In-patient international normalized ratio self-testing instruction after mechanical heart valve implantation.
BACKGROUND
Patient self-testing of the international normalized ratio (INR) has been shown to improve management of anticoagulation with warfarin and reduce risks of thromboembolism and bleeding. Self-testing instruction usually begins several weeks after hospital discharge. We evaluated the feasibility of in-hospital INR self-testing instruction in patients recovering from valve replacement.


METHODS
We instituted an education program on a self-testing device before hospital discharge in 50 adult patients (median age, 54 years; 66% men) undergoing cardiac valve replacement with mechanical prostheses. Patients were monitored for 1 month to assess their ability to self-test and the accuracy of the INR measurements.


RESULTS
Self-testing instruction began on postoperative day 4 (range, 1 to 8 days). Each patient had an average of 3.5 teaching sessions; each session lasted approximately 20 minutes. One month after discharge, all patients (98%) but 1 were able to self-test. No patient required interval instruction. One bleeding episode occurred in a patient whose INR exceeded the therapeutic range. Once warfarin doses were stabilized, 5 patients had subtherapeutic INR values on self-testing. The mean INR test result obtained from the coagulometer correlated well with values obtained by laboratory determination (r = 0.79).


CONCLUSIONS
This evaluation of an in-hospital education program demonstrates that patients are able to learn INR self-testing and that most will continue to use the method without the need for interval instruction. Improved anticoagulation management by early introduction of INR self-testing should reduce thromboembolic and hemorrhagic complications after valve replacement.
Thompson
Jess L
JL
Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
Sundt
Thoralf M
TM
Sarano
Maurice E
ME
Santrach
Paula J
PJ
Schaff
Hartzell V
HV
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation*; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D019934:International Normalized Ratio / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D010353:Patient Education as Topic; D019095:Point-of-Care Systems; D011183:Postoperative Complications / Q000097:blood*; D012648:Self Care / Q000295:instrumentation*; D012984:Software; D014859:Warfarin / Q000627:therapeutic use*
D000925:Anticoagulants; D014859:Warfarin