Chapter 111. Venous Thrombosis (Part 6) ppsx

Chapter 111. Venous Thrombosis
(Part 6)
Table 111-3 Long-
Term Treatment with Vitamin K Antagonists for
Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE)

Patient Categories Duration,
months
Comments
First episode of DVT
or PE secondary to a transie
nt
(reversible) risk factor
3
Recommendation applies
to both proximal and calf vein
thrombosis
First episode of
idiopathic DVT or PE
6–12
Continuation of
anticoagulant therapy after 6–
12
months may be considered
First episode of DVT
6–12
Continuation of
or PE with a document
ed
thrombophilic abnormality
anticoagulant therapy after 6–

12
months may be considered
First episode of DVT
or PE with documented
antiphospholipid or two or
more thrombophilic
abnormalities
12
Continuation of
anticoagulant therapy aft
er 12
months may be considered


The preferred intensity of VKA treatment for DVT is an INR between 2
and 3. Higher intensities are not more effective, whereas lower intensities are less
effective with a similar bleeding risk. Although VKAs are generally used for long-
term treatment, LMWH is preferred in patients with DVT and concomitant cancer.
This treatment is associated with a lower risk of recurrent thrombosis than VKA
and a similar risk of bleeding.
The role of thrombolytic therapy as well as surgical removal of the
thrombus in the initial treatment of DVT is controversial; the current
recommendations are to refrain from their use with the single exception of patients
with massive, recent ileofemoral DVT at risk of limb gangrene.
Patients with DVT are at risk of developing the postthrombotic syndrome
in the first years after the initial episode. This syndrome can range from mild, with
some swelling and pain at the end of the day, to severe, with massive swelling and
skin ulceration. Graduated elastic compression stockings to the knee with an ankle
pressure of 30–40 mmHg fitted in the first weeks after the initial thrombosis and
worn for 2 years reduce the risk of the postthrombotic syndrome by ~50%.

As a result of the introduction of LMWH for the initial treatment of DVT,
most patients with DVT can be treated at home either entirely or after a short
hospital stay. The LMWH can be self-injected or given by family members or
visiting nurses.
Pulmonary Embolism
The initial treatment with LMWH followed by a VKA for patients with PE
is identical to that for patients with DVT. The intensity and duration of VKA
treatment is also no different (Table 111-3). An alternative for LMWH is
unfractionated heparin, which is still often used. The main disadvantage of
unfractionated heparin is the need for continuous IV infusion and the requirement
of frequent laboratory monitoring and dose adjustments. In contrast, LMWH can
be given in fixed doses adjusted only for body weight. Another alternative for the
initial LMWH therapy is fondaparinux, which can be given as a 2.5-mg once-a-
day SC injection, without laboratory monitoring.
The treatment with LWMH or fondaparinux followed by VKA is indicated
for PE patients who are hemodynamically stable—the great majority of patients.
However, for those patients with PE who are hemodynamically unstable (usually
defined as a systolic blood pressure <90–100 mmHg), a course of thrombolytic
therapy should be considered. When no contraindications for thrombolysis (such
as recent surgery or a bleeding diathesis) exist, this therapy reduces the short-term
risk of recurrent PE or death by ~50% as compared to heparin. Although
streptokinase and urokinase have been used in patients with PE, the most widely
applied regimen is recombinant tissue plasminogen activator r(tPA) (bolus of 10
mg IV, followed by 90 mg in 2 h).
A controversial area is the best therapy for PE patients who are
hemodynamically stable, but who have echocardiographic evidence of right
ventricular dysfunction (usually defined as paradoxical interventricular septal
motion and right ventricular dilatation and impaired systolic function). Although
these patients have a higher mortality risk compared to patients without right
ventricular dysfunction, it is unclear whether more aggressive therapy (with

thrombolytic therapy or catheter removal of thrombus) is beneficial in terms of
mortality, recurrent PE, and major hemorrhage.
Another area of controversy is vena caval interruption, usually with caval
filters. The current recommendation is that a filter, preferably removable, should
be considered only for patients with a contraindication for anticoagulant therapy,
as well as in those with recurrent PE despite adequate treatment.
Further Readings
Colman RW et al (eds): Hemostasis and Thr
ombosis: Basic Principles and
Clinical Practice, 5th ed. Philadelphia, Lippincott Williams & Wilkins, 2006
Prandoni P: Links between arterial and venous disease. J Intern Med
262:341, 2007 [PMID: 17697155]
Rosendaal FR: Venous thrombosis, a multicausal
disease. Lancet 353:1167,
1999 [PMID: 10209995]
The Seventh ACCP Conference on Antithrombotic and Thrombolytic
Therapy. Chest 126(3 Suppl):167S, 2004