Cardiac Computed Tomographic Angiography (CCTA)

POLICY NUMBER

L.6.01.415

DESCRIPTION

Contrast-enhanced computed tomography angiography (CTA) is a noninvasive imaging test that requires the use of intravenously administered contrast material and high-resolution, high-speed CT machinery to obtain detailed volumetric images of blood vessels. CTA can be applied to image blood vessels throughout the body; however, for the coronary arteries, several technical challenges must be overcome to obtain high-quality diagnostic images. First, very short image acquisition times are necessary to avoid blurring artifacts from the rapid motion of the beating heart. In some cases, premedication with beta-blocking agents is used to slow the heart rate below approximately 60–65 beats per minute to facilitate adequate scanning, and electrocardiographic triggering or gating (retrospective or prospective) is used to obtain images during diastole when motion is reduced. Second, rapid scanning is also helpful so that the volume of cardiac images can be obtained during breath-holding. Third, very thin sections (1 mm or less) are important to provide adequate spatial resolution and high-quality 3D reconstruction images.

Volumetric imaging permits multiplanar reconstruction of cross-sectional images to display the coronary arteries. Curved multiplanar reconstruction and thin-slab maximum intensity projections provide an overview of the coronary arteries, and volume-rendering techniques provide a 3D anatomical display of the exterior of the heart. Two different CT technologies can achieve high-speed CT imaging. Electron beam CT (EBCT, also known as ultrafast CT) uses an electron gun rather than a standard x-ray tube to generate x-rays, thus permitting very rapid scanning, on the order of 50–100 milliseconds per image. Helical CT scanning (also referred to as spiral CT scanning) also creates images at greater speed than conventional CT by continuously rotating a standard x-ray tube around the patient so that data are gathered in a continuous spiral or helix rather than as individual slices. Helical CT is able to achieve scan times of 500 milliseconds or less per image, and use of partial ring scanning or post-processing algorithms may reduce the effective scan time even further.

Multidetector row helical CT (MDCT) or multislice CT scanning is a technologic evolution of helical CT, which uses CT machines equipped with an array of multiple x-ray detectors that can simultaneously image multiple sections of the patient during a rapid volumetric image acquisition. MDCT machines currently in use have 64 or more detectors.

A variety of noninvasive tests are used in the diagnosis of coronary artery disease. They can be broadly classified as those that detect functional or hemodynamic consequences of obstruction and ischemia (exercise treadmill testing, myocardial perfusion imaging [MPI], stress echo with or without contrast), and others identifying the anatomic obstruction itself (cardiac CTA and coronary magnetic resonance imaging [MRI]). Functional testing involves inducing ischemia by exercise or pharmacologic stress and detecting its consequences. However, not all patients are candidates. For example, obesity or obstructive lung disease can make obtaining echocardiographic images of sufficient quality difficult. Conversely, the presence of coronary calcifications can impede detecting coronary anatomy with cardiac CTA. Accordingly, some tests will be unsuitable for particular patients.

Evaluation of obstructive coronary artery disease (CAD) involves quantifying arterial stenoses to determine whether significant narrowing is present. Lesions with greater than 50% to 70% diameter stenosis accompanied by symptoms are generally considered significant and often result in revascularization procedures. It has been suggested that cardiac CTA may be helpful to rule out the presence of CAD and to avoid invasive coronary angiography (ICA) in patients with a low clinical likelihood of significant CAD. Also of note is the interest in the potential important role of non-obstructive plaques (i.e., those associated with <50% stenosis) because their presence is associated with increased cardiac event rates. Cardiac CTA can also visualize the presence and composition of these plaques and quantify the plaque burden better than conventional angiography, which only visualizes the vascular lumen. Plaque presence has been shown to have prognostic importance.

The information sought from angiography after coronary artery bypass graft surgery may depend on the length of time since surgery. Bypass graft occlusion may occur during the early postoperative period; whereas, over the long term, recurrence of obstructive CAD may occur in the bypass graft, which requires a similar evaluation as CAD in native vessels.

Congenital coronary arterial anomalies (i.e., abnormal origination or course of a coronary artery) that lead to clinically significant problems are relatively rare. Symptomatic manifestations may include ischemia or syncope. Clinical presentation of anomalous coronary arteries is difficult to distinguish from other more common causes of cardiac disease; however, an anomalous coronary artery is an important diagnosis to exclude, particularly in young patients who present with unexplained symptoms (e.g., syncope). There is no specific clinical presentation to suggest a coronary artery anomaly.

