Publication
Quality of vitamin K antagonist oral anticoagulation in 322 patients with atrial fibrillation - real-life data from a survey in Eastern Switzerland
Journal Paper/Review - Oct 6, 2017
Maeder Micha, König Tabea, Bogdanovic Sanja, Schneider Irene, Eugster Werner, Ammann Peter, König Marius, Beer Jürg, Rickli Hans
Units
PubMed
Doi
Citation
Type
Journal
Publication Date
Issn Electronic
Pages
Brief description/objective
AIM OF THE STUDY
To better appreciate the role of the non-vitamin K oral anticoagulants (NOACs) for patients with non-valvular atrial fibrillation in Switzerland we aimed to assess the quality of vitamin K antagonist (VKA) anticoagulation in daily practice.
METHODS
In a cross-sectional study, clinically stable patients on VKA treatment for non-valvular atrial fibrillation for at least 6 months, documentation of international normalised ratio (INR) values for at least 3 months and with at least two INR values were included. The percentage of INR values within the therapeutic range of 2.0 to 3.0 and the time in therapeutic range (TTR; Rosendaal method) and predictors for these measures of VKA anticoagulation quality were assessed.
RESULTS
We studied 332 patients (62% male, mean age 74 ± 9 years) with median (interquartile range) CHA2DS2Vasc and HAS-BLED scores of 4 (3-5) and 3 (2-4) points. The median number of INR values per patient was 8 (5-14), and the average interval between INR measurements was 20 (13-27) days. The percentage of INR values between 2.0 and 3.0 was 67% (50-83%). The median TTR was 69% (51-89%), and TTR ≥65% was found in 202 (61%) patients. Independent predictors of ≥80% INR values between 2.0 and 3.0 included a longer interval between INR measurements and the non-use of spironolactone. The non-use of amiodarone and spironolactone and a longer interval between INR measurements were the only independent predictors of a TTR ≥65%.
CONCLUSIONS
The quality of VKA anticoagulation in Switzerland is highly variable. Importantly, only 60% of patients achieve a TTR ≥65%, which is currently considered to be the minimal acceptable TTR required for VKA therapy. There are few clinical predictors of a good VKA anticoagulation quality. These data may represent a novel basis for decision making regarding the choice of anticoagulation for atrial fibrillation in Switzerland.