Vascular-ABCs of AC

Question 1

Symptoms of VTE (Venous thromboembolism)

Answer 1

-Swelling, pain, cramping, redness

Question 2

Dx of VTE

Answer 2

-WELLS criteria
-Doppler US
-CT Venogram
-May-Thurner Syndrome: hemodynamically significant compression of the left common iliac vein by the right common iliac artery.

Question 3

Risk Factors for VTE

Answer 3

-Surgery, trauma, prolonged immobilization
-Pregnancy or childbirth or estrogen use (3 months to wear off)
-Genetic or autoimmune thrombophilias
-Underlying disease
-Cancer
-Multifactorial blood clots

Question 4

Treatment for VTE

Answer 4

-AC is the mainstay tx
-Rare cases for thrombolysis or thrombectomy
-Phlegmasia Alba or Cerulea Dolans (“milk leg”)-triad of edema, pain, and white blanching skin without cyanosis.

Question 5

When not to treat VTE

Answer 5

-Patients with active bleeding or who are at risk for substantial bleeding. IVC filter needed?
-Superficial thrombophlebitis is treated with compression, warmth, anti-inflammatories.
-Surveillance Ultrasound can be done weekly x 3 weeks in isolated calf vein thrombosis in patients at risk for bleeding.

Question 6

When not to Anticoagulate: Absolute contraindications

Answer 6

Active bleeding
Severe bleeding diathesis
Recent, planned or emergency high bleeding-risk surgery/procedure
Major trauma
ICH
Cerebral amyloidosis with ICH hx
—Consider IVC in these cases

Question 7

When not to anticoagulated; Relative contraindications

Answer 7

●Recurrent bleeding from multiple gastrointestinal telangiectasias
●Intracranial or spinal tumors
●Large abdominal aortic aneurysm with concurrent severe hypertension
●Stable aortic dissection
●Recent, planned, or emergent low bleeding-risk surgery/procedure
-Thrombocytopenia is not always a contraindication to anticoagulation
-Patients with a history of intracranial hemorrhage

Question 8

Anticoagulant Options: Outpatient

Answer 8

-Low-molecular weight heparin
Enoxaparin (Lovenox)
Dalteparin (Fragmin)
-Very-Low-molecular weight heparin
Fondaparinux (Arixtra)
-Warfarin
-Direct Oral Anticoagulants (DOACs)
Apixaban (Eliquis)
Rivaroxaban (Xarelto)
Dabigatran (Pradaxa)
Edoxaban (Savaysa)

Question 9

Anticoagulants: Inpatient

Answer 9

-IV unfractionated heparin: if patient is unstable or at high risk for bleeding, this may be the first best choice. Can be “turned off” quickly
-Subcu low-molecular weight heparin. Check creatinine first.
-Other choices include direct thrombin inhibitors (argatroban or bivalirudin) in patients with heparin allergy
-Oral agents

Question 10

Antiplatelet Agents

Answer 10

-ASA-can be used as primary or secondary prevention of arterial thrombosis, VTE prophylaxis and tx of superficial thrombophlebitis
-Plavix (clopidogrel)-Used primarily after arterial or venous stent placements to keep stents patent. Often prescribed for 6 months-1 year after DES placement. Also used as 2nd line therapy after failure of aspirin.
-Brillinta (ticagrelor)
-Effient (prasugrel)

Question 11

Heparin

Answer 11

-Heparin blocks the activation of factor IX and neutralizes activated factor X by activating factor X inhibitor.

Question 12

Warfarin Sodium or Jantoven

Answer 12

-Vit. K antagonist
-Peak Response: The peak anticoagulant effect of warfarin usually occurs within 72 to 96 hrs.
-Duration: Anticoagulation. Following a single dose of warfarin, the duration of action was 2 to 5 days.
-Warfarin sodium is an anticoagulant that works by inhibiting synthesis of vitamin K-dependent clotting factors which include factors 2, 7, 9 and 10, (II, VII, IX and X), and the anticoagulant proteins C and S.

Question 13

Pradaxa (dabigatran), Argatroban, Bivalirudin

Answer 13

-Direct thrombin inhibitors
-By reversibly binding to the thrombin active site, they act as a direct thrombin inhibitor
-Pradaxa Dosing: 5 days minimum of parenteral anticoagulation (Lovenox). Then 150 mg twice daily.
-Can be used as a bridge to warfarin.

Question 14

Eliquis (apixaban), Savaysa (edoxaban), Xarelto (rivaroxaban)

Answer 14

-Anti-Xa Inhibitors
-Direct factor Xa inhibitors: are selective active site inhibitors of factor Xa without the need of a cofactor (e.g. anti-thrombin III)-for activity
-VTE Dosing: Individualized for each drug. Eliquis 10 mg twice daily for 7 days then 5 mg twice daily. Savaysa 60mg daily after 5 days parenteral therapy, Xarelto 15mg twice daily for 3 weeks then 20 mg once daily.
-Dosing for A fib varies from dosing for VTE: Look up dosing when prescribing, if not familiar.

