Angioplasty when a "balloon" is inserted to clear the blockage is no better than drug therapy in preventing death (N Eng J Med, 1996; 335; 1253-60). This conclusion was borne out by research which showed that angioplasty fared badly against bypass surgery (N Eng J Med, 1997; 336: 92-9). In the study, angioplasty patients were able to return to work earlier but bypass patients could perform more daily activities such as housework and walking. Both procedures added an average of 4.4 years to the lives of patients. But angina levels in the angioplasty group were 26 per cent, compared to 11 per cent in the bypass patients. Nearly 60 per cent of the angioplasty group had to have further treatment because the arteries started to clog up again.

It's not all good news for bypass surgery, which has been associated with a high rate of stroke following the procedure. About 6 per cent of patients may suffer a stroke directly afterwards. Of these 5 per cent die and nearly half suffer deterioration in mental functions (N Eng J Med, 1996; 335: 1857-63).

There is much that heart attack victims can do for themselves. Diet and lifestyle are factors within an individual's control. There is plenty of research to show that eating raw foods can prevent heart attacks. Two or three servings a day of fruit, high in vitamin C and soluble fibre, can reduce the risk of heart disease by as much as 25 per cent (N Eng J Med, 1987; 316: 235-40; Am J Epidemiol 1987; 126: 1093-102; Am J Epidemiol, 1994; 139: S47). One 17 year study showed that people who eat fresh fruit every day are less likely to suffer from heart problems, with 24 per cent less fatal heart disease, a 32 per cent reduction in death from stroke and overall a 21 per cent lower mortality rate (BMJ, 1996; 313: 775-79). The same study revealed that if you have a raw salad every day your risk of fatal heart disease is lowered by 26 per cent.

A recent study of heart attack patients used a CAT scanner to measure the arteries of those who followed a vegetarian diet. The results showed that over five years arterial disease was actually reversing in 99 per cent of them (JAMA, 1995; 274: 894-901). This good news needs to be taken in context. Some very low fat diets can change levels of HDL cholesterol or result in low levels of essential fatty acids, both of which have been associated with an increased risk of heart attack (JAMA, 1996; 275: 1402-3).

There is no agreement on whether it is best to follow a strict vegetarian diet or a low or high carbohydrate diet. Certainly the stress of radically altering your diet may do more harm than good. Low levels of cholesterol can also cause violent mood swings and suicidal depression (see box page 2).

This is particularly true in the campaign to lower cholesterol levels. Universal screening for cholesterol has been condemned by the American College of Physicians, who recommend that those over 75 can safely ignore screening since cholesterol is not a risk factor in this age group. It is also not recommended for men under 35 or women under 45 unless they have a family history or more than two of the following risk factors: high blood pressure, cigarette smoking and diabetes.

The cholesterol lowering drug pravastatin has been shown to be little better than a sugar pill in protecting against a second heart attack. In one study of 4000 heart attack survivors with average cholesterol levels, 10 per cent on pravastatin had a second attack, compared to 13 per cent on a placebo within the first five years (N Eng J Med, 1996; 335: 1001-9).