VENOUS THROMBOEMBOLISM - RISK OF RECURRENCE

Clinical Bottom Line:
DVT: Patients with DVT, especially those with nontransient risk factors, have a high risk of recurrence

Citation:Prandoni P, Lensing WA, Cogo A et al. The long-term clinical course of acute deep venous thrombosis. Ann Intern Med 1996;125:1-7.

Clinical Question: In a pt with DVT, what is the risk of recurrence at 1 year?

Search terms: "DVT", "prognosi" filter in MEDLINE

The Study

355 consecutive patients with 1^st DVT (confirmed by venography) at referral, information about risk factors was obtained (cancer, recent surgery or trauma, immobilisation>7 days, pregnancy/childbirth, estrogen use)
pts were treated with unfractionated or LMWH
oral anticoagulants started on days 5 to 7 and maintained for 3 months with target INR of 2-3
all pts wore compression stockings

The Evidence

Risk Factor for Recurrent VTE	Hazard Ratio (95%CI)
cancer	1.72 (1.31 to 2.25)
impaired coagulation inhibition	1.44 (1.02 to 2.01)
surgery	0.36 (0.21 to 0.62)
trauma or fracture	0.51 (0.32 to 0.87)

Outcome	Event Rate (95%CI)
Severe post-thrombotic syndrome	2.6% (0.8 to 4.4) at 1 yr 9.3% (18 to 27.5)at 2 yrs
Major bleeding	3.1% at 3 months
Mortality	(12.7 to 20.6) at 1 yr *presence of cancer increased risk of death with hazard ratio of 8.1 (3.6 to 18.1)

Appraised by: Straus, 1998;

Expiry date 1999