Coronary artery stent thrombosis (CAST) is considered as one of the severe complications that are likely to develop in patients who had undergone placement of coronary stent, a device frequently used for the management of CAD.
Coronary Artery Disease (CAD): CAD is described as the constriction or blockage of blood vessels known as coronary arteries, by a process called atherosclerosis – resulting in decreased blood supply to the heart muscle. Stenting is one of the ways of opening the blocked vessels. Stents: A stent is known as a wire basket or mesh tube that is placed in the blood vessels particularly, the coronary arteries to maintain patency of the vessels. There are two main types of stents:
Bare-metal stents (BMS): These are made of stainless steel or other metal alloys and have no coating on the uterine surface.
Drug-eluting stents (DES): These are coated with medication that helps counteract restenosis which is the re-narrowing of the artery. Stent Thrombosis: This is when there is formation of thrombus or blood clot within the stent, this may cause acute coronary events inclusive of myocardial infarction or sudden cardiac death. Stent thrombosis can be classified into early stent thrombosis which is within a span of one month from the time of stent deployment and late stent thrombosis which occurs after one month.
Epidemiology
Incidence : The overall rate of stent thrombosis is small, approximately 1-2% of patients who received bare metal stents and 0.5–1.5% of patients who received drug eluting stents. Early vs. Late Stent Thrombosis: Early Stent Thrombosis: It occurs within 30 days of the procedure and is associated with procedural complications, technical issues such as suboptimal stent deployment, or acute thrombogenic events. Late Stent Thrombosis: Occur after 30 days and may be linked to such factors as late stent deployment, endothelial dysfunctions, and early withdrawal from antiplatelet therapy. The rate of late thrombosis is between 0.5 and 1 percent in the first year after the procedure.
Anatomy
Pathophysiology
Vascular Injury: Mechanical injury of the arterial wall occurs during stenting which in turn leads to endothelial dysfunction and exposure of subendothelial components that promote platelet activation and coagulation.
Platelet Activation: The exposed collagen surfaces retain activated platelets which in turn release agents that lead to aggregation. This procedure helps to build up a thrombus inside the stent.
CoagulationCascade: Endothelial tissue is exposed at the site of injury, and tissue factor is released in the vicinity which turns on the coagulation pathway, and thrombin is formed which aids in converting soluble fibrinogen to insoluble fibrin and firming up the blood clot. Stent Factors: Thrombosis depends on the choice of the stent the bare metal or drug eluting stent. DES can inhibit endothelialisation, keeping the base of the created structures open for a longer period. Hemodynamic Changes: Recirculation of blood around the stent is turbulent and this leads to formation of thrombus.
Etiology
Patient-Related Risk Factors for Stent Thrombosis (ST):
Premature Discontinuation of DAPT: Significantly associates to early ST, especially if halted in the first thirty days after implantation (HR: 26.8).
Malignant Disease: Raises the chances of late ST by a factor of 17.45 times its normal rate.
Diabetes Mellitus: Closely related to the higher ST risk increase the odds ratio to 3.14.
Reduced Left Ventricular Function: Many of the usual risk factors for early ST are significantly associated with early ST, such as ejection fraction < 30%.
Other Factors: Younger age, smoking, peripheral arterial occlusive disease, thrombocytosis and genetic polymorphisms.
Procedural Aspects:
Intracoronary Imaging: Assists in knowing the structural problems that may affect the chance of thrombosis.
Guided Procedures: It observed that non-image procedure in the angiography has a higher incidence of ST than non-image procedure in imaging modality 1.2% and 0.6% respectively.
Stent Characteristics:
Type of Stent: First generation DES already have higher ST rates; however contemporary DES combine better with tissues and registered decreased amounts of ST.
Stent Strut Thickness: Low ST incidence is related to thinner struts with ST rate of 0,4% for thinner than the rate of 1,2% for thicker struts.
Genetics
Prognostic Factors
Coating and Alloy Composition: New developments such as biodegradable polymer coatings are equally designed to prevent occurrences of thrombosis.
Premature Discontinuation of DAPT: This is a critical predictor particularly if initially noted in the first month after stent implantation, greatly increasing ST risk.
Presence of Malignant Disease and Diabetes: They are both prominent markers of late ST and should be watched closely with possible modification of the DAPT time.
Clinical History
Age group
Most diagnosed in patients of 50 years of age or older; however, it may be found in younger patients when risk factors are present.
Physical Examination
When physical examination is being conducted to minimize the risk of ST on a patient with coronary artery stent, clinicians should first note the general demeanor, blood pressure, pulse and cardiovascular fitness of the patient. Essential checks include abnormal heart sounds, strength, and symmetry of peripheral pulses, and jugular venous pressure to check if fluids are retained. The state of perfusion should be assessed by monitoring skin temp of extremities and capillary refill. Respiratory assessment for children includes examination of breath sounds for those associated with heart failure. Also, mental status should be assessed as well as the patient’s adherence to antiplatelet therapy and their risk factors.
