LCD L39863: Artificial Intelligence Enabled CT Based Quantitative Coronary Topography (AI-QCT)/Coronary Plaque Analysis (AI-CPA)

AI-QCT/AI-CPA using CCTA* is considered reasonable and medically necessary as a diagnostic study when:

• The patient has acute or stable chest pain with no known CAD 1 and is eligible for CCTA*, AND

• CCTA classifies patient as:

• Intermediate risk ** OR

• CAD-RADs 1, CAD-RADS 2 or CAD-RADS 3*** category on CCTA 1,2 AND

• Cardiac evaluation is negative or inconclusive for acute coronary syndrome (ACS) 1

*See L33559 for criteria for CCTA. AI-QCT/AI-CPA should not be performed until after the base study (CCTA) has been completed and interpreted. Software to perform AI-QCT/AI-CPA must be FDA cleared or approved.

**Intermediate and high-risk as defined in the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain 1

*** CAD-RADS 1-CAD-RADS 3 category as defined by CAD-RADS™ 2.0–2022 Coronary Artery Disease Reporting and Data System (CAD-RADS) : an Expert Consensus document of the Society of Cardiovascular Computed Tomography (SCCT), the American College of Cardiology (ACC), the American College of Radiology (ACR), and the North America Society of Cardiovascular Imaging (NASCI). 2,3

Limitations

Software to perform AI-CPA must be FDA cleared or approved.

AI-QCT/AI-CPA is NOT considered reasonable or necessary in the following clinical circumstance (non-covered):

• Screening, i.e., in the absence of signs, symptoms, or disease.

• When there is a contraindication to CCTA.*

• In conjunction with invasive coronary catheterization.

• In the presence of normal CCTA results (CAD RADS=0 or no plaque disease).

• In the presence of high grade stenosis (>70%) or CAD RADS-4 and RADS-5.

• Within 30 days of a myocardial infarction (MI).

• In the presence of unstable coronary symptoms.

• For disease surveillance.

*See CCTA policy ( L33559) for full listing of contraindications.

Definitions

Artificial Intelligence Enabled CT Based Quantitative Coronary Topography ( AI-QCT )/ Coronary Plaque Analysis (AI-CPA)- artificial intelligence application to imaging obtained through coronary CT scans to calculate coronary artery dimensions and degree of stenosis per vessel and coronary plaque composition and burden. 4

Calcified Plaque - Higher density plaque, mostly composed of calcium, thought to be associated with lower clinical risk than non-calcified plaque. Traditionally, the overall burden of calcified plaque has been assessed indirectly through a coronary artery calcium score (CACS) or using cut off >350 HU. 5 There is both calcified and non-calcified tissue present. 6

Coronary Artery Disease (CAD)- Narrowing of the coronary arteries usually caused by plaque and atherosclerosis that can lead to ischemia of the heart. 1

• Known CAD includes patient with prior anatomic testing with identified nonobstructive atherosclerotic plaque and obstructive CAD. 1

Coronary Artery Disease Reporting and Data System (CAD-RADS)- A standardized method to communicate findings of CCTA. 2

Category

Degree of maximal coronary stenosis

Interpretation

CAD-RADS 0

0%

Absence of CAD

CAD-RADS 1

1-24%

Minimal non-obstructive CAD

CAD-RADS 2

25-49%

Mild non-obstructive CAD

CAD-RADS 3

50-69%

Moderate stenosis

CAD-RADS 4

70-99% or left main ≥50% or 3-vessel obstructive (≥70%) disease

Severe stenosis

CAD-RADS 5

100%

Total coronary artery occlusion or sub-total occlusion

CAD-RADS N

Non-diagnostic study

Obstructive CAD cannot be excluded

Coronary Computed Tomography Angiography (CCTA) - a non-invasive test using advanced computed tomography angiography imaging to view the tissues and blood vessels of the heart. This can be used to determine the presence and extent of CAD.

Coronary Plaque Analysis (CPA)- Analysis of coronary plaque composition and burden.

Fibrotic Plaque- a plaque with density of 131-350 HU.

High Risk Plaque (HRP)- High risk plaque findings include napkin-ring sign, low-attenuation plaque, positive vessel remodeling, low CT attenuation and spotty calcification. 5,7

Invasive Coronary Angiography (ICA)- Invasive procedure done at the time of cardiac catheterization to look at the arteries of the heart and can determine the presence and extent of CAD.

