| Medical Policy |
| Subject: Myocardial Sympathetic Innervation Imaging with or without Single-Photon Emission Computed Tomography (SPECT) | |
| Document #: RAD.00064 | Publish Date: 04/15/2026 |
| Status: Reviewed | Last Review Date: 02/19/2026 |
| Description/Scope |
This document addresses the use of myocardial sympathetic innervation imaging with or without single-photon emission computed tomography (SPECT) to assist with identification of individuals at increased risk of short-term mortality associated with heart failure (HF).
Note: For a high-level overview of this document, please see “Summary for Members and Families” below.
| Position Statement |
Investigational and Not Medically Necessary:
Myocardial sympathetic innervation imaging is considered investigational and not medically necessary for all indications, including the evaluation of heart failure.
| Summary for Members and Families |
This document describes clinical studies and expert recommendations, and explains whether myocardial sympathetic innervation imaging is appropriate. The following summary does not replace the medical necessity criteria or other information in this document. The summary may not contain all of the relevant criteria or information. This summary is not medical advice. Please check with your healthcare provider for any advice about your health.
Key Information
Myocardial sympathetic innervation imaging is a type of heart scan that uses a special radioactive substance called meta-iodobenzylguanidine (also known as MIBG or AdreView) to look at how the nerves in the heart are working. This test is done by injecting the substance into the body and taking images of the heart to measure something called the heart-to-mediastinum (H/M) ratio. A higher ratio has been linked with a lower risk of death or serious heart problems in people with heart failure. The idea is that this imaging may help doctors better understand the condition of a person’s heart and possibly guide treatment decisions. However, studies have not shown that using this type of imaging scan to make treatment choices actually helps people live longer or feel better. Because of this, experts recommend more research to find out if this test improves health.
What the Studies Show
MIBG imaging has been studied in adults with heart failure, especially those with moderate symptoms and low heart function. In these studies, people with higher H/M ratios had better outcomes, such as fewer deaths and fewer dangerous heart rhythms. The ADMIRE-HF study, which included nearly 1,000 adults, showed that those with an H/M ratio of 1.6 or higher had better survival and fewer heart-related problems over a two-year period. Other studies also found that this ratio added helpful information when used along with other tools, such as the Seattle Heart Failure Model (SHFM). A five-year follow-up of this same group showed similar results. Despite these findings, none of the studies tested whether using this scan to guide care decisions helped people live longer or avoid hospital stays. Experts say this kind of evidence is needed before this test can be recommended as part of routine care.
Is this Clinically Appropriate?
This test is not appropriate because it has not been proven to improve health. While studies show that higher scan scores are linked to better outcomes, no studies have shown that using these scores to guide care actually helps people. Experts and health groups agree that more research is needed to show whether this test improves health, especially compared to standard care without the scan. Unnecessary or unproven tests like this may lead to care that is not needed and may cause worry or confusion.
| Rationale |
Summary
Cardiac myocardial sympathetic innervation imaging, using the FDA-approved radiotracer 123I-MIBG (AdreView), is a non-invasive method for evaluating myocardial sympathetic innervation and has been proposed as a prognostic tool in heart failure (HF). The ADMIRE-HF trial and its extension studies demonstrated that a higher H/M ratio on MIBG imaging correlates with significantly lower rates of cardiac events and mortality in individuals with NYHA class II/III HF and reduced ejection fraction. Multiple studies have confirmed the H/M ratio’s independent predictive value when combined with established markers like the SHFM, b-type natriuretic peptide (BNP) levels, and left ventricular ejection fraction (LVEF). A higher H/M ratio is consistently associated with improved survival and fewer arrhythmic events. However, despite strong associations with prognosis, no studies have yet shown that clinical decisions guided by MIBG imaging improve health outcomes, prompting calls from organizations like the National Heart, Lung, and Blood Institute (NHLBI), American Society of Nuclear Cardiology (ASNC), and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) for further trials to establish its clinical utility beyond risk stratification.
Discussion
The autonomic nervous system is involved in the control of cardiac function, including regulating blood flow, heart rate, and contractility. The detection of abnormalities in the cardiac sympathetic nervous system has been proposed as a diagnostic and prognostic tool in individuals with HF. One non-invasive method of detecting cardiac autonomic nervous system abnormalities involves use of radiotracers to image the cardiac autonomic nervous pathways of the heart.
