft to bypass an obstructed coronary vessel. Like Edmund Hillary and Tenzig Norgay, the first climbers to reach the summit of Mount Everest, or Roger Bannister, the first to run a four-minute mile, Favaloro opened a terrain deemed beyond human reach. In coronary artery vascular surgery he sundered the barrier to the seemingly impossible. Within ten years 100,000 patients were subjected to coronary bypass operations in the U.S.; by 1990s the number had quadrupled.’ Essay by Bernard Lown.

I suppose everyone has heard of the Coronary Artery Bypass Graft (CABG), pronounced cabbage by most doctors. What a wonderful idea, you use a bit of vein (sometimes a bit of artery, if you can find one) to bypass the narrowing. Huzzah!

You would think that someone would have tried to find out if it did any good, or not. But no-one really wanted to know. This operation bypassed a narrow coronary artery, increasing blood supply to the heart. This is such a simple and straightforward idea that to question it was to question common sense itself.

Which is why we ended up with four hundred thousand people being operated on each year in the USA alone. Yet no-one had ever done a study to find out if it did any good.

The someone who did try mighty hard was Bernard Lown. He is a Nobel laureate, and he also invented the defibrillator. So he was not some unqualified nut case. However, he had become very worried about ever increasing number of interventions:

‘Dealing with the growing tide of interventions, most of which I regarded as unwarranted, was morally challenging. To remain silent was complicit. To speak out was to invite confrontation with a powerful and unforgiving establishment. One pressing question was, how could we identify the subset of coronary patients that did well without surgical treatment? To determine how to proceed entangled me in a welter of contradictory views and emotions. One thing was certain, something needed to be done.’

And so he set out to try and find out if CABGs did any good. This was very tricky as he found that the moment he did an angiogram (an x-ray test for looking at coronary arteries), anyone who had a narrowing wanted a CABG straight away. At first, could not recruit a single person into his ‘control’ arm.

Eventually, though, he did manage to study this area and he found that….

‘…we recruited 144 consecutive patients with advanced coronary artery disease. These were followed for an average period of nearly five years, during which time 11 patients died, for an annual rate of 1.4 percent. We referred only 9 patients for CABG (1.3 percent annually). These results were better than the best outcomes being reported for those undergoing CABG.’

These results were better than the best outcomes being reported for those undergoing CABG. Of course, the net effect of this was that the entire world applauded. Er, no

‘Our sense of achievement was short-lived. Leading medical journals refused to publish these findings.’

Of course, as is the way of such things, the world moved on. Instead of CABG, we now have angioplasty. This is a procedure where you open up the artery from the inside using a small balloon, or inserting a wire mesh (stent).

Angioplasty is now taking over from CABG as the intervention du jour and, guess what, it is less effective than CABG – which makes it less effective than doing something that is less effective than doing nothing. Which means that every day it grows in popularity.

Ah yes, the tyranny of the simple solution continues.

I am indebted to Paul Rosch for sending me the essay from Bernard Lown on this issue.