LCD L34338: Transthoracic Echocardiography (TTE)

Abstract:

Echocardiography is the ultrasonic examination of the heart. Transthoracic echocardiography (TTE) affords unique insight into cardiac structure and function. Two-dimensional (2D) imaging defines the configuration and changing dimensions of the chambers, dynamic cyclic variation in myocardial thickness, and the associated valvular motions throughout the cardiac cycle. The proximal great vessels and the pericardium can also be directly visualized, although transesophageal echocardiography (TEE) often permits better visualization of the thoracic aorta and great veins than does TTE. (ACC/AHA/ASE 2003 Guideline Update for the Clinical Application of Echocardiography [hereafter referred to as the "ACC/AHA/ASE Guideline Update"], pg. 41).

A Doppler examination is a valuable adjunct to a complete echocardiographic examination. The basic principle utilizes the changes in frequency when a transmitted ultrasound wave is reflected from moving surfaces (e.g., heart valves, red blood cells), allowing the capability of measuring normal and abnormal velocities of blood flow. Such data may lead to the calculation of valvular stenosis, valvular regurgitation, cardiac output, intracardiac pressures or intracardiac shunts.

Some cardiac ultrasound machines have become increasingly compact and portable. Certain "hand carried" scanners are "full featured" and permit a skilled examiner to image and record permanent records of all of the tomographic images and Doppler data (both color and spectral) needed to perform a complete transthoracic echocardiographic examination that may be quite comparable, in diagnostic value, to that obtained with a larger, "state of the art" instrument. In order to qualify as a valid echocardiographic service, the study must be done for an accepted clinical indication by a properly trained examiner and must include a permanent record of the findings, data sufficient to support the conclusions and an appropriate interpretation and written report. Such a study would meet the standards required for a complete echocardiographic examination, regardless of the size of the instrument used to perform the study.

All echocardiography services require a referral or an order from a treating physician.

This policy addresses the medically necessary and appropriate application of TTE, including stress echocardiography. Transesophageal echocardiography (TEE) is the subject of a separate policy statement.

Indications:

Echocardiography is indicated in the evaluation of derangements of valvular, myocardial and pericardial structure and function. The general applications for coverage include:

A. Transthoracic Echocardiogram

INDICATIONS:

1. Ventricular Function, Cardiomyopathies and Heart Failure

Changes in myocardial thickness (hypertrophy and thinning), in derived parameters of contractility, and in chamber volume and morphology, can be quantitated and charted over time by TTE. Cardiac responses to volume perturbations, chronic pressure excess and therapeutic interventions can be monitored. Recognition of the relative contributions of myocardial and valvular functional perturbations to a clinical presentation is facilitated. TTE aids in the recognition of myopathies and their classification into hypertrophic, dilated and restrictive types. Absent clinically documented, discrete (abrupt change in signs and symptoms) episodes of deterioration, it is not generally medically necessary to augment clinical assessments with TTE measurements at more frequent than annual examinations.

There is increasing data to support the prognostic value of diastolic function parameters in patients with systolic dysfunction. "When the etiology is in doubt, echocardiography can document or rule out the common cardiac causes of pulmonary congestion: left-sided valvular disease, depressed systolic or diastolic function, and cardiomyopathy. In this regard, echocardiography is the preferred initial diagnostic test when the history, physical examination, and routine laboratory tests suggest (or cannot eliminate) cardiac disease." (ACC/AHA/ASE 2003 Guideline Update, pg. 35) "Echocardiography is recommended for patients with edema with clinical signs of elevated central venous pressure when a potential cardiac etiology is suspected or when central venous pressure cannot be estimated with confidence and clinical suspicion of heart disease is high." TTE is also recommended for patients experiencing "dyspnea with clinical signs of heart disease."(ACC/AHA/ASE 2003 Guideline Update, pg. 37) "Echocardiography is not recommended in patients with edema when the jugular venous pressure does not appear to be elevated." (ACC/AHA/ASE 2003 Guideline Update, pg. 35).

2. Hypertensive Cardiovascular Disease

"Echocardiography is the noninvasive procedure of choice in evaluating the cardiac effects of systemic hypertension, the most common cause of LV hypertrophy and congestive heart failure in adults." (ACC/AHA/ASE 2003 Guideline Update, pg. 42) Left ventricular hypertrophy (LVH) correlates with prognosis in hypertensive cardiovascular disease. However, "the usefulness of echocardiography in an individual patient with hypertension without suspected concomitant heart disease depends on the clinical relevance of the assessment of LV mass or function in that patient. Thus, not every patient with hypertension should have resting LV function assessed (Class I), but if such an assessment is relevant, echocardiography is a well-documented and accepted method by which to achieve it. The value of repeated studies in asymptomatic hypertensive patients with normal LV function is not clearly established." (ACC/ AHA 2003 Guideline Update, pg. 42).