Acute Presentation: If chest pain, shortness of breath, or any other usual angina sign occurs abruptly, then it is an acute ST event. The triad of myocardial ischemia or infarction may manifest in patients.
Subacute Presentation: It also includes patients with recurrent angina or discomfort occurring weeks after stenting, which may be representative of stent complications.
Chronic Presentation: May include stable angina or asymptomatic periods in which risk factors remain high and prompt prevention measures are required.
Differential Diagnoses
Myocardial infarction
Unstable Angina
Aortic dissection
Pulmonary Embolism
Pericarditis
Coronary Artery Disease
Acute Coronary Syndrome
Arrythmias
Musculoskeletal pain
Laboratory Studies
Imaging Studies
Procedures
Histologic Findings
Staging
Treatment Paradigm
Pharmacological Therapy:
         Dual Antiplatelet Therapy: Normally encompasses aspirin as well as a P2Y12 receptor antagonist (clopidogrel, ticagrelor or prasugrel). It may range from 6 to 12 months after stent implantation; however, decisions depend on the type and risk factors of the patient.
         Anticoagulation: In particular, high-risk patient populations, including individuals with atrial fibrillation or those who suffered acute coronary syndrome, might be benefited by the combined use of more intensive antiplatelet agents (like warfarin or direct oral anticoagulants).
         Statin Therapy: There exist high-intensity statins for cholesterol and additional cardiovascular protection.
Lifestyle Modifications:
         Smoking Cessation: Strongly recommended based on evidence supporting the fact that smoking predisposes a patient to thrombosis.
         Dietary Changes: Being on the issue of diet the patients should be encouraged to take foods that are good for the heart such as vegetables and fruits and healthy fats.
Weight Management: Keeping fit is also desirable when it comes to the health of the blood vessels.
Monitoring and Follow-up: Compliance to medication, monitoring for side effects and general cardiovascular fitness.
Access to Healthy Foods: The availability of choices shifted towards healthy eating can help instigate better selections regarding the meals consumed.
Public Smoking Bans: Smoking restricted areas DIY and smoking control help in smoking elimination and assists in the protection of high-risk groups.
Exercise Facilities: Open spaces such as parks, gym and walking paths enable people engage in physical activities that are important in maintaining cardiovascular health.
PatientEducation Programs: Knowledge regarding ST prevention methods, treatment, and adherence to medication as well as adherence to lifestyle modifications in patient education.
Healthcare Accessibility: Promoting preventive care means clients get checked early before complications and illnesses such as hypertension or diabetes arise.
Role of Antiplatelet agents
Aspirin: Aspirin on this basis prevents the action of cyclooxygenase-1 (COX-1) – the enzyme that catalyses the conversion of arachidonic acid to thromboxane A2. Thromboxane A2 is an active platelet agonist promoting the aggregation and vasoconstriction of the blood vessels. Being an antiplatelet agent, aspirin inhibits platelet activation and aggregation and thus minimises the possibility of clot formation. Aspirin, in doses of no more than 75 to 100 mg daily, is usually taken in combination with other antiplatelet preparations such as clopidogrel or ticagrelor within a dual antiplatelet therapy regimen. This combination is especially recommended after coronary stent positioning or when treating patients with acute coronary syndrome to improve the outcome of cardiovascular protection.
Role of P2Y12 Inhibitors
Clopidogrel: A drug that locks on to the P2Y12 receptor on platelets and prevents aggregation, for the life cycle of the platelet. This leads to a marked decrease in the probability of thrombotic reactions taking place within the patient’s body.
Example: There are several trade names which are utilized for clopidogrel, but perhaps the most widely known is Plavix.
Prasugrel: It operates with much higher speed and intensity in P2Y12 receptor blockade than clopidogrel, which results in increased antiplatelet response, particularly in patients with high risk for PCI. Example: Prasugrel is marketed with the name Effient, that is used along with aspirin for the prevention of thrombotic occurrence.
Ticagrelor: It is a reversible drug that belongs to the P2Y12 receptor antagonist class; due to its fast onset of action it offers sound antiplatelet potential in critical circumstances. Its reversible in comparison with some other anticoagulants which can enable a faster reversal of the effect on platelet function if required.
Example: Ticagrelor which is sold under the trade name Brilinta is a P2Y12 receptor antagonist that is administered in patients with acute coronary syndromes or those who are to undergo percutaneous coronary intervention.
Role of Glycoprotein IIb/IIIa Inhibitors
Abciximab: Glycoprotein IIb/IIIa is a receptor, and it is a monoclonal antibody derived from the human source which gives a reversible blockage of this receptor. This is usually given during high-risk percutaneous coronary interventions (PCI) to lower the chances of acute coronary events.
