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Improved Time in Therapeutic Range With Patient Self-Testing of Their INR Compared to Usual Care

This study has been completed.
Information provided by (Responsible Party):
Hartzell V. Schaff, Mayo Clinic Identifier:
First received: June 10, 2008
Last updated: August 18, 2014
Last verified: August 2014

Patients who receive a mechanical heart valve to replace a diseased heart valve must take an anticoagulation medicine the rest of their lives, and monitor their level of anticoagulation. Until recently, the testing of the level of anticoagulation was performed at medical laboratories or hospitals.

The purpose of this study is to see if patients who test their level of anticoagulation by themselves at home and then call their doctor with the result have better control of their anticoagulation as compared to patients whose anticoagulation is checked only by their physician.

Condition Intervention
Management of Anticoagulation Device: INRatio monitor by Hemosense Other: Usual Care

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator)
Primary Purpose: Diagnostic
Official Title: Improved Time in Therapeutic Range With Patient Self-Testing of Their INR Compared to Usual Care: A Randomized Controlled Trial

Further study details as provided by Hartzell V. Schaff, Mayo Clinic:

Primary Outcome Measures:
  • Mean Percentage of Time in Therapeutic Range [ Time Frame: baseline to 3 months ]

Secondary Outcome Measures:
  • Mean Percentage of INR Tests Within the Therapeutic Range [ Time Frame: baseline to 3 months ]
  • Mean Number of INR Tests Performed [ Time Frame: baseline to 3 months ]

Enrollment: 200
Study Start Date: March 2007
Study Completion Date: March 2009
Primary Completion Date: March 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Usual Care
Subjects will be having their INR tested by their Primary Care Provider as often as their Care Provider dictates. This study phase is twelve weeks long beginning at the day of discharge from our hospital.
Other: Usual Care
Usual care is defined as that care currently received by patients into whom mechanical heart valves are placed. Typically, these patients undergo frequent checks of their INR level until the therapeutic range is achieved. Then periodic INR levels are drawn at the discretion of the managing physician.
Active Comparator: Patient Self Testing
Subjects will be testing their INR at home using an FDA approved device (INRatio monitor by Hemosense) reporting their results to Quality Assured Services (QAS) via an 800 phone number; their Primary Care Provider will receive a fax with the INR result. We ask this group of patients to test at minimum one time a week, additional testing as requested by their Primary Care Provider. This phase lasts twelve weeks, beginning on the day of discharge from our hospital.
Device: INRatio monitor by Hemosense
Home testing monitor to test patients INR by placing a capillary drop of blood from the finger onto a test strip. The test strip is then inserted into the INRatio point-of-care self-testing coagulometer. After approximately 2 minutes of analysis, the INR value will be presented on the meter's display.

Detailed Description:

Prosthetic replacement of diseased heart valves is a routine procedure, and mechanical heart valves have excellent hemodynamic performance and durability. However, mechanical valves are thrombogenic, necessitating lifelong anticoagulation. Hazards of anticoagulation include bleeding when it is excessive or thromboembolism when the intensity of anticoagulation is below the recommended level. Monitoring the level of anticoagulation is accomplished by analyzing the International Normalized Ratio. Until recently, this was performed at medical laboratories or hospitals, but recent literature suggests that patient self-testing of oral anticoagulation improves patient compliance, medical outcomes, and quality of life.

The objective of this study is to evaluate the time in therapeutic range of patients who self-test their INR compared to patients receiving the usual care. Additionally, we will evaluate the educational components and corollaries of self-testing.

Two hundred consecutively enrolled adults, having undergone implantation of a mechanical heart valve, will be randomized to either self-testing or usual care. Those randomized to the self-testing group will undergo self-testing instruction prior to hospital dismissal. For three months after hospital discharge, subject will record their INR results obtained by self-testing or as prescribed by their primary physician. They will then submit the record of the INR results and complete a survey.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Patients that received a mechanical valve while in our hospital
  • Age > 18 years

Exclusion Criteria:

  • Pregnant or lactating women
  • Patients that have genetic clotting disorders such as Factor 5
  • Physical disabilities (for example, poor eyesight, tremor, or other neurological disability) that would prevent the patient from being able to perform finger stick blood sampling. (Patients may not be excluded for physical disabilities if a care giver is willing to learn and assist with performing patient self-testing.)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00703963

United States, Minnesota
Saint Marys Hospital
Rochester, Minnesota, United States, 55906
Sponsors and Collaborators
Mayo Clinic
Principal Investigator: Hartzell V Schaff, M.D. CS Mayo Clinic
  More Information

Responsible Party: Hartzell V. Schaff, PI, Mayo Clinic Identifier: NCT00703963     History of Changes
Other Study ID Numbers: 07-001398
Study First Received: June 10, 2008
Results First Received: August 18, 2014
Last Updated: August 18, 2014

Keywords provided by Hartzell V. Schaff, Mayo Clinic:
International normalized ratio (INR) processed this record on June 23, 2017