One radiotracer in particular, 123iodine meta-iodobenzylguanidine (also known as 123I-MIBG, MIBG, or AdreView™ [lobenguane I123 injection, GE Healthcare, Arlington Heights, IL]), has been investigated as a preferred imaging agent for myocardial sympathetic innervation imaging, with or without the use of SPECT. This is based on the premise that guanethidine acts as a false neurotransmitter analogue to norepinephrine in the cardiac autonomic nervous system and is taken up by the same neural pathways as norepinephrine. Tracing those pathways has been shown to allow insights into the functioning of the autonomic nervous system in the heart and thus heart function.
At this time, the only radiotracer approved by the United States Food and Drug Administration (FDA) for use in myocardial sympathetic innervation imaging is AdreView. Approval was based on two studies published in a single article by Jacobson and colleagues (2010). The studies were known as the AdreView Myocardial Imaging for Risk Evaluation in Heart Failure trial (ADMIRE-HF). The study found that the addition of the MIBG score to a known prognostic index, the SHFM, resulted in improved predictive accuracy and that a low MIBG heart-to-mediastinum (H/M) ratio was associated with a substantially higher 2-year mortality rate. The analysis presented the combined primary efficacy results of the two studies, which included individuals with NYHA functional class II or III HF and an LVEF of 35% or lower. These clinical parameters were then specified by the FDA as the appropriate criteria for use of the AdreView in individuals with HF who were additionally treated with optimum pharmacotherapy. Major exclusion criteria were serum creatinine levels above 3.0 mg/dL, the presence of a functioning ventricular pacemaker or cardiac revascularization (history) and a history of myocardial infarction (MI) or implantable cardioverter-defibrillator (ICD) implantation within the past 30 days.
Trial participants received an injection of MIBG (AdreView) and then underwent planar and single-photon emission computer tomography (SPECT) imaging of the thorax at 15 minutes after injection (early) and at 3 hours and 50 minutes after injection (late). The H/M ratio, on a scale from 0 to 4, was determined from both the early and late images. The primary analysis evaluated the association between the time to first cardiac event occurrence and the late H/M ratio, categorized as < 1.6 or ≥ 1.6. The authors also evaluated the association between the time to first cardiac event occurrence and late H/M ratio as a continuous variable. The composite outcome of cardiac events was defined as the occurrence of: (1) HF progression (that is, an increase of 1 or more in NYHA functional class); (2) a potentially life-threatening arrhythmic event (that is, spontaneous ventricular tachyarrhythmia for more than 30 seconds, resuscitated cardiac arrest, or appropriate discharge of an ICD); or (3) cardiac death.
A total of 985 subjects underwent MIBG imaging and 961 subjects (98%) were available for analysis. There were 760 (79%) subjects with an H/M ratio of less than 1.60 and 201 subjects (21%) with an H/M ratio of at least 1.60. Study subjects were then followed for a median of 17 months (range 2 days to 30 months). Cardiac events occurred in 237 of 961 subjects (25%). The mean late H/M ratio was 1.39 (standard deviation [SD], 0.18) in the group with any of the study’s cardiac events and 1.46 (SD, 0.21) in the group without events. The study results indicated that the risk of cardiac events was significantly lower in those with an H/M ratio of at least 1.6, as compared to those with an H/M ratio of less than 1.6 (hazard ratio [HR], 0.40; 97.5% confidence interval [CI], 0.25 to 0.64; p<0.001). In addition, there was a statistically significant association between the cardiac event rate and the H/M ratio as a continuous variable, with lower event rates seen for subjects with higher H/M ratios (HR, 0.22; 95% CI, 0.10 to 0.47; p<0.001). The estimated 2-year all-cause mortality was 16.1% for subjects with H/M ratios less than 1.60 and 3.0% for those with H/M ratios of at least 1.60 (p<0.001). The authors also compared the H/M ratios to other prognostic markers. In a multivariate model including the H/M ratio, BNP, LVEF, and NYHA functional class, all four markers were independently associated with the time to cardiac events.
An extension study, known as ADMIRE-HFX (Narula, 2015) included 964 individuals from the ADMIRE-HF study who were followed for a median of 24 months. In a Cox proportional hazards analysis, H/M was a significant additional predictor of all-cause mortality, after adjusting for demographic variables (p<0.001). H/M remained a significant predictor of all-cause mortality when LVEF and LVEF and plasma BNP were added to the model (p=0.016).
