American Board of Internal Medicine (ABIM) Certification Practice Exam

What modifiable risk factor for acute myocardial infarction is ranked highest?

1. Smoking

2. Diabetes Mellitus

3. Obesity

4. Hypertension

The correct answer is: Smoking

Smoking is recognized as the highest-ranked modifiable risk factor for acute myocardial infarction due to its significant impact on cardiovascular health. The harmful chemicals in tobacco smoke contribute to endothelial dysfunction, increased inflammation, and a higher likelihood of thrombosis, all of which can lead to the development of coronary artery disease and, subsequently, myocardial infarction. Smoking not only damages the blood vessels but also promotes the formation of atherosclerosis, which is the buildup of plaques in the arteries. The prevalence of smoking in individuals who experience myocardial infarction is notably high, and numerous studies have established a clear link between smoking and increased risk of heart attacks. Quitting smoking has been shown to substantially decrease these risks, further underlining its critical status as a modifiable risk factor. In comparison, while diabetes mellitus, obesity, and hypertension are also important risk factors, they tend to be influenced by a wider range of lifestyle and genetic components. Smoking cessation has more immediate and profound effects on reducing the risk of acute myocardial infarction than addressing the other factors, making it the most impactful modifiable risk factor in clinical practice.