Coronary thrombosis is defined as the formation of a

blood clot A thrombus ( thrombi) is a solid or semisolid aggregate from constituents of the blood (platelets, fibrin, red blood cells, white blood cells) within the circulatory system during life. A blood clot is the final product of the blood coagulatio ...

inside a

blood vessel Blood vessels are the tubular structures of a circulatory system that transport blood throughout many Animal, animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the Tissue (biology), tissues of a Body (bi ...

of the

heart The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...

. This blood clot may then restrict blood flow within the heart, leading to heart tissue damage, or a

myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when Ischemia, blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom ...

, also known as a heart attack. Coronary thrombosis is most commonly caused as a downstream effect of

atherosclerosis 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 is driven by eleva ...

, a buildup of

cholesterol Cholesterol is the principal sterol of all higher animals, distributed in body Tissue (biology), tissues, especially the brain and spinal cord, and in Animal fat, animal fats and oils. Cholesterol is biosynthesis, biosynthesized by all anima ...

and fats in the artery walls. The smaller vessel diameter allows less blood to flow and facilitates progression to a

. Leading risk factors for coronary thrombosis are high low-density lipoprotein cholesterol, smoking,

sedentary lifestyle Sedentary lifestyle is a Lifestyle (social sciences), lifestyle type, in which one is physically inactive and does little or no physical movement and/or exercise. A person living a sedentary lifestyle is often sitting or lying down while enga ...

, and

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

. Symptoms of coronary thrombosis are not always evident at the start. Symptoms include chest pain, shortness of breath, and discomfort in the upper body. A coronary thrombosis is a medical emergency (life threatening) and requires

emergency care Emergency medicine is the medical specialty concerned with the care of illnesses or injuries requiring immediate medical attention. Emergency physicians (or "ER doctors") specialize in providing care for unscheduled and undifferentiated pa ...

at a hospital.

Signs and symptoms

A coronary thrombus is

asymptomatic Asymptomatic (or clinically silent) is an adjective categorising the medical conditions (i.e., injuries or diseases) that patients carry but without experiencing their symptoms, despite an explicit diagnosis (e.g., a positive medical test). P ...

until it causes significant obstruction, leading to various forms of

angina 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. Angina is typically the result of parti ...

or eventually a

. Common warning symptoms are crushing chest pain, shortness of breath, and upper body discomfort.

Pathogenesis

Coronary thrombosis and

are sometimes used as synonyms, although this is technically inaccurate as the thrombosis refers to the blocking of blood vessels with a thrombus, while myocardial infarction refers to heart tissue death due to the consequent loss of

blood flow Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory system is controlled by homeostasis, homeostatic mechanisms of autoregulation, just as hydrau ...

to the heart. Due to extensive

collateral circulation Collateral circulation is the alternate Circulatory system, circulation around a blocked blood vessel, artery or vein via another path, such as nearby minor vessels. It may occur via preexisting vascular redundancy (analogous to redundancy (engi ...

, a coronary thrombus does not necessarily cause tissue death and may be asymptomatic. The formation of coronary thrombosis generally follows the same mechanism as other blood clots in the body, the

coagulation cascade Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The process of coagulat ...

. Also applicable is the Virchow's triad of blood stasis, endothelial injury, and hypercoagulable state.

Atherosclerosis 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 is driven by eleva ...

contributes to coronary thrombosis formation by facilitating blood stasis as well as causing local endothelial injury. Due to the large number of cases of myocardial infarction leading to death and disease in the world, there has been extensive study towards the generation of clots specifically in the

coronary arteries The coronary arteries are the arteries, arterial blood vessels of coronary circulation, which transport oxygenated blood to the Cardiac muscle, heart muscle. The heart requires a continuous supply of oxygen to function and survive, much like any ...

. Some areas of focus: * Coronary thrombosis can be a complication associated with

drug-eluting stent A drug-eluting stent (DES) is a tube made of a mesh-like material used to treat atherosclerosis, narrowed arteries in medical procedures both mechanically (by providing a supporting scaffold inside the artery) and pharmacologically (by slowly ...

s. These stents that are placed to open up narrowed arteries are often infused with medicine to prevent repeat stenosis. However, they may actually lead to an increased coronary thrombus formation due to increased tissue factor expression and delayed healing within the vessels. Furthermore, the downstream

endothelium The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the r ...

has been shown to be impaired, leading to an environment that favors formation of clots. Evidence remains inconclusive about whether these risks outweigh the benefit of a coronary arterial stent. *

Inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

may play a causal role in coronary artery disease and subsequent myocardial infarction due to coronary thrombosis. Increased levels of inflammation may lead to higher risk of clotting as well as an increased risk of stent/device subsequent thrombosis. There is an ongoing search for inflammatory

biomarker In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, ...

s that can help determine at-risk individuals. * Coronary "microembolization" is being explored as a focal point for coronary thrombus formation and subsequent sudden death due to acute myocardial infarction. * High mobility group box-1 (HMGB-1)

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

s as important mediators in thrombus formation. *

Coronary sinus The coronary sinus () is the largest vein of the heart. It drains over half of the deoxygenated blood from the heart muscle into the right atrium. It begins on the backside of the heart, in between the left atrium, and left ventricle; it begi ...

thrombosis as a severe complication after procedures.. The coronary sinus is the venous counterpart to the coronary arteries, where de-oxygenated blood returns from heart tissue. A large thrombus here slows overall blood circulation to heart tissue as well as may mechanically compress a coronary artery.

