Prophylaxis In Venous Thromboembolism In Primary Care, A Pilot Study

Inclusion Criteria: * Age \> 65 years * Confinement to bed for more than 3 days, due to: * Heart failure * Exacerbated chronic obstructive pulmonary disease * Acute rheumatic involvement * Written informed consent Exclusion Criteria: 1. Cancer 2. Anticoagulant treatment in the previous 3 months 3. Stroke or major surgery in the previous 3 months 4. Systolic pressure \>200 mmHg or diastolic pressure \>120 mmHg 5. Known chronic hepatopathy 6. Active hemorrhage in any site in the previous 3 months 7. Active peptic ulcer 8. Bacterial endocarditis 9. Conditions that can increase the risk of hemorrhage 10. Known coagulation disorders 11. Hypersensitivity to heparin or HIT 12. Life expectancy of less than 3 months 13. Previous confinement to bed during more than 3 days