Coronary Artery Disease: Understanding Atherosclerosis, Risk Factors, and Modern Treatments

What Is Coronary Artery Disease?

Coronary artery disease is a condition where the arteries that supply blood to the heart muscle become narrowed or blocked by fatty deposits called plaque. This process, known as atherosclerosis, doesn’t happen overnight. It develops over years, sometimes decades, quietly damaging the heart before symptoms appear.

These arteries - called coronary arteries - are the lifelines for your heart. When they get clogged, your heart doesn’t get enough oxygen-rich blood. That’s when you start feeling chest pain, shortness of breath, or even have a heart attack. According to the World Health Organization, ischemic heart disease, mostly caused by coronary artery disease, was responsible for 13% of all global deaths between 2000 and 2021. In the U.S. alone, about 18.2 million adults over 20 have this condition, and it kills roughly 360,900 people each year.

How Atherosclerosis Starts and Progresses

Atherosclerosis is the root cause of most coronary artery disease. It begins when low-density lipoprotein (LDL), often called "bad" cholesterol, slips into the wall of an artery. Your body sees it as a threat, so immune cells rush in to clean it up. But instead of fixing the problem, they turn into foam cells, creating a fatty streak. Over time, this streak grows into a plaque - a mix of cholesterol, fat, calcium, and cellular debris.

Not all plaques are the same. There are two main types:

• Stable plaques: These build up slowly and can narrow the artery by more than 50%. They cause predictable chest pain during physical activity - called stable angina - because the heart needs more oxygen but can’t get it.
• Unstable plaques: These are more dangerous. They have a thin outer layer, a large oily core, and lots of inflammatory cells. They might only block 30-40% of the artery, but they’re prone to rupture. When they burst, a blood clot forms on top, suddenly cutting off blood flow. That’s what triggers most heart attacks.

What makes unstable plaques so tricky is that they don’t always cause warning signs. You can feel fine one day and have a heart attack the next. That’s why managing risk factors early is so critical.

Top Risk Factors for Coronary Artery Disease

Some risk factors you can’t change - like age, gender, and family history. But most of the big ones are under your control. The 2023 ACC/AHA guidelines list these as key contributors:

• High LDL cholesterol: When LDL levels stay too high, plaque builds faster. Levels above 160 mg/dL significantly raise your risk.
• High blood pressure: Constant pressure on artery walls damages them, making it easier for plaque to stick.
• Smoking: Tobacco chemicals directly harm the lining of your arteries and make blood more likely to clot. Smokers are two to four times more likely to develop CAD.
• Diabetes: High blood sugar damages blood vessels and speeds up plaque formation. People with diabetes are up to four times more likely to have heart disease.
• Obesity: A BMI over 30 increases inflammation and raises blood pressure, cholesterol, and insulin resistance.
• Physical inactivity: Sitting too much lowers HDL (good cholesterol) and raises triglycerides.
• Chronic kidney disease: When your kidneys don’t work well, fluid and toxins build up, straining your heart and arteries.

Here’s something surprising: 75% of all major heart events happen in people classified as high-risk - those with multiple conditions like diabetes, heart failure, or kidney disease. That’s why doctors now focus on risk stratification. If your yearly risk of a heart attack or death is above 3%, you’re in the high-risk group and need aggressive treatment.

How Is Coronary Artery Disease Diagnosed?

Many people don’t know they have CAD until they have a heart attack. But early detection saves lives. Here’s how doctors find it:

1. Electrocardiogram (ECG): This simple test records your heart’s electrical activity. It can show signs of past heart damage or reduced blood flow.
2. Stress tests: You walk on a treadmill or ride a stationary bike while your heart is monitored. If your heart doesn’t get enough blood during exertion, it shows up on the ECG or imaging.
3. Coronary angiography: This is the gold standard. A thin tube is threaded into your artery, dye is injected, and X-rays show exactly where blockages are. It’s invasive, but it gives the clearest picture.
4. Calcium score CT scan: This non-invasive test measures calcium buildup in your coronary arteries. More calcium = more plaque. A score over 100 suggests moderate disease.
5. Ankle-Brachial Index (ABI): This test compares blood pressure in your ankle and arm. A low ratio can mean you also have peripheral artery disease - a red flag that CAD is likely present.