Example: Reopro is trade name for abciximab that is used intravenously during percutaneous interventions.
Eptifibatide: It is a cyclic heptapeptide that has reversible affinity to the glycoprotein IIb/IIIa receptors and works as an efficient antiplatelet agent. It is commonly employed in cases of acute coronary syndromes and during percutaneous coronary intervention.
Example: Integrilin is eptifibatide and it is administered intravenously.
Tirofiban: This is a covalent structure and molecular counteragent from glycoprotein IIb/IIIa receptor. This drug provides a quick relief and is used for antithrombotic prophylaxis in people for invasive high-risk procedures.
Example: Tirofiban under the trade name of Aggrastat is indicated in patients with unstable angina or those candidates for percutaneous coronary intervention.
Percutaneous Coronary Intervention (PCI): This is an endoscopic method for the treatment of the patient who has affected coronary vessels with stenosis or occlusion. This include the use of stent to keep the artery open and to keep blood flowing the chance of restenosis is reduced and the risk of stent thrombosis (ST) is lowered. Common to such procedures is the angioplasty, which is a process that involves the use of catheter that is inflated to open the blood vessel. Subsequently, maintaining its structural integrity a stent is installed.
Intracoronary Imaging Techniques: Fluorescence microscopy is used to observe the position of the stent and determine the presence of malapposition or fractures of struts and characteristics of the adjacent blood vessel using OCT and IVUS.
Thrombectomy: It is done in cases of acute coronary syndromes when there is the need to remove thrombus before stenting to reduce on ST likely to be caused by clots. This intervention involves using a device like aspiration catheter or mechanical thrombectomy device to remove the thrombotic material from the artery of interest efficiently.
Coronary Artery Bypass Grafting (CABG): In this case CABG may be preferred in patients with substantial CAD who are at increased risk of ST rather than PCI and stenting. This surgical procedure increases blood flow to the heart, which can lessen the necessity of using stents to help the blood vessels open and therefore minimise ST risks that are being related to it.
Stent Design Innovations: Newer generations of DES with improved materials, thinner struts, and more effective drug release are the continuing efforts to decrease the risk of ST in patients. Using biodegradable polymer-coated stents or stents with superior anti-restenosis agents reduces inflammation and encourages tissue restoration eliminating other problems that are associated with the use of stents.
For optimum treatment of coronary artery stent thrombosis (ST), a staged approach is an important strategy.
Acute Phase: In this stage, procedures like the percutaneous coronary intervention (PCI) is carried out to deal with any existing acute lesions. DAPT is given on admission to prevent further platelet clot formation and decrease the risk of ST.
Subacute Phase: After the first technique, constant supervision is required. During the index procedure, intracoronary imaging is utilised to evaluate proper stent deployment and determine the presence of any adverse events, Additionally, modification of antiplatelet therapy may be done depending on the patient’s response.
Chronic Phase: Long-term management involves ensuring strict compliance to indicated antiplatelet agents and making appropriate lifestyle changes to prevent cardiovascular risk. Follow-up visits are crucial in the assessment of the patient’s condition and the impact of the preventive interventions.
10,000 KIU test dose ten minutes prior to the procedure.
The loading dose consists of 1,000,000–2,000,000 KIU administered slowly by IV infusion or over a 20–30-minute period following the induction of anesthesia and 250,000–500,000 KIU/hour administered continuously until the procedure is completed
To the heart-lung machine's pump prime, an extra dose of 1,000,000–2,000,000 KIU is added. Maximum: 7 million KIU
Maximum flow: 5–10 mL/min
»
Home » CAD » Coronary Artery Stent Thrombosis, Prevention
Coronary Artery Stent Thrombosis, Prevention
Updated :
September 30, 2024
Coronary artery stent thrombosis (CAST) is considered as one of the severe complications that are likely to develop in patients who had undergone placement of coronary stent, a device frequently used for the management of CAD.
Coronary Artery Disease (CAD): CAD is described as the constriction or blockage of blood vessels known as coronary arteries, by a process called atherosclerosis – resulting in decreased blood supply to the heart muscle. Stenting is one of the ways of opening the blocked vessels. Stents: A stent is known as a wire basket or mesh tube that is placed in the blood vessels particularly, the coronary arteries to maintain patency of the vessels. There are two main types of stents:
Bare-metal stents (BMS): These are made of stainless steel or other metal alloys and have no coating on the uterine surface.
Drug-eluting stents (DES): These are coated with medication that helps counteract restenosis which is the re-narrowing of the artery. Stent Thrombosis: This is when there is formation of thrombus or blood clot within the stent, this may cause acute coronary events inclusive of myocardial infarction or sudden cardiac death. Stent thrombosis can be classified into early stent thrombosis which is within a span of one month from the time of stent deployment and late stent thrombosis which occurs after one month.
