Analysis of factors associated with the indication of anticoagulant therapy in chronic atrial fibrillation. Prospective study of 170 patients admitted to an Internal Medicine Department
Vf. Ferrer et al., Analysis of factors associated with the indication of anticoagulant therapy in chronic atrial fibrillation. Prospective study of 170 patients admitted to an Internal Medicine Department, REV CLIN ES, 200(4), 2000, pp. 203-207
Background. Anticoagulant therapy reduces the risk of stroke among patients
with chronic atrial fibrillation. The objective of this study was to evalu
ate the use of anticoagulant therapy and to analyze the factors associated
with the indication of anticoagulants in patients with chronic atrial fibri
llation.
Patients and methods. Prospective study of all patients with chronic atrial
fibrillation admitted to our Department of Internal Medicine from February
1997 to September 1998. From each patient data related to the cause of atr
ial fibrillation, other associated vascular risk factors, use of anticoagul
ant and/or antiplatelet agents and contraindication to anticoagulants were
recorded.
Results. A total of 170 patients with chronic atrial fibrillation were stud
ied. The mean age of patients was 77 years (range: 49-94). One hundred and
four patients (61%) were older than 75 years. Atrial fibrillation was the m
ain cause for admission only in 11 patients (6.5%). One hundred and sixty-s
even patients (98%) had indication for receiving anticoagulant therapy; how
ever, it was indicated in only 67 patients (39%). In other 68 patients (40%
), antiplatelet agents were used. Patients over 75 years received anticoagu
lants less frequently (p<0.0001). Factors associated with the prescription
of anticoagulants in the bivariate analysis included: diabetes mellitus (p
= 0.046), high cholesterol level (p = 0.023), age less than or equal to 75
years old (p < 0.0001), history of previous embolic events (p = 0.001) and
valvular atrial fibrillation (p < 0.0001). The multivariate analysis showed
that only two factors were indeed associated with the prescription of anti
coagulants: age I 75 years (OR: 6.15) and valvular atrial fibrillation (OR:
4.24).
Conclusions. Anticoagulant therapy is underused in patients with chronic at
rial fibrillation, particularly in elderly patients.