Quality of oral anticoagulation treatment in real-life practice and factors associated with optimal therapeutic response in elderly patients

Introduction. Oral anticoagulation therapy (OAT) is recommended in severalcardiovascular disorders and is increasingly used in elderly patients. Obtaininga stable value of International Normalized Ratio (INR) within the target levelsmay however represent a difficult goal, in this population. Indeed, there is suggestionthat out of range INR values are frequently seen in clinical practice.This fact may be associated with serious adverse events such as bleeding andthromboembolic disorders, which may be often fatal in elderly people. Aim ofthe present study was to evaluate the factors associated with an increased riskof out of range INR levels in this subgroup of patients.Methods. Consecutive patients admitted to the Emergency Department of twoItalian Institutions were analyzed within two hours of their admission. Onlypatients 70 years or older were eligible for the study.Results. 242 patients were enrolled, 151 of whom (62.4%) with abnormal values.When comparing the characteristics of those within or outside the normalrange, it appeared that the former had a higher educational level (27% vs 5%)and more frequently a duration of treatment longer than 5 years (62% vs 27%):OR=7.36; 95% C.I. 3.02-17.95; p < 0.0001, and OR=4.29; 95% C.I. 2.46-7.47;p < 0.0001, respectively.Discussion. The majority of patients in this sample of elderly patients seem unableto maintain optimal INR values. The risk seems higher in patients with alow level of education and with less than 5 year OAT.