Coronary Artery Disease: Overview, Risk Factors, Treatments, and Diagnostic Methods

Arterial Thrombosis
- Clots that form in arteries are rich in platelets and form around ruptured plaques.
- Formed under high shear forces (blood pressure).-
Venous Thrombosis
- Generally occurs with lower pressure, often in veins with less shear force.
- Occurs over time, resulting in reduced clot formation compared to arteries.

High shear forces are primarily caused by blood pressure, which is significantly higher in arteries than in veins.

Definition: Development of new blood vessels in response to blockages in the arteries (e.g., due to plaque accumulation).
Who Develops Collateral Circulation:
- Older adults.
- Individuals who are physically fit.
New blood vessels do not form quickly; collateral circulation takes a significant amount of time to develop.

Nonmodifiable Factors:
- Age: Cannot be changed.
- Gender: Not modifiable; higher incidence in middle-aged men and menopausal women.
- Race: Fixed characteristics.
- Genetics: Generally nonmodifiable, but can consider partner selection for potential genetic risks.
Major Modifiable Factors: These can greatly influence CAD risk, and include:
- Hyperlipidemia
- Hypertension
- Tobacco Use
- Noted as a significant factor; chronic smokers often exhibit compromised coronary arteries.
- Physical Inactivity
- Body Mass Index (BMI)
Contributing Modifiable Factors: These factors can increase risk when paired with another modifiable or nonmodifiable risk.
- Diabetes: Hyperglycemia can also increase the risk of CAD.
- Metabolic Syndrome: Group of conditions including:
- Increased glucose levels, high blood pressure, increased waist circumference, low HDL, and high triglycerides.
- Psychological States: Stress and depression significantly correlate with CAD.
- Substance Use: E.g., methamphetamines causing increased heart rate and blood pressure, leading to higher risk.

Cholesterol: A type of fat crucial for hormone production, synthesized in the liver but can also come from dietary intake.
Types of Fats:
- Saturated Fats
- Unsaturated Fats
- Polyunsaturated Fats
Cholesterol Levels and Types:
- LDL and VLDL are considered "bad" cholesterol; high levels are detrimental and promote plaque buildup.
- HDL is known as "good" cholesterol; functions to remove LDL and VLDL from circulation.
Suggested optimal levels:
- Total cholesterol: Less than 200 mg/dL
- LDL: Less than 100 mg/dL is optimal.
- HDL: Higher than 60 mg/dL is preferred.
- Triglycerides: Less than 150 mg/dL is desired.

Patients with existing clinical atherosclerotic cardiovascular disease require medication immediately.
Individuals with an LDL level greater than 190 mg/dL also require treatment.
Diabetic patients aged 40 and older should be treated if they have high LDL levels or other risk factors.
Risk stratification is often calculated to determine medication necessity.

Maintain a healthy weight with weight loss reducing risk.
Diet modifications: reduce sodium intake, low cholesterol and saturated fats, high fruits, veggies, and lean meats.
Limit alcohol consumption.
Collaborate with dietitians for patient education on dietary intervention.

Exercise: Involved in lifestyle modifications for reducing CAD risks.
Substance Use: Establish limits.
Drug Therapy: Medications are necessary for some patients based on risk factors.

Statins:
- Work by blocking HMG CoA reductase to reduce cholesterol synthesis in the liver.
- Side effects include myopathy, which can lead to rhabdomyolysis (muscle breakdown).
Injectable medications: Newer alternatives improve LDL management but come with limitations like cost and ease of use.
Other Drugs:
- Niacin (Vitamin B3) can cause flushing; less effective in reducing cholesterol.
- Bile Acid Sequestrants bind cholesterol, but can cause digestive symptoms.
- Zetia (cholesterol absorption inhibitor) reduces cholesterol absorption during digestion, should not be taken with bile acid sequestrants.
- Fibric Acid Derivatives can contribute to gallstone formation.

Definition: Angina refers to cardiac-related chest pains, indicative of coronary artery issues.
Types of Angina:
- Chronic Stable Angina: Predictable chest pain that occurs during exertion and resolves with rest.
- Silent Angina: Presents without classic symptoms, especially in diabetic patients, may show nonspecific symptoms.
- Prinzmetal's Angina: Caused by coronary artery spasms resulting in temporary chest pain, potentially associated with conditions like migraines.
- Microvascular Angina: Occurs without significant plaque in major arteries, commonly seen in postmenopausal women; may require advanced imaging to identify.

Stress Testing: Evaluates heart function under exertion; includes treadmill tests or pharmacological stress tests with imaging.
Echocardiograms: Assesses heart muscle function; looks for wall motion abnormalities and estimates ejection fraction.
Angiography: Invasive method involving catheterization to visualize coronary arteries using contrast; weighed against patient risks, such as allergies or renal function.

Different tools and scoring systems estimate patient risk for atherosclerosis and guide treatment decisions.

Ongoing education is crucial, with the understanding that guidelines and recommendations evolve as research progresses in the field of cardiovascular health.