Myocardial Imaging, Positron Emission Tomography (PET) Scan
Coverage Indications, Limitations, and/or Medical Necessity
Cardiac PET studies are techniques in which radioactive tracers are used to diagnose patients with suspected coronary artery disease (CAD) and provide important risk stratification of patients with known CAD. This test is also a valuable tool to assess myocardial viability, myocardial wall motion and ejection fraction, as well as cardiac sarcoidosis. For diagnosis, radionuclides are administered intravenously and distribute in proportion to the regional myocardial blood flow present at the time of injection. In selected patients, Cardiac PET offers certain advantages over standard of care Single Photon Emission Computed Tomography Myocardial Perfusion Imaging (SPECT MPI). Cardiac PET is a useful technique that allows a noninvasive evaluation of myocardial blood flow, function, and metabolism, using physiological substrates prepared with positron-emitting radionuclides, such as oxygen, nitrogen, fluorine, and rubidium. These radionuclides have half-lives that are considerably shorter than those used in SPECT. Positron-emitting radionuclides are produced either using a cyclotron, such as fluoro-2-deoxyglucose (F-18 FDG) with a 110-minute half-life, or nitrogen-13-ammonia (N-13), with a half-life of 9.8 minutes or a generator such as rubidium-82 (Rb-82) with a 75-second half-life. Because of availability, the most common PET blood flow tracer is rubidium-82.
The goal of cardiac PET perfusion imaging is to detect physiologically significant coronary artery narrowing. Results of the test should lead toward risk factor modification in order to delay or reverse the progression of atherosclerosis, alleviate symptoms of ischemia, and improve patient survival by either medical therapy or revascularization procedures such as bypass surgery (CABG) or percutaneous coronary intervention (PCI). Stress and rest paired myocardial perfusion studies are commonly performed to assess myocardial ischemia and/or infarction. Current Food and Drug Administration (FDA)-approved and Centers for Medicare and Medicaid Services-covered PET myocardial blood flow tracers are limited to Rb-82, F-18 FDG, and N-13 ammonia. Normal MPI implies the absence of significant CAD. Abnormal myocardial perfusion on stress imaging suggests the presence of significantly narrowed coronary arteries. If the stress regional perfusion defect is absent on the corresponding rest images, it suggests the presence of stress-induced myocardial ischemia. If the stress perfusion defect persists at rest, it suggests prior infarction. Imaging of myocardial perfusion can also be combined with myocardial metabolism imaging with F-18FDG for the assessment of myocardial viability in areas of resting hypoperfusion and dysfunctional myocardium. The stress protocols are, for the most part, similar for all cardiac PET perfusion agents. The specific differences in acquisition protocols for Rb-82 and N-13 are related to the duration of uptake and clearance of these radiopharmaceuticals and their physical half-lives.
Indications:
The following cardiac indications may be covered for PET under certain circumstances:
1. For the evaluation of coronary artery disease for perfusion of the heart via myocardial perfusion imaging, PET scans using either FDA-approved radiopharmaceutical Rubidium 82 (RB-82) or Ammonia N-13 when performed at rest or with pharmacological stress used for noninvasive imaging of the perfusion of the heart for the diagnosis and management of patients with known or suspected coronary artery disease provided the following requirements are met:
The PET scan (whether at rest alone or rest with stress) is performed in place of, but not in addition to, a single photon emission computed tomography (SPECT) in persons with conditions that may cause attenuation problems with SPECT, e.g., obesity (BMI greater than or equal to 35), large breasts, breast implants, left mastectomy, chest wall deformity, pleural or pericardial effusion; or
The PET scan (whether at rest alone or rest with stress) is used following a SPECT that was found to be inconclusive. In these cases, the PET scan must have been considered necessary in order to determine what medical or surgical intervention is required to treat the patient. (For purposes of this requirement, an inconclusive test is a test(s) whose results are equivocal, technically uninterpretable, or discordant with a patient’s other clinical data and must be documented in the beneficiary’s file.)
For myocardial perfusion studies, patient selection criteria for PET scans involve an individual assessment of the pretest probability of CAD, based both on patient symptoms and risk factors:
** Patients at low risk for CAD may be adequately evaluated with exercise electrocardiography.
** Patients at high risk for CAD will typically not benefit from non-invasive assessment of myocardial perfusion.
** A negative test will not alter disease probability sufficiently to avoid invasive angiography.
** Myocardial perfusion imaging is potentially beneficial for patients at intermediate risk of CAD (approximately 25% to 75% disease prevalence).
