CAD stands for coronary artery disease, the most common type of heart disease and the leading cause of cardiovascular death worldwide. It develops when the arteries supplying blood to your heart become narrowed or blocked by a buildup of fatty deposits called plaque, reducing the oxygen your heart muscle receives. Ischemic heart disease is projected to cause 20 million deaths annually by 2050, making it a condition worth understanding in detail.
How Plaque Builds Up in Your Arteries
CAD begins quietly, often decades before symptoms appear. Cholesterol particles in your blood seep into the walls of your coronary arteries, where they become trapped and chemically altered. Your immune system treats this trapped cholesterol as a threat, sending white blood cells to absorb it. These cholesterol-stuffed immune cells, called foam cells, accumulate into fatty streaks along the artery wall.
Over time, smooth muscle cells migrate into the area and build a fibrous cap over the fatty deposit, forming a stable plaque. This plaque gradually narrows the artery, restricting blood flow to your heart. In some cases, the fibrous cap weakens and ruptures. When that happens, the body forms a blood clot at the rupture site, which can partially or completely block the artery. A complete blockage triggers a heart attack.
What CAD Feels Like
The hallmark symptom is chest pain or pressure, known as angina. Stable angina is predictable: it shows up during physical activity or stress, lasts about five minutes or less, and eases with rest. You might feel it as tightness, squeezing, or heaviness in the center of your chest.
Unstable angina is more dangerous. It strikes unpredictably, can occur at rest, lasts 20 minutes or longer, and doesn’t respond to rest or medication. This is a medical emergency that signals a plaque rupture or clot formation in progress.
Women often experience CAD differently. Instead of classic chest pressure, symptoms may include jaw or neck discomfort, nausea, shortness of breath, stabbing pain rather than pressure, or stomach pain. These atypical symptoms frequently lead to delays in diagnosis and treatment.
Risk Factors You Can and Can’t Control
Some risk factors are fixed. Having a father or brother diagnosed with CAD before age 55, or a mother or sister diagnosed before 65, increases your risk. Age, sex, and ethnicity also play a role.
The modifiable risk factors carry enormous weight, though. High blood pressure tops the list. It damages artery walls through both mechanical and oxidative stress, and roughly one in three adults has it. High cholesterol is the second most common risk factor for CAD, responsible for an estimated 2.6 million deaths globally.
Smoking accounts for roughly one-fifth to one-third of cardiovascular disease deaths. Even nonsmokers regularly exposed to secondhand smoke face a 25% to 30% higher risk of coronary heart disease. Diet matters in specific, measurable ways: every 2% of daily calories from trans fat is linked to a 23% higher CAD risk, sugary drinks are associated with a 22% higher risk of heart attack, and processed meat consumption raises coronary heart disease risk by 23% to 42%. Physical inactivity alone accounts for about 12% of the population-level risk of heart attack, based on a study spanning 52 countries.
How CAD Is Diagnosed
If your doctor suspects CAD, testing typically starts with non-invasive methods. A treadmill stress test (stress electrocardiography) monitors your heart’s electrical activity during exercise. It’s low-cost and widely available, though it’s less accurate in women, with a positive predictive value of just 47% compared to 77% in men.
For a more detailed picture, stress testing can be combined with imaging. Stress echocardiography uses ultrasound to watch your heart pump under exertion, while nuclear imaging tracks blood flow through the heart muscle. Coronary CT angiography (CCTA) has gained favor in recent years for its ability to detect plaque across the full spectrum, from early, non-obstructive deposits to severe blockages. Current guidelines give CCTA a top-tier recommendation as an initial test for people with chest pain and suspected CAD.
When non-invasive tests suggest significant disease, cardiac catheterization (coronary angiography) provides the definitive answer. A thin tube is threaded into the heart’s arteries, and dye is injected to reveal the exact location and severity of blockages.
Medications for Long-Term Management
Most people with CAD take a combination of medications. Antiplatelet drugs prevent blood cells from clumping into clots at the site of plaque. Statins lower cholesterol and protect artery walls from further damage. The most recent guidelines recommend intensifying cholesterol-lowering treatment for high-risk patients whose LDL cholesterol remains above a certain threshold despite maximum statin doses.
Beta blockers slow the heart rate and lower blood pressure, reducing the workload on your heart. Calcium channel blockers widen blood vessels and, in some cases, also slow heart rate. For acute chest pain episodes, nitrates quickly widen coronary arteries to restore blood flow.
Stents vs. Bypass Surgery
When medications alone aren’t enough, two procedures can restore blood flow. In angioplasty with stenting, a small balloon is threaded into the blocked artery and inflated to compress the plaque. A wire mesh tube (stent) is left behind to keep the artery open. The procedure is less invasive and recovery is faster.
Coronary artery bypass grafting (CABG) is open-heart surgery. A blood vessel taken from your chest, leg, or arm is grafted onto the heart to reroute blood around the blockage. Recovery takes longer, but outcomes are better in certain situations.
The choice depends on which arteries are affected and how many. When three or more coronary arteries are blocked, bypass surgery is generally superior to stenting. Blockages involving the left anterior descending artery, the heart’s main supply line, also favor bypass. For people with diabetes or heart failure who have multiple blocked arteries, bypass surgery offers better survival rates. When the left anterior descending artery isn’t involved and blockages are limited, stenting is typically the first choice.
What Happens if CAD Goes Untreated
Poorly managed CAD leads to serious complications. The most immediate threat is a heart attack, which occurs when a plaque ruptures and a clot cuts off blood supply to part of the heart muscle. Damaged heart muscle doesn’t regenerate, and the scarring that follows can weaken the heart’s pumping ability over time, leading to heart failure.
Irregular heart rhythms (arrhythmias) are another common complication, ranging from atrial fibrillation to life-threatening ventricular arrhythmias. After a heart attack, about 29% of patients develop some degree of valve leakage, where the heart’s mitral valve no longer closes properly. In rare but severe cases, the heart muscle itself can rupture or develop an aneurysm, a weak, bulging area that forms in roughly 31% of patients with heart attacks affecting the front wall of the heart.
Preventing CAD Progression
The American Heart Association recommends at least 150 minutes per week of moderate to vigorous physical activity, along with regular muscle-strengthening exercises. On the dietary side, several eating patterns support heart health: the DASH diet, Mediterranean-style eating, pescetarian diets, and vegetarian approaches all qualify, as long as they share core features.
Those features include eating plenty of vegetables and fruits, choosing whole grains over refined ones, selecting healthy protein sources, favoring unsaturated fats over saturated fats, minimizing added sugars and processed foods, and reducing sodium. Adjusting calorie intake to maintain a healthy weight ties everything together. For people already diagnosed with CAD, these same lifestyle changes work alongside medications and procedures to slow or even partially reverse plaque buildup.