Diagnosis

Clinical signs of myocardial infarction (heart attack) or

if coronary thrombus is symptomatic: Imaging modalities used to evaluate the presence of coronary thrombi: *

angioscopy Angioscopy is a medical technique for visualizing the interior of blood vessels. In this technique, a flexible fibre bundle endoscope An endoscope is an inspection instrument composed of image sensor, optical lens, light source and mechanical d ...

* endocoronary

ultrasound Ultrasound is sound with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...

coronary angiography Coronary () may, as shorthand in English, be used to mean: * Coronary circulation, the system of arteries and veins in mammals ** Coronary artery disease ** Coronary occlusion ** A myocardial infarction, a heart attack As adjective * Referring to ...

* magnetic resonance imaging (MRI)
Postmortem examiners may look for Lines of Zahn, to determine whether blood clotted in the heart vessels before or after death.

Management

Management of symptomatic coronary thrombosis follows established treatment algorithms for myocardial infarction. Treatment options include: * emergency coronary artery bypass grafting *

stent In medicine, a stent is a tube usually constructed of a metallic alloy or a polymer. It is inserted into the Lumen (anatomy), lumen (hollow space) of an anatomic vessel or duct to keep the passageway open. Stenting refers to the placement of ...

implantation * intracoronary

thrombolysis Thrombolysis, also called fibrinolytic therapy, is the breakdown (lysis) of thrombus, blood clots formed in blood vessels, using medication. It is used in ST elevation myocardial infarction, stroke, and in cases of severe venous thromboembolism ( ...

* anticoagulation with

heparin Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Heparin is a blood anticoagulant that increases the activity of antithrombin. It is used in the treatment of myocardial infarction, ...

or glycoprotein IIb/IIIa inhibitors * thrombus aspiration as reperfusion strategy * platelet P2Y12 receptor inhibitors: a study published in 2001 determined that the addition of

clopidogrel Clopidogrel, sold under the brand name Plavix among others, is an antiplatelet drug, antiplatelet medication used to reduce the risk of Cardiovascular disease, heart disease and stroke in those at high risk. It is also used together with aspi ...

showed a positive effect on cardiovascular mortality, non-fatal heart attack, and stroke at the cost of an increased risk of major bleeding. To address the possibility of identifying and treating asymptomatic coronary artery disease to prevent development of coronary thrombosis, a study published 2018 determined that preemptive treatment with

percutaneous coronary intervention Percutaneous coronary intervention (PCI) is a minimally invasive non-surgical procedure used to treat stenosis, narrowing of the coronary artery, coronary arteries of the heart found in coronary artery disease. The procedure is used to place and ...

did not lead to a difference in death or myocardial infarction over a 15-year period. There are numerous treatments currently being studied for management and prevention of coronary thrombosis.

Statin Statins (or HMG-CoA reductase inhibitors) are a class of medications that lower cholesterol. They are prescribed typically to people who are at high risk of cardiovascular disease. Low-density lipoprotein (LDL) carriers of cholesterol play ...

drugs, in addition to their primary

-lowering mechanisms of action, have been studied to target a number of pathways that may decrease coronary

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

and subsequent thrombosis. Another realm of potential treatments in early stages of adoption is in therapeutic use of contrast

on thrombus dissolution.

Notable people

Terminology

Thrombosis Thrombosis () is the formation of a Thrombus, blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (thrombocytes) and fib ...

is defined as the formation of a thrombus (blood clot) inside a

, leading to obstruction of blood flow within the

circulatory system In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart ...

. Coronary thrombosis refers to the formation and presence of thrombi in the coronary arteries of the heart. The heart does not contain veins, but rather

coronary sinus The coronary sinus () is the largest vein of the heart. It drains over half of the deoxygenated blood from the heart muscle into the right atrium. It begins on the backside of the heart, in between the left atrium, and left ventricle; it begi ...

es that serve the purpose of returning de-oxygenated blood from the heart muscle. A thrombus is a type of

embolism An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule (fat embolism), a bubble of air or other gas (air embolism, gas embolism), amniotic ...

, a more general term for any material that partially or fully blocks a blood vessel. An atheroembolism, or cholesterol embolism, is when an atherosclerotic plaque ruptures and becomes an embolism.

is the progressive thickening of blood vessels and plaque formation that eventually can lead to

coronary artery disease Coronary artery disease (CAD), also called coronary heart disease (CHD), or ischemic heart disease (IHD), is a type of cardiovascular disease, heart disease involving Ischemia, the reduction of blood flow to the cardiac muscle due to a build-up ...

References

External links

{{Authority control Heart diseases