The risk can be estimated using the patient’s age, sex, and chest pain quality. The range for intermediate risk can vary.
The following table summarizes a characterization for patient populations at intermediate risk for CAD:
Typical Angina:
Chest pain with all of the following characteristics:
1. Substernal chest discomfort with characteristic quality and duration, and
2. Provoked by exertion or emotional stress, and
3. Relieved by rest or nitroglycerin
-Men ages 30-39
-Women ages 30-60
Atypical Angina:
-Chest pain that lacks one of the characteristics of typical angina
-Men ages 30-70
-Women ages 50 years and older
Nonanginal Chest Pain:
-Chest pain that meets one or none of the typical angina characteristics
-Men ages 50 years and older
-Women ages 60 years and older
2. For the determination of myocardial viability, using Fluorodeoxyglucose (F-18 FDG) as a radioactive tracer, when performed as a primary or initial diagnostic study prior to revascularization, or following an inconclusive SPECT. However, if a patient receives an FDG PET study with inconclusive results, a follow up SPECT test is not covered. The identification of patients with partial loss of heart muscle movement or hibernating myocardium is important in selecting candidates with compromised ventricular function to determine appropriateness for revascularization. Diagnostic tests such as FDG PET distinguish between dysfunctional but viable myocardial tissue and scar tissue in order to affect management decisions in patients with ischemic cardiomyopathy and left ventricular dysfunction.
3. For the determination of cardiac involvement, using Fluorodeoxyglucose (F-18 FDG), to diagnose cardiac sarcoidosis in patients who are unable to undergo magnetic resonance imaging (MRI) scanning. Examples of patients who are unable to undergo MRI include, but are not limited to, patients with pacemakers, automatic implantable cardioverter defibrillators (AICDs), or other metal implants.
Limitations of Coverage:
Myocardial imaging, PET scan is not covered for other diagnostic uses and is not covered for screening (testing of patients without specific symptoms).
Revenue Codes
Code Description
0404 Other Imaging Services – Positron Emission Tomography
Procedure code /HCPCS Codes
Group 1 Codes
78459 Heart muscle imaging (PET)
78491 Heart image (pet) single
78492 Heart image (pet) multiple
A9526 Nitrogen N-13 ammonia
A9552 F18 fdg
A9555 Rb82 rubidium
ICD-10 Codes that Support Medical Necessity
Group 1 Paragraph
The following ICD-10 codes are applicable to procedure codes 78459, 78491, and 78492 only:
Group 1 Codes
A18.84* Tuberculosis of heart
D86.0* Sarcoidosis of lung
D86.1* Sarcoidosis of lymph nodes
D86.2* Sarcoidosis of lung with sarcoidosis of lymph nodes
D86.3* Sarcoidosis of skin
D86.81* Sarcoid meningitis
D86.82* Multiple cranial nerve palsies in sarcoidosis
D86.83* Sarcoid iridocyclitis
D86.84* Sarcoid pyelonephritis
D86.85* Sarcoid myocarditis
D86.86* Sarcoid arthropathy
D86.87* Sarcoid myositis
D86.89* Sarcoidosis of other sites
D86.9* Sarcoidosis, unspecified
I20.1 Angina pectoris with documented spasm
I20.8 Other forms of angina pectoris
I20.9 Angina pectoris, unspecified
I24.0 Acute coronary thrombosis not resulting in myocardial infarction
I24.1 Dressler’s syndrome
I25.10 Atherosclerotic heart disease of native coronary artery without angina pectoris
I25.110 Atherosclerotic heart disease of native coronary artery with unstable angina pectoris
I25.111 Atherosclerotic heart disease of native coronary artery with angina pectoris with documented spasm
I25.118 Atherosclerotic heart disease of native coronary artery with other forms of angina pectoris
I25.119 Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris
I25.3 Aneurysm of heart
I25.41 Coronary artery aneurysm
I25.42 Coronary artery dissection
I25.700 Atherosclerosis of coronary artery bypass graft(s), unspecified, with unstable angina pectoris
I25.701 Atherosclerosis of coronary artery bypass graft(s), unspecified, with angina pectoris with documented spasm
I25.708 Atherosclerosis of coronary artery bypass graft(s), unspecified, with other forms of angina pectoris
I25.709 Atherosclerosis of coronary artery bypass graft(s), unspecified, with unspecified angina pectoris
I25.710 Atherosclerosis of autologous vein coronary artery bypass graft(s) with unstable angina pectoris