Cardiac CTA has several important limitations. The presence of dense arterial calcification or an intracoronary stent can produce significant beam-hardening artifacts and may preclude a satisfactory study. The presence of an uncontrolled rapid heart rate or arrhythmia hinders the ability to obtain diagnostically satisfactory images. Evaluation of the distal coronary arteries is generally more difficult than visualization of the proximal and mid-segment coronary arteries due to greater cardiac motion and the smaller caliber of coronary vessels in distal locations.

Radiation delivered with current generation scanners utilizing reduction techniques (prospective gating and spiral acquisition) has declined substantially—typically to under 10 mSv. For example, an international registry developed to monitor cardiac CTA radiation recently reported a median 2.4 mSv (interquartile range, [IQR]: 1.3 to 5.5) exposure. In comparison, radiation exposure accompanying rest-stress perfusion imaging ranges varies according to isotope used—approximately 5 mSv for rubidium-82 (positron emission tomography, PET), 9 mSv for sestamibi (single-photon emission computed tomography, SPECT), 14 mSv for F-18 FDG (fludeoxyglucose) (PET), and 41 mSv for thallium; during diagnostic invasive coronary angiography, approximately 7 mSv will be delivered. EBCT using electrocardiogram (ECG) (EKG) triggering delivers the lowest dose (approximately 0.7 to 1.1 mSv with 3-mm sections). Any cancer risk due to radiation exposure from a single cardiac imaging test depends on age (higher with younger age at exposure) and gender (greater for women). Empirical data suggest that every 10 mSv of exposure is associated with a 3% increase in cancer incidence over 5 years.

The use of Computed Tomography to Detect Coronary Artery Calcification (Electron-beam CT) is addressed in a separate policy.

POLICY

 I.  Provider Accreditation for CCTA – Network Providers

All Network Providers billing the technical component of the CT must be accredited in Coronary CTA by the Intersocietal Accreditation Commission (IAC) or a Cardiac CT module by the American College of Radiology (ACR) or RadSite. The professional component of the CT will be reimbursed based upon the accreditation of the facility as the ACR, IAC or RadSite facility accreditations require that interpreting professional physicians also be accredited by the ACR, Society of Cardiovascular Computed Tomography or RadSite, respectively.

II.   Medically Necessary CCTA

A diagnosis of chest pain (acute or non-acute) is not in itself an eligible indication for performing CCTA. CCTA using a 64-slice or greater CT scanner is considered medically necessary for the following:

A.  Detection of CAD in Symptomatic Patients

1.  Evaluation of chest pain syndrome

• Intermediate pre-test probability of CAD (see Table A below) and electrocardiogram (ECG) (EKG) uninterpretable or unable to exercise

2.  Evaluation of intra-cardiac structures

• Evaluation of suspected coronary anomalies

3.  Acute chest pain

• Intermediate pre-test probability of CAD (see Table A below) and no electrocardiogram (ECG) (EKG) changes and serial enzymes negative

4.  Abnormal electrocardiogram (ECG) (EKG) 

• Left bundle branch block/left ventricle hypertrophy with ST segment changes

Table A. Pre-test Probability of CAD by Age, Gender and Symptoms

B.  Detection of CAD with Prior Test Results

1.  Evaluation of chest pain syndrome

• Un-interpretable or equivocal stress test (exercise, perfusion, or stress echo)

• Conventional angiography is unsuccessful or equivocal

C.  Evaluation of Acute Chest Pain in the Emergency Room/Emergency Department

1.  Evaluation of acute chest pain in the Emergency Room/Emergency Department for patients with intermediate pre-test probability of CAD (see Table A) that meet ALL of the following criteria:

• No known coronary artery disease;

• Normal or equivocal serum biomarkers such as creatine kinase-myocardial band, myoglobin and/or troponin I;

• Normal or equivocal ischemic electrocardiogram (ECG) (EKG) changes such as ST-segment elevation or depression ≥1mm in 2 or more contiguous leads, and or T-wave inversion ≥2ml

D.  Evaluation of Cardiac Structure and Function

1.  Morphology

a.  Assessment of congenital heart disease including anomalies of coronary circulation, great vessels, and cardiac chambers and valves

b.  Evaluation of coronary arteries in patients with new onset heart failure to assess etiology

2.  Evaluation of intra- and extra-cardiac structures

a.  Evaluation of cardiac mass (suspected tumor or thrombus) and patients with technically limited images from echocardiogram, MRI or TEE

b.  Evaluation of pericardial conditions (pericardial mass, constrictive pericarditis, or complications of cardiac surgery) and patients with technically limited images from echocardiogram, MRI or TEE

c.  Evaluation of pulmonary vein anatomy prior to invasive radiofrequency ablation for atrial fibrillation (e.g., pulmonary vein isolation)

d.  Non-invasive coronary vein mapping prior to placement of biventricular pacemaker or, placement of automatic implantable cardioverter defibrillator (AICD)

e.  Non-invasive coronary arterial and venous bypass mapping, including internal mammary artery and bypass grafts prior to repeat cardiac vascularization

