Family history of cardiovascular disease.

Evidence Where possible, odds ratios (ORs) have been converted to relative risks (RRs). • A total of 2302 male and female Framingham offspring study participants with parental history of premature CVD (father < 55 years, mother < 65 years) were analyzed for CVD risk.1 After 8 years of followup, CVD increased 75% with paternal and about 60% with maternal history of premature CVD. • Using the same cohort for 8 years, CVD increased about 40% in those whose siblings had CVD.2 • In identical (or monozygotic) twins, the hazard ratio of death from coronary artery disease (CAD) increased 3.8 to 15 times if an identical sibling died of CAD before age 75.3 -Risk was 3 times higher for identical than for nonidentical twins. -Risk was greater the earlier the other twin died. • More than 49 000 primarily white men in the United States were analyzed for CAD in their extended families (sibling, aunt or uncle, parent, or grandparent) and the risk of future CVD.4 -After 16 years, a family history of premature CAD (age < 50) conferred a 44% increased risk of CVD mortality. • A large international case-control study5 found an increased risk of myocardial infarction (MI) if -one parent had MI (OR = 1.67); -one parent had MI before age 50 (OR = 2.36); -both parents had MI (OR = 2.90); and -both parents had MI before age 50 (OR = 6.56). —Results were similar when adjusted for CVD risk factors across socioeconomic status of household or country, and for maternal or paternal MI history.