The study has been halted prematurely due to a low recruitment.

Often it is necessary to temporarily discontinue OAT when surgical or other invasive procedures are required. However, there is no consensus on the optimal management in these situations, and heparin bridging therapy is the current usual practice in these situations. No large randomized, controlled clinical trials have been yet performed to evaluate the efficacy and safety of a low molecular weight heparins (LMWH) as bridging therapy.

THE MAIN OBJECTIVE of this study is to evaluate the efficacy and safety of the subcutaneous administration of Bemiparin 3,500 IU, for the peri-operative procedural management of patients requiring temporary interruption of oral anticoagulation therapy (OAT).

PRIMARY EFFICACY ENDPOINT: combined incidence of arterial and venous thromboembolic events and deaths from any causes within 3 months after the invasive procedure.

PRIMARY SAFETY ENDPOINT: incidence of major bleeding within 10 days after the invasive procedure.

Inclusion Criteria:

1. Patients over 18 years who have given their informed consent to participate in the study.
2. Patients receiving oral anticogulants during at least 3 months and who require outpatient surgery, laparoscopy surgery or invasive procedures
3. Procedures must be performed from 8 am to 15 pm.

Exclusion Criteria:

1. Patients with severe renal failure (creatinine clearance <30 ml/min) or hepatic insufficiency (AST and/or ALT>5 times the normal value established by the reference range of the local hospital laboratory).
2. Patients who have shown thromboembolic events with an appropriate INR.
3. Known hypersensitivity to LMWH, heparin or substances of porcine origin.
4. Patients with organic lesions susceptible to bleeding (e.g. active peptic ulcer, stroke, aneurysms).
5. Patients with a history of heparin-induced thrombocytopenia.
6. Patients with suspected inability/or inability to comply with treatment and/or complete the study.
7. Patients who are participating in another clinical trial or have been participated in the past 30 days.
8. Patients with antithrombin deficit and C and S protein deficit
9. Women who are pregnant or breast-feeding, or with the possibility of becoming pregnant during the study.
10. Acute bacterial endocarditis or slow endocarditis.
11. Severe arterial hypertension (systolic blood pressure over 200 mmHg and/or diastolic blood pressure over 120 mmHg).
12. Patients with antiplatelet therapy
13. Patients with mechanical cardiac valves in mitral position and body weight 90 Kg with/or bone mass index (BMI) > 30 or 50 kg
14. Patients with Starr-Edwards valves.