Low-Dose Contrast CT for TAVR Planning

(CT TAVR Trial)

Overseen By Rosy Njonkou, M.S.

Age: 18+

Sex: Any

Trial Phase: Phase 4

Sponsor: University of Maryland, Baltimore

Disqualifiers: Allergy to contrast, GFR<30, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Approved in 6 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 18-24 months

164 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests whether a low-dose contrast CT scan (Dual Energy CT or DECT) can safely and effectively aid in planning heart valve replacement surgery (TAVR). The aim is to use less iodinated contrast dye, potentially saving costs and reducing the risk of kidney problems for patients with reduced kidney function. Participants will receive either a third or a quarter of the usual contrast dose to determine if the images remain clear enough for surgical planning. This trial is suitable for those scheduled for a TAVR procedure who can undergo a CT scan and do not have a severe allergy to contrast dye. As a Phase 4 trial, the treatment is already FDA-approved and proven effective, and it seeks to understand how it benefits more patients.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What is the safety track record for these treatments?

Research has shown that using low amounts of contrast dye in special CT scans is generally safe for patients. These scans assist doctors in planning heart valve replacements. Studies have found that even with reduced contrast dye, the images remain clear, and patients experience few side effects.

This approach is particularly beneficial for patients with kidney problems, as the dye can sometimes cause kidney issues. Overall, this low-dose method is well-tolerated, making it a safer choice for those undergoing heart procedures. ^{1 2 3 4 5}

Why are researchers enthusiastic about this study treatment?

Researchers are excited about the Low-Dose Contrast CT for TAVR Planning because it offers a way to reduce the amount of contrast agent needed during CT scans. Unlike standard CT scans that use higher doses of contrast, this trial explores using just a third to a quarter of the usual amount, which could minimize potential risks and side effects for patients, especially those with kidney issues. This innovative approach aims to maintain image quality while being gentler on the body, potentially making CT scans safer for a broader range of patients.

What evidence suggests that low-dose contrast CT is effective for TAVR planning?

Research shows that using a smaller amount of contrast dye in dual-energy CT scans can effectively aid in planning for transcatheter aortic valve replacement (TAVR). In this trial, participants will divide into two cohorts to assess the effectiveness of different low-dose contrast levels. Cohort 1 will receive a 1/3 reduced dose of iodinated contrast agent (33 ml), while Cohort 2 will be assessed with 1/4 the standard dosage (25 ml) if the initial imaging is satisfactory. Studies have found that these scans excel at identifying patients who need TAVR. One study discovered that even with less contrast dye, the images remained clear enough for planning TAVR. Another study found that using less contrast dye significantly reduced the risk of kidney damage, especially in patients with existing kidney problems. Overall, this evidence suggests that low-dose contrast CT scans are both effective and safer for patients needing TAVR. ^{1 3 4 6 7}

Are You a Good Fit for This Trial?

This trial is for patients scheduled to undergo a CT scan of the abdomen as part of planning for their transcatheter aortic valve replacement (TAVR) procedure. Participants must be able to have a CT scan and not have severely reduced kidney function (GFR<30) or an uncontrolled allergy to IV contrast, even with steroids or Benadryl.

Inclusion Criteria

I am scheduled for a CT scan before my heart valve replacement.

Exclusion Criteria

My kidney function is low.

Cannot undergo CT scan

Allergy to intravenous contrast not controlled by steroids or benadryl

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive reduced doses of iodinated contrast for CT imaging to assess diagnostic quality

18-24 months

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Dual Energy CT
• Omnipaque

Trial Overview The study is testing if using a lower dose of iodinated contrast agent (Omnipaque) during dual-energy CT scans can still provide clear images for TAVR surgery planning. This could help conserve contrast material, reduce costs, and potentially decrease the risk of kidney injury in vulnerable patients.

How Is the Trial Designed?

Group I: Cohort 2 Experimental Treatment 2 Interventions

If imaging with 1/3 dose is satisfactory, a second cohort with 1/4th the standard dosage (25 ml) will be assessed. If images are not satisfactory, contrast dose will be increased to 50 ml.

Group II: Cohort 1 Experimental Treatment 2 Interventions

A cohort will be given a 1/3rd reduced dose of iodinated contrast agent (33 ml).

