AzTrials
AzTrials

Chronic Thromboembolic Pulmonary HypertensionINSPIRENCT03806907

Iodine Subtraction Mapping in the Diagnosis of Chronic Pulmonary Thromboembolic Disease

An observational study of Chronic Thromboembolic Pulmonary Hypertension, run by University of Sheffield.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
Search all trials

Trial summary

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe but treatable disease that is commonly underdiagnosed. Computed tomography lung subtraction iodine mapping (CT-LSIM) in addition to standard CT pulmonary angiography (CTPA) may improve the evaluation of suspected chronic pulmonary embolism and improve… Read more about this study

Who is it for?
Ages 18 to 90 years
What is being tested?
Computed tomography lung subtraction iodine mapping
Type of treatment
Surgery or procedure
How many people
100 participants
Where
No sites listed yet
Study dates
1 Apr 2019to 30 Aug 2020
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 90 years
  • All sexes
  • Adult, Older adult

Study population: Patient suspected to have or diagnosed with chronic thromboembolic disease and require a SPECT and CTPA

Who may be able to join

  • Patients suspected to have CTED and require a SPECT and CTPA

Who cannot join

  • Less than 18 years old
  • Unable to provide informed consent
  • Significant renal dysfunction (GFR <30ml/min)
  • History of hypersensitivity to contrast material
  • Pregnancy

Trial locations and contacts

No sites are listed yet.

Andy J Swift, PhD contact

0114 2159595

a.j.swift@sheffield.ac.uk

Yousef Shahin, MD contact

0114 2159595

y.shahin@sheffield.ac.uk

About this study

Official title: IodiNe Subtraction maPpIng in the Diagnosis of chRonic Pulmonary thromboEmbolic Disease (INSPIRE): An Observational Diagnostic Study

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe but treatable disease that is commonly underdiagnosed. Computed tomography lung subtraction iodine mapping (CT-LSIM) in addition to standard CT pulmonary angiography (CTPA) may improve the evaluation of suspected chronic pulmonary embolism and improve the diagnostic pick up rate. The investigators aim to recruit 100 patients suspected of having CTEPH and perform CT-LSIM scans in addition to the current gold standard test of nuclear medicine test (lung single photon emission computed tomography (SPECT) imaging) as a pilot study which will contribute to and inform the definitive trial. The diagnostic accuracy of CT-LSIM and lung SPECT will be compared. The primary outcome of the full definitive study is non-inferiority of CT-LSIM versus lung SPECT imaging.

Read the detailed description

Chronic thromboembolic pulmonary hypertension (CTEPH) is a treatable, life-threatening disease that occurs in up to 4% of patients following acute pulmonary embolism (PE)(1). The disease is characterised by remodelling of the pulmonary arteries due to poor clearance of clot. Prognosis is very poor without treatment, and pulmonary endarterectomy (PEA) is well established as the definitive and potentially curative treatment method for CTEPH.

The European Society of Cardiology recommends ventilation/perfusion single photon emission tomography (V/Q SPECT) as the first line-screening test for patients with CTEPH. The perfusion image involves injection of 99mTc labelled macroaggregated human albumin, exposing the patient to ionizing radiation and the study acquisition time is 30-40 minutes.

Evaluation of the pulmonary arterial tree by computed tomography pulmonary angiography (CTPA) and lung perfusion is required to determine the appropriate treatment strategy in chronic thromboembolic disease (CTED). Recently, there has been much interest in the application of lung perfused blood volume images using dual-energy CT (DECT) to assess lung perfusion (2, 3). However, DECT is not widely available in hospitals across the UK and V/Q SPECT remains the reference standard. The rationale, methodology and design of the IodiNe SubtracTion mappInG in the diAgnosis of chronic pulmonary ThromboEmbolic disease (INSTIGATE) study are summarised in this paper.

Rationale of the INSTIGATE study:

Computed tomography lung subtraction iodine mapping (CT-LSIM) and accompanying software is now available in routine clinical practice (Sure subtractionTM, Toshiba Medical Systems; FDA report K130960). CT-LSIM images are created using on a non-rigid registration of a low dose unenhanced thoracic CT to a CTPA, with both examinations performed during the same sitting in less than 10 minutes total scanning time. Subtraction of the non-contrast CT from the contrast-enhance CTPA produces the CT-LSIM. CT-LSIM simultaneously provide high-spatial-resolution images of the pulmonary arterial tree and parenchymal anatomy in combination with functional examination of lung perfusion.

