Coronary artery calcification and family history of premature coronary heart disease: Sibling history is more strongly associated than parental history

Background - The objective of the study was to assess the association of a family history (FH) of premature coronary heart disease (CHD) with coronary artery calcification (CAC) in asymptomatic individuals and to compare the effects of sibling or parental FH on the risk of subclinical atherosclerosis. Methods and Results - CAC by electron beam tomography was performed in 8549 asymptomatic individuals (69% men; mean age, 52±9 years). The prevalence and odds of any CAC and extent of CAC stratified according to FH of premature CHD were determined. Those with (1) no FH of CHD, (2) FH of premature CHD in parents, or (3) FH in siblings had a prevalence of CAC of 55%, 64%, and 78% (P<0.0001) among men and 27%, 36%, and 56% (P<0.0001) among women, respectively. The multivariate regression analysis demonstrated that the odds ratio (95% confidence interval) for the presence of CAC was 1.3 (1.1 to 1.6) among those with positive FH of premature CHD in parents only, 2.3 (1.7 to 3.1) and 2.5 (1.8 to 3.3) among those in siblings and a combined FH compared with those without FH of CHD in men, respectively. Among women, the corresponding odds ratios were 1.3 (1.0 to 1.8), 2.3 (1.7 to 3.6), and 1.9 (1.3 to 3.1), respectively. A similar trend was observed in the association of FH of premature CHD with increasing CAC scores. Conclusions - Our study demonstrates a highly significant association between FH of premature CHD and the presence and extent of CAC. Furthermore, within the limits of self-reporting of family history, our findings suggest that a sibling history is more strongly associated with subclinical coronary atherosclerosis than a parental history of premature CHD.