It is commonly suggested that more than 50% of patients with coronary
heart disease (CHD) lack any of the conventional risk factors (cigarette smoking,
diabetes, hyperlipidemia, and hypertension). This claim implies that other
factors play a significant role in CHD and has led to considerable interest
in nontraditional risk factors and genetic causes of CHD.
To determine the prevalence of the 4 conventional risk factors among
patients with CHD.
Design, Setting, and Patients
In 2002-2003, we analyzed data for 122 458 patients enrolled in
14 international randomized clinical trials of CHD conducted during the prior
decade. Patients included 76 716 with ST-elevation myocardial infarction,
35 527 with unstable angina/non–ST-elevation myocardial infarction,
and 10 215 undergoing percutaneous coronary intervention.
Main Outcome Measures
Prevalence of each conventional risk factor and number of conventional
risk factors present among patients with CHD, compared between men and women
and by age at trial entry.
Among patients with CHD, at least 1 of the 4 conventional risk factors
was present in 84.6% of women and 80.6% of men. In younger patients (men ≤55
years and women ≤65 years) and most patients presenting either with unstable
angina or for percutaneous coronary intervention, only 10% to 15% of patients
lacked any of the 4 conventional risk factors. This pattern was largely independent
of sex, geographic region, trial entry criteria, or prior CHD. Premature CHD
was related to cigarette smoking in men and cigarette smoking and diabetes
in women. Smoking decreased the age at the time of CHD event (at trial entry)
by nearly 1 decade in all risk factor combinations.
In direct contrast with conventional thinking, 80% to 90% of patients
with CHD have conventional risk factors. Although research on nontraditional
risk factors and genetic causes of heart disease is important, clinical medicine,
public health policies, and research efforts should place significant emphasis
on the 4 conventional risk factors and the lifestyle behaviors causing them
to reduce the epidemic of CHD.