A coronary occlusion, or coronary artery disease, is the partial or complete obstruction of blood flow in a coronary artery. This condition was first discussed in 1910 by Sir William Osler.[1] This condition slows or blocks the supply of oxygen-rich blood to the heart.[2] This condition can lead to myocardial ischemia[2] and if untreated, may cause a heart attack and heart failure.[3] It is the most common form of cardiovascular disease, and is the leading cause of death in the United States, affecting 18 million adults.[4]
A coronary occlusion can be caused by smoking, having other heart or blood conditions, or being physically inactive. It is also hereditary.[4] Symptoms include chest pain, shortness of breath, pain in upper body, fatigue, nausea, an irregular heartbeat, and drowsiness.[5]
To diagnose a coronary occlusion, a doctor may view a patient's medical history, or perform a coronary angiography; a doctor will stick a catheter into the wrist or groin, lead it to the heart, and inject a liquid for X-ray imaging.[4]
A completely blocked coronary artery will cause a heart attack.[6] Common heart attack symptoms include chest pain or angina, pain or discomfort that spreads to the shoulder, arm, back, neck jaw, teeth or the upper belly, cold sweats, fatigue, heartburn, nausea, shortness of breath, or lightheadedness.[6]
Causes
Image depicting atherosclerosis.
Coronary occlusion is caused by the buildup of fats, cholesterol and other substances in and on the walls of the hearts arteries.[6] As plaque builds up, the arteries narrow.[7] Plaque often starts building up during childhood and is heavily influence by genetics, but also lifestyle and high blood cholesterol.[7] This condition is referred to as atherosclerosis.[6] The buildup on the walls of the hearts arteries is referred to as plaque. Plaque causes arteries to narrow and block blood flow.[6]
Risk Factors that are not controllable are age, birth sex, and family history.[6] Getting older increases the risk of damaged and narrowed arteries.[6] Men are at a greater risk of coronary artery disease, with women's risk increasing after menopause.[6]
Pathophysiology
Coronary occlusion is caused by plaque inside of the blood vessels that direct oxygen rich blood to the heart.[8] Plaque is caused by fatty deposits and scar tissue that cling to the walls of coronary arteries.[9] The development of plaque takes years and leads to stenosis of the coronary arteries and progressively reduces blood flow.[8] Due to the slower development of this condition, the body will adapt and create small blood vessels that circumvent the blockage.[8] The small blood vessels form a natural bypass of the blockage, but often do not supply enough blood to meet an increased demand when stressors are applied like exercise.[8]
When a plaque has a greater than 50% diameter stenosis, the reduced blood flow through the coronary artery during exertion may lead to angina.[10] Acute coronary events occur when a thrombus forms due to disruption of a plaque.[10] In acute heart attack, occlusion is greater than in unstable angina, where arterial occlusion is not full blockage. Downstream embolism of thrombus may also produce microinfarcts.[10]
Diagnosis
Heart disease is often undiagnosed until a serious problem occurs, such as heart attack or cardiac arrest.[11] Regular checkups can lead to an early diagnosis and preventative treatment.[11] Screening tests and risk assessments should begin around age 20 if one does not have any risk factors.[11] Screenings should begin in childhood if one has risk factors such as obesity, sedentary lifestyle, or a family history of heart conditions.[11]
Preventative procedures like bariatric surgery can help lower coronary heart disease risk.[12]
Prognosis
Coronary artery disease cannot be reversed. [3] To reduce future problems, a patient may be referred to get exercise-based cardiac rehabilitation.[13]
Patients with coronary artery disease over 15-year period based off expectations in a 1-year follow up saw a mortality rate of those in the highest quartiles of expectations are 28-30 deaths per 100 patients.[14] The lowest quartile of expectations are 50-57 deaths per 100 patients.[14]
Prognosis for heart attacks when people reach emergency care promptly improve dramatically, though many people still die before reaching the hospital.[15] One out of every 10 patients who have a heart attack die within the first three to four months.[9]
Epidemiology
Coronary artery disease is the leading cause of death in men and women.[16] This condition is the cause of one third of all deaths, which is especially worse in areas with lower socioeconomic status.[16] Mortality is nearly five times higher in men than women, but mortality difference narrows with age.[16]
Black women are more likely than white women to have a heart attack. Black adults have a higher mortality rate than white adults from heart attack. [17]
Asian adults have the least incidence of coronary artery disease. Asian Indian men, Filipino men and Filipino women have a higher risk than white people.[17]
Young Hispanic women who have a heart attack have a higher mortality rate than young Hispanic men. They have a higher mortality rate than young Black adults and young white adults.[17]
Research directions
Image of a computed tomography scanner.
