International Normalized Ratio Self-Management Lowers the Risk of Thromboembolic Events After Prosthetic Heart Valve Replacement

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 p 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.