Question 15

Enoxaparin (Lovenox): Clinical Practice

Answer 15

-Injectable
-No IV heparin or injectable needed prior to starting
-Dosing: BID 1mg/kg, Once daily 1.5mg/kg, Prevention: 40 mg daily
-Monitoring not regularly done
-Minimal medication interactions, no special diet or activities
-No antidote: partial reversal with protamine and andexanet alpha (Andexxa).
-out of the system in 12-24 hrs
-Not used in pts with creatinine clearance <30 mL/min
-Morbid obesity-check anti Xa hep level to see if therapeutic-often underdosed
-Don’t use in dialysis patients

Question 16

Warfarin (Jantoven) (Coumadin): Clinical Practice

Answer 16

-Pill form
-Need injectable or IV heparin for bridging for 5-10 days
-INR dosing, taken once daily in PM
-Many medication interactions, special diet (avoid foods high in vitamin K) and activities
-No antidote: reversal with Vit K & plasma products
-Out of the system in 5 days

Question 17

Dabigatran (Pradaxa): Clinical Practice

Answer 17

-Pill Needs to be stored in original bottle.
-Needs bridging with IV injectable or IV heparin for 5-10 days
-Treatment: 150mg twice daily/Prevention: 110mg first day, then 220 mg daily.
-Monitoring not regularly done
-Low medication interactions, no special diet or activities
-Antidote: available-Idarucizumab (Praxbind)
-Out of the system in 3 days

Question 18

Rivaroxaban (Xarelto): Clinical Practice

Answer 18

-Pill: Take with biggest meal of the day
-No bridging
-Treatment: 15 mg twice daily for first 21 days. 20 mg daily thereafter. Prevention: 10 mg daily.
-Monitoring not regularly done
-Medications low interaction, no special diet or activities

Question 19

Apixaban (Eliquis): Clinical Practice

Answer 19

-Pill form
-No bridging
-Treatment: 10 mg twice daily for 7 days, 5 mg twice daily thereafter. Preventions: 2.5 mg twice daily.
-No regular monitoring
-Low medication interactions, no special diet or activities
-Antidote available in some locations: (Andexxa), possible reversal with Kcentra/Bebulin
-Out of the system in 2 days

Question 20

Edoxaban (Savaysa): Clinical Practice

Answer 20

-Pill form
-Bridging for 5 days with injectable or IV heparin
-Treatment: 60 mg daily. Prevention: 30 mg daily.
-No monitoring, low med interactions, no special diet or activities
-Antidote available in some locations: . (Andexxa, but not FDA approved), possible reversal with Kcentra/Bebulin
-Out of system in 2 days

Question 21

Provoked DVT or PE

Answer 21

-Tx: 3 months of AC followed by reassessment with Duplex US
-If provoking event is NOT resolved, consider carefully whether to end anticoagulant therapy.

Question 22

Unprovoked DVT or PE

Answer 22

-Consider all causes
-Genetic, Cancer, Idiopathic-consider lifelong AC

Question 23

Prophylaxis VTE

Answer 23

Heparin 5,000 units subcu t.i.d.
Lovenox 40 mg subcu daily.
Eliquis: Amplify-Extend trial, 2.5 mg b.i.d.
Xarelto: Einstein-Choice trial, 10 mg daily.

For surgical patients: The Caprini Score for Venous Thromboembolism (2005) stratifies risk of VTE in surgical patients. Use MDCalc.

Question 24

Post-phlebitis Syndrome

Answer 24

-Chronic edema with ulceration
-This is why compression is so important in pts with DVT and swelling.
-Other causes of venous stasis is: PAD, immobility, obesity, impaired circulation.
-Tx aimed to prevent venous stasis ulcers: Compression is key
-Encourage walking
-If they have chronic swelling, then they need compression to help prevent venous stasis dermatitis and skin changes that can lead to ulceration

Question 25

Types of blood clots: Arterial and Risk factors

Answer 25

-CVA (stroke)-thromboembolic vs. atherosclerotic
-TIA (ministroke)
-Arterial embolism
-Afib (CHA(2)DS(2)-VASc)
-Mechanical heart valve
-Prior Arterial Thrombosis
-Antiphospholipid Antibody Syndrome
-PFO with right-to-left shunt (Paradoxical)
-Low Ejection Fraction

Question 26

Mechanical Heart Valves

Answer 26

-Warfarin is the recommended anticoagulant for mechanical heart valves lifelong. DOACs are not acceptable. (Bioprosthetic valves need 3 months of warfarin therapy.)
-Goal INR range: Defined by cardiologist. 2.0-3.0 for Aortic, and 2.5-3.5 for all others.
-Aortic valves with NO history of A fib or stroke do not require bridging with Lovenox. All others do require bridging.

Question 27

Arterial Embolism

Answer 27

-Cause is what guides Tx
-Start with TTE, Carotid US or CTA neck, holter monitor
-PFO-get TEE with bubble study
-US to look for DVT

Question 28

Managing Bleeding Complications

Answer 28

-Assess underlying cause
-Drug-drug interactions
-Renal failure or liver disease
-Caution in holding ACs-remember why they’re on them in the first place

Question 29

Heparin–induced Thrombocytopenia

Answer 29

-Platelet decrease by 50% or more from initial count after exposure to heparin. Get Hematology consult.
-Treatment involves stopping all heparin immediately and giving an alternative thrombin inhibitor.
i.e Bivalirudin

Question 30

Assess for Clots: background workup

Answer 30

-Genetic testing: Thrombophilias i.e (Factor V Leiden, Prothrombin G20210A, Protein S def, Protein C def, Antithrombin III, MTHFR-don’t test this, JAK2 Mutation-heme consult, PNH (paroxysmal nocturnal hemoglobinuria)
-Lupus testing-best done with pt not on AC
-Cancer