Incidence : The overall rate of stent thrombosis is small, approximately 1-2% of patients who received bare metal stents and 0.5–1.5% of patients who received drug eluting stents. Early vs. Late Stent Thrombosis: Early Stent Thrombosis: It occurs within 30 days of the procedure and is associated with procedural complications, technical issues such as suboptimal stent deployment, or acute thrombogenic events. Late Stent Thrombosis: Occur after 30 days and may be linked to such factors as late stent deployment, endothelial dysfunctions, and early withdrawal from antiplatelet therapy. The rate of late thrombosis is between 0.5 and 1 percent in the first year after the procedure.
Vascular Injury: Mechanical injury of the arterial wall occurs during stenting which in turn leads to endothelial dysfunction and exposure of subendothelial components that promote platelet activation and coagulation.
Platelet Activation: The exposed collagen surfaces retain activated platelets which in turn release agents that lead to aggregation. This procedure helps to build up a thrombus inside the stent.
CoagulationCascade: Endothelial tissue is exposed at the site of injury, and tissue factor is released in the vicinity which turns on the coagulation pathway, and thrombin is formed which aids in converting soluble fibrinogen to insoluble fibrin and firming up the blood clot. Stent Factors: Thrombosis depends on the choice of the stent the bare metal or drug eluting stent. DES can inhibit endothelialisation, keeping the base of the created structures open for a longer period. Hemodynamic Changes: Recirculation of blood around the stent is turbulent and this leads to formation of thrombus.
Patient-Related Risk Factors for Stent Thrombosis (ST):
Premature Discontinuation of DAPT: Significantly associates to early ST, especially if halted in the first thirty days after implantation (HR: 26.8).
Malignant Disease: Raises the chances of late ST by a factor of 17.45 times its normal rate.
Diabetes Mellitus: Closely related to the higher ST risk increase the odds ratio to 3.14.
Reduced Left Ventricular Function: Many of the usual risk factors for early ST are significantly associated with early ST, such as ejection fraction < 30%.
Other Factors: Younger age, smoking, peripheral arterial occlusive disease, thrombocytosis and genetic polymorphisms.
Procedural Aspects:
Intracoronary Imaging: Assists in knowing the structural problems that may affect the chance of thrombosis.
Guided Procedures: It observed that non-image procedure in the angiography has a higher incidence of ST than non-image procedure in imaging modality 1.2% and 0.6% respectively.
Stent Characteristics:
Type of Stent: First generation DES already have higher ST rates; however contemporary DES combine better with tissues and registered decreased amounts of ST.
Stent Strut Thickness: Low ST incidence is related to thinner struts with ST rate of 0,4% for thinner than the rate of 1,2% for thicker struts.
Coating and Alloy Composition: New developments such as biodegradable polymer coatings are equally designed to prevent occurrences of thrombosis.
Premature Discontinuation of DAPT: This is a critical predictor particularly if initially noted in the first month after stent implantation, greatly increasing ST risk.
Presence of Malignant Disease and Diabetes: They are both prominent markers of late ST and should be watched closely with possible modification of the DAPT time.
Age group
Most diagnosed in patients of 50 years of age or older; however, it may be found in younger patients when risk factors are present.
When physical examination is being conducted to minimize the risk of ST on a patient with coronary artery stent, clinicians should first note the general demeanor, blood pressure, pulse and cardiovascular fitness of the patient. Essential checks include abnormal heart sounds, strength, and symmetry of peripheral pulses, and jugular venous pressure to check if fluids are retained. The state of perfusion should be assessed by monitoring skin temp of extremities and capillary refill. Respiratory assessment for children includes examination of breath sounds for those associated with heart failure. Also, mental status should be assessed as well as the patient’s adherence to antiplatelet therapy and their risk factors.
Acute Presentation: If chest pain, shortness of breath, or any other usual angina sign occurs abruptly, then it is an acute ST event. The triad of myocardial ischemia or infarction may manifest in patients.
Subacute Presentation: It also includes patients with recurrent angina or discomfort occurring weeks after stenting, which may be representative of stent complications.
Chronic Presentation: May include stable angina or asymptomatic periods in which risk factors remain high and prompt prevention measures are required.
Myocardial infarction
Unstable Angina
Aortic dissection
Pulmonary Embolism
Pericarditis
Coronary Artery Disease
Acute Coronary Syndrome
Arrythmias
Musculoskeletal pain
Pharmacological Therapy:
         Dual Antiplatelet Therapy: Normally encompasses aspirin as well as a P2Y12 receptor antagonist (clopidogrel, ticagrelor or prasugrel). It may range from 6 to 12 months after stent implantation; however, decisions depend on the type and risk factors of the patient.