Certain antihypertensive medications have been reported to stabilize and possibly contribute to the regression of left ventricular hypertrophy and the insidiously progressive development of left ventricular dysfunction and dilatation. In young individuals and in individuals with borderline hypertension, the decision to commit to long-term antihypertensive therapy may be determined by the presence of left ventricular hypertrophy and /or left ventricular mass calculation.

3. Acute Myocardial Infarction and Coronary Insufficiency

TTE can detect ischemic and infarcted myocardium. Regional motion, systolic thickening perturbations and mural thinning can be quantitated and global functional adaptation assessed. The relative contributions of right ventricular ischemia and/or infarction can be evaluated. Complications of acute infarction (e.g., mural thrombi, papillary muscle dysfunction and rupture, septal defects, true or false aneurysm and myocardial rupture) can be diagnosed and their contribution to the overall clinical status placed in perspective. Following an initial TTE in the setting of acute infarction, repetition frequency will typically be dictated by the acute clinical course. The medical record should document the medical necessity of the frequency for TTE assessment.

"Evaluation of chest pain in patients with suspected acute myocardial ischemia, when baseline ECG and other laboratory markers are nondiagnostic and when study can be obtained during pain or within minutes after its abatement" is recommended in the ACC/AHA/ASE 2003 Guideline Update. "The use of echocardiography for diagnosis of acute myocardial infarction provides the greatest amount of incremental information when the clinical history and ECG findings are nondiagnostic." (ACC/AHA/ASE 2003 Guideline Update, pg. 15) This application may be used as part of a thoughtful clinical evaluation, especially as a triage decision on chest pain syndrome.

4. Exposure to Cardiotoxic Agents (chemotherapeutic and external)

Measures of myocardial contractility, thinning and dilatation are important in the titration of therapeutic agents with known myocardial toxicity. When echocardiography is used to monitor cardiac toxicity of chemotherapeutic agents (e.g., degenerative cardiomyopathy produced by doxorubicin therapy), an initial complete TTE may be performed prior to first administration of the agent with the frequency of repeat studies determined by the patient's clinical course and the toxicity profile of the agent being administered, although tests performed bimonthly during chemotherapy and at six (6) months following therapy are generally considered medically appropriate.

5. Cardiac Transplant and Rejection Monitoring

TTE is an integral part of the cardiac donor-selection and donor-recipient matching process. Evaluation focuses on analysis of ventricular function and valvular integrity. TTE is also incorporated into the management of allograft recipients. Myocardial thickness, refractile properties, contractile patterns and indices, restrictive hemodynamics, and the late development of pericardial fluid may alert the clinician to a rejection episode. None of these findings has achieved diagnostic sensitivity or specificity. Typically, TTE is performed weekly for the first four to eight (4-8) weeks following transplant, with decremental frequency over time. Absent acute rejection episodes, approximately two (2) TTE examinations are typically performed yearly in chronic transplant recipients. TTE of cardiac allografts is most appropriately serially performed at transplant centers by examiners with expertise in the management of cardiac allograft recipients. Uses in excess of the generally accepted frequency will be expected to have appropriate medical necessity documentation provided.

6. Native Valvular Heart Disease

TTE is well established as a technique of primary choice for the evaluation of valvular pathology and its effect upon global myocardial function. The relative severity of multi-valve pathologies can be quantified. Visualization of the valve and valvular apparatus facilitates therapeutic decisions when competing therapeutic options exist. For example, noninvasive TTE remains the study of choice for monitoring chronic aortic pathology with images suitable for serial quantitation. In some patients, Doppler echocardiography is the only noninvasive method capable of identifying the cause of a heart murmur. (ACC/AHA/ASE 2003 Guideline Update, pg. 7) Absent acute intervention, or a discrete change in otherwise stable clinical signs and symptoms, it is not medically necessary to repeat these examinations more frequently than annually. when the patient's clinical status shows evidence of change or the plan of care includes consideration for imminent valvular surgery, more frequent exams may be necessary.

7. Prosthetic Heart Valves (Mechanical & Bio-prostheses)

TTE assessment soon after prosthetic valve implant is important in establishing a baseline structural and hemodynamic profile unique to the individual and the prosthesis. Size, position, underlying ventricular function and concomitant valve pathologies all impact this unique profile. Reassessment following convalescence (3-6 months) for establishment of a baseline is appropriate. Thereafter, re-evaluation of patients with suspected dysfunction, thrombosis or a change in clinical status or symptoms is indicated.

