No matter where you live, how old you are or what you look like, health researchers have recently discovered that 90 % of first heart attacks (myocardial infarction) suffered by people can be attributed to nine risk factors.

The risk factors include: cigarette smoking, an abnormal ratio of blood lipids, high blood pressure, diabetes, abdominal obesity, stress, a lack of daily consumption of fruits and vegetables, as well as a lack of daily exercise.

Modest alcohol consumption (three-to-four drinks weekly) has been determined to be a preventative measure.

INTERHEART is a global study led by McMaster University's Dr. Salim Yusuf that focuses on cardiovascular disease (CVD) and was co-funded by the Canadian Institutes of Health Research (CIHR), the Heart and Stroke Foundation of Ontario and 37 other funding sources. The study involved 15,000 patients with a first acute myocardial infarction (AMI) and 15,000 asymptomatic control subjects (age and sex matched) drawn from 262 centres in 52 countries throughout Asia, Europe, the Middle East, Africa, Australia, and North and South America.      

Structured questionnaires were administered and physical examinations were undertaken similarly in patients and controls. Information was gathered relating to demographic factors, socioeconomic status, lifestyle, personal and family history of CVD, and psychosocial factors. Non-fasting blood samples were taken from every individual and frozen immediately after processing for later analysis. Waist measurements and hip circumferences were recorded.

Current smokers were defined as individuals who smoked any tobacco in the previous 12 months and included those who had quit within the past year. Former smokers were defined as those who had quit more than a year earlier.

All of this information was collected and sent to the Population Health Research Institute, McMaster University and Hamilton Health Sciences for quality control and statistical checks.

The effect of these nine risk factors is consistent in men and women, across different geographic regions, and by ethnic group, making the study applicable worldwide.

This landmark study was published in the September 11, 2004 edition of the Lancet and was voted runner-up for the magazine's scientific paper of the year. Among implications of the study, the concept of a uniform preventative strategy for heart attack across the world appears very attractive and of great potential impact.  The ways in which the heart attacks that follow from the nine risk factors reflect the interplay of environmental and constitutional (genetic) influences remain to be further explored.

Dr. Bruce McManus
Scientific Director, CIHR Institute of Circulatory and Respiratory Health

(adapted from Healthcare Quarterly, Vol. 8, no. 1, 2005 - link is http://www.longwoods.com/hq/HQ81-2005/HQ81index.html)

Source: Salim Yusuf, Steven Hawken, Stephanie Ôunpuu, Tony Dans, Alvaro Avezum, Fernando Lanas, Matthew McQueen, Andrzej Budaj, Prem Pais, John Varigos, Liu Lisheng, "Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study," The Lancet, vol. 364, no. 9438, September 11, 2004.