Health News and Information

Bypass surgery

When bypass surgery was first started, it was usual to take a vein from the leg (we have plenty to spare!) and insert it around the narrowed site in the coronary artery. The blood then flows through the vein, around the stenosis, to reach the myocardium beyond it. The immediate result is a much better flow of blood to the heart muscle, carrying much more oxygen and glucose to the starved area.

There has been a more recent trend to use a small segment of artery from inside the chest wall—the internal mammary artery—instead of the vein. Among the reasons for the change is that the artery is more readily available than a leg vein, and that an arterial graft is probably more appropriate than a vein graft for what, after all, is another artery. There have been reports that the internal mammary graft is more effective in the long term, but other comparisons between the two seem to suggest that there is little difference in the merits of the two types of graft.

Bypass grafts are, of course, done under general anaesthetic, and patients must stay in the hospital for several days afterwards. I was astonished to be called to a patient’s home on a Friday to see him, to be told that he had had his bypass just four days before, on the Monday! The pressure to remove patients from hospital care in today’s fast-paced health care climate is surely immense!

Bypass surgery appears to work best for those who have left-main or severe three-vessel blockages.

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That guidance may be based not just on the work of Professor Williams and Dr. Beevers, but also on the most recent results of the many studies of the possible links between alcohol and heart disease. Unfortunately, the results are far from clear, and many different conclusions have been drawn from them.

Probably the most reliable conclusions were drawn by Professor A. G. Shaper, of the British Regional Heart Study mentioned in the introduction/in 1994. This showed that moderate drinkers (sixteen to forty-two units a week) suffered 34 percent fewer deaths from heart attack, and 13 percent fewer deaths from other circulation disorders (mainly stroke) than nondrinkers.

This would seem to be encouraging for drinkers, but Professor Shaper stressed that it was not. First, the actual overall numbers of such deaths were so small that the differences could not be considered as reliable or statistically significant. Worse, there was no reduction in overall death rate among the moderate drinkers, so that they were more likely to die from other diseases at the same time.

Professor Shaper showed that the extra heart deaths among the teetotalers included several in people who had been diagnosed as having heart disease when they entered the study. They may well have been drinkers who had turned teetotal because they were already feeling ill, and this could account for the difference in death rates. He concluded that if moderate drinking does protect against heart attacks, the effect is relatively small, and is not accompanied by a reduction in deaths from all types of circulation disorders, or by a reduction in deaths over all.

He compared his results with those of studies in other countries. In Trinidad, the lowest mortality for all causes was in men labeled as abstemious, who did not usually drink, and had no history of drinking problems. In the large Kaiser Permanente Study, which used lifelong abstainers as a comparison, none of the drinking groups— ranging from occasional, through mild, moderate, and heavy—showed any benefit from their alcohol consumption, and those drinking more than six units a day were decidedly worse off.

In a study carried out by the American Cancer Society, in the data on deaths from all causes, only occasional drinkers and those taking one or two drinks a day had a significantly lower risk than nondrinkers. Here, too, the figures may be distorted by some people who gave up drinking because they were already unwell before they entered the study. Above the lowest alcohol intake level, death rates rose progressively with each step up in alcohol consumption.

In this same study, at the level of alcohol intake associated with the lowest risk of coronary heart disease death (four drinks per day), there was an increased risk for all-cause deaths, particularly from accidents and violence, cancer and stroke, which more than outweighed the apparent savings in heart deaths. This bleak statistic does not take into account the increased rates of illness that may stem from consuming much lower amounts of alcohol than four drinks a day.

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Start off by making the right decision. Don’t listen to that voice inside you that says “I’ll start next week,” or “I’ve tried to before and couldn’t keep it up,” or “I can’t make the change just now.” You can make the change, even if it is just with a first small step. There are a few rules for beginning exercise:

• If you have a health problem, such as angina, discuss with your doctor the best type and amount of exercise for you.

• Choose a type of exercise you will enjoy, one that feels right for you.

• Do exercise that involves the large muscles in your legs, such as in brisk walking, cycling, and swimming.

• Start easily and gently, and build up your activity slowly and gradually.

• Be sensible about starting and stopping. Listen to your body, and don’t overdo things.

• Do not exercise if you are unwell—for example, if you have a throat infection or flu.

• Do not exercise if you have a muscle strain or injury. Wait until it is pain-free before you start again, and do so slowly.

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Among the early studies was the Los Angeles Veterans Administration Study, which took place between 1959 and 1967. This followed 846 men aged between fifty-four and eighty-eight years, of whom a quarter initially had evidence of coronary heart disease (mainly angina). Half were allocated to a diet in which the ratio of polyunsaturated fats to saturated fats was two to one. Vegetable and fish oils were used instead of animal fats. Half were left as the control group. After eight years, fewer deaths from heart disease and nonfatal heart attacks had occurred in the treatment group (85 in 424) than in the control group (119 in 422). The benefit of cholesterol lowering was greatest in the men under sixty-five years old.

Diet also seemed to work in seven hundred men and six hundred women in the Finnish Mental Hospitals Study, which was undertaken from 1959 to 1971. For six years, those in one hospital were on the same polyunsaturated/saturated two-to-one diet as in the Los Angeles study, whereas those in the other hospital were left alone. After six years, the positions were reversed. Although the patient populations changed greatly during the twelve years, and there were many problems with the data analysis, the diet was linked with a moderate benefit in reduction of heart attack and stroke for both men and women (though less so for women).

The North Karelia Study described in chapter 4, which targeted a whole community, produced a similar benefit, in that heart attacks became fewer after the low cholesterol educational project started.

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The answer is that it can be, (and it will take the rest of this book to explain how) with a combination of sensible eating, exercise, a different lifestyle, drugs, and perhaps surgery. Yet it is important, in understanding how this can be done, to look at all the other contributors to angina, for cholesterol is not the only danger to angina sufferers.

Atheroma is the necessary background to most kinds of angina, but it is hardly ever the sole cause of the symptoms. In most angina sufferers, it is the combination of underlying atheroma with many other changes in the blood that causes the illness. For example, the blood may be more viscous (sticky) than normal, slowing the flow through the narrowed areas. It can be more likely than normal to clot. It can carry too little oxygen due to lung disease or anemia, or perhaps because the oxygen-carrying red cells are full of carbon monoxide instead. All of these possibilities can reduce the supply side of the equation.

Or there may be high blood pressure, which, by increasing the force of the heartbeat even at rest, increases the heart’s demand for oxygen and glucose, causing further imbalance to the supply-demand equation.

How all these changes can combine together to create angina, and how they can all be reversed, is explained later, but in order to understand them, it is first necessary to outline the components of healthy blood.

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