3.  Evaluation of aortic and pulmonary disease

a.  Evaluation of suspected aortic dissection or thoracic aortic aneurysm

b.  Evaluation of suspected pulmonary embolism

III.  Not Medical Necessary CCTA

The following are considered not medically necessary for CCTA:

• CCTA performed for screening purposes in asymptomatic patients (absence of signs, symptoms, or disease)

• CCTA performed for low risk pre-test probability of CAD

  • Patients with non anginal chest pain in whom the history, physical exam, and appropriate diagnostic tests demonstrate non cardiac causes of chest pain.

  • Patients with low risk of coronary artery disease based on clinical information and any other normal noninvasive coronary anatomic test within the past six months

• CCTA performed for high risk pre-test probability of CAD

  • Patients who meet the ACC/AHA Guidelines for Coronary Angiography

  • Patients with high pretest likelihood of coronary artery disease (by age, gender, and symptoms) in whom coronary angiography is indicated and or has been scheduled.

• CCTA services conducted by Network Providers who do not meet the requirements outlined in the Provider Accreditation section above

IV.   Relative Contraindications to CCTA

The following are relative contraindications to CCTA:

• Irregular rhythm (e.g., atrial flutter, frequent irregular premature ventricular contractions or premature atrial contractions, and high grade heart block).

• Very obese patients, body mass index > 40 kg/m2.

• Renal insufficiency, creatinine > 1.8 mg/dl.

• Heart rate > 70 beats/minute refractory to heart-rate lowering agents (e.g., a combination of beta-blocker and calcium-channel blocker)

• Calcium score > 1,000

• Previous stents <2.5 mm in diameter

POLICY EXCEPTIONS

State Health Plan (SHP) Members: Effective 07/01/2017, the Provider Accreditation requirements listed in the Policy section apply to SHP members.

Federal Employee Program (FEP) Members: The Provider Accreditation requirements do not apply to FEP members. For FEP members:

Contrast-enhanced coronary computed tomography angiography for evaluation of patients with acute chest pain and without known coronary artery disease in the emergency department setting is considered medically necessary.

Contrast-enhanced coronary computed tomography angiography for evaluation of patients with stable chest pain and meeting guideline criteria for a noninvasive test in the outpatient setting (see Policy Guidelines) is considered medically necessary.

Contrast-enhanced coronary computed tomography angiography for evaluation of patients with suspected anomalous (native) coronary arteries is considered medically necessary.

Contrast-enhanced coronary computed tomography angiography for coronary artery evaluation is considered investigational for all other indications.

POLICY GUIDELINES

The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.

Only one professional component and one technical component will be allowed for the performance of CCTA.

Federal Employee Program (FEP) Members:

The 2012 collaborative medical association guidelines for the diagnosis and management of patients with stable heart disease list several class I recommendations on the use of noninvasive testing in patients with suspected stable ischemic heart disease. A class I recommendation indicates that a test should be performed. In general, patients with at least intermediate risk (10% to 90% risk by standard risk prediction instruments) are recommended to have some type of test, the choice depending on interpretability of the electrocardiogram capacity to exercise, and presence of comorbidity.

Medically Necessary is defined as those services, treatments, procedures, equipment, drugs, devices, items or supplies furnished by a covered Provider that are required to identify or treat a Member's illness, injury or Mental Health Disorders, and which Company determines are covered under this Benefit Plan based on the criteria as follows in A through D:

A.  consistent with the symptoms or diagnosis and treatment of the Member's condition, illness, or injury; and

B.  appropriate with regard to standards of good medical practice; and

C.  not solely for the convenience of the Member, his or her Provider; and

D.  the most appropriate supply or level of care which can safely be provided to Member. When applied to the care of an Inpatient, it further means that services for the Member's medical symptoms or conditions require that the services cannot be safely provided to the Member as an Outpatient.

For the definition of medical necessity, “standards of good medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. BCBSMS makes no payment for services, treatments, procedures, equipment, drugs, devices, items or supplies which are not documented to be Medically Necessary. The fact that a Physician or other Provider has prescribed, ordered, recommended, or approved a service or supply does not in itself, make it Medically Necessary.

