Introduction: Atrial fibrillation (AF) is the most common arrhythmia that increases by age, doubles for every decade after age of 50 years and reaches about 10% patients ≥ 80 years. Despite direct oral anticoagulants (DOACs’) predictable pharmacokinetics and pharmacodynamics, the laboratory tests are necessary for effective and safe medical treatment, also for prediction and detection of thrombotic and bleeding events, as well as in situations when temporary discontinuation could be desirable.
Aim: of this study was to identify and analyze the need of coagulation tests for AF patients with high cardiovascular risk in clinical practice.
Methods: Quantitative, analytic, cross-sectional clinical trial, during the period from October 2016 till June 2017, was performed at Pauls Stradins Clinical University Hospital, Center of Cardiology, Latvia. There were collected data about patients with non-valvular AF, under anticoagulative therapy ≥ 3 months, defined as a high-risk group by CHA2DS2 -VASc score-more or equal to 2 or 3, men and women respectively. Data were analyzed using SPSS.
Results: There were collected data about 143 patients of whom 46.2% (n=66) were male; the mean age was 69.7 (SD ± 9.9) years. About 2/3 (73.1%) of all patients the AF were longer than 1 year. The mean CHA2DS2 -VASc score was 4.2 (SD ± 1.5). The most common comorbidies were arterial hypertension (65.0%; 93), chronic heart failure (48.3%; 69), coronary artery disease (32.9%; 47), diabetes mellitus (24.5%; 35), and dyslipidemia (25.9%; 37). Almost half of patients (46.2%; 66) used DOACs, 31.5% rivaroxaban and 14.7% dabigatran respectively; furthermore, 1.4% patients used DOACs’ with antiaggregants. 49.7% (71) patients had increased risk of possible drug-drug interactions, most frequently with proton pump inhibitors (16.8%; 24), amiodarone (24.5%; 35), antiinflammatory drugs (49.0%; 70). The use of DOACs and possible drug-drug interactions increases by risk score, reaching the maximum score 3 (16.1%; 23) and the mean frequent score 4.4 of 86 (60.1%) AF patients respectively.
Conclusion: Coagulation tests were applicable more than half of patients (60.1%) to detect DOACs concentration in plasma. Despite DOACs’ expected pharmacokinetics and pharmacodynamics, the anticoagulant tests are necessary for effective and safe medical treatment, also for prediction and detection of thrombotic and bleeding events, as well as in situations when temporary discontinuation is desirable