Thrombotic disease in the elderly

Introduction to thrombotic diseases in the elderly A blood clot formed by blood components in the heart and/or lumen of a blood vessel, called thrombosis. The pathological phenomenon of thrombosis in clinical practice is called thrombotic disease. Type: According to the location of thrombosis, it can be divided into arterial thrombotic diseases (coronary heart disease, ischemic cerebrovascular disease and diabetes), and venous thrombotic diseases (pulmonary infarction and deep vein thrombosis). basic knowledge The proportion of illness: 0.026% Susceptible people: the elderly Mode of infection: non-infectious Complications: angina pectoris myocardial infarction venous thrombosis

The cause of thrombotic diseases in the elderly

Abnormal blood flow (25%):

Systemic or local blood stasis caused by various causes, slow blood flow is an important factor in thrombosis, the following mechanisms are involved in thrombosis:

1 Red blood cells aggregate into a cluster to form a red thrombus.

2 promote the adhesion and aggregation of platelets and endothelium, and release the reaction.

3 damage to the vascular endothelium, initiate the coagulation process, seen in hyperlipidemia, erythrocytosis, hyperfibrinogenemia, dehydration, various types of tumors, inflammation and other high-viscosity syndrome and circulatory disorders.

Reduced anticoagulant activity (20%):

The reduction of human physiological anticoagulant activity is an important condition for thrombosis, and the common causes of the decrease in human anticoagulant activity are:

1 Congenital or acquired AT-III reduction or deficiency.

2PC and PS deficiency.

3 Anti-protein C phenomenon (APC-R) caused by structural abnormalities such as FII and FV; 4 Heparin cofactor II (HC-II) deficiency.

Low fibrinolytic activity (15%):

1 plasminogen structure or function abnormalities, such as abnormal plasminogenemia.

2 plasminogen activator (PA) release disorder.

3 plasmin activator inhibitors are too much, these factors lead to decreased ability of the body to remove fibrin, which is conducive to thrombosis and expansion.

Endothelial injury (22%):

When mechanical, infection, immunity, and autologous lesions damage vascular endothelial cells, thrombosis can be promoted by a hemostatic mechanism.

Pathogenesis

Vascular wall damage (mechanical, infection, hypoxia, immunity and metabolism, etc.), increased blood coagulation (platelet hyperfunction, elevated clotting factors, decreased anticoagulant function and decreased fibrinolytic activity) and abnormal blood flow (slow, stagnant and Vortex) is the three major elements of thrombosis. The location of thrombosis is different, and its mechanism is also emphasized. Endothelial injury and platelet hyperfunction play a major role in arterial thrombosis, while slow blood flow and blood coagulation are venous thrombosis. Prerequisites for the formation, different stages of disease development, pathological changes are also different, early hypercoagulable state, its ability to form thrombus exceeds antithrombotic ability, there is a tendency to form thrombus in the body, but not necessarily abnormal in vitro coagulation, thrombosis The formation phase is thrombosis in the cardiovascular cavity, and the thromboembolic phase is the ischemic change of the distal tissue caused by thrombus detachment.

Prevention of thrombotic diseases in the elderly

1. Prevention should first aim to reduce the risk of atherosclerosis, for which it is necessary to quit smoking, prohibit alcohol and change bad habits.

2. Actively treat basic diseases such as prevention and treatment of arteriosclerosis, control of hypertension, hyperlipidemia and diabetes.

Complications of thrombotic diseases in the elderly Complications angina pectoris myocardial infarction venous thrombosis

Common coronary thrombosis can be complicated by angina pectoris, myocardial infarction, venous thrombosis can be complicated by pulmonary infarction.

Symptoms of thrombotic diseases in the elderly Common symptoms Angina venous thrombosis Myocardial infarction Awareness disorder Skin temperature rise edema

The clinical manifestations and consequences of thrombosis and embolism depend on the location and size of the thrombus, coronary artery thrombosis causes acute myocardial infarction or unstable angina; carotid or cerebral arterial thrombosis is hemiplegia, disturbance of consciousness; lower extremity deep vein thrombosis leads to lower limbs Swelling, pain, elevated skin temperature and lymphedema.

Thrombosis is caused by comprehensive factors, so there are many methods for diagnosis. Some indicators can predict the state of hypercoagulable crisis before thrombosis; some are diagnosed after thrombosis. So far, there is no specific index that can correctly To diagnose thrombosis, sometimes some indicators are abnormal, but the patient does not necessarily form a thrombus. It is not easy to correctly predict thrombosis, and further research is needed.

Examination of thrombotic diseases in the elderly

1. Arterial thrombotic disease mainly chooses to reflect the blood vessel wall (PGI2) and platelet (TXB2, -TG, PF4 platelet aggregation) indicators, appropriate selection of coagulation (fibrinogen, vWF, etc.), anticoagulation (AIIII) and Fibrinolysis (tPA, PAI) and other indicators.

2. Venous thrombotic diseases mainly choose coagulation, anticoagulation and fibrinolysis indicators, and can also do some indicators of platelets and blood vessels.

3. Angiography is valuable for determining the location and extent of a thrombus, such as coronary angiography.

4. Radioactive fibrinogen test Because the thrombus that is being formed can take up I125-labeled fibrinogen, it is important for the diagnosis of early thrombosis.

5. Electrical impedance plethysmography deep inhalation reduces lower extremity venous return, blood stagnant in the lower leg, resulting in increased blood volume in the lower extremities; deep exhalation is beneficial to venous return, reducing blood volume in the lower extremities, so this method can measure lower limb blood volume Changes, indirectly to understand the presence or absence of venous obstruction of the lower extremities, but can not distinguish between thrombosis and non-thrombotic obstruction.

6. Ultrasound can detect the disappearance or abnormality of blood flow in the blocked blood vessels, but can not find small thrombus.

7. CT has a high diagnostic rate for cerebral thrombosis and celiac vascular thrombosis.

Diagnosis and diagnosis of thrombotic diseases in the elderly

Hematological diagnosis

(1) Endothelin-1 test (ET-1): ET-1 is a smooth muscle strong contraction agent, which can show damage to the vascular endothelium.

(2) Platelet activation index: When platelets are activated, a series of substances can be released. These substances can be used to determine platelet activation, such as TXB2, -TG, PE4, GMP-140, and the like.

(3) Platelet aggregation rate: This index is increased, indicating that thrombosis is easy to form.

(4) Thrombomodulin (TM): Under normal circumstances, there is anticoagulant effect, such as its weakened effect, which is conducive to thrombosis.

(5) Anticoagulant indicators in plasma: such as AT-III, protein C, protein S, heparin cofactor-II.

(6) Fibrinolytic index: plasminogen and plasmin activity, t-PA, PAI activity, fibrin peptide A, peptide B determination.

(7) Blood rheology measurement: including whole blood viscosity, plasma viscosity, red blood cell electrophoresis and the like.

2. Device inspection

(1) angiography: can show the location of intravascular thrombus, but because it is a traumatic examination, some patients with iodine allergy, the examination itself can damage the vascular endothelium to cause thrombosis, so this examination is subject to certain restrictions.

(2) Ultrasound: Dual-dominant scanning can accurately locate the thrombus and is a desirable non-invasive diagnostic technique.

(3) CT and MRI: can clearly and accurately diagnose the infarct lesions of thrombosis in parenchymal organs, but the diagnosis of limb vascular thrombosis is not ideal.

(4) Others: Radioactive fibrinogen test and resistance antibody plethysmography can also be used, and the former is better.

Differential diagnosis

Congenital thrombosis

This is a group of diseases that cause thrombosis due to a link between hereditary coagulation, anticoagulation, and fibrinolysis systems, often occurring in adolescents (Table 1).

The following clinical manifestations often suggest that the disease may be:

1 has a family history of thrombosis.

2 multiple thrombosis without obvious predisposing factors.

3 thrombosis in childhood or adolescence.