         Anticoagulation: In particular, high-risk patient populations, including individuals with atrial fibrillation or those who suffered acute coronary syndrome, might be benefited by the combined use of more intensive antiplatelet agents (like warfarin or direct oral anticoagulants).
         Statin Therapy: There exist high-intensity statins for cholesterol and additional cardiovascular protection.
Lifestyle Modifications:
         Smoking Cessation: Strongly recommended based on evidence supporting the fact that smoking predisposes a patient to thrombosis.
         Dietary Changes: Being on the issue of diet the patients should be encouraged to take foods that are good for the heart such as vegetables and fruits and healthy fats.
Weight Management: Keeping fit is also desirable when it comes to the health of the blood vessels.
Monitoring and Follow-up: Compliance to medication, monitoring for side effects and general cardiovascular fitness.
Cardiology, General
Health Promotion:
Access to Healthy Foods: The availability of choices shifted towards healthy eating can help instigate better selections regarding the meals consumed.
Public Smoking Bans: Smoking restricted areas DIY and smoking control help in smoking elimination and assists in the protection of high-risk groups.
Exercise Facilities: Open spaces such as parks, gym and walking paths enable people engage in physical activities that are important in maintaining cardiovascular health.
PatientEducation Programs: Knowledge regarding ST prevention methods, treatment, and adherence to medication as well as adherence to lifestyle modifications in patient education.
Healthcare Accessibility: Promoting preventive care means clients get checked early before complications and illnesses such as hypertension or diabetes arise.
Cardiology, General
Aspirin: Aspirin on this basis prevents the action of cyclooxygenase-1 (COX-1) – the enzyme that catalyses the conversion of arachidonic acid to thromboxane A2. Thromboxane A2 is an active platelet agonist promoting the aggregation and vasoconstriction of the blood vessels. Being an antiplatelet agent, aspirin inhibits platelet activation and aggregation and thus minimises the possibility of clot formation. Aspirin, in doses of no more than 75 to 100 mg daily, is usually taken in combination with other antiplatelet preparations such as clopidogrel or ticagrelor within a dual antiplatelet therapy regimen. This combination is especially recommended after coronary stent positioning or when treating patients with acute coronary syndrome to improve the outcome of cardiovascular protection.
Cardiology, General
Clopidogrel: A drug that locks on to the P2Y12 receptor on platelets and prevents aggregation, for the life cycle of the platelet. This leads to a marked decrease in the probability of thrombotic reactions taking place within the patient’s body.
Example: There are several trade names which are utilized for clopidogrel, but perhaps the most widely known is Plavix.
Prasugrel: It operates with much higher speed and intensity in P2Y12 receptor blockade than clopidogrel, which results in increased antiplatelet response, particularly in patients with high risk for PCI. Example: Prasugrel is marketed with the name Effient, that is used along with aspirin for the prevention of thrombotic occurrence.
Ticagrelor: It is a reversible drug that belongs to the P2Y12 receptor antagonist class; due to its fast onset of action it offers sound antiplatelet potential in critical circumstances. Its reversible in comparison with some other anticoagulants which can enable a faster reversal of the effect on platelet function if required.
Example: Ticagrelor which is sold under the trade name Brilinta is a P2Y12 receptor antagonist that is administered in patients with acute coronary syndromes or those who are to undergo percutaneous coronary intervention.
Cardiology, General
Abciximab: Glycoprotein IIb/IIIa is a receptor, and it is a monoclonal antibody derived from the human source which gives a reversible blockage of this receptor. This is usually given during high-risk percutaneous coronary interventions (PCI) to lower the chances of acute coronary events.
Example: Reopro is trade name for abciximab that is used intravenously during percutaneous interventions.
Eptifibatide: It is a cyclic heptapeptide that has reversible affinity to the glycoprotein IIb/IIIa receptors and works as an efficient antiplatelet agent. It is commonly employed in cases of acute coronary syndromes and during percutaneous coronary intervention.
Example: Integrilin is eptifibatide and it is administered intravenously.
Tirofiban: This is a covalent structure and molecular counteragent from glycoprotein IIb/IIIa receptor. This drug provides a quick relief and is used for antithrombotic prophylaxis in people for invasive high-risk procedures.
Example: Tirofiban under the trade name of Aggrastat is indicated in patients with unstable angina or those candidates for percutaneous coronary intervention.
Cardiology, General
Percutaneous Coronary Intervention (PCI): This is an endoscopic method for the treatment of the patient who has affected coronary vessels with stenosis or occlusion. This include the use of stent to keep the artery open and to keep blood flowing the chance of restenosis is reduced and the risk of stent thrombosis (ST) is lowered. Common to such procedures is the angioplasty, which is a process that involves the use of catheter that is inflated to open the blood vessel. Subsequently, maintaining its structural integrity a stent is installed.
