Adherence and Coagulation Assays in Dabigatran-treated Patients With Atrial Fibrillation

Study Overview
=================
Brief Summary
-----------------
In patients with non-valvular atrial fibrillation treated with dabigatran etexilate, the level of adherence will be measured using a questionnaire, the Danish National Prescription Registry and pillcount and will be related to plasma levels of dabigatran measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) and coagulation assays. The aim of the study is to measure the level of adherence and evaluate the usefulness of different coagulation assays to measure adherence in these patients. Furthermore, the aim is to determine the correlation between the anticoagulant effect of dabigatran using different coagulation assays and plasma levels of dabigatran. Most studies so far have been performed in vitro with plasma samples spiked with dabigatran. In this study the present knowledge from results of coagulation assays in dabigatran spiked plasma samples will be compared to the results of coagulation assays using blood samples from real-life patients.

Official Title
-----------------
Adherence and the Role of Coagulation Assays in Patients Treated With Dabigatran Etexilate for Non-valvular Atrial Fibrillation

Conditions
-----------------
Atrial Fibrillation, Medication Adherence, Blood Coagulation Tests, Anticoagulants; Circulating, Hemorrhagic Disorder, Drug Effect, Drug Use, Drug Toxicity, Drug Intolerance, Blood Clot, Blood Coagulation Disorder, Laboratory Problem, Bleeding, Thrombosis

Intervention / Treatment
-----------------
* Other: Bloodtest
* Other: Questionnaires


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age 18 years or older Non-valvular atrial fibrillation Indication for dabigatran etexilate Exclusion Criteria: Use of anticoagulant medication within the last month Contra-indication to dabigatran etexilate Unable or not wishing to give informed consent

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| A healthy volunteers<br>Pre-clinical study. Healthy volunteers. Plasma pooled and spiked with dabigatran. Measurement of plasma concentration of dabigatran with liquid chromatography tandem mass-spectrometry and the anticoagulant effect of dabigatran using coagulation assays. | Other: Bloodtest<br> <br> |
| A patients<br>Pre-clinical study. Patients with atrial fibrillation treated with dabigatran etexilate. | Other: Bloodtest<br> <br> |
| B<br>Patients with an indication for treatment with dabigatran etexilate for atrial fibrillation and intended for electrocardioversion. Inclusion before initiation of anticoagulation. | Other: Bloodtest<br> <br> Other: Questionnaires<br> <br> |
| C<br>Patients with an indication for treatment with dabigatran etexilate for atrial fibrillation. Inclusion before initiation of anticoagulation. | Other: Bloodtest<br> <br> Other: Questionnaires<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Medication adherence Stability after storage at -80 degrees C; correlation between plasma concentration and the anticoagulant effect of dabigatran | Measured by pillcount, bloodtests, the Danish National Prescription Registry and the Morisky Medication Adherence Scale | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient treatment satisfaction | Measured by the Anticlot Treatment Scale | 2 years | 
| Medication persistence | Time from start to end of dabigatran treatment | 2 years | 
| Kidney function | Creatinine and Glomerular Filtration Rate calculated by the Cockroft Gault formula | 2 years | 
| Side-effects | Bleeding, gastrointestinal side-effects | 2 years | 
| Dabigatran plasma concentrations | Measured by liquid-chromatography tandem mass spectrometry (ng/mL) | 2 years | 
| Weight | kilograms | 2 years | 
| Height | meters | 2 years | 
| Waist circumference | centimeters | 2 years | 
| Prothrombin time | seconds | 2 years | 
| Activated partial thromboplastin time | seconds | 2 years | 
| ROTEM | Clotting time (seconds) | 2 years | 
| Diluted thrombin time (calibrated for dabigatran) | ng/mL | 2 years | 
| Ecarin chromogenic assay | ng/mL | 2 years |