Age is associated with time in therapeutic range for warfarin therapy in patients with atrial fibrillation

Abstract

BackgroundWarfarin is the most prescribed oral anticoagulant used for preventing stroke in patients with atrial fibrillation. Time in the therapeutic range (TTR) has been accepted as the best method to evaluate the quality of warfarin therapy. The main aim of the present study was to evaluate the impact of variables on the time in the therapeutic range for warfarin therapy in patients with atrial fibrillation from a referral cardiovascular hospital.MethodsThis retrospective study included 443 patients were included (190 patients with age < 65 years and 253 patients with age ≥65 years) from 2011 to 2014 and TTR was computed according to Rosendaal's method.ResultsPatients with age ≥65 years had higher TTR value (67±22%) compared with patients with < 65 years (60±24%) (p = 0.004). In a linear regression model, only age ≥65 years emerged as a significant predictor of greater TTR values. In multivariate logistic regression model, the variable age ≥65 years was associated with higher OR for having a TTR higher than the median value (OR = 2.17, p < 0.001).ConclusionWe suggest that the age influenced TTR through greater drug adherence. Strategies for increasing drug adherence might improve quality of warfarin anticoagulation.

Quality control of oral anticoagulation with vitamin K antagonists in primary care patients in Poland: a multi-centre study

“…We also revealed that patients aged up to 60 years had worse oral anticoagulation control than older individuals. Similar results were presented by other authors, who also suggested that younger age was associated with poorer anticoagulant control [14], that patients aged ≥ 65 years had higher TTR value than patients < 65 years, and that age had an influence on TTR through greater drug adherence [20].…”

<p>Polymorphisms of <em>CYP2C9*2</em>, <em>CYP2C9*3</em> and <em>VKORC1</em> genes related to time in therapeutic range in patients with atrial fibrillation using warfarin</p>

“…Measurement of the quality of anticoagulation evaluates whether therapy is being maintained within a therapeutic range. A high TTR is associated with a reduced risk of thromboembolic and/or hemorrhagic events, indicating a good quality of treatment 11. For TTR values below 60%, the use of strategies that promote the stimulation of adherence and other related actions for patients with TTR below the range is recommended 12,13,14…”

Evaluation of the Long-Term Impact on Quality After the End of Pharmacist-Driven Warfarin Therapy Management in Patients With Poor Quality of Anticoagulation Therapy

“…It is likely that all patients included in the study did not reach an optimal control of >70% because our sample is composed of patients with poor quality of anticoagulation with warfarin, which makes it harder to reach an optimal control. In addition, many factors were related to poor anticoagulation control, such as dietary habits, concomitant therapy, comorbidities, genetics and others ( Santos et al., 2013 ; Marcatto et al., 2016b ). “Although the literature shows that many factors can influence warfarin dose, we did not find these significant associations in our study, probably due to our specific type of patient cohort and selection methods.…”