Intracoronary Imaging Techniques: Fluorescence microscopy is used to observe the position of the stent and determine the presence of malapposition or fractures of struts and characteristics of the adjacent blood vessel using OCT and IVUS.
Thrombectomy: It is done in cases of acute coronary syndromes when there is the need to remove thrombus before stenting to reduce on ST likely to be caused by clots. This intervention involves using a device like aspiration catheter or mechanical thrombectomy device to remove the thrombotic material from the artery of interest efficiently.
Coronary Artery Bypass Grafting (CABG): In this case CABG may be preferred in patients with substantial CAD who are at increased risk of ST rather than PCI and stenting. This surgical procedure increases blood flow to the heart, which can lessen the necessity of using stents to help the blood vessels open and therefore minimise ST risks that are being related to it.
Stent Design Innovations: Newer generations of DES with improved materials, thinner struts, and more effective drug release are the continuing efforts to decrease the risk of ST in patients. Using biodegradable polymer-coated stents or stents with superior anti-restenosis agents reduces inflammation and encourages tissue restoration eliminating other problems that are associated with the use of stents.
Cardiology, General
For optimum treatment of coronary artery stent thrombosis (ST), a staged approach is an important strategy.
Acute Phase: In this stage, procedures like the percutaneous coronary intervention (PCI) is carried out to deal with any existing acute lesions. DAPT is given on admission to prevent further platelet clot formation and decrease the risk of ST.
Subacute Phase: After the first technique, constant supervision is required. During the index procedure, intracoronary imaging is utilised to evaluate proper stent deployment and determine the presence of any adverse events, Additionally, modification of antiplatelet therapy may be done depending on the patient’s response.
Chronic Phase: Long-term management involves ensuring strict compliance to indicated antiplatelet agents and making appropriate lifestyle changes to prevent cardiovascular risk. Follow-up visits are crucial in the assessment of the patient’s condition and the impact of the preventive interventions.
Coronary artery stent thrombosis (CAST) is considered as one of the severe complications that are likely to develop in patients who had undergone placement of coronary stent, a device frequently used for the management of CAD.
Coronary Artery Disease (CAD): CAD is described as the constriction or blockage of blood vessels known as coronary arteries, by a process called atherosclerosis – resulting in decreased blood supply to the heart muscle. Stenting is one of the ways of opening the blocked vessels. Stents: A stent is known as a wire basket or mesh tube that is placed in the blood vessels particularly, the coronary arteries to maintain patency of the vessels. There are two main types of stents:
Bare-metal stents (BMS): These are made of stainless steel or other metal alloys and have no coating on the uterine surface.
Drug-eluting stents (DES): These are coated with medication that helps counteract restenosis which is the re-narrowing of the artery. Stent Thrombosis: This is when there is formation of thrombus or blood clot within the stent, this may cause acute coronary events inclusive of myocardial infarction or sudden cardiac death. Stent thrombosis can be classified into early stent thrombosis which is within a span of one month from the time of stent deployment and late stent thrombosis which occurs after one month.
Incidence : The overall rate of stent thrombosis is small, approximately 1-2% of patients who received bare metal stents and 0.5–1.5% of patients who received drug eluting stents. Early vs. Late Stent Thrombosis: Early Stent Thrombosis: It occurs within 30 days of the procedure and is associated with procedural complications, technical issues such as suboptimal stent deployment, or acute thrombogenic events. Late Stent Thrombosis: Occur after 30 days and may be linked to such factors as late stent deployment, endothelial dysfunctions, and early withdrawal from antiplatelet therapy. The rate of late thrombosis is between 0.5 and 1 percent in the first year after the procedure.
Vascular Injury: Mechanical injury of the arterial wall occurs during stenting which in turn leads to endothelial dysfunction and exposure of subendothelial components that promote platelet activation and coagulation.
Platelet Activation: The exposed collagen surfaces retain activated platelets which in turn release agents that lead to aggregation. This procedure helps to build up a thrombus inside the stent.
CoagulationCascade: Endothelial tissue is exposed at the site of injury, and tissue factor is released in the vicinity which turns on the coagulation pathway, and thrombin is formed which aids in converting soluble fibrinogen to insoluble fibrin and firming up the blood clot. Stent Factors: Thrombosis depends on the choice of the stent the bare metal or drug eluting stent. DES can inhibit endothelialisation, keeping the base of the created structures open for a longer period. Hemodynamic Changes: Recirculation of blood around the stent is turbulent and this leads to formation of thrombus.
Patient-Related Risk Factors for Stent Thrombosis (ST):
Premature Discontinuation of DAPT: Significantly associates to early ST, especially if halted in the first thirty days after implantation (HR: 26.8).
Malignant Disease: Raises the chances of late ST by a factor of 17.45 times its normal rate.
