Evaluation of Risk Factors for Stroke/Embolism and of Complications Due to Anticoagulant Therapy in Atrial Fibrillation

BACKGROUND AND PURPOSE: We sought to assess in outpatients with atrial fibrillation and oral anticoagulation (1) whether the complication rate is influenced by the presence of the risk factors age >65 years, arterial hypertension, diabetes, or previous stroke; (2) whether the complication rate is influenced by the number of additional drugs taken by patients; and (3) whether problems and interventions differ between patients with or without complications. METHODS: - Clinical characteristics, drugs, problems, interventions, and complications were registered during 2 years. RESULTS: - Three hundred sixty patients (mean age, 68 years; 43% female) were observed for 383 patient-years. Patients aged >65 years had more serious, life-threatening, or fatal complications (11% versus 5.3%/100 patient-years; P=0.0428) than younger patients. Patients with diabetes had more life-threatening and fatal complications (2.8% versus 0.6%/100 patient-years; P=0.0354) than patients without. The complication rate did not differ regarding the presence of previous stroke or hypertension. Patients who took </=3 drugs had fewer complications than patients who took more (4.3% versus 24.4%/100 patient-years; P=0.0041). Patients with complications complained more of chest (48% versus 28%/100 patient-years; P=0.0113) and abdominal pain (30% versus 13%/100 patient-years; P=0.0057), more frequently failed to keep appointments (134% versus 107%/100 patient-years; P=0.0321), had a higher tracking rate (134% versus 105%/100 patient-years; P=0.0272), and took more additional drugs (4.6 versus 3.5 drugs per day; P=0.0063) than patients with no complications. CONCLUSIONS: - Patients with increased age or diabetes mellitus or those who take >3 drugs per day have an increased complication rate and thus need especially careful monitoring of oral anticoagulation, including adequate pain control.