Algorhithmic diagnosis of DVT and its treatment with conventional and newer anticoagulants

1. DVT - Diagnosis and management
(Conventional/ NOACS)
Dr Akshay Mehta
Nanavti Superspeciality Hospital
Holy Family Hospital
Hinduja Health Care

2. What percentage of people with
image-documented venous
thrombosis lack specific symptoms ?
• 30 %
• 60%
• 50%
• 15%

3. Clinical suspicion :
• Pts at risk
• Symptoms Pretest likelihood
• Signs

4. Diagnosis of DVT
- an algorithmic approach
Pretest Probability
D Dimer Venous US

5. Risk Factors
• Age
• Immobilization longer than 3 days
• Pregnancy and the postpartum period
• Major surgery in previous 4 weeks
• Long plane or car trips (> 4 hours) in
previous 4 weeks
• Cancer
• Previous DVT
• Stroke
• Acute myocardial infarction (AMI)
• Congestive heart failure (CHF)
• Sepsis
• Nephrotic syndrome
• Ulcerative colitis
• Multiple trauma
• CNS/spinal cord injury
• Burns
• Lower extremity fractures
• Systemic lupus erythematosus (SLE) and
the lupus anticoagulant
• Behçet syndrome
• Homocystinuria
• Polycythemia rubra vera
• Thrombocytosis
• Inherited disorders of
coagulation/fibrinolysis
• Antithrombin III deficiency
• Protein C deficiency
• Protein S deficiency
• Prothrombin 20210A mutation
• Factor V Leiden
• Dysfibrinogenemias and disorders of
plasminogen activation
• Intravenous (IV) drug abuse
• Oral contraceptives
• Estrogens
• Heparin-induced thrombocytopenia (HIT)

6. Common risk factors
• Presence of an acute infectious disease
• Age older than 75 years
• Cancer
• History of prior VTE
• Obesity
• Surgery
• Immobility.
• Genetic thrombophilia is identified in 30% of
patients with idiopathic venous thrombosis

7. Symptoms
• Edema - Most specific symptom
• Leg pain - Occurs in 50% of patients but is
nonspecific
• Tenderness - Occurs in 75% of patients
• Warmth or erythema of the skin over the area of
thrombosis
• Clinical symptoms of pulmonary embolism (PE) as
the primary manifestation

8. Signs
• Calf pain on dorsiflexion of the foot with knee extended
(Homans sign) present in 33% of pts with DVT, 50% of pts
without DVT
• A palpable, indurated, cordlike, tender subcutaneous
venous segment (superficial phlebitis-40% have DVT)
• Variable discoloration of the lower extremity
• Blanched appearance of the leg because of edema
(relatively rare)

9. Pre test probability-Well’s Criteria
Active cancer (any treatment within past 6 months) 1 point
Calf swelling where affected calf circumference measures >3 cm more
than the other calf (measured 10 cm below tibial tuberosity)
1 point
Prominent superficial veins (non-varicose) 1 point
Pitting oedema (confined to symptomatic leg) 1 point
Swelling of entire leg 1 point

10. …contd……Well’s criteria
Localised pain along distribution of deep venous system 1 point
Paralysis, paresis, or recent cast immobilisation of lower
extremities
1 point
Recent bed rest for >3 days or major surgery requiring
regional or general anaesthetic within past 12 weeks
1 point
Previous history of DVT or PE 1 point
Alternative diagnosis at least as probable
Subtract 2 points

11. Well’s score
Wells' score is 2 or greater- DVT likely (40% risk).
Wells' score of <2 – DVT unlikely (<15% probability)

13. Investigations :
• In patients with low pretest probability of DVT or PE
• -high-sensitivity D-dimer
• In patients with intermediate to high pretest
probability of lower-extremity DVT -US
• In patients with intermediate or high pretest
probability of PE, diagnostic imaging studies (eg, VQ
scan, CT angiography)
• Tests for thrombophilia when appropriate

14. The percentage of patients having
silent PE with DVT is :
• 10%
• 40%
• 70%
• 55%

15. Potential complications of DVT
• As many as 40% of patients have silent PE
when symptomatic DVT is diagnosed
• Paradoxic emboli (rare)
• Recurrent DVT
• Postthrombotic syndrome (PTS)

16. Management principles
• The goals of pharmacotherapy for DVT are to reduce
morbidity, prevent post thrombotic syndrome (PTS),
and prevent PE.
• Anticoagulation (mainstay of therapy) - Heparins,
warfarin, factor Xa inhibitors, and various emerging
anticoagulants
• Pharmacologic thrombolysis
• Endovascular and surgical interventions
• Physical measures (eg, elastic compression stockings
and ambulation)

17. Which is better for DVT ?
• Home treatment
• Hospital treatment

19. Contraindications to home treatment
• Suspected or proven concomitant PE
• Significant cardiovascular or pulmonary
comorbidity
• Contraindications to anticoagulation
• Pregnancy
• Morbid obesity (>150 kg)
• Renal failure (creatinine >2 mg/dL)
• Unable to follow instructions or follow up care

22. • Obviate need for heparins or overlap with heparin
• No INR monitoring
• Less bleeding risk

