| Medical Policy |
| Subject: | Coronary Artery Imaging: Contrast-Enhanced Computed Tomography Angiography (CTA) and Cardiac Magnetic Resonance Angiography (MRA) | ||
| Policy #: | RAD.00035 | Current Effective Date: | 04/16/2008 |
| Status: | Revised | Last Review Date: | 02/21/2008 |
| Description/Scope |
This document addresses the cardiac applications of contrast-enhanced computed tomography angiography (CTA) of the coronary arteries and magnetic resonance angiography (MRA) of the coronary arteries.
Note: This document does not address the use of electron beam computed tomography (EBCT) to quantify coronary calcification, which is addressed in RAD.00001 Computed Tomography to Detect Coronary Artery Calcification.
For further information regarding the use of CTA/MRA imaging for additional indications, refer to:
| Policy Statement |
Medically Necessary:
Contrast-enhanced cardiac computed tomography angiography (CTA) is considered medically necessary for the evaluation of suspected anomalous coronary arteries when conventional angiography has been unsuccessful or has provided equivocal results and the results could impact treatment.
Investigational and Not Medically Necessary:
Cardiac computed tomography angiography (CTA) of the coronary arteries is considered investigational and not medically necessary for all other indications, including, but not limited to, the following:
Cardiac magnetic resonance angiography (MRA) for the evaluation of coronary arteries is considered investigational and not medically necessary for all indications.
| Rationale |
A 2006 TEC Assessment was completed to determine the usefulness of CTA as a substitute for coronary angiography for two indications: for determining the diagnosis of coronary artery stenosis and in the evaluation of acute chest pain in the emergency room setting. Seven studies compared CTA to angiography for the diagnosis of coronary artery stenosis, ranging in size from 30 to 84 patients, all of whom were scheduled to undergo angiography. No study specifically addressed a lower risk subgroup, which has been suggested as the target population for this testing. The sensitivity of CTA in identifying a 50% stenosis ranged from 88-100% with four of five studies reporting sensitivities of at least 95%. Specificity ranged from 86-100%. In a per-segment (not per patient) analysis, sensitivity ranged from 79-99% and specificity ranged from 95-98%. Four of the seven studies excluded either patients or segments from the analysis. Two studies evaluated the use of CTA for patients with acute chest pain in the ER; (sample sizes were 31 and 69). No alternative strategies for diagnosis were evaluated in these studies, and the sensitivity of CTA was reported as 83% and 96%. These studies evaluating use of CTA in comparison to angiography are relatively small from single centers. Since these studies enrolled patients being referred for angiography, the results may not generalize to lower risk populations. Due to the limitations of the reviewed studies, the TEC Assessment found that CTA as a substitute for coronary angiography in the diagnosis of coronary artery stenosis and CTA in the evaluation of acute chest pain in the emergency room setting did not meet the TEC criteria. These findings are consistent with a prior 2005 TEC Assessment of CTA for Screening or Diagnostic Evaluation of the Coronary Arteries.
The Centers for Medicare and Medicaid Services (CMS) through the Agency for Healthcare Research and Quality (AHRQ) commissioned the Duke Center for Clinical Health Policy Research Evidence-based Practice Center to perform a preliminary evaluation of the available scientific evidence on direct non-invasive imaging tests (NITs) for coronary artery disease. The specific focus of this report was CTA and MRA in the evaluation of native coronary arteries, as well as new non-invasive imaging technologies on the horizon. Published literature related to non-invasive coronary imaging tests was reviewed, based on extant systematic reviews and was limited to articles published in English in the years 2005 and 2006. Twenty-nine studies were identified using 16-slice or greater multi-detector computed tomography and 13 studies using magnetic resonance angiography for the evaluation of coronary arteries. The preliminary findings noted that currently available evidence is limited regarding the test performance of CTA and MRA in identifying, quantifying or otherwise characterizing coronary artery stenoses. In these studies, patients providing suboptimal images were often excluded from calculations of test accuracy. Studies conducted to date primarily used patients having a high pre-test probability of coronary artery disease. As such, future work is needed to examine test performance in larger, less selected populations representing the clinical settings in which these tests are actually expected to be used.
In 2006, the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group published Appropriateness Criteria for Cardiac Computed Tomography and Cardiac Magnetic Resonance Imaging (Hendel, 2006). This ACCF/ACR/SCCT/SCMR/ASNC/NASCI/SCAI/SIR Report took a consensus approach to the evaluation of test performance of these technologies by purpose and within specific clinical scenarios.
