From clinical trials to clinical practice: oral anticoagulation among patients with non-rheumatic, atrial fibrillation

Objectives: The aim of the present study was to evaluate the impact of the results of clinical trials on the prophylactic treatment of non-rheumatic atrial fibrillation with oral anticoagulants. Methods: Retrospectively, we studied a random sample of 375 patients discharged from our hospital with a diagnosis of non-rheumatic atrial fibrillation between 1991 and 1993. Information about diagnoses, other clinical variables and treatments prescribed at discharge was obtained from the hospital medical records. Results: During the whole study period, 14% of patients were prescribed an oral anticoagulant agent and 17% were prescribed acetylsalicylic acid. A non-significant increase in the proportion of patients prescribed oral anticoagulant drugs, from 9% to 17%, was observed. Multivariate analysis showed that a history of stroke (OR = 5.96) and younger age were significantly associated with the prescription of oral anticoagulants. ASA prescription was strongly associated with a history of concomitant vascular disease (OR = 5.8), but not with other risk factors for stroke. Sixty-five percent of patients had one or more risk factors for stroke, did not present any contraindications to anticoagulant agents, but nevertheless were not prescribed one of these drugs. Conclusions: Anticoagulant agents and acetylsalicylic acid were largely underprescribed to patients with nonrheumatic atrial fibrillation, and oral anticoagulants were not prescribed according to the individual patients' risk of stroke.