Background: Few studies have examined the relationship between parental history of stroke and myocardial infarction (MI) and subclinical atherosclerosis, especially among young, asymptomatic individuals. This study investigates the association between coronary artery calcification (CAC) and parental history of stroke and MI in African-Americans and Caucasians from the CARDIA study.
Methods: Parental history of stroke and MI was determined by self-administered family history questionnaire at baseline and Year 5 examinations. Presence of coronary calcification was determined by computed tomography on 3041 individuals, age 32 to 47, including 1375 African-Americans and 1666 Caucasians. Analyses were restricted to individuals free of clinically manifest coronary heart disease (CHD) and stroke.
Results: Parental history of stroke is associated with a two-fold greater risk of CAC in African-Americans, and this relationship is independent from established CHD risk factors (95% CI=1.14-3.43). There is no relationship between parental history of stroke and CAC status in Caucasians. Parental history of MI is associated with a two-fold greater risk of CAC in Caucasians (95% CI=1.38-2.92). The impact of parental history of MI in African-Americans is lower (OR=1.65; 95% CI=1.01-2.69) and no longer statistically significant after adjusting for known CHD risk factors.
Conclusions: The identification of individuals with a parental history of stroke and MI provides important information for clinicians by which to target primary prevention efforts. Further characterization of familial factors, especially genetic factors, contributing to increased risk of CAC will shed light on the basis of the observed associations.