Family history of coronary heart disease as a risk factor for developing coronary heart disease – a literature study Family history of coronary heart disease as a risk factor for developing coronary heart disease – a literature study
ABSTRACT Background and aims: Family history of coronary heart disease (CHD) has been proposed to be an important risk factor for developing CHD, but much remains to be explored on whether any increased risk is independent of other established risk factors, and how the risk is dependent on other aspects such as the age and gender of the various family members. The aim of this study was to examine the literature on the subject, and investigate whether a family history can be seen as an independent risk factor, and how other aspects, such as age, gender and the number of affected relatives influences the risk association. Methods: This study is a literature review. Articles were found either by repeated searches in PubMed in a period from autumn 2012 until spring 2015, using the following search terms: family history AND coronary heart disease , family history AND myocardial infarction , coronary heart disease AND heritability and myocardial infarction AND heritability , or via the bibliography of relevant articles and UpToDate.com. 11 articles were included in the final analyses. Results: The articles included in this literature review all showed that a family history of CHD was, at least in many scenarios, an independent risk factor for developing CHD. The studies that have adjusted for numerous established risk factors, generally find a modest effect of such an adjustment. CHD occurring at a younger age and family histories with more than one affected relative appears to be of greater importance. Other investigated aspects, such as the effect of gender, show inconsistent results. Conclusion: Family history of CHD is a risk factor for developing CHD that can be independent of other established risk factors. However, it cannot be interpreted as a binary risk factor that the index individual either has or has not. There appears to be greater risk with increasing number of affected relatives and with the CHD event occurring at a younger age. Gender of the index individual and affected relative may be of importance, but more research is needed to establish the exact pattern of this effect. Socioeconomic factors are an underexplored potential confounding factor. More research is needed to establish the degree to which the effect of a family history can be explained by established risk factors, the social environment and genetic mechanisms.