The opinion of the ACC Appropriateness Criteria supported the use of CTA, as appropriate, in the evaluation of suspected anomalous coronary arteries. This is supported further by small case series that have reported that CTA is able to delineate the course of these anomalous arteries, even when conventional angiography may not (Berbarie, 2006; Datta, 2005; Schmitt, 2005; Chandran, 2005). However, these case series did not report results when the initial reason for the CTA was to identify these anomalies. Thus, this use of CTA is considered medically necessary when conventional angiography has been non-diagnostic.
In addition, the 2006 ACC Appropriateness Criteria suggested that CTA was appropriate for use in the detection of coronary artery disease (CAD) in selected clinical settings. Specifically it was viewed as appropriate in symptomatic patients with an intermediate probability of CAD when the EKG is uninterpretable, or in the evaluation of chest pain syndrome with uninterpretable or equivocal stress tests. Finally, it was rated as appropriate for the evaluation of coronary arteries in those with new onset heart failure to assess etiology. However, as previously noted, the studies for use of this test in these settings do not provide sufficient information to permit conclusions regarding the use of CTA in these specific cardiac applications. As previously noted, this document was a consensus statement of the panel members.
In 2006, a scientific statement was published from the American Heart Association (AHA) Committee on Cardiovascular Imaging and Intervention, Council on Cardiovascular Radiology and Intervention, and Committee on Cardiac Imaging, Council on Clinical Cardiology entitled, Assessment of Coronary Artery Disease by Cardiac Computed Tomography (Budoff, 2006). Within this position paper, the AHA provided two Class IIa* recommendations for the use of CTA, as follows:
"CT coronary angiography is reasonable for the assessment of obstructive disease in symptomatic patients." (AHA Level of Evidence: B***) and
"…the high resolution…and the speed of image acquisition make it reasonable to use CT as one of the first choice imaging modalities in the workup of known and suspected coronary anomalies." (AHA Level of Evidence: C****)
When discussing CT angiography in a clinical context, the AHA paper states:
"In a clinical context, the high negative predictive value may be useful in obviating the need for invasive coronary angiography in patients whose symptoms or abnormal stress test results make it necessary to rule out the presence of coronary artery stenoses. Especially if symptoms, age, and gender suggest a low to intermediate probability of hemodynamically relevant stenoses, ruling out hemodynamically relevant stenoses by CT coronary angiography may be clinically useful and may help avoid invasive angiography…Use of CT angiography in asymptomatic persons as a screening test for atherosclerosis is not recommended." (Class III**; AHA Level of Evidence: C****)
However, while the AHA makes the aforementioned recommendations, it further notes the following:
"Especially in the context of ruling out stenosis in patients with low to intermediate pretest likelihood of disease, CT coronary angiography may develop into a clinically useful tool. However, the studies that have evaluated the accuracy of electron beam computed tomography (EBCT) and multi-detector computed tomography (MDCT) for the assessment of coronary artery stenoses have been relatively small. They recruited somewhat selected patients (e.g., excluding patients with acute coronary syndromes or atrial fibrillation), and all studies have been validated against invasive coronary angiography as a gold standard. No outcomes-based analyses that made further clinical management dependent on the EBCT or MDCT results have been published."
Note: According to the American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) guideline recommendations documents, the following are the definitions of Classifications of Recommendations and Levels of Evidence, as expressed in the ACC/AHA/ESC format:
Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is beneficial, useful, and effective.
Class II: Conditions for which there is conflicting evidence and/or divergence of opinion about the usefulness/efficacy of a procedure or treatment.
*Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy.
Class IIb: Usefulness/efficacy is less well established by evidence/opinion.
**Class III:Conditions for which there is evidence and/or general agreement that a procedure/treatment is not useful/effective and in some cases may be harmful. (Budoff, 2006)
Level of Evidence A: Data derived from multiple randomized clinical trials or meta-analyses.
***Level of Evidence B: Data derived from a single randomized trial or nonrandomized studies.
****Level of Evidence C: Only consensus opinion of experts, case studies, or standard-of-care.
Since the publication of the TEC Assessment, AHRQ Evaluation and ACC Appropriateness Criteria and AHA Recommendations, there have been multiple additional case series published regarding the use of CTA in the setting of CAD, some reporting results using newer 64-slice scanning equipment. This imaging is often referred to as multislice computed tomography (MSCT) or multidetector computed tomography (MDCT). While there have been improvements in temporal resolution and spatial resolution with this equipment, the visualization of the vessels remains impacted by many factors, including the calcification of the vessel, heart rate, and presence of arrhythmias. In addition, the studies themselves suffer from the same methodological issues as previous reports on this technology. They tend to be on selected patient groups who were undergoing coronary angiography, are not randomized, and do not account for patients or vessels removed from the analysis, due to inability to interpret studies and also do not report health outcomes.
