Objective Evaluation of the effectiveness and safety of long-term low molecular weight heparin (LMWH) in patients with antiphospholipid syndrome (APS) that had not previously responded to or tolerated oral vitamin K antagonists.

Methods 23 patients with confirmed diagnosis of APS were retrospectively recruited. All patients were receiving LMWH as a result of intolerance and/or lack of response to warfarin therapy. The type of LMWH, the duration of treatment, the reason for switching to LMWH and the adverse effects were recorded. Outcomes were classified as no improvement, partial improvement or total improvement after at least 1 year of using LMWH.

Results The average duration of LMWH treatment was 36 months. Most of the patients were on treatment with enoxaparin (n=16, 69%) and were switched to LMWH from warfarin mainly because of thrombosis despite therapeutic international normalised ratio (n=9, 39%). Good quality of life with no evidence of recurrent thrombotic events was noted in nine patients (39%), whereas 11 (48%) showed partial clinical improvement but no evidence of recurrent thrombotic episodes. Osteoporosis was reported in five patients (23%), all of whom were also receiving treatment with corticosteroids.

Conclusions Long-term LMWH may be a safe and effective alternative to warfarin for APS patients.