Medical Program (Internal Medicine), Timmins and District Hospital, Timmins, Ontario, Canada
* Correspondence to: +1 705-268-8066; fax: +1 705-268-8066
E-mail address: atbeat{at}ntl.sympatico.ca
Received 28 December 2002; accepted 20 June 2003
In a large, prospective study, Andresdottir et al.1reported that 15% of coronary events were attributable to family history of coronary artery disease, when they used history of myocardial infarction at any age (not premature coronary artery disease) in first-degree relatives. It is interesting that despite using a broader definition of family history of coronary artery disease, the reported prevalence was lower (16.8% in men and 21.6% in women) compared to other studies2,3that could be because about 20% of men and women did not know their family history, but was still much less than was reported in a recent Canadian study4where 67% of women reported positive family history. Although the authors did not verify the family history in participants, it appears that the population of this cohort was well educated and reported proper family history of coronary artery disease in first degree relatives compared to other cohorts where patients may include the history of coronary artery disease in second and third degree relatives that thereby exaggerated the family history but diluted its significance.4
It would have been important if the authors had analysed the proper significance of the commonly used definition of premature coronary artery disease that has been utilized in the Framingham study (family history of <55 years in men and <65 years in women, first degree relatives) and others. As the average age was 5354 years, this study does not clearly define the significance of true family history of premature coronary artery disease in younger populations where this risk might be more important in overall control of other modifiable risk factors and prevention of coronary artery disease. However, it is clear from table 3 of the paper, that patients with positive family history of coronary artery disease had a higher prevalence of established coronary artery disease at entry and this further strengthens the implications of established coronary disease, as both men and women with previous myocardial infarction (in table 2 of the paper) had highest hazard ratios of future coronary events.
So, the main questionwhat is the proper definition of family history of coronary artery disease in 2003? It is important to properly define the family history of coronary artery disease during an encounter with the patient, as shown by the authors that family history if coronary heart disease, if the history if taken properly, it not have high prevalence but has greater predictive value than a casual family history whose prevalence might be higher but then loses its predictive value.4,5
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