Diabetes Mellitus: Closely related to the higher ST risk increase the odds ratio to 3.14.
Reduced Left Ventricular Function: Many of the usual risk factors for early ST are significantly associated with early ST, such as ejection fraction < 30%.
Other Factors: Younger age, smoking, peripheral arterial occlusive disease, thrombocytosis and genetic polymorphisms.
Procedural Aspects:
Intracoronary Imaging: Assists in knowing the structural problems that may affect the chance of thrombosis.
Guided Procedures: It observed that non-image procedure in the angiography has a higher incidence of ST than non-image procedure in imaging modality 1.2% and 0.6% respectively.
Stent Characteristics:
Type of Stent: First generation DES already have higher ST rates; however contemporary DES combine better with tissues and registered decreased amounts of ST.
Stent Strut Thickness: Low ST incidence is related to thinner struts with ST rate of 0,4% for thinner than the rate of 1,2% for thicker struts.
Coating and Alloy Composition: New developments such as biodegradable polymer coatings are equally designed to prevent occurrences of thrombosis.
Premature Discontinuation of DAPT: This is a critical predictor particularly if initially noted in the first month after stent implantation, greatly increasing ST risk.
Presence of Malignant Disease and Diabetes: They are both prominent markers of late ST and should be watched closely with possible modification of the DAPT time.
Age group
Most diagnosed in patients of 50 years of age or older; however, it may be found in younger patients when risk factors are present.
When physical examination is being conducted to minimize the risk of ST on a patient with coronary artery stent, clinicians should first note the general demeanor, blood pressure, pulse and cardiovascular fitness of the patient. Essential checks include abnormal heart sounds, strength, and symmetry of peripheral pulses, and jugular venous pressure to check if fluids are retained. The state of perfusion should be assessed by monitoring skin temp of extremities and capillary refill. Respiratory assessment for children includes examination of breath sounds for those associated with heart failure. Also, mental status should be assessed as well as the patient’s adherence to antiplatelet therapy and their risk factors.
Acute Presentation: If chest pain, shortness of breath, or any other usual angina sign occurs abruptly, then it is an acute ST event. The triad of myocardial ischemia or infarction may manifest in patients.
Subacute Presentation: It also includes patients with recurrent angina or discomfort occurring weeks after stenting, which may be representative of stent complications.
Chronic Presentation: May include stable angina or asymptomatic periods in which risk factors remain high and prompt prevention measures are required.
Myocardial infarction
Unstable Angina
Aortic dissection
Pulmonary Embolism
Pericarditis
Coronary Artery Disease
Acute Coronary Syndrome
Arrythmias
Musculoskeletal pain
Pharmacological Therapy:
         Dual Antiplatelet Therapy: Normally encompasses aspirin as well as a P2Y12 receptor antagonist (clopidogrel, ticagrelor or prasugrel). It may range from 6 to 12 months after stent implantation; however, decisions depend on the type and risk factors of the patient.
         Anticoagulation: In particular, high-risk patient populations, including individuals with atrial fibrillation or those who suffered acute coronary syndrome, might be benefited by the combined use of more intensive antiplatelet agents (like warfarin or direct oral anticoagulants).
         Statin Therapy: There exist high-intensity statins for cholesterol and additional cardiovascular protection.
Lifestyle Modifications:
         Smoking Cessation: Strongly recommended based on evidence supporting the fact that smoking predisposes a patient to thrombosis.
         Dietary Changes: Being on the issue of diet the patients should be encouraged to take foods that are good for the heart such as vegetables and fruits and healthy fats.
Weight Management: Keeping fit is also desirable when it comes to the health of the blood vessels.
Monitoring and Follow-up: Compliance to medication, monitoring for side effects and general cardiovascular fitness.
Cardiology, General
Health Promotion:
Access to Healthy Foods: The availability of choices shifted towards healthy eating can help instigate better selections regarding the meals consumed.
Public Smoking Bans: Smoking restricted areas DIY and smoking control help in smoking elimination and assists in the protection of high-risk groups.
Exercise Facilities: Open spaces such as parks, gym and walking paths enable people engage in physical activities that are important in maintaining cardiovascular health.
PatientEducation Programs: Knowledge regarding ST prevention methods, treatment, and adherence to medication as well as adherence to lifestyle modifications in patient education.
Healthcare Accessibility: Promoting preventive care means clients get checked early before complications and illnesses such as hypertension or diabetes arise.
Cardiology, General
Aspirin: Aspirin on this basis prevents the action of cyclooxygenase-1 (COX-1) – the enzyme that catalyses the conversion of arachidonic acid to thromboxane A2. Thromboxane A2 is an active platelet agonist promoting the aggregation and vasoconstriction of the blood vessels. Being an antiplatelet agent, aspirin inhibits platelet activation and aggregation and thus minimises the possibility of clot formation. Aspirin, in doses of no more than 75 to 100 mg daily, is usually taken in combination with other antiplatelet preparations such as clopidogrel or ticagrelor within a dual antiplatelet therapy regimen. This combination is especially recommended after coronary stent positioning or when treating patients with acute coronary syndrome to improve the outcome of cardiovascular protection.
