Prevalence of conventional risk factors in patients with coronary heart disease

Abstract

Context: 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.

Objective: 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 122458 patients enrolled in 14 international randomized clinical trials of CHD conducted during the prior decade. Patients included 76716 with ST-elevation myocardial infarction, 35527 with unstable angina/non-ST-elevation myocardial infarction, and 10215 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.

Results: 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 < or =55 years and women < or =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.

Conclusions: 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.