Treatment Approach Valvular Heart Disease, HIT, Anticoagulation Reversal

Question 1

main types of valvular heart disease

Answer 1

1. stenosis: calcification and narrowing of the valve (decreases ability to push blood)
2. regurgitation: blood flow backwards through the valve

Question 2

aortic valve disease

Answer 2

• most common valvular disease
• often occurs as patients age
• decreases cardiac output

Question 3

types of aortic valve replacements

Answer 3

1. surgical aortic valve replacement (SAVR): requires open heart surgery for mechanical or bioprosthetic valve
2. transcatheter aortic valve replacement (TAVR): percutaneous access (less invasive catherization procedure) for only bioprosthetic valve

Question 4

mechanical aortic valve

Answer 4

• last 20-30 years
• risk of thromboembolism is higher
• requires lifelong anticoagulation with warfarin (INR goal 2-3)

Question 4

mitral stenosis

Answer 4

• most commonly from rheumatic fever
• may require mitral valve replacement if too severe

Question 4

mitral regurgitation

Answer 4

• most common mitral valve disease
• often due to HF
• can treat this with adequate diuresis

Question 5

bioprosthetic aortic/mitral valve

Answer 5

• lasts about 10 years
• risk of thromboembolism is lower
• requires about 3 months of anticoagulation or antiplatelet therapy

Question 6

mechanical mitral valve

Answer 6

• lasts 20-30 years
• risk of thromboembolism is higher
• requires lifelong anticoagulation with warfarin (INR goal 2.5-3.5)

Question 7

Heparin Induced Thrombocytopenia (HIT)

Answer 7

prothrombotic disorder associated with unfractionated heparin or low molecular weight heparin

UFH: 5% of patients
LMWH: 0.5-1% of patients

Question 8

types of HIT

Answer 8

1. HIT = isolated HIT (labs are positive but patient doesn’t have a clot)
2. HITT = HIT complicated by thrombosis

Question 9

risk factors for HIT

Answer 9

1.source of heparin
* bovine > porcine

2.type of heparin product used
* UFH>LMWH

3.patient population
* surgical patients>medical and obstetric patients

4.duration of exposure
* longer exposure is higher risk

5.route of admin
* IV>SQ

Question 10

diagnosis of HIT

Answer 10

1. platelet trend decreasing while patient receiving heparin or LMWH
2. determine pretest probability score using 4T score
3. if score is not low, stop all heparin, consider alternative anticoagulant, and send testing
4. PF4 IgG ELISA Immunoassay or Serotonin Release Assay

Question 11

treatment choices for HIT

Answer 11

non-heparin anticoagulants for selection: argatroban, bivalirudin, fondaparinux, or DOAC

Question 12

DOAC treatment choice for HIT

Answer 12

• HIT: rivaroxaban 15 mg bid until platelets 150k then 20 mg daily for 30 days
• HITT: rivaroxaban 15 mg bid for 3 weeks then 20 mg daily for 3 months

Question 13

transition from DTI to warfarin

Answer 13

1. stop heparin and let platelets recover to 150k
2. administer 5 doses of warfarin overlap with DTI
3. if INR >4 stop argatroban, if INR >3 stop bivalirudin
4. recheck ptt/inr in 2-4 hours
5. if ptt baseline and inr in range (2-3), leave DTI off
6. if ptt baseline and inr below range, restart DTI

Question 14

when do we reverse anticoagulation?

Answer 14

for life-threatening bleeds or an urgent surgery/procedure

prefer to washout instead of reversal

Question 15

reversal agent for warfarin

Answer 15

1. specific: vitamin k
2. nonspecific: fresh frozen plasma or PCC

Question 16

reversal agent for apixaban, rivaroxaban, edoxaban

Answer 16

1. specific: andexxa
2. nonspecifc: PCC

Question 17

reversal agent for dabigatran

Answer 17

specific: praxbind
nonspecific: activated PCC

Question 18

reversal agent for heparin and LMWH

Answer 18

protamine

Question 19

onset for reversal agents

Answer 19

• andexxa: 2 minutes
• PCC: 10 minutes
• praxbind: 5 minutes
• activated PCC: 30 minutes
• vitamin k: 10-12 hours (no SQ)

po vitamin k: 24-48 hour
iv vitamin k: 12 hours but full effect 24 hours

Question 20

warfarin reversal in non-bleeding patients

Answer 20

1.if INR 3-4.5 w/o bleeding
* omit doses of warfarin recheck INR in 3-7 days

2.INR 4.5-10 w/o bleeding
* risk factors for bleeding: omit doses of warfarin, provide 5 mg oral vitamin k and recheck INR in 24 houra
* no risk factors for bleeding: omit doses of warfarin, recheck INR in 3-7 days

3.INR > 10 without bleeding
* omit doses of warfarin, provide 5 mg oral vitamin k and recheck INR in 24 hours

Question 21

heparin reversal

Answer 21

1 mg protamine neutralizes 100 units of heparin
* Patient on a heparin infusion: calculate heparin given in
last 3 hours
* Past hour = give 1 mg per 100 units
* Two hours = give 0.5 mg per 100 units
* Three hours = give 0.25 mg 100 units
* Max dose = 50 mg

Question 22

LMWH reversal

Answer 22

1 mg protamine neutralizes about 1 mg of enoxaparin
* If LMWH dose was given within 8 hours,
administer 1 mg protamine per 1 mg of
enoxaparin
* If LMWH dose was given more than 8 hours
before protamine, administer 0.5 mg per 1 mg of
enoxaparin
* Max dose = 50 mg