25. A few days’ overlap of VKA with
heparins is required because :
• VKA take a few days to act
• There could be paradoxical increased risk of
clotting when warfarin is initiated alone
because of decreased levels of the vitamin K–
dependent anticoagulant proteins C and S

28. Pradaxa PI[3]; Xarelto PI[1]; Eliquis PI[2]; Savaysa PI.[4]
NOACs in Renal Dysfunction
US Labeling
Dabigatran Rivaroxaban
CrCl > 30 mL/min 150 mg × 2 CrCl > 50 mL/min 20 mg × 1
CrCl 15-30 mL/min 75 mg × 2 CrCl 15-50 mL/min 15 mg × 1
CrCl < 15 mL/min Not recommended CrCl < 15 mL/min Not recommended
Apixaban Edoxaban
≥2 of the following:
age ≥ 80 years,
weight ≤ 60 kg,
serum Cr≥ 1.5 mg/dL
2.5 mg × 2
CrCl > 50 to ≤ 95
mL/min
60 mg × 1
CrCl 15-50 mL/min 30 mg × 1

30. Endovascular therapy
• To reduce the severity and duration of lower-
extremity symptoms
• To prevent PE
• To prevent recurrent VTE
• To prevent PTS

31. CDT: Catheter-directed thrombolysis
• For patients with massive iliofemoral vein thrombosis
associated with limb ischemia or vascular compromise
-ACCP recomm.
• A randomized controlled trial comparing catheter-
directed thrombolysis to conventional anticoagulation
demonstrated a lower incidence of postthrombotic
syndrome and improved iliofemoral patency in patients
with a high proximal DVT and low risk of bleeding.
• Mechanical thrombectomy
• Angioplasty
• Stenting of venous obstructions

32. Are elastic stockings useful to prevent
PTS ?
• RCT - SOX trial 2014
• Meta analysis
• No definite benefit

33. IVC filters
• American Heart Association (AHA) recommendations
for inferior vena cava filters include the following :
• Confirmed acute proximal DVT or acute PE in patients
contraindicated for anticoagulation
• Recurrent thromboembolism while on anticoagulation
• Active bleeding complications requiring termination of
anticoagulation therapy

34. Summary
• Diagnosis of DVT rests on clinical suspicion and interplay
b/w pretest likelihood, D Dimer and US
• Home Rx suffices for most
• Although overlapping heparins and VKA are effective and
std of Rx….
• NOAC’s gaining popularity due to possibility of single drug
therapy from start (Rivaroxaban,Apixaban) or without
overlap with heparin (Dabigatran, Edoxaban)
• Also, more effective with less bleeding
• Convenient
• Duration of Rx depends on whether provoked or not and
bleeding risk.

36. Thank you

37. PE in pts with DVT
• Approximately 4% of individuals treated for
DVT develop symptomatic PE.
• As many as 40% of patients have silent PE
when symptomatic DVT is diagnosed
• Clinical signs and symptoms of PE as the
primary manifestation occur in 10% of
patients with confirmed DVT.

38. DVT in pts with PE
• More than two thirds of patients with proven PE
lack any clinically evident phlebitis.
• Nearly one third of patients with proven PE have
no identifiable source of DVT, despite a thorough
investigation
• Autopsy studies suggest that even when the
source is clinically inapparent, it lies undetected
within the deep venous system of the lower
extremity and pelvis in 90% of cases.

50. NOACS - Extension trials

52. Wells Score Risk Stratification
Probability Score DVT probability
Low risk 0 5%
Moderate risk 1-2 17%
High risk >2 53%

56. Incidence
• DVT is one of the most prevalent medical problems
today, with an annual incidence of 80 cases per
100,000.
• Each year in the United States, more than 200,000
people develop venous thrombosis; of those, 50,000
cases are complicated by PE.
• Lower-extremity DVT is the most common venous
thrombosis, with a prevalence of 1 case per 1000
population.
• In addition, it is the underlying source of 90% of acute
PEs, which cause 25,000 deaths per year in the United
States

57. • With anticoagulation alone, as many as 75% of
patients with symptomatic DVT present with
PTS at 5-10 years.[40, 41] However, the
incidence of venous ulceration is far less, at
5%.

58. Lower-extremity deep venous
thrombosis
• In the postoperative patient, as many as one half of all isolated calf
vein thrombi resolve spontaneously within a few hours
• , whereas approximately 15% extend to involve the femoral vein.
• A many as one third of untreated symptomatic calf vein DVT extend
to the proximal veins.[44]
• At 1-month follow-up of untreated proximal DVT, 20% regress and
25% propagate.
• Although calf vein thrombi are rare sources of clinically significant
PE, the incidence of PE with untreated proximal thrombi is 29-
50%.[44, 45]
• Most PEs are first diagnosed at autopsy.

59. • Upper-extremity deep venous thrombosis
• The 2 forms of upper-extremity DVT are (1)
effort-induced thrombosis (Paget-von
Schrötter syndrome) and (2) secondary
thrombosis.

60. • The main laboratory studies to be considered
include the following:
• D-dimer testing
• Coagulation studies (eg, prothrombin time
and activated partial thromboplastin time) to
evaluate for a hypercoagulable state