There is continued interest in the use of CTA as an imaging technique for the evaluation of chest pain in the emergency room setting. It has been suggested that the negative predictive value of this test, in patients with symptoms not felt to have an acute coronary syndrome, is of value in avoiding additional testing. Hayes, Inc. performed an assessment of this topic and assigned a 'B' rating* to the use of 16- and 64-slice CT, as a triage tool for eliminating CAD as a cause of symptoms in adult patients who have no known history of CAD and who are at low to intermediate risk of CAD. However, in 2007, Goldstein and colleagues reported on a randomized study of 197 patients who presented to the ER with chest pain who were felt to have a low risk of infarction and/or complications based on clinical factors. Ninety eight (98) were randomized to be evaluated with MSCT with 64-slice technology, and 97 were evaluated with nuclear stress testing. Patients were followed for six months, and no deaths, myocardial infarctions or other major adverse events were reported in either group. The number of cardiac catheterizations at six months was not significantly different, but was higher in the MSCT group (12% vs 7%). The MSCT scans were considered inadequate in 24 of the 99 patients who underwent nuclear stress testing.
Note: According to the Hayes, Inc. Rating System, the ratings are scaled from A through D reflecting the strength and direction of the evidence regarding the safety and efficacy of a medical technology, its impact on health outcomes, indications for use, patient selection criteria, and comparison with other technologies. The ratings are defined as follows:
A Established benefit. Use of the technology is supported by a high level of positive published evidence regarding safety and efficacy for the cited application(s). Drugs, biologics, and devices with an A rating have FDA approval, but not necessarily for the specific clinical application.
*B Some proven benefit. Use of the technology is supported by a moderate level of positive published evidence regarding safety and efficacy for the cited application(s). Further research is required to fully clarify clinical indications, contraindications, treatment parameters, comparison with other technologies, and/or impact on health outcomes. Drugs, biologics, and devices with a B rating have FDA approval, but not necessarily for the specific clinical application.
C Potential but unproven benefit. Use of the technology is supported by some positive published data regarding safety and/or efficacy for the cited application(s), but a beneficial impact on health outcomes has not been proven for one of two reasons: (1) Data are sparse and the level of evidence is low, or (2) Data are inconsistent or conflicting.
D No proven benefit and/or not safe. This rating conveys one of two conclusions: (1) Use of the technology has been shown to be unsafe and/or there is no evidence in the current scientific literature that its use improves health outcomes; or (2) The research regarding use of the technology is so limited that an appraisal of safety and efficacy cannot be made. (Hayes, 2007)
Currently the use of CTA for the evaluation of suspected anomalous coronary arteries is considered medically necessary when the results of conventional testing have been inconclusive/equivocal and when this testing will impact treatment planning, consistent with the AHA statement above. Regarding use of CTA in the diagnostic workup of coronary artery disease in symptomatic patients, the current evidence is insufficient to support this application.
Although CTA provides high-resolution images, it also poses some potential risks. The radiation exposure associated with CTA imaging greatly exceeds that of coronary angiography, from 4 to 21.4 milliSieverts (mSv). In fact, a conservative estimate of 8 mSv for a typical multislice CT scan is 400 times the radiation dose of one chest x-ray. This radiation dose places CT scans at an intermediate (1–10 mSv) to moderate (10 mSv) level of risk under international guidelines, a risk level for which the corresponding benefit should be "moderate" to "substantial." Einstein and colleagues (2007) reported that their "Simulation models suggest that use of 64-slice CTCA is associated with a non-negligible LAR (lifetime attributable risk) of cancer" and that the risk is "Considerably greater for women, younger patients and for combined cardiac and aortic scans." Like coronary angiography, CTA also presents the risk of renal damage from the use of nephrotoxic contrast agents and of complications from the use of medicines to slow the heart rate to obtain a usable image.
There is very little published data currently available regarding the use of MRA for cardiac applications, such as the evaluation of coronary artery disease. Further studies are needed to investigate both CTA and MRA, as compared with conventional diagnostic alternatives, to determine specific patient selection criteria and to demonstrate how results will impact patient management and health outcomes.
| Background/Overview |
Description of Computed Tomographic Angiography (CTA)
Contrast enhanced cardiac CTA has been proposed as a noninvasive alternative to invasive coronary angiography, particularly in patients with a low probability of significant coronary artery stenosis. In other circumstances, CTA may be proposed instead of, or in addition to, other noninvasive cardiac tests. The information from CTA may be used to guide further diagnostic evaluations and/or appropriate therapy, (e.g., revascularization versus medical management), and this may, over the long-term, influence the morbidity of CAD, (e.g., angina or subsequent MI rate), functional status, or mortality.
Computed tomographic angiography, or CTA, is a noninvasive imaging test that requires the use of intravenously administered contrast material and high-resolution, high-speed CT machinery (multi-detector row scanner) to obtain detailed volumetric images of blood vessels.