8. Acute Endocarditis

TTE can provide diagnostic information; larger vegetations may be directly visualized; and valvular anatomy and ventricular function directly assessed. The complications or sequelae of acute infective endocarditis can be detected and monitored over time. Examination frequency in the acute phase of illness is dictated by the individual clinical course. When the acute process has been stabilized, the frequency of serial TTE evaluation will be determined by the residual pathophysiology and discrete clinical events, analogous to the serial assessment of chronic valvular dysfunction and/or normally functioning prosthetic valves.

9. Pericardial Disease

Detection and quantitation of the amount of pericardial effusion were among the first, and remain important, applications of TTE. Pericardial fluid accumulations of as little as twenty (20) milliliters have been reliably diagnosed by TTE. Cardiac motion and blood flow patterns demonstrated by TTE characterize the hemodynamic consequences of pericardial fluid accumulation. A collage of TTE findings has been found to be reliable indices of cardiac tamponade. TTE can be a valuable adjunct during the removal of pericardial fluid and creation of pericardial windows. The acute clinical status will dictate examination frequency. In a patient with evolving pericardial pathology, a limited focused TTE exam may be appropriate. TTE and Doppler techniques are quite helpful in identifying pericardial constriction and differentiating it from restrictive myocardial disease.

10. Abnormalities of the Great Vessels

Aorta: TTE can provide valuable information when acute or chronic aortic pathology is present; however, the posterior window of TEE, coupled with the more posterior position of the thoracic aorta, has rendered TEE a more determinative study. Noninvasive TTE remains the study of choice for chronic aortic pathology when images suitable for serial quantitation can be obtained. Routine (yearly) evaluation is indicated in patients with severe aortic stenosis or regurgitation, in whom the information obtained will be used in determining or modifiying the plan of care. In some individuals, such as those with ascending aortic dilatation or aneurysms, a focused limited follow-up exam (93308) to serially measure ascending aortic diameters may be indicated. Although TTE may visualize the intimal flap in patients with aortic dissection, TEE has proved to be a far more sensitive diagnostic procedure. TEE is the technique that is indicated in examination of the entire aorta, especially in emergency situation.

Pulmonary Artery: It is also indicated for visualization of the main pulmonary artery segment and the proximal right and left pulmonary arteries.

Venae Cavae: Echocardiography is indicated for visualizing the vena cavae and diagnosing various congenital and acquired abnormalities such as vena caval thrombosis, vena caval dilation, and thrombosis or extension of tumors from the inferior vena cava to the right-heart chambers.

11. Congenital Heart Disease

In children and small adults TTE provides accurate anatomic definition of most congenital heart diseases. Coupled with Doppler hemodynamic measurements, TTE usually provides accurate diagnosis and noninvasive serial assessment. A technically adequate TTE can obviate the need for preoperative catheterization in select individuals. When the disease process and therapy are stable, serial assessment by TTE requires contemporaneous medical necessity documentation, if the frequency exceeds an annual evaluation. In asymptomatic patients following repair of ASD, PFO, VSD or PDA follow up examination is only indicated within the first year after correction.

12. Suspected Cardiac Thrombi and Embolic Sources

TTE is indicated for the evaluation for cardiovascular source of embolic events (PFO/ASD, atrial or ventricular thrombus, intracardiac tumor) in evaluation for patients with abrupt occlusion of a major peripheral or visceral artery or for with neurological events without evidence of cerebrovascular disease or other obvious cause. Limited visualization of atrial appendages and the more peripheral and superior portions of the atria render TTE less sensitive than TEE in the detection of atrial thrombus and potentially embolic material. In those instances where the precise diagnosis and localization of potentially embolic material is of paramount therapeutic importance and the information so obtained will potentially and substantively alter therapy, or the risk of anticoagulants is inordinately high, consideration should be given to TEE if TTE provides inadequate decisional information.

13. Cardiac Tumors and Masses

Infiltrative and ventricular tumors and masses can be visualized, their extent quantitated and their hemodynamic consequences assessed by TTE. Right atrial space-occupying masses are usually well visualized by TTE. TEE provides a more detailed view of the left atrium and is more sensitive in quantifying mass characteristics (solid, cystic, etc.), extensions and attachments. Serial TTEs may be medically necessary to monitor tumor size or tumor recurrence.

