A history of myocardial infarction (MI) in either or both parents increases a person’s odds of having a  MI, and may prevail above other traditional risk factors.  Clara K. Chow, from McMaster University (Canada), and colleagues involved in the INTERHEART multinational study, have found that a near doubling in MI risk with a positive parental history was consistent across income, sex, and age groups and all regions of the world from which data was collected.  Analyzing data on 12,149 individuals presenting with a first MI (matched with 14,467 control subjects), the team found that cases were more likely to report a history of MI in either parent (18.1% versus 12.0% of controls); as well, an earlier age of MI and MI in both parents appeared to have a dose-dependent effect.  Further, by adding parental history, the researchers improved predictability with the nine risk factors considered in the main INTERHEART study: hypertension, diabetes, lipids, waist-to-hip ratio, tobacco use, alcohol use, physical activity, fruit and vegetable intake, and psychosocial risk factors. The researchers urge that their international results add to the growing body of evidence to support the use of family history as a factor in risk calculation in myocardial infarction.