Individual and population risk in acute myocardial infarction:: The Chilean INTERHEART study

Background: Acute myocardial infarction (AMI) is the first cause of death in Chile. Aim: To assess the magnitude of risk (of individuals and population associated with AMI risk factors. Material and methods. 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) A1 and B were determined. Odds ratio (OR) and population attributable risk (PAR) were calculated with 95% confidence interval. Results. Three hundred thirty two cases and 672 controls were included. Mean age was 61.6 +/- 12years 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/ApoA1 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/ApoA1 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 abdominal obesity: 166% (2.4-61.2), permanent stress: 12.0% (2.3-44.1) and diabetes: 10.8% (6.1-18.3). Conclusions: Known risk factors like dyslipidemia, smoking and hypertension explain most (of the AMI cases in Chile. Me control of these risk factors should have a major effect on morbidity and mortality due to coronary artery disease in our country (Rev Med Chile 2008; 136: 555-60).