Recent studies focus on advanced imagining techniques, pharmacological advancements, and regenerative therapies. A new heart disease diagnosis approach has led to a 99.1% accuracy in diagnosing heart disease.[18] This new diagnosis approach uses CT-scan imagery to focus on coronary artery diseases and blockages in contrast to angiography.[18]
Further research directions in preventing and treating coronary artery disease include:[19]
Cardiology is the study of the heart. Cardiology is a branch of medicine that deals with disorders of the heart and the cardiovascular system. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease, and electrophysiology. Physicians who specialize in this field of medicine are called cardiologists, a sub-specialty of internal medicine. Pediatric cardiologists are pediatricians who specialize in cardiology. Physicians who specialize in cardiac surgery are called cardiothoracic surgeons or cardiac surgeons, a specialty of general surgery.
Coronary artery disease (CAD), also called coronary heart disease (CHD), or ischemic heart disease (IHD), is a type of heart disease involving the reduction of blood flow to the cardiac muscle due to a build-up of atheromatous plaque in the arteries of the heart. It is the most common of the cardiovascular diseases. CAD can cause stable angina, unstable angina, myocardial ischemia, and myocardial infarction.
Angina, also known as angina pectoris, is chest pain or pressure, usually caused by insufficient blood flow to the heart muscle (myocardium). It is most commonly a symptom of coronary artery disease.
Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. This is a chronic inflammatory disease involving many different cell types and driven by elevated levels of cholesterol in the blood. These lesions may lead to narrowing of the arterial walls due to buildup of atheromatous plaques. At the onset there are usually no symptoms, but if they develop, symptoms generally begin around middle age. In severe cases, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney disorders, depending on which body part(s) the affected arteries are located in the body.
Arteriosclerosis, literally meaning "hardening of the arteries", is an umbrella term for a vascular disorder characterized by abnormal thickening, hardening, and loss of elasticity of the walls of arteries; this process gradually restricts the blood flow to one's organs and tissues and can lead to severe health risks brought on by atherosclerosis, which is a specific form of arteriosclerosis caused by the buildup of fatty plaques, cholesterol, and some other substances in and on the artery walls.
Peripheral artery disease (PAD) is a vascular disorder that causes abnormal narrowing of arteries other than those that supply the heart or brain. PAD can happen in any blood vessel, but it is more common in the legs than the arms.
Microvascular angina (MVA), previously known as cardiac syndrome X, also known as coronary microvascular dysfunction(CMD) or microvascular coronary disease is a type of angina (chest pain) with signs associated with decreased blood flow to heart tissue but with normal coronary arteries.
Coronary thrombosis is defined as the formation of a blood clot inside a blood vessel of the heart. This blood clot may then restrict blood flow within the heart, leading to heart tissue damage, or a myocardial infarction, also known as a heart attack.
A vulnerable plaque is a kind of atheromatous plaque – a collection of white blood cells and lipids in the wall of an artery – that is particularly unstable and prone to produce sudden major problems such as a heart attack or stroke.
Acute coronary syndrome (ACS) is a syndrome due to decreased blood flow in the coronary arteries such that part of the heart muscle is unable to function properly or dies. The most common symptom is centrally located pressure-like chest pain, often radiating to the left shoulder or angle of the jaw, and associated with nausea and sweating. Many people with acute coronary syndromes present with symptoms other than chest pain, particularly women, older people, and people with diabetes mellitus.
Carotid artery stenosis is a narrowing or constriction of any part of the carotid arteries, usually caused by atherosclerosis.
