REVIEW ER 'S CONCLUSIONS Quitting smoking is associated with a substantial reduction in risk of all-cause mortality among patients with CHD .
This 36 % risk reduction appears substantial compared with other secondary preventive therapies such as cholesterol lowering which have received greater attention in recent years .
The risk reduction associated with quitting smoking seems consistent regardless of differences between the studies in terms of index cardiac events , age , sex , country , and time period .
BACKGROUND Although the importance of smoking as a risk factor for coronary heart disease is beyond doubt , the speed and magnitude of risk reduction when a smoker with coronary heart disease quits are still subjects of debate .
OBJECTIVES To estimate the magnitude of risk reduction when a patient with CHD stops smoking .
The role of risk factors in heart attacks occurring in men with pre-existing ischaemic heart disease.
The importance of three risk factors -- serum total cholesterol , systolic blood pressure , and cigarette smoking -- on the risk of new major ischaemic heart disease events in men who already have evidence of ischaemic heart disease was assessed . Data from the initial examination in a large prospect i ve study of cardiovascular disease in middle aged men ( the British Regional Heart Study ) were used to separate 7710 men into three groups on the basis of a resting electrocardiogram , a st and ardised chest pain question naire , and recall of a doctor 's diagnosis of angina or of a previous heart attack : ( group 1 ) no evidence of ischaemic heart disease ( 75 % ) , ( group 2 ) evidence of ischaemic heart disease short of a definite myocardial infa rct ion ( 20 % ) , ( group 3 ) definite myocardial infa rct ion ( 6 % ) . In the average follow up period of 7.5 years , 443 men suffered a new major event caused by ischaemic heart disease ( fatal or non-fatal myocardial infa rct ion or sudden cardiac death  ) . Age st and ardised event rates were determined for each of the three groups for varying levels of the established risk factors . Cigarette smoking is strongly associated with the event rate in group 1 but in men with existing heart disease , especially group 3 , differences in risk between the smoking categories were smaller . The strong relation between systolic blood pressure and event rate persisted in groups 1 and 2 but not in group 3 . The positive association between serum concentration of total cholesterol and the event rate was strongest in group 1 and weaker in groups 2 and 3 , though it remained highly significant . These observations , taken together with the results of previous prospect i ve studies and intervention trials , suggest that the important association between serum total cholesterol and the risk of heart attack persists in men with pre-existing ischaemic heart disease , including myocardial infa rct ion . Therefore , in these men the reduction of serum total cholesterol concentration may be at least as important as it is in men without evidence of ischaemic heart disease
REVIEW ER 'S CONCLUSIONS Quitting smoking is associated with a substantial reduction in risk of all-cause mortality among patients with CHD .
This 36 % risk reduction appears substantial compared with other secondary preventive therapies such as cholesterol lowering which have received greater attention in recent years .
The risk reduction associated with quitting smoking seems consistent regardless of differences between the studies in terms of index cardiac events , age , sex , country , and time period .
BACKGROUND Although the importance of smoking as a risk factor for coronary heart disease is beyond doubt , the speed and magnitude of risk reduction when a smoker with coronary heart disease quits are still subjects of debate .
OBJECTIVES To estimate the magnitude of risk reduction when a patient with CHD stops smoking .