Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study.
Level 4 - case-series / case-control
Standardized multicenter case-control study
PubMed 15364185 · doi:10.1016/S0140-6736(04)17018-9
What was done
A standardized multicenter case-control study enrolled 15,152 acute myocardial infarction cases and 14,820 controls across 52 countries representing all inhabited continents. Investigators assessed the relationship between acute myocardial infarction and nine risk factors: smoking, history of hypertension, history of diabetes, waist/hip ratio, diet (fruits/vegetables), physical activity, alcohol consumption, blood apolipoproteins (ApoB/ApoA1 ratio), and psychosocial factors. Odds ratios (ORs) with 99% confidence intervals and population attributable risks (PAR) were calculated.
What was found
All nine risk factors were significantly related to acute myocardial infarction (p < 0.0001 for eight factors; p = 0.03 for alcohol): - Raised ApoB/ApoA1 ratio (top vs. lowest quintile): OR 3.25 (PAR 49.2% for top four quintiles vs. lowest quintile) - Current smoking (vs. never): OR 2.87 (PAR 35.7% for current and former vs. never) - Psychosocial factors: OR 2.67 (PAR 32.5%) - History of diabetes: OR 2.37 (PAR 9.9%) - History of hypertension: OR 1.91 (PAR 17.9%) - Abdominal obesity: OR 1.12 for top vs. lowest tertile and 1.62 for middle vs. lowest tertile (PAR 20.1% for top two tertiles vs. lowest tertile) - Daily consumption of fruits and vegetables: OR 0.70 (PAR 13.7% for lack of daily consumption) - Regular physical activity: OR 0.86 (PAR 12.2%) - Regular alcohol consumption: OR 0.91 (PAR 6.7%) Collectively, these nine factors accounted for 90% of the PAR in men and 94% in women, with consistent associations across both sexes, all age groups, and all world regions.
Why it matters
This study demonstrates that the vast majority of myocardial infarction risk worldwide is attributable to a small set of modifiable factors that operate similarly across developed and developing nations. It provides an empirical foundation for global cardiovascular prevention strategies.
Limits
The case-control design is subject to recall bias and selection bias. Enrolling hospital-admitted cases introduces survivor bias by excluding patients who died before reaching clinical care. Lifestyle and psychosocial exposures were based on self-report rather than objective prospective measurement.
Cited by
- supports Cardiovascular disease is 80% to 90% preventable through lifestyle, while cancer and neurodegenerative diseases are 40% to 50% preventable through lifestyle.