Summary
Three-month anticoagulation is recommended to treat provoked or first distal deep-vein
thrombosis (DVT), and indefinite-duration anticoagulation should be considered for
patients with unprovoked proximal, un-provoked recurrent, or cancer-associated DVT.
In the prospective Out-patient Treatment of Deep Vein Thrombosis in Switzerland (OTIS-DVT)
Registry of 502 patients with acute objectively confirmed lower extremity DVT (59%
provoked or first distal DVT; 41% unprovoked proximal, unprovoked recurrent, or cancer-associated
DVT) from 53 private practices and 11 hospitals, we investigated the planned duration
of anticoagulation at the time of treatment initiation. The decision to administer
limited-duration anticoagulation therapy was made in 343 (68%) patients with a median
duration of 107 (interquartile range 91–182) days for provoked or first distal DVT,
and 182 (interquartile range 111–184) days for unprovoked proximal, unprovoked recurrent,
or cancer-associated DVT. Among patients with provoked or first distal DVT, anticoagulation
was recommended for <3 months in 11%, ≥3 months in 63%, and for an indefinite period
in 26%. Among patients with unprovoked proximal, unprovoked recurrent, or cancer-associated
DVT, anticoagulation was recommended for <6 months in 22%, 6–12 months in 38%, and
for an indefinite period in 40%. Overall, there was more frequent planning of indefinite-duration
therapy from hospital physicians as compared with private practice physicians (39%
vs. 28%; p=0.019). Considerable inconsistency in planning the duration of anticoagulation
therapy mandates an improvement in risk stratification of outpatients with acute DVT.
Keywords
Deep-vein thrombosis - anticoagulants - outpatient treatment