First three months of anticoagulation for venous thromboembolism in non-cancer patients: LMWH VS. VKAs. Findings from the RIETE registry

Background: The use of low-molecular-weight heparin (LMWH) for long-term therapy of venous thromboembolism (VTE) in patients without cancer has not been consistently evaluated. Methods: We used the data in the RIETE registry to compare the 3-month outcomes (VTE recurrences, major bleeding or death) in non-cancer patients with VTE, according to long-term therapy with LMWH or vitamin K antagonists (VKAs). Results: As of March 2018, 14,582 non-cancer patients with VTE had received initial therapy with LMWH and then switched to VKAs, while 9151 were prescribed LMWH for initial and long-term therapy. Overall, 11,494 had initially presented with pulmonary embolism (PE) and 12,239 with isolated deep vein thrombosis (DVT). Among 11,494 patients initially presenting with PE, 84 had VTE recurrences, 204 major bleeding and 406 died. Among 12,239 patients with isolated DVT, 133 developed VTE recurrences, 137 bled and 289 died. On propensity score analysis, PE patients on long-term LMWH therapy were at increased risk for PE recurrences (OR: 3.30; 95%CI: 1.67–6.48), major bleeding (OR: 1.68; 95%CI: 1.21–2.32) or death (OR: 3.16; 95%CI: 2.43–4.09) compared with those receiving VKAs. In patients with DVT, those on long-term LMWH also were at increased risk for PE recurrences (OR: 2.31; 95%CI: 1.13–4.73), major bleeding (OR 2.28; 95%CI: 1.51–3.44) or death (OR: 2.32; 95%CI: 1.54–3.51). Conclusions: In the RIETE non-cancer patients with VTE, long-term therapy with VKAs was associated with a lower risk for recurrences, major bleeding or death.