Long-term low-molecular-weight heparin versus usual care in proximal-vein thrombosis patients with cancer.
OBJECTIVE
A substantial clinical need exists for an alternative to vitamin K antagonists for treating deep-vein thrombosis in cancer patients who are at high risk of both recurrent venous thromboembolism and bleeding. Low-molecular-weight heparin, body-weight adjusted, avoids anticoagulant monitoring and has been shown to be more effective than vitamin-K-antagonist therapy.


METHODS
Subjects were patients with cancer and acute symptomatic proximal-vein thrombosis. We performed a multi-centre randomized, open-label clinical trial using objective outcome measures comparing long-term therapeutic tinzaparin subcutaneously once daily with usual-care long-term vitamin-K-antagonist therapy for 3 months. Outcomes were assessed at 3 and 12 months.


RESULTS
Of 200 patients, 100 received tinzaparin and 100 received usual care. At 12 months, the usual-care group had an excess of recurrent venous thromboembolism; 16 of 100 (16%) versus 7 of 100 (7%) receiving low-molecular-weight heparin (P=.044; risk ratio=.44; absolute difference -9.0; 95% confidence interval [CI], -21.7 to -0.7). Bleeding, largely minor, occurred in 27 patients (27%) receiving tinzaparin and 24 patients (24%) receiving usual care (absolute difference -3.0; 95% CI, -9.1 to 15.1). In patients without additional risk factors for bleeding at the time of randomization, major bleeding occurred in 0 of 51 patients (0%) receiving tinzaparin and 1 of 48 patients (2.1%) receiving usual care. Mortality at 1 year was high, reflecting the severity of the cancers; 47% in each group died.


CONCLUSIONS
Our findings confirm the limited but benchmark data in the literature that long-term low-molecular-weight heparin is more effective than vitamin-K-antagonist therapy for preventing recurrent venous thromboembolism in patients with cancer and proximal venous thrombosis.
Hull
Russell D
RD
University of Calgary, Calgary, Alta, Canada. jeanne.sheldon@calgaryhealthregion.ca
Pineo
Graham F
GF
Brant
Rollin F
RF
Mah
Andrew F
AF
Burke
Natasha
N
Dear
Richard
R
Wong
Turnly
T
Cook
Roy
R
Solymoss
Susan
S
Poon
Man-Chiu
MC
Raskob
Gary
G
D000328:Adult; D000368:Aged; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D013997:Time Factors; D000078222:Tinzaparin; D020246:Venous Thrombosis / Q000188:drug therapy* / Q000209:etiology*
D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D000078222:Tinzaparin