Dual Energy CT is already approved in European Union, United States, Canada, Japan, China, Switzerland for the following indications:

Approved in European Union as Dual Energy CT for:

• Cardiovascular imaging
• TAVR planning

Approved in United States as Dual Energy CT for:

• Cardiovascular imaging
• TAVR planning

Approved in Canada as Dual Energy CT for:

• Cardiovascular imaging
• TAVR planning

Approved in Japan as Dual Energy CT for:

• Cardiovascular imaging
• TAVR planning

Approved in China as Dual Energy CT for:

• Cardiovascular imaging
• TAVR planning

Approved in Switzerland as Dual Energy CT for:

• Cardiovascular imaging
• TAVR planning

Who Is Running the Clinical Trial?

University of Maryland, Baltimore

Lead Sponsor

Trials

729

Recruited

540,000+

Published Research Related to This Trial

Dual energy CT (DECT) technology, which uses two X-ray sources of different energies, significantly improves the contrast between adjacent structures, making it particularly useful in cardiac imaging due to its higher temporal resolution.

DECT can also enhance imaging in other areas such as craniocervical and peripheral vasculature, allowing for better differentiation of vascular lumina from calcified plaques, and it shows promise in characterizing ureteric stones and evaluating hepatic lesions, potentially leading to dose savings in imaging procedures.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dual Energy CT and its use in neuroangiography. Hegde, A., Chan, LL., Tan, L., et al.[2020]

Dual-energy computed tomography (DECT) offers advanced imaging capabilities by using two X-ray energy levels, allowing for better analysis of cerebrovascular diseases through techniques like virtual noncontrast and iodine overlay images.

DECT enhances the identification and differentiation of various cerebrovascular conditions, such as detecting active bleeding in intracranial hemorrhages and improving the assessment of atheromatous plaques, which can lead to more accurate diagnoses and treatment planning.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Principles and Clinical Application of Dual-energy Computed Tomography in the Evaluation of Cerebrovascular Disease. Hsu, CC., Kwan, GN., Singh, D., et al.[2020]

A dual energy CT (DECT) protocol using 50% less iodinated contrast provided adequate image quality for imaging the thoracic aorta, comparable to standard single energy CT (SECT) in 14 patients.

The best image quality was achieved with DECT using ASIR-V 80% reconstructions at 55 keV, although the increased radiation dose associated with DECT may limit its use in certain patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The potential of iodinated contrast reduction in dual-energy CT thoracic angiography; an evaluation of image quality. Johansen, CB., Martinsen, ACT., Enden, TR., et al.[2022]

Diagnostic dual energy CT (DECT) of the chest can be safely performed at submillisievert (sub-mSv) doses, achieving a mean effective dose of 0.7 mSv while maintaining good image quality in all 20 patients studied.

This study is the first to demonstrate that DECT can be conducted at such low radiation doses without losing relevant diagnostic information, indicating a significant advancement in imaging safety.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Submillisievert chest dual energy computed tomography: a pilot study. Canellas, R., Ackman, JB., Digumarthy, SR., et al.[2019]

Low-dose dual-energy computed tomography (DECT) significantly reduces metallic artifacts from orthopedic devices compared to both dose-neutral DECT and dose-reduced single-energy computed tomography (SECT), based on a study involving 30 implants in 20 cadavers.

The optimized monoenergetic DECT images (OPTkeV) provided superior image quality, especially at lower doses, demonstrating that low-dose DECT can achieve artifact reduction similar to neutral-dose DECT while outperforming reduced-dose SECT.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Performances of low-dose dual-energy CT in reducing artifacts from implanted metallic orthopedic devices. Filograna, L., Magarelli, N., Leone, A., et al.[2022]

Dual-energy computed tomography (DECT) aortography using a 70% reduced iodine dose provides similar aortic attenuation and image quality compared to standard single-energy CT (SECT) aortography with a full iodine dose, based on a study of 21 patients.

Despite a significant reduction in iodine dose, DECT showed acceptable subjective image quality, although slightly lower than SECT, indicating that DECT could be a safer alternative with reduced iodine exposure while maintaining diagnostic efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prospective comparison of dual-energy CT aortography using 70% reduced iodine dose versus single-energy CT aortography using standard iodine dose in the same patient. Shuman, WP., O'Malley, RB., Busey, JM., et al.[2018]

In a study involving 100 patients with primary hyperparathyroidism, virtual non-contrast (VNC) images from dual-energy computed tomography (DECT) showed good agreement with true non-contrast (TNC) images for most neck anatomical structures, potentially reducing radiation exposure.