Description of Cardiac Magnetic Resonance Angiography (MRA)
MRA of the coronaries involves the use of traditional MRI technology while a gadolinium-based contrast agent is injected intravenously during image acquisition. This technique does not involve radiation exposure, and the contrast agent, at the dose used for MRA, is not considered nephrotoxic. MRA provides detailed images of blood vessels and is currently being investigated as a noninvasive alternative diagnostic modality.
| Definitions |
CAD: coronary artery disease
Computed tomography angiography: (CTA) a non-invasive radiological imaging technique that utilizes iodinated contrast agents followed by rapid imaging with a multi-detector row scanner, in order to acquire images of the heart and blood vessels
Coronary arteries: the blood vessels supplying blood to the heart
Magnetic resonance angiography: (MRA) a non-invasive radiological imaging technique that utilizes traditional MRI technology to provide detailed images of blood vessels
| Coding |
The following codes for treatments and procedures applicable to this policy are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage or these services as it applies to an individual member.
When services may be Medically Necessary when criteria are met:
CPT |
|
0146T | Computed tomography, heart, with contrast material(s), including noncontrast images if performed, cardiac gating and 3D image post processing; computed tomographic angiography of coronary arteries (including native and anomalous coronary arteries, coronary bypass grafts), without quantitative evaluation of coronary calcium |
0147T | Computed tomography, heart, with contrast material(s), including noncontrast images if performed, cardiac gating and 3D image postprocessing; computed tomographic angiography of coronary arteries (including native and anomalous coronary arteries, coronary bypass grafts), with quantitative evaluation of coronary calcium |
0148T | Computed tomography, heart, with contrast material(s), including noncontrast images if performed, cardiac gating and 3D image post processing; cardiac structure and morphology and computed tomographic angiography of coronary arteries (including native and anomalous coronary arteries, coronary bypass grafts), without quantitative evaluation of coronary calcium |
0149T | Computed tomography, heart, with contrast material(s), including noncontrast images if performed, cardiac gating and 3D image post processing; cardiac structure and morphology and computed tomographic angiography of coronary arteries (including native and anomalous coronary arteries, coronary bypass grafts), with quantitative evaluation of coronary calcium |
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ICD-9 Diagnosis | |
746.85 | Coronary artery anomaly |
786.50-786.59 | Chest pain |
V81.2 | Special screening for other and unspecified cardiovascular conditions |
When services are Investigational and Not Medically Necessary:
For the procedure codes listed above, when criteria are not met, for all other diagnoses, or when the code describes a procedure indicated in the Policy section as investigational and not medically necessary.
When services are also Investigational and Not Medically Necessary:
CPT |
|
| No specific code for cardiac magnetic resonance angioangraphy |
|
|
ICD-9 Diagnosis | |
| All diagnoses |
| References |
Peer Reviewed Publications:
Government Agency, Medical Society, and Other Authoritative Publications:
| Web Sites for Additional Information |
| Index |
CAD
Computed Tomography Angiography
Coronary Artery Disease
CTA
Virtual Angiography
| Policy History |
Status | Date | Action |
Revised | 02/21/2008 | Medical Policy & Technology Assessment Committee (MPTAC) review. No change to stance. The title was changed from Contrast-Enhanced Cardiac Computed Tomography Angiography (CTA) and Cardiac Magnetic Resonance Angiography (MRA) to: Coronary Artery Imaging: Contrast-Enhanced Computed Tomography Angiography (CTA) and Cardiac Magnetic Resonance Angiography (MRA). The phrase "investigational/not medically necessary" was clarified to read "investigational and not medically necessary." This change was approved at the November 29, 2007 MPTAC meeting. References, coding, and Background sections were updated. |
Reviewed | 03/08/2007 | MPTAC review. No change to policy stance/criteria. Information in the Rationale section was updated to include comments from the 2006 AHA Scientific Statement (Budoff, 2006). References and Coding sections were also updated. |
Revised | 12/07/2006 | MPTAC review. Policy stance was revised to consider CTA medically necessary for the evaluation of suspected anomalous coronary arteries, subject to criteria being met. Also added policy statement regarding MRA for evaluation of coronary arteries as investigational/not medically necessary. Rationale, coding, and reference sections were also updated. |
Reviewed | 03/23/2006 | MPTAC review. No changes to policy criteria. References were updated. |
Reviewed | 01/01/2006 | Updated coding section with 01/01/2006 CPT/HCPCS changes |
| 11/17/2005 | Added reference for Centers for Medicare and Medicaid Services (CMS) – National Coverage Determination (NCD). |
New | 04/28/2005 | MPTAC initial policy development. |