title: International normalized ratio self-management lowers the risk of thromboembolic events after prosthetic heart valve replacement.
abstract: BACKGROUND
  Although prosthetic valves are durable and easy to implant, the need for lifetime warfarin-based anticoagulation restricts their exclusive usage. We investigated if anticoagulation self-management improves outcome in a single-center series.
  
  
  METHODS
  Between 1994 and 1998, 765 patients with prosthetic valve replacements were prospectively enrolled and randomized to receive conventional anticoagulation management by their primary physician (group 1, n = 295) or to pursue anticoagulation self-management (group 2, n = 470). A study head office was implemented to coordinate and monitor anticoagulation protocols, international normalized ratios (INR), and adverse events. Patients were instructed on how to obtain and test their own blood samples and to adjust warfarin dosages according to the measured INR (target range, 2.5 to 4).
  
  
  RESULTS
  Mean INR values were slightly yet significantly smaller in group 1 than in group 2 (2.8 +/- 0.7 vs 3.0 +/- .6, p < 0.001). Moreover, INR values of patients with conventional INR management were frequently measured outside the INR target range, whereas those with anticoagulation self-management mostly remained within the range (35% vs 21%, p < 0.001). In addition, the scatter of INR values was smaller if self-managed. Freedom from thromboembolism at 3, 12, and 24 months, respectively, was 99%, 95%, and 91% in group 1 compared with 99%, 98%, and 96% in group 2 (p = 0.008). Bleeding events were similar in both groups. Time-related multivariate analysis identified INR self-management and higher INR as independent predictors for better outcome.
  
  
  CONCLUSIONS
  Anticoagulation self-management can improve INR profiles up to 2 years after prosthetic valve replacement and reduce adverse events. Current indications of prosthetic rather than biologic valve implantations may be extended if the benefit of INR self-management is shown by future studies with longer follow-up.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center North Rhine-Westphalia, Ruhr Universität Bochum, Bad Oeynhausen, Germany. teitz@hdz-nrw.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Eitz
authors.forename: Soren
authors.initials: S
authors.lastname: Schenk
authors.forename: Dirk
authors.initials: D
authors.lastname: Fritzsche
authors.forename: Andreas
authors.initials: A
authors.lastname: Bairaktaris
authors.forename: Otto
authors.initials: O
authors.lastname: Wagner
authors.forename: Heinrich
authors.initials: H
authors.lastname: Koertke
authors.forename: Reiner
authors.initials: R
authors.lastname: Koerfer
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012648:Self Care; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants