Basic plasma coagulation function is readily assessed with a few simple laboratory tests: The partial thromboplastin time (PTT), prothrombin time (PT), thrombin time (TT), or a quantitative fibrinogen determination. The partial thromboplastin time (PTT) test is an in vitro laboratory test used to assess the intrinsic coagulation pathway and monitor heparin therapy.

Indications

1. The PTT is most commonly used to quantitate the effect of therapeutic unfractionated heparin and to regulate its dosing.  Except during transitions between heparin and warfarin therapy, in general both the PTT and PT are not necessary together to assess the effect of anticoagulation therapy.  PT and PTT must be justified separately. (See "Limitations" section for further discussion.)
   
   
2. A PTT may be used to assess patients with signs or symptoms of hemorrhage or thrombosis.  For example: abnormal bleeding, hemorrhage or hematoma petechiae or other signs of thrombocytopenia that could be due to Disseminated Intravascular Coagulation; swollen extremity with or without prior trauma.
   
   
3. A PTT may be useful in evaluating patients who have a history of a condition known to be associated with the risk of hemorrhage or thrombosis that is related to the intrinsic coagulation pathway.  Such abnormalities may be genetic or acquired.  For example: dysfibrinogenemia; afibrinogenemia (complete); acute or chronic liver dysfunction or failure, including Wilson's disease; hemophilia; liver disease and failure; infectious processes; bleeding disorders; disseminated intravascular coagulation; lupus erythematosus or other conditions associated with circulating inhibitors, e.g., Factor VIII Inhibitor, lupus-like anticoagulant, etc.; sepsis; von Willebrand's disease; arterial and venous thrombosis, including the evaluation of hypercoagulable states; clinical conditions associated with nephrosis or renal failure; other acquired and congenital coagulopathies as well as thrombotic states.
   
   
4. A PTT may be used to assess the risk of thrombosis or hemorrhage in patients who are going to have a medical intervention known to be associated with increased risk of bleeding or thrombosis.  An example is as follows:  evaluation prior to invasive procedures or operations of patients with personal or family history of bleeding or who are on heparin therapy.

Limitations

1. The PTT is not useful in monitoring the effects of warfarin on a patient's coagulation routinely.  However, a PTT may be ordered on a patient being treated with warfarin as heparin therapy is being discontinued.  (See coding guidelines for instructions on the use of code V58.61 in this situation.)  A PTT may also be indicated when the PT is markedly prolonged due to warfarin toxicity.
   
   
2. The need to repeat this test is determined by changes in the underlying medical condition and/or the dosing of heparin.
   
   
3. Testing prior to any medical intervention associated with a risk of bleeding and thrombosis (other than thrombolytic therapy) will generally be considered medically necessary only where there are signs or symptoms of a bleeding or thrombotic abnormality or a personal history of bleeding, thrombosis or a condition associated with a coagulopathy.  Hospital/clinic-specific policies, protocols, etc., in and of themselves, cannot alone justify coverage.

With the exception of routine or screening, any diagnosis other than those listed under the “Covered Diagnosis Codes” section will be denied as not medically necessary.  A provider cannot bill the member for the denied service unless the provider has given advance written notice, informing the member that the service may be deemed not medically necessary and providing an estimate of the cost. The member must agree in writing to assume financial responsibility, in advance of receiving the service. The signed agreement, in the form of a Pre-Service Denial Notice, should be maintained in the provider's records.

Partial thromboplastin time testing for routine or screening purposes is excluded from coverage.  Therefore, any diagnosis code listed under the “Screening Diagnosis Codes” section will deny as not covered.  The provider can bill the member for the non-covered service.

NOTE:

A claim for a test for which there is a national coverage or local medical review policy will be denied as not reasonable and necessary if it is submitted without a diagnosis code or narrative diagnosis listed as covered in the policy unless other medical documentation justifying the necessity is submitted with the claim. Also, if a national or local policy identifies a frequency expectation, claim for a test that exceeds that expectation may be denied as not reasonable and necessary, unless it is submitted with documentation justifying increased frequency.

Documentation Requirements

Failure to provide documentation of the medical necessity of tests may result in denial of claims.  Such documentation may include notes documenting relevant signs, symptoms or abnormal findings that substantiate the medical necessity for ordering the tests.  In addition, failure to provide independent verification that the test was ordered by the treating physician (or qualified nonphysician practitioner) through documentation in the physician’s office may result in denial.

NOTE:

This policy is designed to address medical guidelines that are appropriate for the majority of individuals with a particular disease, illness, or condition. Each person's unique clinical circumstances may warrant individual consideration, based on review of applicable medical records.

When patients are being converted from heparin therapy to warfarin therapy, use code V58.61 to document the medical necessity of the PTT.

When coding for Disseminated Intravascular Coagulation (DIC), use 286.6 or code for the signs and symptoms clinically indicating DIC.

Assign codes 289.8 – other specified disease of blood and blood-forming organs only when a specific disease exists and is indexed to 289.8 (for example, myelofibrosis).  Do not assign code 289.8 to report a patient on long term use of anticoagulant therapy (for example, to report a PTT value or re-check need for medication adjustment).  Assign code V58.61 to referrals for PTT checks or re-checks.

Title XVIII of the Social Security Act, Section 1862(a)(7). This section excludes routine physical examinations.

Title XVIII of the Social Security Act, Section 1862(a)(1)(A) states that no payment shall be made for items or services which are not reasonable and necessary for the diagnosis or treatment of illness or injury.

Title XVIII of the Social Security Act, Section 1833(e) states that no payment shall be made to any provider for any claim that lacks the necessary information to process the claim.

National Coverage Determination - 190.16

On-Line NCD Coding Policy Manual and Change Report

On-Line Manual 100-4, Chapter 23, Section 40

Transmittal 651, CR 4005

Transmittal 758, CR 4161

Transmittal 864, CR 4328

Transmittal 1050, CR 5293

Transmittal 1093, CR 5384

Transmittal 1606, CR 6213

Transmittal 1645, CR 6304

Transmittal 1684, CR 6383

Transmittal 1766, CR 6548

Transmittal 1963, CR 6964

Transmittal 2001, CR 7057

Covered Diagnosis Codes

Non-covered Diagnosis Codes

Screening Diagnosis Codes