Thrombosis

Question 1

What can a bad clot lead to ?

Answer 1

DVT, PE

Question 2

What characteristic features are seem in arterial thrombosis?

Answer 2

fatty streaks in arteries - we will already have some
narrowing of the lumen => plaque rupture
both obesity and smoking exacerbate this condition

Question 3

How many deaths due to VTE occur in Europe?

Answer 3

about 543 454 = exceeds combined deaths due to AIDS, breast cancer, prostate cancer, transport accidents

Question 4

What is the cascade of events with a DVT?

Answer 4

DVT = source clot that tends to occur in lower limb but can also occur in upper limb
=> can lead to a PE which can lead to death/ pulmonary hypertension and then onto death
=> also causes deep vein insufficiency => post-thrombotic syndrome => venous ulcers

Question 5

What is the crude mortality in the elderly of DVT?

Answer 5

15-20% within 3 months of diagnosis

Question 6

What is PTS?

Answer 6

Post-thrombotic syndrome= continuing burden
- after symptomatic DVT
- overall frequency is 20-50%
- severe PTS occurs in 5-10% of patients
pain, swelling and ulceration of the legs

Question 7

What is virchow’s triad?

Answer 7

• alterations in normal blood flow (stasis) - can be due to intrinsic pressure
• injuries to the vascular endothelium
• alterations in the constitution of the blood (hyper coagulability)

Question 8

How much more likely is VT in pregnancy and why?

Answer 8

10x more likely 
- state of hyper coagulability = increased clotting factors, reduced fibrinolysis, increased platelet adhesiveness = in preparation for birth 

Venous stasis resulting from pressure of the gravid uterus on inferior vena cava and decreased venous tone
- may compress R iliac vein therefore always roll pregnancy women onto L side

Question 9

Other than pregnancy when else is the risk of DVT increased?

Answer 9

when in hospital - 100 fold increased risk - give heparin (blood thinning)
- every patient is given a leaflet on DVT pre-admission clinic

Question 10

How does protein C activation occur and what does it do?

Answer 10

stops clot propagating but you need an intact endothelium

• protein c is activated by thrombin-thrombomodulin complex
• activation protein c binds free protein s which then inactivates activated FV and FVIII

Question 11

Which FV is slight resistance to activated protein c?

Answer 11

FV leiden

Question 12

Which SNPs predict risk of VTE recurrence?

Answer 12

F5 FV leiden = non-penetrant 
F2 20210 G>A 
ABO
FGG 10034 C>T 
FXI 

Low GRS (<1risk allele) = 9.4% recurrence at 6 years
high GRS (>5 risk alleles) = 20.3% recurrence at 6 years

Question 13

Why do VTEs arise?

Answer 13

from a combination of interacting genetic and acquired risk factors
with increasing age your risk increases