Clinical trial NCT00933738: Evaluation of the Accuracy of the INRatio Prothrombin Time (PT) Monitoring System With a New Test Strip for the Oral Anticoagulation Therapy Patient in the Presence of Heparin and Low Molecular Weight Heparin (e.g., Enoxaparin or Dalteparin)
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Coagulation
Keywords: Patients needing OAT (Oral Anticoagulation Therapy)
Lead sponsor: Abbott RDx Cardiometabolic
Sponsor class: OTHER
First posted: 2009-07-07
Enrollment: 150
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients undergoing heparin bridging onto OAT with warfarin.

Brief summary: This is a multi-center study designed to evaluate the heparin insensitivity of the INRatio Prothrombin Time (PT) Monitoring System, utilizing an INRatio test strip additionally modified for low sample volume. The INRatio test strip is used for the quantitative determination of PT and International Normalized Ratio (INR) results in fingerstick blood from subjects on oral anticoagulation therapy (OAT) with warfarin. This study is designed to evaluate the accuracy of the modified INRatio test strip during heparin-warfarin bridge therapy with unfractionated heparin (UH) or low molecular weight heparin (LMWH), such as enoxaparin or dalteparin. These INR results will be compared to the INR results obtained on plasma from the same subjects as analyzed at a central laboratory with the heparin-insensitive reference method: the Sysmex CA-560 System. The levels of UH or LMWH in the plasma samples will be assessed using activated partial thromboplastin time (aPTT) and anti-factor-Xa assays respectively.


Eligibility criteria: Inclusion Criteria:

* Adults (18 years of age or older).
* Willing and able to provide written informed consent and comply with study procedures.
* Receiving warfarin/heparin bridge therapy.
* Therapy with both warfarin and one of the heparins listed below must have been initiated for at least 12 hours before the first study specimens are obtained.
* UH (last known aPTT prior to enrollment (if available†) must confirm heparin has been administered)
* Dalteparin (last known anti-factor Xa prior to enrollment (if available†) must confirm heparin has been administered)
* Enoxaparin (last known anti-factor Xa prior to enrollment (if available†) must confirm heparin has been administered) † If a pre-study aPTT or anti-factor Xa is not available, subsequent testing of the study phlebotomy or a phlebotomy as a part of routine medical care taken before or during the time of the study phlebotomy must confirm the presence of heparin (unfractionated or low molecular weight) in order for that data point to be included in the analysis.

Exclusion Criteria

* Known or suspected hematocrit less than 25 or greater than 55%;
* Auto-immune disorders known to interfere with INR measurements, such as lupus or anti-phospholipid syndrome (APS)
* Already participated in this specific study

Primary outcomes:
Secondary outcomes:
Other outcomes:
Locations:
city: Loma Linda
country: United States
facility: Loma Linda VA
state: California
city: Aurora
country: United States
facility: University of Colorado-Denver
state: Colorado
city: Detroit
country: United States
facility: Henry Ford Hospital
state: Michigan
city: Lansing
country: United States
facility: Emergency Medicine Research Group
state: Michigan
city: Petoskey
country: United States
facility: Cardiac and Vascular Research Center of Northern Michigan
state: Michigan
city: Missoula
country: United States
facility: International Heart Institute of Montana
state: Montana
city: Albuquerque
country: United States
facility: University of New Mexico
state: New Mexico
city: Brooklyn
country: United States
facility: New York Methodist Hospital
state: New York
city: Port Jefferson
country: United States
facility: John T Mather Memorial Hospital
state: New York
city: Tomball
country: United States
facility: Northwest Heart Center
state: Texas
city: Seattle
country: United States
facility: Swedish Medical Center
state: Washington
city: Wenatchee
country: United States
facility: Wenatchee Valley Medical Center
state: Washington
Study officials:
References: