title: Evaluation of the impact of warfarin time in therapeutic range on outcomes of patients with atrial fibrillation in Turkey: perspectives from the observational, prospective WATER Registry.
abstract: BACKGROUND
  Warfarin is highly efficacious in reducing stroke risk in patients with atrial fibrillation (AF). However, its safety and efficacy in stroke prevention is markedly influenced by its time in therapeutic range (TTR). The quality of anticoagulant therapy varies considerably among countries. Representative data concerning the quality of anticoagulant therapy and its effects on clinical outcomes in Turkey are lacking.
  
  
  METHODS
  Warfarin in Therapeutic Range (WATER) registry is a prospective, observational study which followed 572 AF patients (mean age 67.3 ± 12 years; females 60%; 71% non-valvular AF) treated with warfarin.
  
  
  RESULTS
  At a median of 22-month follow-up, the mean TTR value was 42.3 ± 18% (median: 40%) for the whole population and lower in non-valvular AF su group than valvular AF subgroup (40.3 ± 18 vs. 46.9 ± 19, respectively, p < 0.001). Death, cardiac hospital-ization and minor bleeding rates were higher in the group with TTR value < 40% than the group with > 40% (3.4% vs. 5.9%; 28.6% vs. 35.4%; 36.5% vs. 41.7%, respectively, all of them p < 0.001). A correlation analysis showed a negative correlation between age and TTR value (r = -0.178, p < 0.001). Mean CHA2DS2VASc score was 3.63 ± 1.5 and mean HASBLED score was 2.38 ± 1.01 in the non-valvular AF group. A negative correlation was observed between TTR levels and CHA2DS2VASc score.
  
  
  CONCLUSIONS
  WATER provides insight into the anticoagulation control status of AF patients in Turkey. The quality of anticoagulation was poor. Strategies should be undertaken by clinicians and patients to improve TTR. New oral anticoagulant agents may be perfect alternatives for non-valvular AF patients.
authors.affiliation: Department of Cardiology, Central Hospital, Izmir, Turkey. droturk@yahoo.com.
authors.forename: Ugur Onsel
authors.initials: UO
authors.lastname: Turk
authors.forename: Esref
authors.initials: E
authors.lastname: Tuncer
authors.forename: Emin
authors.initials: E
authors.lastname: Alioglu
authors.forename: Kivanc
authors.initials: K
authors.lastname: Yuksel
authors.forename: Nihat
authors.initials: N
authors.lastname: Pekel
authors.forename: Emre
authors.initials: E
authors.lastname: Ozpelit
authors.forename: Ozcan
authors.initials: O
authors.lastname: Vuran
authors.forename: Istemihan
authors.initials: I
authors.lastname: Tengiz
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D001777:Blood Coagulation / Q000187:drug effects*; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006760:Hospitalization; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D019984:Quality Indicators, Health Care; D012042:Registries; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014421:Turkey; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: atrial fibrillation; international normalized ratio; registry; warfarin