Evaluation of risk factors for stroke/embolism and of complications due toanticoagulant therapy in atrial fibrillation

Background and Purpose-We sought to assess in outpatients with atrial fibri llation and oral anticoagulation (1) whether the complication rate is influ enced by the presence of the risk factors age > 65 years, arterial hyperten sion, diabetes, or previous stroke; (2) whether the complication rate is in fluenced by the number of additional drugs taken by patients; and (3) wheth er problems and interventions differ between patients with or without compl ications. Methods-Clinical characteristics, drugs, problems, interventions, and compl ications 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-thr eatening and fatal complications (2.8% versus 0.6%/100 patient-years; P=0.0 354) than patients without. The complication rate did not differ regarding the presence of previous stroke or hypertension. Patients who took :less th an or equal to3 drugs had fewer complications than patients who took more ( 4.3%a versus 24.4%/100 patient-years; P=0.0041). Patients with complication s 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 frequent ly failed to keep appointments (134% versus 107%/100 patient-years; P=0.032 1), had a higher tracking rate (134% versus 105%/100 patient-years; P=0.027 2), 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 t ake >3 drugs per day have an increased complication rate and thus need espe cially careful monitoring of oral anticoagulation, including adequate pain control.