From the Guidelines
Epicardial coronary arteries are the major blood vessels that lie on the surface of the heart and supply oxygen-rich blood to the heart muscle, with contemporary management strategies focusing on detecting and assessing epicardial coronary atherosclerosis through coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) 1.
Definition and Importance
Epicardial coronary arteries are defined as the blood vessels that originate from the aorta and travel along the heart's surface, branching into smaller vessels that penetrate into the heart muscle. The three main epicardial coronary arteries are the left anterior descending artery, the left circumflex artery, and the right coronary artery. These vessels are critically important because they are the primary blood supply to the heart tissue, and blockages in these vessels can lead to coronary artery disease, angina, or heart attacks.
Clinical Significance
The epicardial coronary arteries are susceptible to atherosclerotic plaque buildup due to their larger diameter and exposure to hemodynamic stress, making them a key target for diagnostic and therapeutic procedures. According to the 2024 ESC guidelines for the management of chronic coronary syndromes, the diagnostic and prognostic risk prediction models applied in the past to identify obstructive epicardial CAD in patients with suspected angina pectoris have required updating and refinement 1.
Diagnostic and Therapeutic Approaches
The use of coronary computed tomography angiography (CCTA) for detecting and assessing epicardial coronary atherosclerosis is increasingly being adopted, showing similar performance to non-invasive stress testing for detecting segmental myocardial ischaemia 1. Invasive coronary angiography (ICA) has expanded to become a functional test that includes refined haemodynamic assessment of epicardial stenoses, provocative testing for the detection of epicardial or microvascular spasm, and a functional assessment of CMD. Revascularization through percutaneous coronary intervention (PCI) can provide more angina relief than a placebo procedure in patients with stable angina and evidence of ischaemia, on minimal or no antianginal therapy, confirming the beneficial effects of revascularization 1.
From the Research
Definition and Location of Epicardial Coronary Arteries
- Epicardial coronary arteries are located in the epicardial space, which is the anatomic region between the myocardium and the pericardium 2.
- The epicardial space includes the visceral pericardium and the epicardial fat that contains the epicardial coronary arteries, cardiac veins, lymphatic channels, and nerves 2.
Anatomy and Histology
- The major epicardial coronary arteries can be assessed using echocardiographic imaging techniques, which can evaluate changes in the lumen and walls of these arteries 3.
- The anatomy, histology, and pathology of the major epicardial coronary arteries are relevant to echocardiographic imaging techniques 3.
Clinical Significance
- Coronary artery disease is the most common cause of morbidity and mortality, and the epicardial coronary arteries play a crucial role in this disease 4, 5.
- The prevalence of stenosis is more common in left dominance patterns, followed by right dominance patterns, and least in co-dominant patterns 4.
- The disease patterns in coronary artery disease are predominantly in the left dominant or in the co-dominant hearts 4.
Development and Signaling
- The epicardium, the tissue layer covering the cardiac muscle, develops from the proepicardium and gives rise to a population of epicardium-derived cells, which invade the heart and differentiate into various cell types, including cells of coronary blood vessels 6.
- Epicardial cells and epicardium-derived cells signal to the adjacent cardiac muscle in a paracrine fashion, promoting its proliferation and expansion 6.