title: Effectiveness and safety of therapy with vitamin K antagonists in Italian patients aged 80 years or older: a multicentre retrospective study comparing the Zeus algorithm with the PARMA algorithm or manual therapy.
abstract: BACKGROUND
  The use of oral anticoagulant therapy (OAT) has constantly increased in the prevention of thromboembolism, particularly in patients 80 years of age or older.
  
  
  OBJECTIVE
  The aim of this multicentre study was to evaluate the efficacy and safety of vitamin K antagonists (VKAs) in elderly patients managed with a computer dosing algorithm compared with a dosage decided by expert physicians.
  
  
  METHODS
  Nine Italian thrombosis centres utilising the Zeus dosing algorithm were involved. The before-after study enrolled patients managed firstly by medical staff (manual system) or with the PARMA algorithm for 12 months from July 2008 to June 2009 and then with the Zeus algorithm during the analogous period from 2010 to 2011. Of 7605 patients in the OAT maintenance phase, 2281 were older than 80 years (mean age 84.2 years). Data for these 2281 patients managed with both modalities were analysed.
  
  
  RESULTS
  Of the 2281 patients 80 years of age or older, 1776 underwent OAT for atrial fibrillation (AF). Use of a dosing algorithm increased the OAT quality: time in therapeutic range (TTR) was significantly (p < 0.001) higher during the Zeus period than during the manual period (71.6 vs. 68.8 %). The TTR achieved with Zeus was similar to that obtained with the PARMA algorithm. In addition, patients managed with Zeus took a weekly drug dosage significantly (p < 0.01) lower than that both suggested by PARMA and prescribed by expert physicians, with a reduced number of adverse events.
  
  
  CONCLUSIONS
  This study confirms that the effectiveness and safety of VKA therapy in patients 80 years of age or older increases with computer dosing algorithms.
authors.affiliation: Dipartimento di Biotecnologie Cellulari ed Ematologia, "Sapienza" Università, Via Benevento, 6 00161, Rome, Italy, cafolla@bce.uniroma1.it.
authors.forename: Arturo
authors.initials: A
authors.lastname: Cafolla
authors.forename: Luigia
authors.initials: L
authors.lastname: Manisco
authors.forename: Erminia
authors.initials: E
authors.lastname: Baldacci
authors.forename: Alessandro
authors.initials: A
authors.lastname: Porcu
authors.forename: Melissa
authors.initials: M
authors.lastname: Campanelli
authors.forename: Maria Concetta
authors.initials: MC
authors.lastname: Cursano
authors.forename: Enza
authors.initials: E
authors.lastname: Rossi
authors.forename: Francesco
authors.initials: F
authors.lastname: Dragoni
authors.forename: Roberto
authors.initials: R
authors.lastname: Foà
mesh_terms: D000369:Aged, 80 and over; D000465:Algorithms; D000925:Anticoagulants / Q000008:administration & dosage / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D013923:Thromboembolism / Q000517:prevention & control*; D013927:Thrombosis / Q000517:prevention & control; D014812:Vitamin K / Q000037:antagonists & inhibitors*
chemical_list: D000925:Anticoagulants; D014812:Vitamin K