Age-related differences in oral anticoagulant therapy between Italian and Western Europe countries patients with non-valvular atrial fibrillation. Insights from the GLORIA-AF registry

Introduction: Atrial fibrillation (AF) is the most frequent sustained arrhythmia found in clinical practice. Despite the association of AF with thromboembolic (TE) events, and with dementia, the use of oral anticoagulant therapy (OAC) is still unsatisfactory. Non-Vitamin K oral anticoagulants (NOACs) could allow a wider use of OAC. The aim of this study was to compare the clinical characteristics of NVAF patients taking NOACs or Vitamin K antagonists (VKA) in Italy and in the other Western Europe Countries (OWE). Methods: The Global Registry on Long-Term Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) Registry Program is a large, global, prospective study, involving newly diagnosed AF patients with >1 stroke risk factors. The registry consists of three overlapping phases. Present analysis refer to the baseline character- istics in GLORIA-AF Phase III, including all eligible patients, independently of the pre- scribed OAC. Patients were also stratified into two age-groups (<75 and >75 years). Comparisons of baseline characteristics and antithrombotic therapy between Italy and OWE were based on standardized differences (SD; unbalanced distributions for values >0.10). Results: Between 2014 and 2016, 9135 (43.0%) patients out of 21, 248 in Phase III were enrolled from Western European countries. Italian and OWE subjects were 1378 and 7757, respectively. Patients in the age group of >75 years were 47.8% (N 1⁄4 659) and 44.8% (N 1⁄4 3473) for Italy and OWE, respectively. No differences in age, gender and TE risk were noticed by area of origin both in the younger (Italy—age: 65 6 8 years; men: 61.5%; CHA2DS2-VASc score: 2.4 6 1.2 / OWE—age: 65 6 7 years; men: 61.5%; CHA2DS2- VASc score: 2.561.2) and in the older (Italy—age: 8165years; men: 45.8%; CHA2DS2- VASc score: 4.261.2 / OWE—age: 8165years; men: 48.1%; CHA2DS2-VASc score: 4.3 6 1.3) group. In the whole population, OAC was less adopted in Italy compared to OWE (84.0 vs. 90.6%, SD1⁄4-0.20). Regarding the <75years group, OAC was prescribed less frequently in Italian than in OWE patients (80.4 vs. 90.2%; SD1⁄4-0.28). This was especially true for NOACs (49.8 vs. 67.6%; SD1⁄4-0.37). Also the use of antiplatelet ther- apy (9.0 vs. 4.6%) and the lack of any anti-thrombotic drug (10.6 vs. 5.2%) were more common in the younger Italian subjects. In the >75years population, no differences existed between Italy and OWE in the prescription of oral anticoagulants (87.9 vs. 91.1%) and, especially, of NOACs (60.5 vs. 63.5%). The proportion of those taking anti- platelets did not differ between older Italian and OWE (6.4 vs. 4.9%) subjects; the same was true for those not receiving any drug (5.8 vs. 4.0%). On the whole, lower dos- ages of NOACs were more frequently found in Italian patients as compared to OWE patients, particularly in those treated with rivaroxaban 15mg QD (29.8 vs. 16.6%; SD 1⁄4 0.32) and apixaban 2.5 mg BID (28.6 vs. 20.2%; SD 1⁄4 0.20). Small differences were observed for dabigatran 110 mg (47.2 vs. 40.7%; SD 1⁄4 0.13). These findings can be explained by a more frequent use of the lower NOACs doses in >75years Italian patients. Proton pump inhibitors (PPI) for gastric protection were more often chosen in Italy than in OWE (43.0 vs. 29.0%; SD 1⁄4 0.30) independently of age and OAC. Conclusions: GLORIA-AF Phase III results show the existence of relevant differences in OAC use between Italy and other Western European Countries. Older Italian NOACs users more often receive the lower dosages of the drugs. The prevalence of those not taking anticoagulants is still high, highlighting the importance of a better AF management in routine clinical practice.