Background: Family history of coronary heart disease (CHD) has been well studied as an independent risk factor for CHD events in the short term (<10 years). However, data are sparse on the association between family history and risk for CHD across long-term follow-up.
Methods and results: We included 49 255 men from the Cooper Center Longitudinal Study. Premature family history of CHD was defined as the presence of angina, myocardial infarction, angioplasty, or bypass surgery in a relative <50 years of age. Cause-specific mortality was obtained from the National Death Index. The association between premature family history and cardiovascular disease (CVD) or CHD death was compared across 3 unique follow-up periods (0-10, >10-20, and >20 years). Lifetime risk was estimated by use of a modified survival analytic technique adjusted for competing risk with non-CVD death as the competing event. After 811 708 person-years of follow-up, there were 919 CHD deaths and 1456 CVD deaths. After adjustment for traditional risk factors, premature family history was associated with CHD mortality >10 to 20 years (1.59; 95% confidence interval, 1.14-2.22) and >20 years (1.43; 95% confidence interval, 1.05-1.95) with wider confidence intervals at 0 to 10 years (1.32; 95% confidence interval, 0.76-2.31). Similar findings were observed for CVD mortality. Compared with men without a family history of coronary artery disease, premature family history was associated with an ≈50% higher lifetime risk for both CHD and CVD mortality (13.7% versus 8.9% and 21% versus 14.1%, respectively).
Conclusion: Premature family history was associated with a persistent increase in both CHD and CVD mortality risk across long-term follow-up, resulting in significantly higher lifetime risk estimates.