Coronary Artery Disease and Myocardial Ischemia
Coronary artery disease (CAD) is the narrowing or obstruction of the epicardial coronary arteries, most often by atherosclerosis, which limits blood supply to the myocardium and produces myocardial ischemia. As a reference area it groups the disease's underlying biology, its acute and chronic clinical presentations, and the ischemic injury to heart muscle that follows when coronary blood flow falls short of demand.
Definition
Coronary artery disease is a chronic, usually atherosclerotic, disease of the coronary arteries in which luminal narrowing or plaque rupture reduces myocardial perfusion, causing myocardial ischemia and, when severe or prolonged, myocardial infarction.
Scope
This area orients the reader across the spectrum from the pathogenesis of coronary atherosclerosis through stable ischemia to the acute coronary syndromes and myocardial infarction, and to the cellular injury that occurs during ischemia and on reperfusion. It is positioned within cardiothoracic and vascular surgery as the conceptual background to surgical coronary revascularization, but the entry itself is educational and describes the disease rather than prescribing management.
Sub-topics
Core questions
- How does atherosclerosis in the coronary arteries develop and progress to flow-limiting or unstable lesions?
- What distinguishes stable myocardial ischemia from the acute coronary syndromes?
- How does an imbalance between myocardial oxygen supply and demand translate into ischemic injury and infarction?
- Why can restoring coronary blood flow itself contribute to myocardial injury?
Key concepts
- Atherosclerotic plaque
- Myocardial oxygen supply-demand mismatch
- Stable versus unstable coronary syndromes
- Plaque rupture and coronary thrombosis
- Myocardial ischemia and infarction
- Ischemia-reperfusion injury
- Coronary revascularization
Mechanisms
Lipid retention and chronic inflammation in the arterial wall build atherosclerotic plaques that narrow the coronary lumen and limit the increase in flow needed during exertion, producing demand ischemia (Libby, 2019; Hansson, 2005). When a vulnerable plaque ruptures or erodes, thrombus forms acutely on its surface and can abruptly occlude the artery, causing an acute coronary syndrome and, if flow is not restored, infarction of the supplied myocardium. The severity and duration of the supply-demand mismatch determine whether ischemia is reversible or progresses to cell death, and reperfusion of previously ischemic tissue can add its own injury.
Clinical relevance
Coronary artery disease is the leading single cause of death worldwide, and understanding its pathogenesis, acute presentations, and ischemic consequences underpins both medical and surgical cardiology (Wang, 2016; Byrne, 2023). This area describes how the disease arises and behaves to support appraisal of the evidence base; it is not a protocol for diagnosis or treatment of any individual.
Epidemiology
Ischemic heart disease is consistently ranked among the top causes of global mortality and disability, with burden concentrated in older adults and influenced by smoking, dyslipidemia, hypertension, diabetes, and other cardiovascular risk factors (Wang, 2016).
Evidence & guidelines
Contemporary professional-society guidelines, such as the 2023 European Society of Cardiology guidelines on acute coronary syndromes, synthesize the evidence on definition, risk stratification, and management of CAD presentations and are the standard reference for current practice (Byrne, 2023).
History
The recognition of coronary atherosclerosis as the basis of angina and infarction developed across the twentieth century, and the modern inflammatory understanding of the disease was consolidated in reviews such as Hansson (2005) and Libby (2019), reframing CAD as an immune-inflammatory as well as a lipid-driven disorder.
Key figures
- Peter Libby
- Göran K. Hansson
Related topics
Seminal works
- hansson-2005
- libby-2019
Frequently asked questions
- Is coronary artery disease the same as myocardial ischemia?
- They are closely related but not identical. Coronary artery disease is the disease of the arteries, usually atherosclerotic; myocardial ischemia is the resulting state in which heart muscle receives insufficient blood. CAD is the most common cause of myocardial ischemia.
- Why is this area placed under cardiothoracic and vascular surgery?
- Because surgical coronary revascularization is one of the major treatments for advanced coronary artery disease, the disease's biology and presentations are foundational background for that surgical field. The entry itself describes the disease and does not give surgical or medical advice.