Background: Several aspects of the relation between family history of ischemic heart disease (IHD) and risk of acute myocardial infarction (AMI) need further quantification.
Methods: A case-control study was conducted in Italy in 1995-1999 on 378 men and 129 women with a first nonfatal AMI, and 297 male and 181 female controls in a hospital for selected acute conditions. Odds ratios (OR) of AMI according to family history of IHD were estimated using unconditional logistic regression, adjusting for other AMI risk factors and family size.
Results: The overall OR for those having > or =1 first-degree relatives with IHD was 2.1, and 3.8 for > or =2 relatives. The OR for those with an affected parent or sibling were similar. The OR were also similar across strata of sex, age at diagnosis of the proband or the relative, and selected AMI risk factors, which were risk factors also in those with a positive family history.
Conclusions: Family history of IHD is an independent risk factor for AMI, and intervention on modifiable risk factors may be beneficial also in those with a family history of the disease.