Microvolt T-Wave Alternans Testing (MTWA)
The CIGNA Government Services (CGS) Local Coverage Determination (LCD) for this test has been retired, effective September 15, 2007 . It is replaced with this article to assist providers who may use this technology. A National Coverage Determination (NCD) is in effect for this testing as well, and takes precedence (CMS IOM Pub 100-3, Ch 1, Sect 20.30). The NCD is excerpted below:
Microvolt T-wave Alternans (MTWA) testing is a non-invasive diagnostic test that detects minute electrical activity in a portion of the electrocardiogram (EKG) known as the T-wave. MTWA testing has a role in the risk stratification of patients who may be at risk for sudden cardiac death (SCD) from ventricular arrhythmias.
Within patient groups that may be considered candidates for implantable cardioverter defibrillator (ICD) therapy, a negative MTWA test may be useful in identifying low-risk patients who are unlikely to benefit from, and who may experience worse outcomes from ICD placement.
The test is performed by placing highly sensitive electrodes on a patient's chest prior to a period of controlled exercise. These electrodes detect tiny beat-to-beat changes, on the order of one-millionth of volt, in the EKG T-wave. Spectral analysis is used to calculate these minute voltage changes. Spectral analysis is a sensitive mathematical method of measuring and comparing time and the EKG signals. Software then analyzes these microvolt changes and produces a report to be interpreted by a physician.
Indications and Limitations of Coverage
Nationally Covered Indications
Microvolt T-wave Alternans diagnostic testing is covered for the evaluation of patients at risk for SCD, only when the spectral analysis method is used.
Nationally Non-Covered Indications
Microvolt T-wave Alternans diagnostic test is non-covered for the evaluation of patients at risk for SCD if measurement is not performed employing the spectral analysis.
For the CGS jurisdictions ( Idaho , North Carolina & Tennessee ), MTWA assessment using spectral analysis is indicated in special circumstances where the predictability of a cardiac event adds significantly to marginal clinical decisions. The following clinical situations are considered appropriate for use of T-Wave Alternans testing:
- Unexplained syncope or presyncope in patients with either known or suspected heart disease, or abnormal ECG, or occurring suddenly or with exercise, or with risk factors for coronary artery disease (following a thorough workup for usual causes).
- History of syncope or complex ectopy where there is a suspicion of congenital cardiac disorder or family history of sudden death.
- Patients with sustained VT or ventricular fibrillation (VF) associated with a transient event or reversible cause (i.e., acute ischemia, cardiac surgery, rejection of a transplanted heart, drug overdose, etc.) to establish that treatment of the reversible cause has reduced the risk for catastrophic cardiac events.
- Patients with non-sustained ventricular tachycardia (NSVT) and left ventricular dysfunction, who are deemed at risk to deteriorate to ventricular fibrillation.
LIMITATIONS OF COVERAGE:
- MTWA is not covered for the general assessment of a patient with atherosclerotic heart disease, congestive heart failure, pre-surgical evaluation or other circumstances where the index of suspicion of VT/VF is low, or the knowledge of possible VT/VF will not alter the management of the patient.
- This procedure is not covered as part of a routine physicial examination, in the routine evaluation of patients with hypertension or atherogenic coronary artery disease, as part of stress testing on a screening basis, or in the patient where electrophysiologic testing and the possible implantation of an ICD is being considered.
- This procedure is not covered as an "add-on" to a diagnostic exercise test, unless the above specified indications of coverage and /or medical necessity are met.
- T-WA is not medically necessary if testing is not likely to alter the management of the patient.
MTWA is billed with AMA-CPT code 93025, microvolt T-wave alternans for assessment of ventricular arrhythmias.
The ICD-9 diagnostic codes that will be covered for this test when performed by the spectral analysis method are:
| 410.10 - 410.92 | ACUTE MYOCARDIAL INFARCTION OF OTHER ANTERIOR WALL EPISODE OF CARE UNSPECIFIED - ACUTE MYOCARDIAL INFARCTION OF UNSPECIFIED SITE SUBSEQUENT EPISODE OF CARE |
| 411.89 | OTHER ACUTE AND SUBACUTE FORMS OF ISCHEMIC HEART DISEASE OTHER |
| 425.0 - 425.9 | ENDOMYOCARDIAL FIBROSIS - SECONDARY CARDIOMYOPATHY UNSPECIFIED |
| 427.1 | PAROXYSMAL VENTRICULAR TACHYCARDIA |
| 427.41 | VENTRICULAR FIBRILLATION |
| 427.42 | VENTRICULAR FLUTTER |
| 780.2 | SYNCOPE AND COLLAPSE |
| 794.31 | NONSPECIFIC ABNORMAL ELECTROCARDIOGRAM (ECG) (EKG) |
| V15.1 | PERSONAL HISTORY OF SURGERY TO HEART AND GREAT VESSELS PRESENTING HAZARDS TO HEALTH |
