Causes of Coronary Artery Disease
The major causes of coronary artery disease include tobacco smoking, high blood pressure, elevated LDL cholesterol, diabetes mellitus, advancing age, and low HDL cholesterol levels. 1
Major Risk Factors
- Tobacco smoking is a particularly powerful risk factor for atherosclerosis of the coronary arteries, with smoking cessation reducing risk by 50-70% within 1-5 years compared to current smokers 2
- High blood pressure (both systolic and diastolic) increases risk in a graded fashion, with each 1 mmHg reduction in diastolic blood pressure producing a 2-3% decline in coronary heart disease risk 2, 1
- Elevated LDL cholesterol directly contributes to atherosclerosis, with a 1% reduction in serum cholesterol producing a 2-3% decline in coronary heart disease risk 2, 1
- Diabetes mellitus significantly increases coronary artery disease risk and is considered a coronary heart disease risk equivalent 1, 3
- Advancing age independently predicts cardiovascular disease, reflecting the accumulation of atherosclerosis over time 1
- Low HDL cholesterol is considered a major risk factor because it independently predicts the incidence of cardiovascular disease 1, 4
Underlying Risk Factors
- Obesity and overweight contribute to coronary artery disease risk through multiple mechanisms including effects on blood pressure, lipid metabolism, and glucose tolerance 1, 5
- Physical inactivity is a significant modifiable risk factor, with even modest activity (30 minutes at least 5 days per week) documented to reduce cardiovascular event risk 1, 3
- Atherogenic diet high in saturated fats and low in fruits and vegetables increases risk 1, 6
- Family history of premature coronary artery disease reflects genetic predisposition 1, 4
- Genetic factors including chromosome 9p21.3 variants have been associated with premature onset of coronary artery disease 3
- Socioeconomic and psychosocial stress independently contribute to coronary artery disease risk 1
Pathophysiological Mechanisms
- Atherosclerosis is the primary pathological process underlying coronary artery disease, involving:
Emerging Risk Factors
- Left ventricular hypertrophy significantly increases risk of sudden cardiac death, with the Framingham study showing a hazard ratio of 1.45 for each 50 g/m² increment in left ventricular mass 1
- Elevated heart rate has been reported in several studies as a specific predictor of sudden cardiac death 1
- Heavy alcohol consumption has been associated with increased risk in multiple studies 1
- Inflammatory markers such as high-sensitivity C-reactive protein may provide additional prognostic information, though their routine measurement is not currently recommended 1
- Chronic kidney disease is closely associated with coronary artery disease risk 6
Multiple Risk Factor Interaction
- Persons with multiple major risk factors are at significantly higher risk than those with a single risk factor 1
- Risk factors interact synergistically - for example, smoking carries a much higher risk for coronary heart disease in persons with high cholesterol values 2
- The presence of peripheral atherosclerotic disease places a person in a high-risk category for coronary events 1
Preventive Approaches
- Lifestyle modifications including smoking cessation, increased physical activity, and dietary changes are fundamental to reducing coronary artery disease risk 6, 5
- Pharmacological interventions including lipid-lowering drugs, antihypertensives, and antiplatelet therapies are effective for risk reduction in appropriate patients 5
- Population-based approaches targeting the underlying causes of risk factors are essential to reduce the global burden of coronary artery disease 6, 1
Understanding these causes and risk factors is crucial for effective prevention and management of coronary artery disease, which remains the leading cause of death in most developed countries despite significant advances in treatment 7, 5.