Family history as an independent risk factor for incident coronary artery disease in a high-risk cohort in Utah.

To test independence of family history of coronary artery disease (CAD) as a risk factor for the development of new clinical CAD, data collected at 2 clinic visits on 1,196 men and women, ages greater than 20 years, were analyzed using Cox proportional hazard method. During a mean follow-up of 2.5 years, 16 new CAD cases were observed. After adjustment for age, sex, total cholesterol, high density lipoprotein cholesterol, hypertension, diabetes, cigarette smoking and body mass index, family history remained a highly significant predictor of future CAD (p = 0.0017). Only age was a more significant covariate (p = 0.0001) than family history. Sex (p = 0.00074) and serum total cholesterol (p = 0.015) also contributed significantly to CAD incidence while high density lipoprotein cholesterol, hypertension, diabetes, body mass index and several interaction terms did not improve the prediction in this population. These results provide evidence for the existence of other heritable risk factors which appear to contribute strongly to the occurrence of early CAD in many high-risk families.