Low Attenuation Plaque (LAP)- Low density plaque with dark appearance on CCTA and higher lipid content usually defined as attenuation of 5,8

Major Adverse Cardiac Events (MACE)- Fatal and non-fatal myocardial infarction. Some studies also include unstable angina requiring hospitalization or revascularization. 7

Non-Calcified Plaque (NCP) – A lower density plaque, often earlier in development and associated with higher clinical risk with density of 50-130 HU. 5,8 There is no discernible calcification present. 6

Nonobstructive CAD - CAD with 1

Obstructive CAD- CAD with >50% stenosis 1

Plaque- The presence of tissue structures ≥ 1mm 2 within or adjacent to the coronary artery lumen, identified in at least two independent planes, that can be distinguished from the surrounding tissues (epicardial fat) and the lumen. 6

Quantitative Coronary Plaque Analysis (QCPA)- Imaging technique that provides objective and reproducible measurements of coronary artery dimensions and composition of the atherosclerotic plaques.

Quantitative Coronary Topography (QCT)- CT scan imaging that provides objective and reproducible measurements of the coronary artery dimensions and degree of stenosis per vessel.

Provider Qualifications

The Medicare Program Integrity Manual states services will be considered medically reasonable and necessary only if performed by appropriately trained providers.

Patient safety and quality of care mandate that healthcare professionals who interpret CCTA and QCPA and AI-QCT/AI-CPA are appropriately trained and/or credentialed by a formal residency/fellowship program. Credentialing or privileges are required for procedures performed in inpatient and outpatient settings. 4

All aspects of care must be within the provider’s medical licensure and scope of practice. Reimbursement for procedures utilizing imaging techniques may be made to providers who meet training requirements for the procedures in this policy only if their respective state allows such in their practice act and formally licenses or certifies the practitioner to use and interpret these imaging modalities. At a minimum, training must cover and develop an understanding of anatomy and drug pharmacodynamics and kinetics as well as proficiency in diagnosis and management of disease, the technical performance of the procedure, and utilization of the required associated imaging modalities. Supervision, interpretation, and reports shall/must be performed by a physician with the advanced training requirements and or credentialing for CCTA and AI-QCT/AI-CPA. The technical and professional portions must meet the criteria for performance for CCTA ( L33559 ).

Providers must also meet the FDA requirements which includes “The software is not intended to replace the skill and judgment of a qualified medical practitioner and should only be used by people who have been appropriately trained in the software’s functions, capabilities and limitations.” 9 Radiology technicians must also meet all training requirements for performance of AI-QCT/AI-CPA.

Notice: Services performed for any given diagnosis must meet all the indications and limitations stated in this LCD, the general requirements for medical necessity as stated in CMS payment policy manuals, all existing CMS national coverage determinations, and all Medicare payment rules.

A Contractor Advisory Meeting “ Non-Invasive Technology for Coronary Artery Plaque Analysis” was hosted 5/25/23 by CGS Administrators, Noridian Healthcare Solutions, National Government Services, Palmetto GBA, and WPS Government Health Administrators. The transcript and audio are available on each MACs website.

Background

CCTA has become an effective gate keeper for invasive angiography helping guide referral for obstructive CAD. It has been demonstrated to be superior to exercise electrocardiography and single-photon emission computed tomography (SPECT) for detection of obstructive CAD (>50% stenosis). 10,11 . Studies have demonstrated excellent prognostic value of a normal CCTA for both short and long term mortality rates. 12 The updated 2021 American College of Cardiology and American Heart Association Chest Pain Guideline 1 states CCTA has become a first line tool in evaluation of acute and chronic coronary artery disease particularly in symptomatic patients with stable symptoms and intermediate or high pre-test probability of obstructive coronary artery disease, or among intermediate-risk acute chest pain patients.

CCTA can also provide information on plaque burden and adverse coronary artery plaque characteristics which has been demonstrated to be an independent predictor of disease and prognosis. 12 The characterization of coronary atherosclerotic plaques can be calculated from CCTA, but the process is time consuming and often with variable results. 4,13 At least 5 different software have been developed as an adjunct to CCTA to aid in the visualization, reduce evaluation time, and improve accuracy of this assessment. The gold standard is considered intravascular ultrasound (IVUS) and optical coherence tomography (OCT) which are the tools that are often used to validate the software. 5 This is intended to improve clinical diagnosis and management of CAD. 14