I25.711 Atherosclerosis of autologous vein coronary artery bypass graft(s) with angina pectoris with documented spasm
I25.718 Atherosclerosis of autologous vein coronary artery bypass graft(s) with other forms of angina pectoris
I25.719 Atherosclerosis of autologous vein coronary artery bypass graft(s) with unspecified angina pectoris
I25.720 Atherosclerosis of autologous artery coronary artery bypass graft(s) with unstable angina pectoris
I25.721 Atherosclerosis of autologous artery coronary artery bypass graft(s) with angina pectoris with documented spasm
I25.728 Atherosclerosis of autologous artery coronary artery bypass graft(s) with other forms of angina pectoris
I25.729 Atherosclerosis of autologous artery coronary artery bypass graft(s) with unspecified angina pectoris
I25.730 Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with unstable angina pectoris
I25.731 Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with angina pectoris with documented spasm
I25.738 Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with other forms of angina pectoris
I25.739 Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with unspecified angina pectoris
I25.750 Atherosclerosis of native coronary artery of transplanted heart with unstable angina
I25.751 Atherosclerosis of native coronary artery of transplanted heart with angina pectoris with documented spasm
I25.758 Atherosclerosis of native coronary artery of transplanted heart with other forms of angina pectoris
I25.759 Atherosclerosis of native coronary artery of transplanted heart with unspecified angina pectoris
I25.760 Atherosclerosis of bypass graft of coronary artery of transplanted heart with unstable angina
I25.761 Atherosclerosis of bypass graft of coronary artery of transplanted heart with angina pectoris with documented spasm
I25.768 Atherosclerosis of bypass graft of coronary artery of transplanted heart with other forms of angina pectoris
I25.769 Atherosclerosis of bypass graft of coronary artery of transplanted heart with unspecified angina pectoris
I25.790 Atherosclerosis of other coronary artery bypass graft(s) with unstable angina pectoris
I25.791 Atherosclerosis of other coronary artery bypass graft(s) with angina pectoris with documented spasm
I25.798 Atherosclerosis of other coronary artery bypass graft(s) with other forms of angina pectoris
I25.799 Atherosclerosis of other coronary artery bypass graft(s) with unspecified angina pectoris
I25.810 Atherosclerosis of coronary artery bypass graft(s) without angina pectoris
I25.811 Atherosclerosis of native coronary artery of transplanted heart without angina pectoris
I25.812 Atherosclerosis of bypass graft of coronary artery of transplanted heart without angina pectoris
I43* Cardiomyopathy in diseases classified elsewhere
I44.30 Unspecified atrioventricular block
I44.39 Other atrioventricular block
I44.4 Left anterior fascicular block
I44.5 Left posterior fascicular block
I44.60 Unspecified fascicular block
I44.69 Other fascicular block
I44.7 Left bundle-branch block, unspecified
I45.0 Right fascicular block
I45.10 Unspecified right bundle-branch block
I45.19 Other right bundle-branch block
I45.2 Bifascicular block
I45.3 Trifascicular block
I45.4 Nonspecific intraventricular block
I45.5 Other specified heart block
I48.0 Paroxysmal atrial fibrillation
I48.2 Chronic atrial fibrillation
I48.91 Unspecified atrial fibrillation
I50.1 Left ventricular failure
I50.20 Unspecified systolic (congestive) heart failure
I50.21 Acute systolic (congestive) heart failure
I50.22 Chronic systolic (congestive) heart failure
I50.23 Acute on chronic systolic (congestive) heart failure
I50.30 Unspecified diastolic (congestive) heart failure
I50.31 Acute diastolic (congestive) heart failure
I50.32 Chronic diastolic (congestive) heart failure
I50.33 Acute on chronic diastolic (congestive) heart failure
I50.40 Unspecified combined systolic (congestive) and diastolic (congestive) heart failure
I50.41 Acute combined systolic (congestive) and diastolic (congestive) heart failure
I50.42 Chronic combined systolic (congestive) and diastolic (congestive) heart failure
I50.43 Acute on chronic combined systolic (congestive) and diastolic (congestive) heart failure
I50.9 Heart failure, unspecified
R07.9 Chest pain, unspecified