Variant angina, also known as Prinzmetal angina,vasospastic angina, angina inversa, coronary vessel spasm, or coronary artery vasospasm, is a syndrome typically consisting of angina. Variant angina differs from stable angina in that it commonly occurs in individuals who are at rest or even asleep, whereas stable angina is generally triggered by exertion or intense exercise. Variant angina is caused by vasospasm, a narrowing of the coronary arteries due to contraction of the heart's smooth muscle tissue in the vessel walls. In comparison, stable angina is caused by the permanent occlusion of these vessels by atherosclerosis, which is the buildup of fatty plaque and hardening of the arteries.
A vascular bypass is a surgical procedure performed to redirect blood flow from one area to another by reconnecting blood vessels. Often, this is done to bypass around a diseased artery, from an area of normal blood flow to another relatively normal area. It is commonly performed due to inadequate blood flow (ischemia) caused by atherosclerosis, as a part of organ transplantation, or for vascular access in hemodialysis. In general, someone's own vein (autograft) is the preferred graft material for a vascular bypass, but other types of grafts such as polytetrafluoroethylene (Teflon), polyethylene terephthalate (Dacron), or a different person's vein (allograft) are also commonly used. Arteries can also serve as vascular grafts. A surgeon sews the graft to the source and target vessels by hand using surgical suture, creating a surgical anastomosis.
Vascular disease is a class of diseases of the vessels of the circulatory system in the body, including blood vessels – the arteries and veins, and the lymphatic vessels. Vascular disease is a subgroup of cardiovascular disease. Disorders in this vast network of blood and lymph vessels can cause a range of health problems that can sometimes become severe, and fatal. Coronary heart disease for example, is the leading cause of death for men and women in the United States.
A coronary stent is a tube-shaped device placed in the coronary arteries that supply blood to the heart, to keep the arteries open in patients suffering from coronary heart disease. The vast majority of stents used in modern interventional cardiology are drug-eluting stents (DES). They are used in a medical procedure called percutaneous coronary intervention (PCI). Coronary stents are divided into two broad types: drug-eluting and bare metal stents. As of 2023, drug-eluting stents were used in more than 90% of all PCI procedures. Stents reduce angina and have been shown to improve survival and decrease adverse events after a patient has suffered a heart attack—medically termed an acute myocardial infarction.
Coronary ischemia, myocardial ischemia, or cardiac ischemia, is a medical term for abnormally reduced blood flow in the coronary circulation through the coronary arteries. Coronary ischemia is linked to heart disease, and heart attacks. Coronary arteries deliver oxygen-rich blood to the heart muscle. Reduced blood flow to the heart associated with coronary ischemia can result in inadequate oxygen supply to the heart muscle. When oxygen supply to the heart is unable to keep up with oxygen demand from the muscle, the result is the characteristic symptoms of coronary ischemia, the most common of which is chest pain. Chest pain due to coronary ischemia commonly radiates to the arm or neck. Certain individuals such as women, diabetics, and the elderly may present with more varied symptoms. If blood flow through the coronary arteries is stopped completely, cardiac muscle cells may die, known as a myocardial infarction, or heart attack.
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction to the heart muscle. The most common symptom is retrosternal chest pain or discomfort that classically radiates to the left shoulder, arm, or jaw. The pain may occasionally feel like heartburn. This is the dangerous type of Acute coronary syndrome.
Spontaneous coronary artery dissection (SCAD) is an uncommon but potentially lethal condition in which one of the coronary arteries that supply the heart, spontaneously develops a blood collection, or hematoma, within the artery wall due to a tear in the wall. SCAD is one of the arterial dissections that can occur.
Arterial embolism is a sudden interruption of blood flow to an organ or body part due to an embolus adhering to the wall of an artery blocking the flow of blood, the major type of embolus being a blood clot (thromboembolism). Sometimes, pulmonary embolism is classified as arterial embolism as well, in the sense that the clot follows the pulmonary artery carrying deoxygenated blood away from the heart. However, pulmonary embolism is generally classified as a form of venous embolism, because the embolus forms in veins. Arterial embolism is the major cause of infarction.
Arterial occlusion is a condition involving partial or complete blockage of blood flow through an artery. Arteries are blood vessels that carry oxygenated blood to body tissues. An occlusion of arteries disrupts oxygen and blood supply to tissues, leading to ischemia. Depending on the extent of ischemia, symptoms of arterial occlusion range from simple soreness and pain that can be relieved with rest, to a lack of sensation or paralysis that could require amputation.
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