However, significant differences in CT density were observed in the thyroid gland, indicating that VNC images cannot fully replace TNC images when specifically examining the thyroid and surrounding tissues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Can virtual non-contrast imaging replace true non-contrast imaging in multiphase scanning of the neck region? Al-Difaie, Z., Scheepers, MH., Bouvy, ND., et al.[2023]

Dual-energy CT (DECT) significantly reduces metal-related artifacts in head CT angiography, particularly for patients with surgical clips, as shown in a study of 13 patients.

The study found that noise levels were lower at higher photon energy levels and that coils produced more artifacts than clips, indicating that DECT is more effective for clips than for coils.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The utility of dual-energy CT for metal artifact reduction from intracranial clipping and coiling. Mera Fernández, D., Santos Armentia, E., Bustos Fiore, A., et al.[2021]

In a study of 860 children undergoing abdominopelvic exams, dual-energy computed tomography (DECT) was found to deliver lower radiation doses compared to conventional single-energy CT (SECT), with significant reductions in both size-specific dose estimates (SSDE) and volume CT dose index (CTDIvol).

The image quality of DECT was comparable to that of SECT across different patient sizes, indicating that DECT can be a safer alternative without compromising diagnostic quality.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of radiation dose and image quality between contrast-enhanced single- and dual-energy abdominopelvic computed tomography in children as a function of patient size. Siegel, MJ., Mhlanga, JC., Salter, A., et al.[2021]

Dual-energy CT (DECT) offers significant advantages in clinical imaging, such as material decomposition and the ability to eliminate misregistration artifacts, enhancing the accuracy of diagnoses across various applications including neurology, thorax, and abdominal imaging.

DECT can replace traditional unenhanced images by generating virtual non-contrast images, allowing for improved characterization of conditions like liver and pancreas masses, and even differentiating between types of urinary calculi, making it a versatile tool in medical imaging.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dual-energy CT revisited with multidetector CT: review of principles and clinical applications. Karçaaltıncaba, M., Aktaş, A.[2022]

Dual energy CT (DECT) enhances imaging by using two energy spectra to differentiate materials with similar CT attenuation, allowing for improved detection and quantification of substances like iodine and uric acid, which is particularly useful in emergency settings.

Recent advances in DECT technology have expanded its clinical applications, including differentiating types of intracranial hemorrhage, diagnosing pulmonary embolism, and identifying uric acid stones, making it a valuable tool for emergency radiologists.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dual Energy CT Physics-A Primer for the Emergency Radiologist. Odedra, D., Narayanasamy, S., Sabongui, S., et al.[2023]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11214918/

Diagnostic Efficacy and Safety of Low-Contrast-Dose Dual- ... This study aimed to evaluate the diagnostic efficacy and safety of low-contrast-dose, dual-source dual-energy CT before transcatheter aortic valve ...

2. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/38942457/

Diagnostic Efficacy and Safety of Low-Contrast-Dose Dual- ... Objective: This study aimed to evaluate the diagnostic efficacy and safety of low-contrast-dose, dual-source dual-energy CT before transcatheter aortic valve ...

3. ahajournals.org ahajournals.org/doi/10.1161/JAHA.120.020655

Prognostic Impact of Myocardial Extracellular Volume ... This study evaluated the association between ECV measured with dual‐energy CT and clinical outcomes in patients with aortic stenosis who underwent ...

4. pubs.rsna.org pubs.rsna.org/doi/abs/10.1148/radiol.14140763

Dual-Source CT Imaging to Plan Transcatheter Aortic ... Our data demonstrate that transcatheter aortic valve replacement (TAVR) planning CT imaging has high sensitivity and negative predictive value.

5. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1934592519301820

Low dose contrast CT for transcatheter aortic valve ... Low dose contrast CT for transcatheter aortic valve replacement assessment: Results from the prospective SPECTACULAR study (spectral CT assessment prior to TAVR).

6. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0037198X23000895

Computed Tomography of Transcatheter Aortic Valve ... TAVR has a low periprocedural mortality rate, estimated between 1.1% and 4.2%.2 In 2016, overall in-hospital mortality rate was lower for TAVR than for surgical ...

7. link.springer.com link.springer.com/article/10.1007/s00330-023-10403-x

Reduction of contrast medium for transcatheter aortic valve ... Dual-energy or spectral computed tomography (DECT) has shown favorable results in vascular imaging because of its potential for post-processing ...