4 The effect of conventional antithrombotic therapy is poor. In the suspicious subjects, thrombin time (TT) and euglobulin lysis test (ELT) can be used for preliminary screening: prolongation of TT suggests fibrinogen defects, prolongation of ELT Fibrinolytic activity is reduced; if both tests are normal, it may be a defect of anticoagulant substances. To further determine the specific link of defects, ATIII, protein C, protein S, plasminogen, fibrinogen may be sequentially prepared as needed. The examination of heparin cofactor II, t-PA and PAI, combined with clinical diagnosis.

2. Malignant tumors and thrombosis

The incidence of thrombosis in patients with malignant tumors is 5% to 15%, and pancreatic cancer can reach 50%. The main reason is that the tumor can increase the procoagulant activity, such as factor II, V, VIII: C, IX, X, and sometimes abnormalities. Proteinemia, infiltration and destruction of normal cells by tumor cells, and release of procoagulant substances may cause DIC. In addition, chemotherapy drugs, hormones, infections, surgery, and traumatic exploration may also be used as predisposing factors, and anticoagulant activity of tumor patients is weakened. As AT-III, protein C levels decline, it should be acknowledged that there are many mechanisms that have not been elucidated and are for further study.

3. Systemic lupus erythematosus

4% to 14% of patients can develop thrombosis, the disease is caused by autoimmune mechanism, the anti-phospholipid antibody in the blood can damage the vascular endothelium, so the production of PGI2 and t-PA is reduced; can increase the release of fibronectin (FN) Activation of platelets; the presence of various types of cryoglobulin can cause hyperviscosity syndrome; circulating immune complexes cause endothelial thrombosis and fibrin deposition, which can lead to thrombophlebitis in patients with SLE due to various reasons Necrotizing vasculitis, myocardial infarction, pulmonary embolism, ischemic osteonecrosis, etc.

4. Heart and brain diseases and blood clots

The causal relationship between coronary heart disease and thrombosis has been controversial in the past, whether it is platelet adhesion caused by atherosclerosis, aggregation and activation of the coagulation system to form a thrombus, or hypercoagulable state in patients with coronary heart disease leading to thrombosis, confirmed by a large number of autopsy studies. The correct view is that coronary atherosclerosis is the key to thrombosis in coronary heart disease, which leads to myocardial infarction.

The incidence of ischemic cerebrovascular disease is increasing in China. The embolism is generally younger, caused by abnormal cardiac and coagulation function. The middle-aged and elderly people are more common with thrombosis, with hypertension and atherosclerosis. For the main reason, the mechanism is related to hemodynamics, blood vessels, platelets, coagulation and fibrinolysis.

5. Diabetes and thrombosis

Diabetic patients have a high incidence of atherosclerosis, the incidence of coronary heart disease is 25 times higher than that of the normal population, and domestic data account for 38%. Others can cause retinopathy, gangrene of the extremities, cerebrovascular accidents, etc. Controlling hypercoagulable state is preventing and treating blood vessels. The key to the lesion.

6. Liver, kidney disease and thrombosis

Severe liver disease is often caused by microthrombosis, DIC occurs, the incidence is generally 8.8% to 16%, the mechanism is mainly the activation of coagulation factors, the synthesis of anticoagulant factors is reduced, and the mononuclear-phagocytic system is incomplete.

Thrombosis of kidney disease is mainly seen in nephrotic syndrome, lupus nephritis, microscopic lesions and membranous nephritis. It is more common in renal vein thrombosis and multiple pelvic venous thrombosis, and may also be microthrombotic.

7. Other diseases and blood clots

The relationship between lung disease and thrombosis is also very close, such as chronic obstructive pulmonary disease, thrombosis due to local vascular endothelial injury and hemorheological changes; acute respiratory distress syndrome can cause micro-thrombosis of cellulose; Thromboembolism is mainly caused by other substances, such as amniotic fluid, pyogenic bacteria, tumor cell mass, etc. In addition, hemodialysis, peritoneal dialysis, extracorporeal circulation, artificial valve, organ transplantation, etc. can induce thrombosis, as for surgical scope The thrombosis is not described here.

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