14. Critically Ill and Trauma Patients

There is a role for echocardiography in the management of critically ill patients and trauma victims. The diagnosis of suspect aortic or central pulmonary pathology, cardiac contusion, or a pericardial effusion may be confirmed. Perturbations of volume status may be more completely defined and management strategies modified. The frequency of these typically acute studies will be dictated by the exigencies of the clinical milieu.

15. Arrhythmias and Palpitations

Transthoracic echocardiography is useful in defining cardiac function in which arrhythmias occur, and may be useful in the management of cardiac arrhythmias. Some arrhythmias are frequently associated with underlying organic heart disease or may predispose the patient to hemodynamic deterioration. Atrial fibrillation and atrial flutter are examples of arrhythmias in which echocardiography may be appropriate to assess the underlying disorder. Echocardiographic studies are appropriate only when there is evidence of heart disease. Palpitations without evidence of arrhythmias, or minor arrhythmias (e.g., isolated APC's or VPC's) without evidence of heart disease, are not covered indications for transthoracic echocardiography.

16. Syncope

Determination of the etiology of syncopal episodes can be a difficult clinical problem. The origin may be cardiac, neurological, or due to other causes. Syncope due to cardiac origin is most commonly related to vasodepressor reflexes, bradyarrhythmias, or tachyarrhythmias. Syncope is less commonly caused by cardiac structural disorders. Patients with a structurally normal heart generally have a much more benign prognosis than those with underlying structural coronary artery disease or cardiomyopathic disease. Echocardiography is only appropriate as the initial evaluation, and when other findings are suggestive of valvular heart disease or obstructive cardiomyopathy.

17. Pulmonary

Pulmonary heart disease may result from acute changes in the pulmonary circulation (e.g., pulmonary embolus), or chronic changes produced by chronic hypoxia which may cause significant right ventricular dysfunction and hypertrophy. Echocardiography may assess right ventricular size and performance, and quantify the severity of pulmonary hypertension using Doppler interrogation of valvular flow signals. Indications include unexplained pulmonary hypertension, and pulmonary emboli with suspected right atrial or right ventricular sources of emboli.

18. Contrast Echocardiography

Contrast echocardiography is indicated when a conventional study has failed to provide adequate and critically needed information on left ventricular function. A contrast agent is considered medically necessary when it is used to improve the delineation of the left ventricular endocardial borders in a patient whose non-contrast study is inadequate or suboptimal, and for whom the LV function information is essential to the management of the patient. Contrast is indicated when more than two (2) contiguous segments of the left ventricular border are not visualized.

19. CAMZYOS™ (mavacamten) treatment

Patients with symptomatic obstructive hypertrophic cardiomyopathy NYHA Class II-III may be prescribed mavacamten by a certified and enrolled provider and pharmacy through a restricted program called the CAMZYOS Risk Evaluation and Mitigation Strategy (REMS) program. 1,2 This requirement is due to serious risk of heart failure due to systolic dysfunction associated with this agent in this population, however there are few options for treatment and improvement in health status on this agent in select patients leading to the REMS program to provide treatment while furthering understanding of the risk: benefit ratio. 1,3,4 This program requires echocardiograms at:

i. Prior to enrollment

ii. 4, 8, and 12 weeks after treatment initiation, then every 12 weeks thereafter

iii. 4 weeks after interruption of treatment

iv. 4 and 12 weeks after any dose change (including restart of treatment)

v. 4 and 12 weeks after initiating a weak CYP2C19 inhibitor or a moderate CYP3A4 inhibitor

LIMITATIONS:

1. Echocardiography performed for screening purposes is not covered. Screening includes testing performed on patients who present with risk factors (including the risk factor as having a positive family history, e.g., familial history of Marfan's disease). A screening service for high-risk patients is considered good medical practice but is not covered by Medicare. When the result of the test is abnormal, subsequent services may be billed with the test-result diagnosis; however, the initial screening test must be listed as screening, even though the result of the screening test may be a covered condition.

The following indications (#2-15) are deemed to be not medically necessary and are therefore not reimbursable:

2. Routine (yearly) evaluation of asymptomatic patients with corrected ASD, VSD or PDA more than one year after successful correction.

3. Routine (yearly) re-evaluation of mitral valve prolapse in patients with no or mild mitral regurgitation and no change in clinical status.

4. Routine (yearly) re-evaluation of an asymptomatic patient with mild native aortic stenosis or mild-moderate native mitral stenosis and no change in clinical status.

5. Routine (yearly) re-evaluation of native valvular regurgitation in an asymptomatic patient with mild regurgitation, no change in clinical status and normal left ventricular size.

