Management of Anticoagulation
Conditions
Keywords
International normalized ratio (INR)
Brief summary
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.
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.
Interventions
DEVICEINRatio 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.
OTHERUsual 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.
Sponsors
LivaNova
Mayo Clinic
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
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.)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Mean Percentage of Time in Therapeutic Range | baseline to 3 months |
Secondary
| Measure | Time frame |
|---|---|
| Mean Percentage of INR Tests Within the Therapeutic Range | baseline to 3 months |
| Mean Number of INR Tests Performed | baseline to 3 months |
Countries
United States
Participant flow
Recruitment details
Subjects were recruited from the Mayo Clinic, Rochester, Minnesota from June 2007 to January 2009.
Participants by arm
| Arm | Count |
|---|---|
| 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. | 100 |
| 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. | 100 |
| Total | 200 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Physician Decision | 0 | 1 |
| Overall Study | Withdrawal by Subject | 7 | 13 |
Baseline characteristics
| Characteristic | Usual Care | Patient Self Testing | Total |
|---|---|---|---|
| Age, Continuous | 53 years | 55 years | 54 years |
| Region of Enrollment United States | 100 participants | 100 participants | 200 participants |
| Sex: Female, Male Female | 40 Participants | 33 Participants | 73 Participants |
| Sex: Female, Male Male | 60 Participants | 67 Participants | 127 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 4 / 93 | 1 / 86 |
| serious Total, serious adverse events | 3 / 93 | 8 / 86 |
Outcome results
Primary
Mean Percentage of Time in Therapeutic Range
Time frame: baseline to 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Usual Care | Mean Percentage of Time in Therapeutic Range | 48 percentage of time | Standard Deviation 25 |
| Patient Self Testing | Mean Percentage of Time in Therapeutic Range | 53 percentage of time | Standard Deviation 27 |
Comparison: Statistical significance was defined as p \< 0.05.p-value: 0.2Wilcoxon (Mann-Whitney)
Secondary
Mean Number of INR Tests Performed
Time frame: baseline to 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Usual Care | Mean Number of INR Tests Performed | 10 INR tests | Standard Deviation 6 |
| Patient Self Testing | Mean Number of INR Tests Performed | 14 INR tests | Standard Deviation 9 |
Comparison: Statistical significance was defined as p \< 0.05.p-value: <0.001Wilcoxon (Mann-Whitney)
Secondary
Mean Percentage of INR Tests Within the Therapeutic Range
Time frame: baseline to 3 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Usual Care | Mean Percentage of INR Tests Within the Therapeutic Range | 45 percentage of tests | Standard Deviation 22 |
| Patient Self Testing | Mean Percentage of INR Tests Within the Therapeutic Range | 52 percentage of tests | Standard Deviation 22 |
Comparison: Statistical significance was defined as p \< 0.05.p-value: 0.05Wilcoxon (Mann-Whitney)