Doctors also check your blood for cholesterol, glucose, and markers of inflammation. No single test tells the whole story - it’s the combination that matters.

Modern Treatments: Lifestyle, Medications, and Procedures

Treatment isn’t one-size-fits-all. It’s layered - starting with lifestyle changes, then adding meds, and finally procedures if needed.

Lifestyle Changes: The Foundation

No pill works as well as a healthy lifestyle. The 2023 guidelines stress that every patient needs this:

• Heart-healthy diet: Focus on vegetables, fruits, whole grains, nuts, fish, and lean proteins. Cut back on added sugar, salt, and saturated fats. The DASH or Mediterranean diet lowers LDL and blood pressure.
• Regular exercise: Aim for 150 minutes a week of moderate activity - brisk walking, cycling, swimming. Exercise strengthens your heart and improves blood flow.
• Quit smoking: Within one year of quitting, your risk of heart disease drops by half.
• Weight management: Losing just 5-10% of your body weight can improve cholesterol, blood pressure, and insulin sensitivity.

Medications: Managing the Risks

Most patients need meds long-term. Here’s what’s commonly prescribed:

• Statins: These lower LDL cholesterol by up to 50%. They also stabilize plaques and reduce inflammation. Most patients with CAD take a high-intensity statin like atorvastatin or rosuvastatin.
• Antiplatelets: Aspirin or clopidogrel prevent blood clots from forming on plaques. Your doctor decides which one and how long you need it.
• Beta-blockers: These slow your heart rate and lower blood pressure, reducing heart strain.
• ACE inhibitors or ARBs: These help relax blood vessels and are especially important if you’ve had a heart attack or have diabetes.
• PCSK9 inhibitors: For those who still have high LDL despite statins, these injectable drugs can cut LDL by another 50-60%.

Procedures: Opening Blocked Arteries

If lifestyle and meds aren’t enough, procedures become necessary:

• Percutaneous Coronary Intervention (PCI): Also called angioplasty. A balloon is inflated inside the blocked artery, and a metal mesh stent is placed to keep it open. It’s done through a wrist or groin artery and usually requires a one-day hospital stay.
• Coronary Artery Bypass Grafting (CABG): This open-heart surgery uses a vein or artery from another part of your body to bypass the blocked section. It’s recommended when multiple arteries are blocked, especially in diabetics or those with poor heart function.

PCI is common and fast. CABG lasts longer and is better for complex cases. The choice depends on how many arteries are blocked, your age, and other health conditions.

The Rise of Cardio-Oncology and Personalized Care

As people live longer after cancer, more are dealing with both heart disease and cancer. That’s where cardio-oncology comes in. Some cancer drugs can damage the heart. Others raise blood pressure or cholesterol. Doctors now work together - cardiologists and oncologists - to treat both conditions safely.

Also, treatment is becoming more personalized. The 2023 guidelines emphasize that risk assessment isn’t just about numbers - it’s about your life. Are you active? Do you have support? Can you afford your meds? Your treatment plan should fit your reality, not just your lab results.

What Happens After Diagnosis?

Coronary artery disease is a lifelong condition. But it’s not a death sentence. Many people live full, active lives after diagnosis - if they stick to their plan.

After a heart attack or stent placement, you’ll need:

• Regular follow-ups with your cardiologist
• Annual blood tests to check cholesterol and kidney function
• Continued use of antiplatelets (often for at least a year after stenting)
• Cardiac rehab - a supervised program with exercise, nutrition counseling, and stress management

Medication doses can change. A statin might be switched if you have side effects. Blood pressure targets may be adjusted as you age. The goal isn’t just to survive - it’s to thrive.

Looking Ahead: What’s New in CAD Treatment?

Research is moving fast. Scientists are testing new drugs that target inflammation directly - not just cholesterol. One drug, canakinumab, showed a 15% reduction in heart attacks in trials, even when LDL was already low.

Imaging is getting smarter. New CT scans can now show not just how much plaque is there, but whether it’s inflamed or likely to rupture. That helps doctors decide who needs a stent and who just needs better meds.

And the focus is shifting from treating blockages to preventing them entirely. That means earlier screening, better risk prediction tools, and more emphasis on prevention in young adults - even those who feel fine.