Purpose: We have studied the haemorrhagic episodes occurred in patients treated with oral anticoagulants, with special reference to their type, frequency and severity and analyzing the risk factors that could influence in their production.
Patients and methods: We carried out a retrospective study in 435 patients of the haemorrhagic episodes occurred since January 1989 to December 1991, determining in each one the prothrombin time expressed as INR, the time from the beginning of treatment, the patient's age and the known or underlying pathologies that could predispose to haemorrhage; depending on their severity these episodes were classified as moderate and major.
Results: We observed 50 haemorrhagic episodes in 50 patients (11.5%) which represents 7 x 100 patient/years, 30 (6.8% of the total patients or 4.2 x 100 patient-years) were moderate and 20 (4.5% of the total patients or 2.8 x 100 patient/years) were major. The mean age in patients with haemorrhage was 50.5 years. The incidence of hemorrhages in the first month of treatment was 60.8 x 100 patient/years; 9.4 x 100 patient/years in the period from the first month to the first year of treatment; and 3.6 x 100 patient/years in the period from the first year of treatment. The most frequent type of haemorrhage among the moderate ones was haematuria (46%) and among major ones digestive haemorrhages (26%). Depending on the coagulation level, 37 patients (66%) were within therapeutical range. Depending on patients' sex, the incidence was 23 (46%) males and 27 (54%) females. We observed at risk predisposing factors hypertension (18%), stroke (12%), hepatic disease (8%) and myocardial infarction (8%).
Conclusion: We have found no relationship between haemorrhagic episodes and patients' age or sex. The risk of haemorrhage is higher at the beginning of the treatment and increases with the level of anticoagulation, which makes the beginning of treatment with lower doses more desirable, increasing them progressively until the desired level is achieved. Previous hypertension, stroke, hepatic disease and myocardial infarction are factors predisposing to haemorrhage.