This measure assesses the number of patients diagnosed with confirmed VTE who received an overlap of parenteral (intravenous [IV] or subcutaneous [subcu]) anticoagulation and warfarin therapy. For patients who received less than five days of overlap therapy, they should be discharged on both medications or have a reason for discontinuation of overlap therapy. Overlap therapy should be administered for at least five days with an international normalized ratio (INR) greater than or equal to 2 prior to discontinuation of the parenteral anticoagulation therapy, discharged on both medications or have a reason for discontinuation of overlap therapy.

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LOINC(R) is a registered trademark of the Regenstrief Institute.

This material contains SNOMED Clinical Terms (R) (SNOMED CT(c)) copyright 2004-2010 International Health Terminology Standards Development Organization. All rights reserved.

These performance measures are not clinical guidelines and do not establish a standard of medical care, and have not been tested for all potential applications. The measures and specifications are provided without warranty.

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For patients who present with a confirmed acute VTE, parenteral anticoagulation is the first line of therapy because of its rapid onset of action (Buller et al., 2004).  Warfarin can be initiated on the first day of treatment after the first dose of a parenteral anticoagulant has been given. Because the warfarin has a very slow onset of action, it cannot be used as mono-therapy for acute VTE (Ansell et al., 2008). 

The strong (Level I) recommendations to overlap parenteral anticoagulation with oral warfarin therapy in the initial treatment of VTE events is based in part on the known effect of warfarin on the coagulation cascade (Brandjes, et al.,1992). The early increase in the Pro thrombin time (PT) and INR often reflects the laboratory finding of initial reduction in clotting factors of the extrinsic pathway of coagulation resulting in prolongation of the PT/INR, while the patient is still at risk of thromboembolic events due to persistent levels of coagulation factors of the intrinsic pathway and common pathways of coagulation.

The recommendation that heparins and warfarin overlap for a five-day period is based on pharmacokinetic, pharmacologic, pathophysiologic, and clinical evidence as noted by Wittkowsky A.K. (2005). All studies support the pharmacokinetic characteristics of warfarin and the time delay in achieving an antithrombotic effect suggesting the need for overlap of heparin during initial warfarin dosing in order to prevent thrombus extension, embolization to the lungs, death due to Pulmonary Emboli (PE), and the development of complications such as recurrent thromboembolic events and the postthrombotic syndrome. Kearon et al, 2008 also denotes current recommendation for treatment of confirmed VTE to begin with oral warfarin therapy, with combination of initial anticoagulation therapy for a minimum of 5 days and until the INR is >2.0 for at least 24 hours, and then a recommended target rate.

Overlap therapy of both warfarin and parenteral therapy is the recommended treatment for VTE patients if there are no contraindications. This therapy should take place over five or more days, until an INR greater than or equal to 2.0 is reached prior to discontinuation of parenteral therapy.

An increase in the rate

Ansell J, Hirsch J, Hylek E, Jacobson A, Crowther M, Palareti G. Pharmacology and management of the vitamin K antagonists: The Eighth ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2008 133:160S-198S.

Brandjes DP, Heijboer H, B�ller HR, et al. Acenocoumarol and heparin compared with acenocoumarol alone in the initial treatment of proximal-vein thrombosis. N Engl J Med. 1992; 327:1485-9.

Guyatt, G.H., Akl, E.A., Crowther, M., Gutterman, D., Schunemann, H. Antithromboitic Therapy and Prevention of Thrombosis, 9th edition: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. CHEST 2012; 141(2) (Supp):7S-47S.

Wittkowsky AK. Why warfarin and heparin need to overlap when treating acute venous thromboembolism. Dis Mon 2005; 51:112-115.

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The unit of measurement for this measure is an inpatient episode of care. Each distinct hospitalization should be reported, regardless of whether the same patient is admitted for inpatient care more than once during the measurement period. In addition, the eMeasure logic intends to represent events within or surrounding a single occurrence of an inpatient hospitalization.

For date difference calculations, use the LAST (most recent) of the alternative dates as the end date and the EARLIEST of the alternative dates as the start date. The calculation should be performed as end date minus start date.

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Patients with a diagnosis code for venous thromboembolism (VTE), a patient age greater than or equal to 18 years, and a length of stay less than or equal to 120 days.

Patients with confirmed VTE who received warfarin.

•	Patients with Comfort Measures documented
•	Patients discharged to a health care facility for hospice care
•	Patients discharged to home for hospice care
•	Patients who expired
•	Patients who left against medical advice
•	Patients discharged to another hospital
•	Patients without warfarin therapy during hospitalization 
•	Patients without VTE confirmed by diagnostic testing

Patients who received overlap therapy (warfarin and parenteral anticoagulation):

•	Five or more days, with an INR greater than or equal to 2 prior to discontinuation of parenteral therapy OR
•	Five or more days, with an INR less than 2 and discharged on overlap therapy OR
•	Less than five days and discharged on overlap therapy OR
•	With documentation of reason for discontinuation of parenteral therapy OR
•	With documentation of a reason for no overlap therapy

Not Applicable

None

Not Applicable

Not Applicable

For every patient evaluated by this measure also identify payer, race, ethnicity and sex.