In 2012, Ketchum and colleagues published an analysis incorporating MIBG imaging findings into the SHFM, using survival data from the trial subjects included in the ADMIRE-HF primary efficacy analysis. The late H/M ratio from MIBG imaging was divided into 5 categories: less than 1.2, 1.2-1.39, 1.40-1.59, 1.6-1.79 and > 1.8. In a Cox proportional hazards model, SHFM and H/M ratios were both independent predictors of overall survival. There was an 82.1% increase in risk for one SD change in the SHFM (p<0.001) and a 60.3% increase in risk for one SD change in the late H/M ratio (p<0.001). For the outcome of cardiac mortality, each SD increase in SHFM was associated with an 86.1% increase in risk (p<0.001), and each SD increase in the late H/M ratio was associated with a 57.9% increase in risk (p=0.002). In an area under the curve (AUC) analysis, the addition of H/M ratio to the SHFM significantly improved the prediction of all-cause mortality compared to the SHFM alone. When the H/M ratio was added to the SHFM, the AUC increased by 0.039 (p=0.026) for 1-year mortality and the AUC increased by 0.028 (p<0.05) for 2-year mortality.
A number of other cohort studies have been published (Doi, 2012; Jain, 2014; Marshall, 2012). Nakata and colleagues (2013) pooled data from six multicenter cohort studies, with a total of 1322 individuals, examining MIBG imaging to determine prognosis in HF. Individuals were followed for a mean of 78 months. A Cox proportional hazard analysis found that cardiac MIBG uptake was a significant predictor of all-cause mortality, along with age, NYHA functional class and LVEF.
In 2011, a working group of the NHLBI published a report on the translation of cardiovascular molecular imaging. Regarding cardiac MIBG imaging, the report cited the ADMIRE-HF trial and stated that additional clinical trials are needed to determine the efficacy of HF management strategies with MIBG, compared to usual care without MIBG imaging (Buxton, 2011).
In 2015, the ASNC published a joint policy statement with the SNMMI with specific MIBG recommendations as follows (Sciammarella, 2015):
For patients with NYHA class II or III heart failure with LVEF ≤ 35% to help stratify risk and to promote more informed clinical decision-making when the result of 123I-mIBG study is likely to influence the decision regarding ICD implant.
However, there is no quality of evidence rating provided and the studies cited in support of the specific recommendation do not address MIBG imaging and the potential clinical impact on decision-making and net health outcomes.
In 2021, Agostini and colleagues published 5-year follow-up data from 964 subjects who participated in the ADMIRE-HF study and were still alive at the 2-year follow-up. Mean follow-up was 62.7 months. Subjects were stratified according to the heart/mediastinum (H/M) ratio on planar 123I-MIBG scintigraphic images obtained at baseline in ADMIRE-HF (< 1.60 vs. ≥ 1.60). The all-cause mortality data indicated significantly lower number of deaths in the low H/M group vs. the high H/M group (30.9% vs. 39.4; HR, 0.45, p<0.0001). Kaplan-Meier analysis indicated a significantly higher 5-year survival rate in the high H/M group (82.9% vs. 56.7%, p<0.0001). A total of 137 (41%) of the 334 reported all-cause deaths were due to cardiac-related causes. Similar to the all-cause data, the cardiac-specific death data indicated a significantly lower rate of cardiac deaths in the high H/M group (4.5% vs. 16.8%; HR, 0.22, p<0.0001). A Kaplan-Meier analysis of time to cardiac death found that 5-year survival was significantly higher in the high H/M group (96.4% vs. 84.2%; p<0.0001). Overall, there were 182 subjects (18.9%) who had either sudden cardiac death or a potentially fatal arrhythmia aborted by intervention. Such events were reported to be significantly less common in the high H/M group (10.9% vs. 21.1%; HR, 0.42, p=0.0002). The proportion of subjects without sudden cardiac death or a potentially fatal arrhythmia aborted by intervention at 5 years was higher in the high H/M group (92.7% vs 78.8%, p=0.0004). In the 5-year study period, 417 subjects (43.4%) died or required a potentially life-saving intervention, with the risk of this outcome found to be lower for the subjects with high H/M (HR, 0.46, p<0.0001). As with previous reports of the ADHERE-HF study, this retrospective data indicates that the use of myocardial sympathetic innervation imaging with MIBG may be useful in identifying individuals at high-risk of cardiac-related mortality and morbidity, however the limitations of this type of study still apply. Additional issues related to loss to follow-up, a predominately male subject pool, missing data from all subjects, also impair the application of these findings to the general population.
Although studies have found associations between cardiac MIBG imaging findings and mortality in individuals with heart failure, there is a lack of evidence that prospective use of MIBG imaging improves health outcomes. Studies are needed that compare clinical outcomes in individuals managed using MIBG imaging to HF management without MIBG imaging.
| Background/Overview |
An estimated 6.2 million adults in the United States have heart failure (HF), which is the main cause of death of approximately 1 in 8 deaths (CDC, 2024). An early mechanism to compensate for the decreased myocardial function seen in HF is activation of the sympathetic nervous system. This increase in sympathetic activity initially helps compensate for HF by increasing the heart rate and myocardial contractility in order to maintain blood pressure and organ perfusion. Over time, additional strain is placed on the myocardium, increasing coronary perfusion requirements, which can lead to worsening of ischemic heart disease and/or myocardial damage. As the ability of the heart to compensate diminishes, clinical symptoms of HF develop. Additionally, heightened sympathetic activity increases the presentation of potentially fatal ventricular arrhythmias.
Overactive sympathetic innervation associated with HF involves increased neuronal release of norepinephrine, which is the main neurotransmitter of the cardiac sympathetic nervous system. In response to sympathetic stimulation, vesicles containing norepinephrine are released into the neuronal synaptic cleft. The released norepinephrine binds to post-synaptic beta-1, beta-2 and alpha-receptors, enhances adenyl cyclase activity and brings about the desired cardiac stimulatory effects. Norepinephrine is then taken back into the presynaptic space for storage or catabolic disposal that terminates the synaptic response by the uptake-1 pathway. The increased release of norepinephrine is usually accompanied by decreased norepinephrine reuptake, which increases circulating NE levels.
Guanethidine (an antihypertensive drug) is a false neurotransmitter that is an analogue of norepinephrine; it is also taken up by the uptake-1 pathway. 123Iodine meta-iodobenzylguanidine (known as 123I-MIBG or MIBG) is guanethidine that has been chemically modified and labeled with radioactive iodine. MIBG moves into the synaptic cleft and is taken up and stored in the presynaptic nerve space similar to norepinephrine. However, unlike norepinephrine, MIBG is not catabolized and concentrates in myocardial sympathetic nerve endings. This concentrated MIBG can be imaged with a conventional gamma camera (Chirumamilla, 2011). MIBG myocardial imaging is conducted by an injection of MIBG and planar images are then acquired 15 minutes (early image) and 4 hours (late image) after injection. Optional SPECT imaging can be performed following the early and late planar images. MIBG uptake is semi-quantified by determining the average count per pixel in regions of interest (ROI) drawn over the heart and the upper mediastinum in the planar anterior view. The concentration of MIBG over several hours after injection of the agent is a reflection of sympathetic neuronal activity, which may correlate with HF severity. MIBG activity has also been suggested for potential use in guiding treatment decisions or in the monitoring of HF treatment effectiveness.
AdreView (lobenguane I123 injection, GE Healthcare, General Electric Company, Medi-Physics, Inc., Arlington Heights, IL), is a commercially available MIBG product. This diagnostic injectable agent was originally approved for intravenous use by the U.S. Food and Drug Administration (FDA) in 2008. According to the FDA, AdreView as a radiopharmaceutical agent for gamma-scintigraphy is indicated for:
It was noted that, while the H/M ratio can purportedly be used as either a dichotomous or continuous variable, the FDA-approved indication is a dichotomous variable with a cutoff in H/M ratio of 1.6. A ratio less than 1.6 indicates higher risk for cardiac events and early mortality associated with HF, and a ratio of 1.6 or greater indicates lower risk.
According to the FDA prescribing information (2020):
Limitations of Use:
In patients with congestive heart failure, AdreView utility has not been established for:
Contraindications:
Known hypersensitivity to iobenguane or iobenguane sulfate.
Warnings and Precautions:
Hypersensitivity reactions have followed AdreView administration. Have anaphylactic and hypersensitivity treatment measures available prior to AdreView administration.
| Definitions |
Heart failure (HF), also referred to as Congestive Heart Failure (CHF): A condition in which the heart no longer adequately functions as a pump. As blood flow out of the heart slows, blood returning to the heart through the veins backs up, causing congestion in the lungs and other organs.
