Cardiac Applications of Positron Emission Tomography Scanning

Section: Radiology
Effective Date: January 01, 2020
Revised Date: January 22, 2020
Last Reviewed: January 22, 2020

Description

Positron Emission Tomography

PET scans use positron-emitting radionuclide tracers, which simultaneously emit two high-energy photons in opposite directions. These photons can be simultaneously detected (referred to as coincidence detection) by a PET scanner, comprising multiple stationary detectors that encircle the thorax. Compared with single-photon emission computed tomography (SPECT) scans, coincidence detection offers a greater spatial resolution.

Myocardial Perfusion Imaging

For myocardial perfusion studies, individual selection criteria for PET include an individual assessment of the pretest probability of coronary artery disease (CAD), based both on individual symptoms and risk factors. Individuals at low-risk for CAD may be adequately evaluated with exercise electrocardiography. Individuals at high-risk for CAD typically will not benefit from noninvasive assessment of myocardial perfusion; a negative test will not alter disease probability sufficiently to avoid invasive angiography.

Myocardial Viability

Individuals selected to undergo PET scanning for myocardial viability are typically those with severe left ventricular dysfunction who are being considered for revascularization. A PET scan may determine whether the left ventricular dysfunction is related to the viable or nonviable myocardium. Individuals with viable myocardium may benefit from revascularization but those with nonviable myocardium will not. As an example, PET scanning is commonly performed in potential heart transplant candidates to rule out the presence of viable myocardium.

Criteria

Cardiac positron emission tomography (PET) scanning may be considered medically necessary to assess myocardial perfusion and thus diagnose coronary artery disease in individuals with indeterminate single-photon emission computed tomography (SPECT) scan; or in individuals for whom SPECT could be reasonably expected to be suboptimal in quality on the basis of body habitus

Cardiac PET scanning may be considered medically necessary to assess myocardial viability in individuals with severe left ventricular dysfunction as a technique to determine candidacy for a revascularization procedure

Cardiac PET scanning is investigational for quantification of myocardial blood flow in individuals diagnosed with coronary artery disease

Cardiac PET scanning may be considered medically necessary for diagnosing cardiac sarcoidosis in individuals who are unable to undergo magnetic resonance imaging

Examples of individuals who are unable to undergo magnetic resonance imaging include, but are not limited to, individuals with pacemakers, automatic implanted cardioverter defibrillators, or other metal implants

Procedure Codes

78429 78430 78431 78432 78433 78434 78459
78491 78492 A9526 A9552 A9555 A9598

 

Diagnosis Codes

D86.85 I25.10 I25.110 I25.111 I25.118 I25.119 I50.1
I51.9

Professional Statements and Societal Positions Guidelines

Practice Guidelines and Position Statements

American College of Cardiology et al

The American College of Cardiology, American Heart Association, and American Society for Nuclear Cardiology (2003) updated their joint guidelines for cardiac radionuclide imaging, including cardiac applications of PET. Table 6 summarizes the guidelines for PET and SPECT imaging in individuals with an intermediate risk of coronary artery disease (CAD).

Table 6. Guidelines for PET and SPECT in Individuals at Intermediate Risk of Coronary Artery Disease

Indication

Classa

 

SPECT

PET

Identify extent, severity, and location of ischemia (SPECT protocols vary according to whether individual can exercise)

I

IIa

Repeat test after 3-5 y after revascularization in selected high-risk asymptomatic individuals (SPECT protocols vary according to whether individuals can exercise)

IIa

-

As initial test in individuals who are considered to be at high-risk (i.e., individuals with diabetes or those with a >20% 10-y risk of a coronary disease event) (SPECT protocols vary according to whether individuals can exercise)

IIa

-

Myocardial perfusion PET when prior SPECT study has been found to be equivocal for diagnostic or risk stratification purposes

Not appropriate

I

Adapted from Klocke et al (2003).

PET: positron emission tomography; SPECT: single-photon emission computed tomography.
a Class I is defined as conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective. Class IIa is defined as conditions for which there is conflicting evidence or a divergence of opinion, but the weight of evidence/opinion is in favor of usefulness/efficacy. Class IIb is similar to class II except that the usefulness/efficacy is less well-established by evidence/opinion.

These guidelines concluded that PET "appears to have slightly better overall accuracy for predicting recovery of regional function after revascularization in individuals with left ventricular dysfunction than single-photon techniques (i.e., SPECT scans)." However, the guidelines indicated that both PET and SPECT scans are class I indications for predicting improvement in regional and global left ventricular function and natural history after revascularization; therefore, the guidelines did not indicate a clear preference for PET or SPECT scans in this situation.

The American College of Cardiology Foundation and American Heart Association (2009) collaborated with 6 other imaging societies to develop Appropriate Use Criteria for cardiac radionuclide imaging. Their report stated:

"...use of cardiac RNI for diagnosis and risk assessment in intermediate- and high-risk individuals with coronary artery disease (CAD) was viewed favorably, while testing in low-risk individuals, routine repeat testing, and general screenings in certain clinical scenarios were viewed less favorably. Additionally, use for perioperative testing was found to be inappropriate except for high selected groups of individuals."

American College of Radiology

The ACR Appropriateness Criteria (2011) considered both SPECT and PET to be appropriate for the evaluation of individuals with a high probability of CAD. The ACR indicated that PET perfusion imaging has advantages over SPECT, including higher spatial and temporal resolution. Routine performance of both PET and SPECT are unnecessary. The 2017 update stated:

"Hybrid PET scanners use CT [computed tomography] for attenuation correction (PET/CT) following completion of the PET study. By coupling the PET perfusion examination findings to a CCTA [coronary computed tomographic angiography], PET/CT permits the fusion of anatomic coronary arterial and functional (perfusion) myocardial information and enhances diagnostic accuracy. The fused examinations can accurately measure the atherosclerotic burden and identify the hemodynamic functional significance of coronary stenosis. The results of the combined examinations can more accurately identify individuals for revascularization."

The ACR Appropriateness Criteria (2012) also recommended PET for the evaluation of individuals with chronic chest pain and the low-to-intermediate probability of CAD.

The ACR does not recommend PET for individuals with acute nonspecific chest pain who have a low probability of CAD or for asymptomatic individuals at risk for CAD.

ND Committee Review

Internal Medical Policy Committee 1-22-2020 North Dakota has added PET scans to precert list

Links

Disclaimer

Current medical policy is to be used in determining a Member's contract benefits on the date that services are rendered. Contract language, including definitions and specific inclusions/exclusions, as well as state and federal law, must be considered in determining eligibility for coverage. Members must consult their applicable benefit plans or contact a Member Services representative for specific coverage information. Likewise, medical policy, which addresses the issue(s) in any specific case, should be considered before utilizing medical opinion in adjudication. Medical technology is constantly evolving and the Company reserves the right to review and update medical policy periodically.