Table 2 Evidence base for benefit of risk factor modification

Smoking

Smoking cessation will reduce the risk of death by

Patients who continue to smoke after a myocardial infarction

50% [45]. Men who stop smoking have a reduced risk

had a 22-47% increase in mortality risk [49]. In patients

of myocardial infarction [46] and within 2-3 years the

followed up for 15 years, 82% mortality was seen in those

risk is similar to those who have never smoked [47].

patients who continued to smoke after the first myocardial

infarction or unstable angina. In patients who had stopped

smoking, the figure was 37% [50].

Diet

Dietary changes (reduction in saturated fat, cholesterol

There was a 29% reduction in 2-year all-cause mortality in

and an increase in polyunsaturated fat) can result in

post-myocardial infarction patients who received advice on an

decreased mortality from CHD [46,51]. The addition of

increase in fatty fish intake [53]. However the incidence of

stanol esters and plant sterols (which reduce

re-infarction and CHD mortality was not significantly changed.

cholesterol absorption) to food, for example margarine,

A Mediterranean-type diet (replacing red meat with poultry and

has been shown to reduce plasma cholesterol

increasing fish, vegetables, fruit, and use of olive oil) in

concentrations by about 10%. The effect equates with

myocardial infarction patients demonstrated a 76% reduction in

a mortality risk reduction of about 23%; lack of control

the risk of CHD mortality.

over intake results in variable effects [52].

Cholesterol

Total serum cholesterol of >6 mmol/l is associated with

an increased incidence of CHD risk and risk of CHD

mortality [54].

Exercise

Lack of physical fitness or physical activity are associated

with an increased risk of death from all causes and from

cardiovascular disease both in middle-aged [55] and

older men [56].

Alcohol

Mortality from CHD is lowest in those who reported

drinking 8 to 14 units of alcohol a week. Drinking above

21 units a week increases total mortality [57]. Differences

between types and patterns of alcohol intake remain unclear [58].

Diabetes mellitus

Mortality from CHD increases about 3-fold to 10-fold and 2-fold

to 4-fold in patients with type 1 and type 2 diabetes, respectively [49].

The UKPDS study indicated that for each increment of 1% increase

in HbA1c there was a 1.11-fold increase in the risk of CHD [59].

Blood pressure

Chronic hypertension is closely related to the risk of developing

CHD [60]. A decrease of 5 mmHg in diastolic blood pressure is

associated with a 21% decrease in risk of developing CHD [61].

Obesity

Although increased body mass index is related to increased risk

of CHD [62,63], there are no clinical trials of the effect of weight

reduction on CHD morbidity and mortality [64].