Haemorrhagic and thromboembolic complications in patients with atrial fibrillation on anticoagulant prophylaxis.

We studied clinically relevant haemorrhagic and thromboembolic events in 213 patients with atrial fibrillation (AF) during 818 patient-years of anticoagulant (AC) treatment. The incidence of complicating events per 100 patient-years of treatment in three groups of patients, those with mitral valve disease (MVD; n = 34), without MVD (n = 102) and those with previous thromboembolism (TE; n = 77) was: major peripheral haemorrhages 3.1, 3.3 and 8.2 (non-MVD vs. TE group, P less than 0.05), cerebrovascular events 3.9, 3.0 and 3.0 (NS), and peripheral arterial thromboembolism 0, 0 and 1.5 (non-MVD vs. TE group, P less than 0.05). The proportion of thrombotest values less than 5 and/or greater than 20% at regular check-ups was 9.8% in patients with and 6.9% in patients without major peripheral haemorrhages (P less than 0.01). Major peripheral haemorrhages are frequent in patients with AF receiving AC treatment. They are most likely to occur in those with previous thromboembolism and among those with unstable AC control.