Coronary Artery Disease
Coronary artery disease (CAD) is a condition in which the arteries that supply blood to the heart muscle—the coronary arteries—become narrowed or blocked, most often due to atherosclerosis (buildup of cholesterol-rich plaque). CAD is one of the leading causes of death worldwide and can range from silent disease found on imaging to angina, heart attack, heart failure, and sudden cardiac events. Modern evaluation uses a combination of risk assessment, blood work, ECG, stress testing, and imaging—including coronary CT angiography, calcium scoring, and cardiac catheterization.
What is it?
The heart muscle (myocardium) needs a constant supply of oxygen and nutrients, delivered by a network of arteries called the coronary arteries that run on the surface of the heart and dive into the muscle itself. Coronary artery disease is a chronic condition in which these arteries become narrowed or blocked, most often by the gradual buildup of fatty deposits called plaque—a process known as atherosclerosis. As the arteries narrow, the heart muscle may not receive enough blood, particularly during physical activity, stress, or other times of increased demand.
CAD develops gradually over many years. Cholesterol-rich plaque accumulates in the artery wall, sometimes calcifies, and progressively narrows the channel through which blood flows. In stable CAD, plaque grows slowly and may cause symptoms during exertion (angina) that improve with rest. Acute coronary syndromes—including heart attack (myocardial infarction)—often occur when a plaque ruptures or erodes, triggering blood clot formation that can suddenly block a coronary artery, even one that was only modestly narrowed before. CAD can also cause heart failure (when chronic reduced blood flow weakens the heart muscle), arrhythmias, and sudden cardiac death.
Major risk factors for CAD include high blood pressure, high cholesterol (particularly elevated LDL cholesterol), diabetes, smoking, obesity, physical inactivity, unhealthy diet, family history of early heart disease, increasing age, and male sex (although women’s risk catches up and surpasses men’s after menopause). Other contributors include chronic kidney disease, certain inflammatory and autoimmune conditions, sleep apnea, chronic stress, and certain genetic factors. Recognizing and addressing modifiable risk factors is a central part of prevention.
Symptoms vary widely. Many people with early or moderate CAD have no symptoms at all and the condition is detected only through screening tests, imaging, or as a result of a cardiac event. Classic angina is a pressure, tightness, or squeezing sensation in the chest that occurs with exertion or stress and improves with rest. Symptoms may also radiate to the neck, jaw, arm, or back; some patients experience shortness of breath, fatigue, nausea, sweating, or lightheadedness rather than chest pain. Women, older adults, and patients with diabetes more often present with atypical symptoms or “silent” ischemia. A heart attack typically presents with more severe and sustained chest pain, shortness of breath, and other acute symptoms and requires emergency evaluation.
Evaluation of CAD uses a combination of clinical assessment and testing. Blood work assesses cholesterol levels, blood sugar, kidney function, and other relevant factors. ECG provides important information about heart rhythm and electrical signs of prior or ongoing ischemia. Stress testing—using exercise or pharmacologic stress combined with ECG, echocardiography, or nuclear imaging—evaluates how the heart performs under increased demand. Coronary artery calcium (CAC) scoring uses a low-dose CT to measure calcified plaque and is widely used to refine risk assessment, particularly in patients without symptoms. Coronary CT angiography (CCTA) uses contrast-enhanced CT to directly visualize the coronary arteries, identify plaque (both calcified and noncalcified), and assess the degree of narrowing; it is increasingly used as a first-line test in symptomatic patients with intermediate risk. Cardiac MRI may be used in selected cases to evaluate heart structure, function, and tissue characteristics. Cardiac catheterization with invasive coronary angiography remains the standard for definitive evaluation and is used when intervention is anticipated.
Important to Know
Management of coronary artery disease combines lifestyle changes, medications, and, in selected patients, procedures—tailored to the severity of disease, symptoms, and overall health. Even modest improvements in lifestyle and risk factor control can have substantial benefits.
Lifestyle measures are foundational: not smoking, regular physical activity (typically including aerobic and resistance exercise), a heart-healthy diet (rich in vegetables, fruits, whole grains, healthy fats, and lean proteins; lower in saturated and trans fats, processed foods, added sugars, and excessive salt), weight management, limited alcohol, stress reduction, good sleep, and treatment of sleep apnea when present.
Medications play a central role in many patients. Statins and other lipid-lowering therapies reduce LDL cholesterol and the risk of cardiovascular events. Blood pressure medications, diabetes treatments (including newer agents such as SGLT2 inhibitors and GLP-1 receptor agonists, which provide cardiovascular benefit), antiplatelet agents (such as aspirin in selected patients), and anti-anginal medications (such as beta-blockers, calcium channel blockers, or nitrates) are tailored to individual needs and risk.
For patients with significant narrowing, ongoing symptoms despite optimal medical therapy, or acute coronary syndromes, procedures may be considered. Percutaneous coronary intervention (PCI) uses catheter-based techniques to open narrowed arteries with balloons and stents. Coronary artery bypass grafting (CABG) creates new pathways around blocked arteries using veins or arteries from elsewhere in the body. The choice between PCI, CABG, and medical therapy is individualized and based on the pattern and severity of disease, overall heart function, other medical conditions, and patient preferences.
Cardiac rehabilitation—a structured program of supervised exercise, education, and risk factor management—is an important and underutilized part of care after acute coronary syndromes, PCI, CABG, and in selected patients with stable CAD or heart failure. Care is typically coordinated by primary care clinicians and cardiologists, with input from cardiac surgeons, interventional cardiologists, electrophysiologists, dietitians, and others.
Red flag symptoms include sudden severe chest pain or pressure (especially radiating to the jaw, arm, or back), severe shortness of breath, fainting, palpitations with lightheadedness, signs of stroke, profuse sweating, or signs of shock. These warrant immediate emergency evaluation, as they may indicate a heart attack or another life-threatening cardiovascular condition.