Practical aspects of new oral anticoagulant use in atrial fibrillation

Abstract

Dabigatran, a direct thrombin inhibitor and 2 factor Xa inhibitors, rivaroxaban and apixaban, are target--specific oral anticoagulants (TSOACs) approved for prevention of stroke or systemic embolism in patients with nonvalvular atrial fibrillation (AF). Published data suggest that all 3 agents are at least as efficacious as dose-adjusted warfarin in stroke prevention. Because of their greater specificity, rapid onset of action, and predictable pharmacokinetics, TSOACs have some advantages over vitamin K antagonists, which facilitates their use in clinical practice. The current review addresses the practical questions relating to the use of TSOACs in AF patients based on the available data and personal experience. We discuss topics such as patient selection, renal impairment, drug interactions, switching between anticoagulants, laboratory monitoring, and the risk of bleeding along with its management. We will focus on the aspects of the optimization of treatment with TSOACs in stroke prevention. The understanding of these practical issues by clinicians and patients is of key importance for the safe and effective use of TSOACs in everyday practice. KEY WORDSapixaban, atrial fibrillation, dabigatran, rivaroxaban, stroke REVIEW ARTICLE Practical aspects of new oral anticoagulant use in atrial fibrillation 125With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation [ROCKET-AF], Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation [ARISTOTLE]). [4][5][6] Both dabigatran and apixaban were tested in low-to-moderate-risk patients (mean CHADS 2 [Congestive heart failure, Hypertension, Age, Diabetes, Stroke] score, about 2), whereas rivaroxaban was tested in high-risk patients (mean CHADS 2 score, 3.48). The studies, therefore, provide relatively little data on the efficacy of these drugs in patients at very high risk of stroke or systemic embolization.The recent European Society of Cardiology (ESC) Guidelines on the Management of AF recommend long-term anticoagulation in all patients with nonvalvular AF with at least moderate thromboembolic risk (1 point in the CHA 2 DS 2 VASc score, level of evidence A).7 Scores are presented in TABLE 3.In CHA 2 DS 2 -VASc, the score recommended by the ESC, in contrast to the CHADS 2 score, a relatively younger age (>65 years), female sex, and vascular disease are recognized as additional stroke risk factors in AF patients.7 A CHA 2 DS 2 -VASc score of 0 identifies a "truly low risk" group of subjects. Such patients constitute as few as 7% of the population of AF patients. 7 In conclusion, the current guidelines state that a vast majority of patients with paroxysmal or permanent AF not associated with reversible causes will benefit and should receive life-long oral anticoagulation. published in the Pol Arch Med Wewn). [1][2][3] The results of 3 key clinical trials with TSOACs have been summarized in TABLE 2. 1 Briefly, all 3 TSOACs were noninferior to VKAs in reducing stroke or systemic embolism in patients wi...

Monitoring of anticoagulant effects of dabigatran in everyday practice: first experience in 32 Polish patients

“…We found a large variability in dabigatran concentrations when determined in AF patients with the highest levels 1 to 4 hours after the last dose and an overlap of the results for samples taken at the peak anticoagulant activity versus the later time. The blood sampling time is crucial for the interpretation of the test results 6 as confirmed in our study. Patients' age was identified to be the only independent predictor of dabigatran concentrations in our group.…”

“…2,4 Routine laboratory monitoring of dabigatran using clot -based assays is currently not recommended. [4][5][6] However, there are situations in which measurements of the anticoagulant effect of dabigatran are desirable, for example, in patients who experienced thromboembolism or bleeding events despite regular dabigatran intake.…”

Direct Oral Anticoagulants in Patients with Thrombophilia: Challenges in Diagnostic Evaluation and Treatment

“…No differences in the efficacy or safety of dabigatran use depending on the thrombophilic factors were observed; however, dabigatran was used in as few as 11 AT deficient patients and 25 with PC or PS deficiency. The combined defects or homozygous mutations were not reported [12]. Below we present patients with severe inherited thrombophilia who were treated with DOACs and were reported in the literature.…”

A male patient with myocardial infarction as a first manifestation of antiphospholipid syndrome — treatment with rivaroxaban

“…Dotychczas nie rozstrzygnięto jednoznacznie, czy stwierdzenie aPL u chorego po zawale serca lub tylko niedokrwieniu mózgu jest wskazaniem do zastosowania przewlekłej antykoagulacji. Obecnie u pacjentów z migotaniem przedsionków i VTE powszechnie zamiast VKA stosuje się doustne antykoagulanty niebędące antagonistami witaminy K (NOAC), które w porównaniu z VKA cechują się przewidywalną farmakodynamiką, nielicznymi interakcjami lekowymi, brakiem wpływu diety na działanie oraz brakiem potrzeby monitorowania laboratoryjnego antykoagulacji [1].…”