Cardiology, General
Clopidogrel: A drug that locks on to the P2Y12 receptor on platelets and prevents aggregation, for the life cycle of the platelet. This leads to a marked decrease in the probability of thrombotic reactions taking place within the patient’s body.
Example: There are several trade names which are utilized for clopidogrel, but perhaps the most widely known is Plavix.
Prasugrel: It operates with much higher speed and intensity in P2Y12 receptor blockade than clopidogrel, which results in increased antiplatelet response, particularly in patients with high risk for PCI. Example: Prasugrel is marketed with the name Effient, that is used along with aspirin for the prevention of thrombotic occurrence.
Ticagrelor: It is a reversible drug that belongs to the P2Y12 receptor antagonist class; due to its fast onset of action it offers sound antiplatelet potential in critical circumstances. Its reversible in comparison with some other anticoagulants which can enable a faster reversal of the effect on platelet function if required.
Example: Ticagrelor which is sold under the trade name Brilinta is a P2Y12 receptor antagonist that is administered in patients with acute coronary syndromes or those who are to undergo percutaneous coronary intervention.
Cardiology, General
Abciximab: Glycoprotein IIb/IIIa is a receptor, and it is a monoclonal antibody derived from the human source which gives a reversible blockage of this receptor. This is usually given during high-risk percutaneous coronary interventions (PCI) to lower the chances of acute coronary events.
Example: Reopro is trade name for abciximab that is used intravenously during percutaneous interventions.
Eptifibatide: It is a cyclic heptapeptide that has reversible affinity to the glycoprotein IIb/IIIa receptors and works as an efficient antiplatelet agent. It is commonly employed in cases of acute coronary syndromes and during percutaneous coronary intervention.
Example: Integrilin is eptifibatide and it is administered intravenously.
Tirofiban: This is a covalent structure and molecular counteragent from glycoprotein IIb/IIIa receptor. This drug provides a quick relief and is used for antithrombotic prophylaxis in people for invasive high-risk procedures.
Example: Tirofiban under the trade name of Aggrastat is indicated in patients with unstable angina or those candidates for percutaneous coronary intervention.
Cardiology, General
Percutaneous Coronary Intervention (PCI): This is an endoscopic method for the treatment of the patient who has affected coronary vessels with stenosis or occlusion. This include the use of stent to keep the artery open and to keep blood flowing the chance of restenosis is reduced and the risk of stent thrombosis (ST) is lowered. Common to such procedures is the angioplasty, which is a process that involves the use of catheter that is inflated to open the blood vessel. Subsequently, maintaining its structural integrity a stent is installed.
Intracoronary Imaging Techniques: Fluorescence microscopy is used to observe the position of the stent and determine the presence of malapposition or fractures of struts and characteristics of the adjacent blood vessel using OCT and IVUS.
Thrombectomy: It is done in cases of acute coronary syndromes when there is the need to remove thrombus before stenting to reduce on ST likely to be caused by clots. This intervention involves using a device like aspiration catheter or mechanical thrombectomy device to remove the thrombotic material from the artery of interest efficiently.
Coronary Artery Bypass Grafting (CABG): In this case CABG may be preferred in patients with substantial CAD who are at increased risk of ST rather than PCI and stenting. This surgical procedure increases blood flow to the heart, which can lessen the necessity of using stents to help the blood vessels open and therefore minimise ST risks that are being related to it.
Stent Design Innovations: Newer generations of DES with improved materials, thinner struts, and more effective drug release are the continuing efforts to decrease the risk of ST in patients. Using biodegradable polymer-coated stents or stents with superior anti-restenosis agents reduces inflammation and encourages tissue restoration eliminating other problems that are associated with the use of stents.
Cardiology, General
For optimum treatment of coronary artery stent thrombosis (ST), a staged approach is an important strategy.
Acute Phase: In this stage, procedures like the percutaneous coronary intervention (PCI) is carried out to deal with any existing acute lesions. DAPT is given on admission to prevent further platelet clot formation and decrease the risk of ST.
Subacute Phase: After the first technique, constant supervision is required. During the index procedure, intracoronary imaging is utilised to evaluate proper stent deployment and determine the presence of any adverse events, Additionally, modification of antiplatelet therapy may be done depending on the patient’s response.
Chronic Phase: Long-term management involves ensuring strict compliance to indicated antiplatelet agents and making appropriate lifestyle changes to prevent cardiovascular risk. Follow-up visits are crucial in the assessment of the patient’s condition and the impact of the preventive interventions.
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