[Individual and population risk in acute myocardial infarction: the Chilean INTERHEART study]

Acute myocardial infarction (AMI) is the first cause of death in Chile.

To assess the magnitude of risk of individuals and population associated with AMI risk factors.

Case control study with incident cases and 2 controls paired by age and gender. History of diabetes, hypertension, smoking, stress, depression, diet, weight, height, hip and waist circumference, apolipoprotein (Apo) Al and B were determined. Odds ratio (OR) and population attributable risk (PAR) were calculated with 95% confidence interval.

Three hundred thirty two cases and 672 controls were included. Mean age was 61.6+/-12 years and 22% were women. The higher individual risk was associated with smoking: OR 3.1 (2.3-4.2), hypertension: 2.9 (2.1-3.9), permanent stress: 2.2 (1,3-2,8), increased apoB/ApoAl ratio: 2.1 (1.4-3.0) and diabetes: 2.0 (1.4-2.9). A protective effect of daily consumption of vegetables and/or fruits with and OR of 0.54 (0.4-0.8), was observed. The highest PAR was due to smoking: 42% (33.2-51.4), increased ApoB/ApoAl ratio: 35.2 (19.0-55.8) and hypertension: 32% (24.5-40.8). These three factors explained 71.3% of the AMI risk in Chile. A moderate effect on PAR was observed for abdominal obesity: 16.6% (2.4-61.2), permanent stress: 12.0% (2.3-44.1) and diabetes: 10.8% (6.1-18.3).

Known risk factors like dyslipidemia, smoking and hypertension explain most of the AMI cases in Chile. The control of these risk factors should have a major effect on morbidity and mortality due to coronary artery disease in our country.