Investigative is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized as a generally accepted standard of good medical practice for the treatment of the condition being treated and; therefore, is not considered medically necessary. For the definition of Investigative, “generally accepted standards of medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. In order for equipment, devices, drugs or supplies [i.e, technologies], to be considered not investigative, the technology must have final approval from the appropriate governmental bodies, and scientific evidence must permit conclusions concerning the effect of the technology on health outcomes, and the technology must improve the net health outcome, and the technology must be as beneficial as any established alternative and the improvement must be attainable outside the testing/investigational setting.

POLICY HISTORY

12/17/2012: New policy approved by Cardiology Physician Advisory Committee. Effective 01/01/2013.

03/10/2014: Policy reviewed; no changes

08/28/2015: Medical policy revised to add ICD-10 codes.

02/09/2016: Policy guidelines updated to add medically necessary and investigative definitions.

06/08/2016: Policy number L.6.01.415 added.

07/25/2016: Code Reference section updated to make the following correction: ICD-10 diagnosis code C45.52 should be C45.2.

09/30/2016: Code Reference section updated to add new ICD-10 diagnosis codes Q25.21, Q25.29, and Q25.40 - Q25.49.

06/21/2017: Policy Exceptions section updated to state that effective 07/01/2017, the Provider Accreditation requirements listed in the Policy section apply to SHP members.

09/29/2017: Code Reference section updated to add new ICD-10 diagnosis codes I50.810, I50.811, I50.812, I50.813, I50.814, I50.82, I50.83, I50.84, and I50.89, effective 10/01/2017. Revised description for ICD-10 diagnosis code I50.1. Removed deleted ICD-10 diagnosis codes Q25.2 and Q25.4.

05/30/2018: Updated link in Sources section.

09/23/2019: Code Reference section updated to add new ICD-10 diagnosis codes I26.93, I26.94, I48.20, and I48.21, effective 10/01/2019.

12/13/2021: Code Reference section updated to revise code description for CPT code 75573, effective 01/01/2022. Removed deleted ICD-10 diagnosis code I48.2.

09/27/2022: Policy Guidelines updated to change "Nervous/Mental Conditions" to "Mental Health Disorders" and "Medically Necessary" to "medical necessity." Code Reference section updated to add new ICD-10 diagnosis codes I20.2, I25.752, I25.762, I34.81, I34.89, I71.10, I71.11, I71.12, I71.13, I71.20, I71.21, I71.22, I71.23, I71.50, I71.51, I71.52, I71.60, I71.61, I71.62, Q21.10, Q21.11, Q21.12, Q21.13, Q21.14, Q21.15, Q21.16, Q21.19, Q21.20, Q21.21, Q21.22, and Q21.23, effective 10/01/2022.

01/18/2023: Policy reviewed. Policy statements unchanged. Policy Exceptions updated regarding coverage guidelines for FEP members. Policy Guidelines updated regarding FEP members. Sources updated.

08/22/2023: Policy reviewed; no changes.

09/28/2023: Code Reference section updated to add new ICD-10 diagnosis codes I24.81, I24.89, I20.81, I20.89, and I25.85. Revised the code description for ICD-10 diagnosis codes I71.51, I71.52, I71.61, and I71.62. Effective 10/01/2023.

10/01/2024: Code Reference section updated to add new ICD-10 diagnosis codes Q23.81, Q23.82, and Q23.88. Removed deleted ICD-10 diagnosis codes I20.8, I24.8, I71.1, I71.2, I71.5, I71.6, Q21.1, and Q21.2.

11/07/2024: Policy reviewed; no changes.

11/01/2025: Added RadSite as an imaging accreditation body.

SOURCE(S)

1. Blue Cross Blue Shield Association Policy # 6.01.43

2. Cardiac Computed Tomography (CCT), Cardiac Computed Tomography Angiography (CCTA) medical policy, Blue Cross and Blue Shield of Alabama

3. Cardiology Physician Advisory Committee

4. Computed Tomography, Cardiac and Coronary Artery medical policy, Arkansas Blue Cross and Blue Shield

5. FEP Medical Policy, Contrast-Enhanced Coronary Computed Tomography Angiography for Coronary Artery Evaluation (6.01.43). Retrieved August 23, 2022.

6. Framingham Heart Study Coronary Heart Disease Risk Factors:

   https://www.framinghamheartstudy.org/fhs-risk-functions/coronary-heart-disease-10-year-risk/

7. Intersocietal Accreditation Commission (IAC) CT/ICACTL Standards and Guidelines for CT Accreditation, August 2012.

CODE REFERENCE

This may not be a comprehensive list of procedure codes applicable to this policy. 

The code(s) listed below are ONLY medically necessary if the procedure is performed according to the "Policy" section of this document.

Covered Codes

CPT copyright American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association.