Heart-to-mediastinum (H/M) ratio: This refers to a cardiac measure which is calculated by taking the average count per pixel in the myocardium divided by the average count per pixel in the mediastinum. The H/M ratio is proposed as an independent predictor of risk for cardiac events and early mortality associated with HF.
123Iodine meta-iodobenzylguanidine (known as 123I-MIBG or MIBG) Imaging: This radiopharmaceutical imaging agent (known by the branded name, AdreView) is used with standard or SPECT scanning to measure the heart-to-mediastinum (H/M) ratio, in order to predict risk for cardiac events and death associated with HF.
Myocardial sympathetic innervation imaging: This technology involves use of the AdreView (MIBG) tracer injectable with scintigraphic scanning, in order to image the myocardium and measure myocardial sympathetic innervations. This imaging technique can determine certain cardiac variables, including the H/M ratio, which is proposed as a prognostic marker of HF symptom progression and risk for cardiac arrhythmias and death, associated with HF.
New York Heart Association (NYHA) Definitions:
The NYHA classification of HF is a 4-tier system that categorizes subjects based on subjective impression of the degree of functional compromise; the four NYHA functional classes are as follows:
| Coding |
The following codes for treatments and procedures applicable to this document 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 of these services as it applies to an individual member.
When services are Investigational and Not Medically Necessary:
| CPT |
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| 0331T |
Myocardial sympathetic innervation imaging, planar qualitative and quantitative assessment; |
| 0332T |
Myocardial sympathetic innervation imaging, planar qualitative and quantitative assessment; with tomographic SPECT |
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| ICD-10 Diagnosis |
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All diagnoses |
| References |
Peer Reviewed Publications:
Government Agency, Medical Society, and Other Authoritative Publications:
| Websites for Additional Information |
| Index |
AdreView
Heart Failure, Congestive Heart Failure (CHF)
123iodine meta-iodobenzylguanidine
lobenguane I 123 injection
MIBG, 123I-MIBG
Sympathetic Innervation Imaging, Myocardial
The use of specific product names is illustrative only. It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available.
| Document History |
| Status |
Date |
Action |
| Reviewed |
02/19/2026 |
Medical Policy & Technology Assessment Committee (MPTAC) review. Added “Summary for Members and Families” section. Revised Description/Scope, Rationale, References, and Websites sections. |
| Revised |
02/20/2025 |
MPTAC review. Removed name of radiotracer from INV and NMN statement. Revised Description/Scope, Rationale, Background/Overview, References, and Website sections. Revised Coding section, removed A9582 no longer addressed. |
| Reviewed |
08/08/2024 |
MPTAC review. Revised Description/Scope, Rationale, Background/Overview, Definitions, References, and Websites. |
| Reviewed |
08/10/2023 |
MPTAC review. Revised Rationale and References sections |
| Reviewed |
08/11/2022 |
MPTAC review. Updated Description, Rationale and References sections |
| Reviewed |
08/12/2021 |
MPTAC review. Description/Scope, Rationale, Background/Overview, References, and Websites for Additional Information were updated. |
| Reviewed |
08/13/2020 |
MPTAC review. Rationale, Background/Overview and References sections were updated. |
| Reviewed |
08/22/2019 |
MPTAC review. References were updated. |
| Reviewed |
09/13/2018 |
MPTAC review. References were updated. |
| Reviewed |
11/02/2017 |
MPTAC review. The document header wording was updated from “Current Effective Date” to “Publish Date.” References were updated. |
| Reviewed |
11/03/2016 |
MPTAC review. References were updated. |
| Reviewed |
11/05/2015 |
MPTAC review. References were updated. Removed ICD-9 codes from Coding section. |
| Reviewed |
11/13/2014 |
MPTAC review. The Rationale, Background, and References sections were updated. |
| New |
11/14/2013 |
MPTAC review. Initial document development. |
Federal and State law, as well as contract language, including definitions and specific contract provisions/exclusions, take precedence over Medical Policy and must be considered first in determining eligibility for coverage. The member’s contract benefits in effect on the date that services are rendered must be used. Medical Policy, which addresses medical efficacy, should be considered before utilizing medical opinion in adjudication. Medical technology is constantly evolving, and we reserve the right to review and update Medical Policy periodically.
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