Fondaparinux reduced superficial-vein thrombosis complications, symptomatic extensions

The anticoagulant fondaparinux reduced the risk for symptomatic extensions associated with spontaneous, acute, symptomatic lower-limb superficial-vein thrombosis, according to results of a post-hoc analysis.

Researchers evaluated data from 3,002 patients in the CALISTO study who received placebo (n=1,500) or fondaparinux (n=1,502; Arixtra, GlaxoSmithKline).

The primary endpoint was superficial-vein thrombosis extension — measured as ≤3 cm or >3cm from the saphenofemoral junction — at day 77.

Among patients who received placebo, 54 (3.6%) had symptomatic superficial-vein thrombosis extension to ≤3cm from the saphenofemoral junction and 56 (3.7%) had extension >3cm. These patients then underwent treatment with anticoagulants and saphenofemoral junction ligation.

Subsequent deep vein thrombosis or pulmonary embolism occurred in five (9.3%) of the patients with ≤3cm extensions and five (8.9%) of those with >3cm extensions.

In the fondaparinux group, five patients (0.3%; P<.001) developed superficial-vein thrombosis extension to ≤3cm from the saphenofemoral junction and 12 (0.8%; P<.001) had extension >3cm.

No patients who received fondaparinux developed DVT or PE.

“[This study] shows that symptomatic extensions not reaching the saphenofemoral junction are common and also associated with a significant risk for subsequent deep-vein thrombosis or pulmonary embolism, suggesting that more aggressive therapeutic strategies (anticoagulant treatment and/or surgery) is needed in these patients,” the researchers wrote. “Fondaparinux consistently decreased the risk of symptomatic extensions … [and] was associated with reduced consumption of medical resources, an additional benefit to be taken into account when evaluating the cost-effectiveness of this drug in the treatment of spontaneous, acute, symptomatic superficial-vein thrombosis of the legs.”

Disclosure: The researchers report research grant support, board membership fees, honoraria and consultant fees from Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi-Sankyo, GlaxoSmithKline and Sanofi-Aventis.