McMaster University

McMaster University

Faculty of
Health Sciences

Family history important in predicting heart attack

Published: January 26, 2011
Clara Chow
Dr. Clara Chow, an assistant clinical professor of medicine at the Michael G. DeGroote School of Medicine, McMaster University

A family history of heart disease puts people at greater risk of a heart attack than once thought, according to new research from McMaster University and Hamilton Health Sciences’ Population Health Research Institute (PHRI).

Researchers found a parent’s history of a heart attack increases a person’s risk by 1.74 fold compared to someone without a parental history of heart disease.  The risk is greater if both parents suffered heart attacks and if the attacks occurred when the parents were less than 50 years old.

One parent having a heart attack at 50 years of age or older, results in a 1.67 fold increased risk of a heart attack among their children. If the parent is 50 or younger, the risk increases to 2.36 fold.

If both parents suffered heart attacks at 50 years or older, their offspring have a 2.90 fold increase.  This increases to 3.26 fold if both parents are younger than 50 at the time of their heart attacks.

Data show family history is a significant predictor of a future heart attack, independent of known environmental (smoking, diabetes, hypertension, exercise, alcohol use, body mass index) and some genetic risk markers.

“The unique aspect of this study is that family history nearly doubles your risk of future MI even after accounting for a list of other established risk factors,” said Dr. Clara Chow, an assistant clinical professor of medicine at the Michael G. DeGroote School of Medicine, McMaster University, and first author of the PHRI study.  “This study finds the association is consistent across regions, ethnicities, and socioeconomic groups.”

The study, Parental History and Myocardial Infarction Risk Across the World, appears this week in the Journal of the American College of Cardiology.

It is one of the most comprehensive studies of its kind, making researchers more confident that a parent’s history of a heart attack is a risk factor for their offspring’s risk of a heart attack, said Dr. Sonia Anand. A professor of medicine and epidemiology at the Michael G. DeGroote School of Medicine, McMaster University and one of the study’s authors.

“To the best of our knowledge, individuals with a family history of heart disease should try to minimize their other risk factors for heart disease by exercising, eating healthy foods, avoiding smoking and, when necessary, adhering to drug treatment their physicians prescribe,” said Anand.

Data for the study was collected from the INTERHEART study, a multinational study evaluating risk factors for heart disease led by Dr. Salim Yusuf, a professor of medicine at the Michael G. DeGroote School of Medicine.

For the study, more than 15,000 patients who survived a heart attack between 1999 and 2003 were compared to people who never had one. Genetic analysis included participants from five ethnic groups (Arab, European, Iranian, Nepalese and South Asian). Individuals were also tested for risk according to sex, age, education and socioeconomic status.

Researchers questioned what factors — other than risk factors and genetics — might explain the relationship between family history and heart disease.  They propose that the culprit might be early life stress, poor nutrition early in life, or environmental factors such as indoor air pollution and unmeasured genetic factors.

In an accompanying editorial, Dr. Themistocles Assimes, a cardiologist at Stanford University, said getting a good family history is a useful predictor of future heart disease, both in developed and developing countries, where there is a particular need for cost-effective and non-laboratory based risk assessments.

Study Article

Valid XHTML 1.0 Transitional Level Double-A conformance, W3C WAI Web Content Accessibility Guidelines 2.0