Coronary artery disease (CAD) is one of the leading causes of morbidity and mortality worldwide. Understanding its pathophysiology is crucial for effective prevention and treatment strategies. At its core, CAD involves the narrowing or blockage of the coronary arteries, primarily due to atherosclerosis, which is the build-up of plaque within the arterial walls.

Atherosclerosis begins with endothelial injury, often triggered by risk factors such as high blood pressure, high cholesterol, smoking, and diabetes. This injury leads to the dysfunction of the endothelial cells, making them more permeable and allowing low-density lipoproteins (LDL) to penetrate the arterial walls. Over time, LDL cholesterol accumulates, causing inflammation and attracting immune cells, particularly monocytes, which transform into macrophages.

As macrophages digest the oxidized LDL, they become foam cells, contributing to the formation of fatty streaks within the arteries. These foam cells release various substances that promote inflammation and further damage the endothelium. As the process continues, smooth muscle cells migrate to the affected area, leading to the formation of a fibrous cap over the growing plaque. This cap may become unstable and can rupture, creating a blood clot that can block the artery, resulting in acute coronary events such as heart attacks.

Another key aspect of CAD pathophysiology is the impact of ischemia, which occurs when the blood supply to the heart muscle is insufficient to meet its oxygen demands. Ischemia can lead to angina, a condition characterized by chest pain or discomfort. Prolonged ischemia may cause irreversible damage to heart tissue, further complicating the patient's health status.

The progression of CAD can be influenced by multiple factors, including genetic predisposition, lifestyle choices, and metabolic conditions. Risk stratification and patient assessment are essential in identifying individuals at higher risk for developing CAD. Preventive measures, such as lifestyle modification and pharmacotherapy, are critical in managing and reducing the overall burden of this disease.

In summary, understanding the pathophysiology of coronary artery disease involves recognizing the complex interplay of factors contributing to endothelial injury, atherosclerosis, plaque formation, and ischemic heart disease. Continued research and better clinical strategies are essential in combating this prevalent health issue.