Introduction: Old generation oral anticoagulants (OAC) have been first line medication for prevention of thrombembolic events by patients with non-valvular atrial fibrillation (AF) for a long time, although the usage of vitamin K antagonists cause a lot of problems for patients and physicians. Novel OAC promise to solve those problems, however their implementation in practice is undergoing slowly in Latvia.
Aim, Materials and Methods: The aim of this study was to analyse main problems of OAC clinical usage by patients with non-valvular AF and by professionals treating them. The study enrolled 254 patients with nonvalvular AF under OAC therapy at two Clinical University Hospitals, Riga, Latvia. Problems associated with OAC side effects and interactions, awareness of patients, complexity of OAC usage were analyzed from patients perspective. Second study group included 245 medical practitioner with clinical experience in treatment and care of non-valvular AF patients applying OAC. Difficulties during the choice of OAC and the beginning of the therapy, patient care and communication were analyzed from the physicians point of view.
Results: In patients group were 76,8% users of vitamin K antagonists (VKA) and 23,2% users of novel OAC (NOAC). In VKA group were 31,8% patients prior cardioversion in compare to 86.4% in NOAC group (p<0,001). According to CHA2DS2-VASc scale median in VKA group was score of 3 [95% CI 2-4], in NOAC group score of 2,5 [95% CI 2-4]. Statistically significant higher incidence of side effects and blleding were by VKA users 33.1% vs 3.3% (p<0.001) in NOAK group. No major bleeding were observed in NOAK group, but 17 cases in VKA group..Less than a half of patients followed the interaction of active substances with OAC in both groups, besides patients were less informed about this aspect in compare to OAC side effects and INR controls in VKA group. By VKA users more than 50% had difficulties to adjust OAC dose and to keep the INR between 2,0 and 3,0. 31,8% had problems with INR controls while 90,6% were regulary undergoing INR control, mostly one to two times a month.
In physicians group there were 13,9% cardiologists, 20,8% doctors-internists, 23,8% general practitioners, 8,9% doctors of other specialities, 32,7% resident physicians. 48,5% did use NOAC in their practice, mostly prescribing them rarely/rather rarely, but 81,3% of physicians who did not prescribe/prescribed NOAC rarely were willing to do it more often. High costs and not sufficient clinical experience were mentioned as main problems for NOAC. According to physicians the main problems for VKA are lack of understanding and cooperation from patients, poor INR control and difficulties in dose adjustment. 82% of doctors did explain interaction of active substances with OAC to their patients. Before the beginning of OAC therapy physicians mostly (>50%) considered thrombembolic events in medical history, the age of patient, vascular diseases, patients’ compliance and financial situation. In practice doctors most often face noncompliance, difficulties to control coagulation parameters and to keep them in therapeutic range.
Conclusions: Clinical usage of OAC for AF patients is more complicated in VKA group due to side effects, complexity of use and lack of information.
NOAC are more safety and with significantly less side effects in comparison with VKA.Physicians find use of NOAC less problematic and they would be ready to use NOAC in practice more often if the finansial issues were solved.
Before the beginning of OAC therapy thrombembolic and bleeding risk factors are not considered enough, physicians and patients preferring social aspects of drug use.