Long-term anticoagulation self-testing after mechanical heart valve replacement

Objectives: Management of oral anticoagulation (OA) is a key determent to prevent thromboembolic or hemorrhagic complications after mechanical heart valve (MHV) replacement. We report a single center experience with self-management of OA.

Methods: Follow-up was performed on 889 patients who received MHV between 1993 and 2005. To all INR self-management was offered. Follow up was 97% (862 patients). Only 310 (36%) patients, age: 59.8±10.9yrs wanted INR self-management (group 1). 552 (64%) patients, age: 65.1±9.6yrs (p<0.001) preferred conventional OA by family physicians (group 2). In group 1 77% of patients had higher education versus 25% in group 2 (p<0.001).

Results: Follow-up was 5.6±3.0yrs representing 4873 patient-yrs. In the last 12 months patients of group 1 measured OA more often and were within the therapeutic range for a median of 74% versus group 2 in 57% (p<0.001). During follow-up 1.9% of group 1 had severe bleedings versus 5% of group 2 (n.s.) and 0.6% of group 1 had severe thrombembolic-events versus 5.5% of group 2 (p<0.01).

Group 1 was more satisfied with OA and their health status (p<0.001). Actuarial-survival after 1, 5 and 10 years was in group 1 99%, 98% and 94% versus in group 2 99%, 95% and 81% (p<0.001). Risk factors for mortality were univariate: age (p<0.05), type of operation (p<0.05) and conventional OA (p<0.001), but multivariate only conventional OA (p<0.001). From 1993–2005 the percentage of patients with INR self testing was 36±5% (27%-45%/year) and didn't increase in the period.

Conclusions: Despite improved long-term outcome and treatment quality with INR self-management, acceptance did not increase. Therefore physicians should encourage patients.