Bleeding during oral anticoagulant therapy: warning against a greater hazard.
BACKGROUND
Bleeding is one of the main concerns in patients undergoing oral anticoagulation therapy.


OBJECTIVE
To investigate the determinant causes of bleeding in patients undergoing oral anticoagulant therapy.


METHODS
A total of 360 patients with atrial fibrillation (AF) undergoing oral anticoagulant (ACo) therapy, with a target INR of 2.0-3.5, were followed prospectively for a period of 48 +/- 7.2 months. The patients were evaluated on average every 30 days and were investigated regarding the presence of associated pathology that could lead to bleeding.


RESULTS
A total of 338 patients participated in the present study. Of these, 210 (62.13%) were females. Mitral stenosis was present in 218 patients (64.4%), a mitral biological prosthesis in 64 (18.9%) and mitral valve failure in 56 (16.5%) patients. Bleeding occurred in 65 patients (19.2%), being severe in 7 (10%) patients. In 38/65 patients, a new associated disease was identified, which facilitated bleeding. An associated disease was identified in 100% of the patients with bleeding within the therapeutic range, against 49.05% of associated disease diagnosis in those with an INR > 3.5 (p=0.001).


CONCLUSIONS
The diagnosis of a local disease associated to the bleeding was frequent among those patients undergoing oral anticoagulant therapy (58.5%). There was an association between bleeding with an INR within the therapeutic range (INR=2.0-3.5) and the diagnosis of a pathology predisposing to bleeding (p<0.001). It is mandatory to investigate the cause of bleeding in patients undergoing oral anticoagulant therapy, especially if the INR is within the therapeutic range.
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP - Brasil. m.lavitola@yahoo.com.br
Paulo de Lara
Pde L
Lavítola
Guilherme Sobreira
GS
Spina
Roney Orismar
RO
Sampaio
Flávio
F
Tarasoutchi
Max
M
Grinberg
D000284:Administration, Oral; D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications*; D001938:Brazil / Q000453:epidemiology; D016009:Chi-Square Distribution; D005260:Female; D005767:Gastrointestinal Diseases / Q000517:prevention & control; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced* / Q000453:epidemiology; D005831:Genital Diseases, Female / Q000517:prevention & control; D006801:Humans; D019934:International Normalized Ratio; D007669:Kidney Calculi / Q000150:complications; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012016:Reference Values; D013923:Thromboembolism / Q000517:prevention & control*; D001745:Urinary Bladder Diseases / Q000517:prevention & control; D014592:Uterine Hemorrhage / Q000139:chemically induced* / Q000453:epidemiology
D000925:Anticoagulants