Problems, interventions and complications in long-term oral anticoagulation therapy.

BACKGROUND: If problems, interventions and complications occurring during oral anticoagulation (OAC) are related with age, indication for OAC, hypertension, diabetes, previous stroke, and number of additional drugs.
MATERIAL AND METHODS: Clinical characteristics, additional drugs, problems, interventions and complications of outpatients whose OAC was controlled between two years were registered. Potential gastrointestinal and urologic bleeding sources were eliminated prior to initiation of OAC. Five-hundred-seventy-nine patients (mean age 65 years, 44% female) were observed for 590 patient-years.
RESULTS: Medical problems occurred in 352/100 patient-years (% p-y), organisational problems in 276% p-y, interventions in 636% p-y and complications in 13.8% p-y. Patients >65 years had less organisational problems (254 vs. 302% p-y, p = 0.0092) and interventions (574 vs. 713% p-y, p = 0.0003) than patients < or =65 years. The 35 patients with heart valve prosthesis had more life-threatening and fatal complications (12% p-y) than the 360 patients with atrial fibrillation (1.0% p-y), 128 patients with venous thromboembolism or 56 patients with other indications (0.0% p-y, p = 0.0024). Problems, interventions and complications were not related with hypertension (n = 297), diabetes (n = 97) or previous stroke (n = 90). Patients with >3 additional drugs/day had a higher complication rate than patients with < or =3 drugs/day (21 vs. 8.7% p-y, p = 0.0238). Patients with complications had more headache (27 vs. 20% p-y, p = 0.0036), chest pain (45 vs. 27% p-y, p = 0.0150), abdominal pain (25 vs. 15% p-y, p = 0.0350) and pain in the limbs (55 vs. 42% p-y, p = 0.0044) than patients without complications.
CONCLUSIONS: By careful monitoring, eliminating potential bleeding sources, treating pain adequately and minimizing additional drugs the complications of OAC can be kept low.