Coronary Artery Disease is a condition in which the arteries supplying blood to the heart muscle become narrowed or otherwise impaired, most commonly because of atherosclerotic plaque. It is a major form of Cardiovascular Disease and is also commonly called coronary heart disease or ischaemic heart disease in related clinical contexts, although terminology can vary according to whether the emphasis is on anatomy, underlying atherosclerosis or myocardial ischaemia. Reduced coronary blood flow can cause myocardial ischaemia, particularly when the heart's oxygen demand rises. Plaque rupture and thrombosis can produce acute coronary syndromes, including myocardial infarction, making coronary disease capable of producing both chronic and sudden life-threatening presentations.
Atherosclerosis in Coronary Artery Disease develops through complex interactions involving lipids, endothelial dysfunction, inflammation and vascular remodelling. Low-density lipoprotein cholesterol and other atherogenic lipoproteins contribute to plaque development, while smoking, high Blood Pressure, diabetes and other factors influence progression and plaque instability. Plaques can gradually narrow an artery and restrict blood flow during exertion, producing demand-related ischaemia. A plaque can also rupture or erode, exposing thrombogenic material and causing rapid clot formation. The severity of an angiographic narrowing does not always correspond perfectly to the amount of myocardial ischaemia because blood-flow dynamics, collateral circulation and plaque characteristics also matter.
Stable or chronic Coronary Artery Disease can produce exertional chest discomfort, pressure or tightness that improves with rest or treatment, although symptoms vary substantially. Some people have breathlessness, reduced exercise tolerance or atypical symptoms, while others can have silent ischaemia, particularly in certain populations such as people with diabetes. Acute coronary syndromes can present with persistent or changing chest discomfort, sweating, nausea, breathlessness or other symptoms and require urgent assessment. A normal description of pain does not by itself exclude coronary disease, while chest discomfort has many non-coronary causes. Clinical assessment therefore considers symptom characteristics together with cardiovascular risk and objective testing.
Diagnosis can involve electrocardiography, blood testing for cardiac biomarkers in suspected acute coronary syndromes, echocardiography, functional stress testing and coronary imaging. Coronary CT angiography can visualise coronary anatomy in appropriately selected patients, while invasive coronary angiography provides detailed assessment of the coronary arteries and can permit intervention when indicated. Troponin testing is central to identifying myocardial injury in acute presentations, but an elevated troponin does not automatically mean plaque-mediated coronary disease because other conditions can also cause myocardial injury. Diagnostic interpretation therefore depends on symptoms, serial results, ECG findings and the wider clinical context.
Treatment of Coronary Artery Disease has both preventive and symptom-control components. Lifestyle measures include stopping smoking, maintaining appropriate physical activity, managing body weight and addressing dietary and metabolic risk factors. Medicines can include lipid-lowering treatment, antiplatelet therapy, anti-anginal medicines, blood-pressure treatment and other drugs selected according to the patient's clinical condition. Revascularisation through percutaneous coronary intervention or coronary artery bypass grafting can improve blood flow in selected patients, particularly when symptoms remain significant despite medical treatment or when anatomy and clinical circumstances indicate a prognostic benefit. Revascularisation is not automatically required for every coronary narrowing.
Acute coronary syndromes occur when coronary blood flow is suddenly reduced, commonly through plaque disruption and thrombosis. They include unstable angina and myocardial infarction, with myocardial infarction distinguished by evidence of acute myocardial injury in the appropriate clinical setting. Rapid assessment is important because prolonged ischaemia can cause irreversible myocardial necrosis. Emergency treatment may involve antithrombotic therapy, reperfusion strategies and other interventions according to the specific presentation. The distinction between chronic stable disease and acute coronary syndrome is clinically important because urgency, investigation and treatment pathways differ substantially.
Coronary Artery Disease can lead to myocardial infarction, heart failure, arrhythmias and sudden cardiac death, while chronic myocardial ischaemia can restrict exercise capacity and quality of life. Prognosis depends on the extent of coronary disease, ventricular function, comorbidities, treatment and control of risk factors. Secondary prevention after a myocardial infarction or established coronary disease is particularly important because the underlying atherosclerotic process can continue even after an acute event has been treated. Long-term management therefore commonly involves sustained lipid lowering, blood-pressure control, smoking cessation, appropriate physical activity, medication adherence and management of diabetes and other risk factors.
Coronary Artery Disease should not be confused with every form of chest pain or with all Cardiovascular Disease. It is specifically concerned with the coronary circulation and its consequences. A coronary artery can appear narrowed on imaging without producing clinically significant ischaemia, while microvascular dysfunction or coronary vasospasm can produce anginal symptoms without the classic obstructive plaque pattern. These distinctions have led to broader concepts of chronic coronary syndromes and ischaemic heart disease that recognise multiple mechanisms. Modern management therefore combines anatomical assessment, physiological understanding, prevention and symptom evaluation rather than assuming that every coronary problem is simply a fixed blockage requiring a stent.