6. Routine (yearly) evaluation of a patient with a prosthetic valve in whom there is no suspicion of valvular dysfunction and no change in clinical status.

7. Routine (yearly) re-evaluation of patients with heart failure (systolic or diastolic) in whom there is no change in clinical status.

8. Routine (yearly) evaluation of hypertrophic cardiomyopathy in a patient with no change in clinical status.

9. Patients who have isolated APC or VPC without other evidence of heart disease.

10. Evaluation of LV function with prior ventricular function within the past year with normal (such as prior echocardiogram, left ventriculogram, SPECT, cardiac MRI) in patients in whom there has been no change in clinical status.

11. Initial evaluation of patient with suspected pulmonary embolism in order to establish diagnosis.

12. Evaluation of native and/or prosthetic valves in patients with transient fever but without evidence of bacteremia or new murmur.

13. Re-evaluation of a patient with known hypertensive heart disease without a change in clinical status.

14. Routine evaluation of patients with systemic hypertension without suspected hypertensive heart disease.

15. Evaluation of a patient with atrial fibrillation/flutter for left atrial thrombus or spontaneous contrast when a decision has been made to anticoagulate and not to perform cardioversion.

[Items 2-15, see ACCF/ASE/ACEP/ASNC/SCAI/SCCT/SCMR 2007 Appropriateness Criteria for Transthoracic and Transesophageal Echocardiography, JACC 2007].

16. Echocardiograms for symptomatic obstructive hypertrophic cardiomyopathy and administration of mavacamten must be enrolled in the FDA CAMZYOS REMS program 2 and meet all requirement of this program. Echocardiograms used outside of the protocol will not be covered.

B. Follow-up Studies or Limited Studies

INDICATIONS AND LIMITATIONS

A complete study includes a full evaluation of all aspects of the heart, including the cardiac chambers, valves, blood flow, and great vessels. The images are reviewed, measured, analyzed and interpreted by the physician. A report is prepared for the patient's record. When a less than complete examination is performed for the purpose of evaluation of one specific cardiac problem, or region of the heart, the service performed is described by codes 93304, 93308 and 93321, follow-up or limited studies. When a limited service is performed, or the patient's condition requires only a limited examination, these codes must be used to indicate the appropriate service.

Examples of appropriate use of 93308: a follow-up study of a patient with pericardial effusion following heart surgery, to evaluate progression or resolution of the effusion; or a serial evaluation of left ventricular function during antineoplastic chemotherapy.

Examples of appropriate use of 93321: recording tricuspid regurgitant velocity in order to estimate pulmonary artery systolic pressure; or sequential evaluation of the transmitral velocity profile in a patient with mitral stenosis, in order to evaluate for a change in gradient or valve area.

C. Doppler Color Flow Velocity Mapping

INDICATIONS AND LIMITATIONS

Spectral Doppler echocardiography and Doppler color flow-velocity mapping (93320, 93321, 93325) may be necessary in addition to an echocardiogram when the examination could contribute significant information to the patient's condition or treatment plan (For Dates of service on or after 01/01/2009, code 93306 should be used when Doppler is combined with a complete echocardiogram). Typically, Doppler is indicated in the evaluation of some heart murmurs, valvular problems, shunts, suspected congenital heart disease, complications of myocardial infarction, or cardiomyopathy. Doppler should be medically necessary for the evaluation and management of the patient.

"Color/spectral Doppler may not be useful or appropriate in certain relatively small and well-defined patient populations when there is a recent comprehensive examination and the test is being ordered for re-evaluation of a limited problem." (ASE comment).

The use of the Doppler is inherent in the ultrasonic cardiac evaluation. However, if the test reports fail to document the use of this technique to assess these structures and function (e.g., measurement of valvular insufficiency or stenosis, myocardial diastolic function, etc. as described by the ASE), or if the medical records fail to document that the examination was "clinically necessary" (e.g., follow-up of pericardial effusion size) then the Doppler portion of the test may be considered medically unnecessary and denied.

D. Limited Capability Ultrasound Scanners

INDICATIONS AND LIMITATIONS

Some small scanners have more limited capabilities and lack either the permanent recording capabilities or some of the functional capabilities needed to perform a complete examination. Such a study may be quite useful as an extension of the physical examination. However, an examination that does not meet the standards required for a complete diagnostic echocardiographic examination – whether performed with a "conventional" scanner or a limited capability ultrasound scanner - will not be recognized as a valid echocardiographic service and will be non-covered.

N/A