Outpatient DVT assessment & treatment Daniel Gilada

Prevalence ~1 million cases a year Nearly 2/3 hospitalized Risk factors HereditaryAcquiredReversibleIrreversible

Diagnosis Duplex ultrasound Sensitivity & specificity of 95 & 98% D-Dimer Contrast venogram

Classification ProvokedUnprovoked

Goals of treatment -Prevent recurrence -Embolism -Thrombosis-related death

Outpatient treatment Physician must assess The patient is ambulatory and in stable condition, with normal vital signs There is a low a prior risk of bleeding in the patient Severe renal insufficiency is not present There is a practical system in place for the following: Administration of LMW heparin and/or warfarin with appropriate monitoring, and Surveillance and treatment of recurrent VTE and bleeding complications

Therapies Warfarin Low-molecular weight heparin Fondaparinux Non-vitamin K antagonist oral anticoagulants (NOACs)

Warfarin Vitamin K antagonist Preferred due to longer clinical experience, available antidotes, and cost Drawbacks 1.5-2x recurrence of DVT if treatment was 4-6 wks vs 3-6 months

Low-molecular weight heparin Indirect Xa inhibitor through ATIII Dosing 1 mg/kg SC BID (ABW) If Cl Cr 20-29mL/min, 1mg/kg SC daily Considerations Potential benefits compared to warfarin Post-thrombotic syndrome Recanalization of thrombosed veins Venous ulceration

Fondaparinux Indirect Xa inhibitor through ATIII Monitoring not required Considerations Like enoxaparin, transition from unfractionated heparin can be immediate

Factor Xa and direct thrombin inhibitors Avoid in CKD Patient preference Considerations Ileofemoral DVT Pregnancy Active cancer Rivaroxaban 15mg BID x 3 weeks; then 20mg daily Apixaban 10mg BID x 1 week; then 5mg BID Dabigatran 150mg BID*

Contraindications Active bleeding Severe bleeding diathesis PLT <50,000 Recent, planned, or emergent surgery/procedure, major trauma History of intracranial hemorrhage

Duration Unprovoked DVT or symptomatic PE Indefinitely Second episode of provoked DVT Provoked DVT with persistent risk factors Provoked DVT with persistent risk factors APS, malignancy

American College of Chest Physicians (ACCP) Guidelines 2012 Isolated distal DVT Severe symptoms Treat 3 months regardless of etiology (surgery, hospitalization, estrogen therapy, vs unprovoked Mild symptoms Physician can do serial ultrasound Treat if clot extension present

ACCP Proximal DVT Traditional treatment 3 months Surgery Estrogen therapy Long-distance travel Inpatient status Indefinite Unprovoked (idiopathic)

ACCP Incidental finding Leg, pelvic, or IVC Standard therapy Cancer associated DVT 3 months Upper extremity DVT 3 months Catheter

ACCP Superficial thrombophlebitis LMWH or fondaparinux 45 days IVC filter Active or high risk bleeding

ACCP Compression stockings 2 years

Other considerations Recurrent unprovoked VTE Recurrent provoked VTE Provoked VTE with persistent risk factors Indefinite Depends on risk factors

DASH prediction score Age ≤ 50+1 Male sex+1 Hormone use at the time of VTE-2 D-dimer+2 DASH score: ≤ 1 annual VTE recurrence risk 3.1% ≥ 2 annual VTE recurrence risk 6.4%

Special populations Pregnancy risk factors >35 yo C-sectionPre-eclampsia Prior DVT history LMWH at least 6 weeks post-partum

IVC filter High bleeding risk Active bleeding, major surgery, hemorrhagic stroke

Other considerations Malignancy decision to anticoagulate for extended periods, should be balanced against the risk of bleeding, cost of therapy, quality of life, life expectancy, and patient preference.

Thrombectomy

References Hopkinsmedicine.orgUptodate.comClevlandclinicmeded.com