Magnetic resonance imaging (MRI) is an alternative approach with the advantage of the lack of ionizing radiation and can produce lung perfusion maps with good diagnostic accuracy for CTED (5). MRI is relatively limited in comparison to CT in terms of availability and the lack of ability to provide an out of hours service in some centres. Recently, it has been shown that Gadolinium is deposited in the basal ganglia, the clinical significance of the retained gadolinium in the brain, if any, remains unknown (4). Further research is ongoing.

A recent meta-analysis and systematic review, highlights the diagnostic potential of CT in both screening and for surgical and interventional operability (6).

Replacement of CT for V/Q SPECT in the setting of screening for CTED would lead to a cost saving per patient. The diagnosed incidence of CTEPH is approximately 700 cases in the UK, projected to rise to about 1000 in 2025. Estimated pick up rate of perfusion defects in patients with suspected CTED is 59% at a specialist centre (pick up rates are likely to be much lower at non-specialist centres). An estimated 1186 patients are screened at specialist centres, if these patients were screened using CT instead of SPECT, significant cost savings can be made.

In patients found to have CTED on lung SPECT, CTPA is also required to characterise the extent of pulmonary arterial clot for surgical planning, and this would be a further cost. By using CTPA with iodine subtraction mapping for screening and surgical planning.

Being tested
Computed tomography lung subtraction iodine mapping
Keywords
INSITIGATE, Pulmonary Hypertension, Pulmonary embolism, Chronic Thromboembolism, Iodine Subtraction
Medical subject headings
Hypertension, Pulmonary, Pulmonary Embolism

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Computed tomography lung subtraction iodine mappingRadiation

    Also called CT-LSIM

    Subtraction of the non-contrast CT from the contrast-enhance CTPA produces the CT-LSIM

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Assessment of the diagnostic performance of CT-LSIM for evaluation of pulmonary perfusion in patients with known or suspected chronic thromboembolic pulmonary hypertension (CTEPH)

    Sensitivity and specificity

    Measured: 12 months

Secondary outcomes (5)
  1. Diagnostic accuracy of CT-LSIM compared with single photon emission computed tomography (SPECT)

    Sensitivity and specificity

    Measured: 12 months

  2. Diagnostic accuracy of CT-LSIM compared with CT pulmonary angiography (CTPA)

    Sensitivity and specificity

    Measured: 12 months

  3. Diagnostic accuracy of experienced and less experienced observers

    Sensitivity and specificity

    Measured: 12 months

  4. Number of alternate diagnoses made on CT-LSIM over lung SPECT imaging

    Chi square

    Measured: 12 months

  5. Radiation dose between CT-LSIM, SPECT and CTPA

    Means

    Measured: 12 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Jan 2019
  2. Study start1 Apr 2019 (estimated)
  3. Primary completion1 Apr 2020 (estimated)
  4. Study completion30 Aug 2020 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
100 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03806907
Sponsor's protocol ID
STH20623
Acronym
INSPIRE
Status last verified
Feb 2019
First submitted
15 Jan 2019
Last updated
12 Feb 2019
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Pengo V, Lensing AW, Prins MH, Marchiori A, Davidson BL, Tiozzo F, Albanese P, Biasiolo A, Pegoraro C, Iliceto S, Prandoni P; Thromboembolic Pulmonary Hypertension Study Group. Incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism. N Engl J Med. 2004 May 27;350(22):2257-64. doi: 10.1056/NEJMoa032274.

    PubMed 15163775
  • Hoey ET, Gopalan D, Ganesh V, Agrawal SK, Qureshi N, Tasker AD, Clements L, Screaton NJ. Dual-energy CT pulmonary angiography: a novel technique for assessing acute and chronic pulmonary thromboembolism. Clin Radiol. 2009 Apr;64(4):414-9. doi: 10.1016/j.crad.2008.11.007. Epub 2009 Jan 14. No abstract available.

    PubMed 19264187
  • Hoey ET, Mirsadraee S, Pepke-Zaba J, Jenkins DP, Gopalan D, Screaton NJ. Dual-energy CT angiography for assessment of regional pulmonary perfusion in patients with chronic thromboembolic pulmonary hypertension: initial experience. AJR Am J Roentgenol. 2011 Mar;196(3):524-32. doi: 10.2214/AJR.10.4842.

    PubMed 21343493
  • Gulani V, Calamante F, Shellock FG, Kanal E, Reeder SB; International Society for Magnetic Resonance in Medicine. Gadolinium deposition in the brain: summary of evidence and recommendations. Lancet Neurol. 2017 Jul;16(7):564-570. doi: 10.1016/S1474-4422(17)30158-8. Epub 2017 Jun 13.

    PubMed 28653648
  • Rajaram S, Swift AJ, Capener D, Telfer A, Davies C, Hill C, Condliffe R, Elliot C, Hurdman J, Kiely DG, Wild JM. Diagnostic accuracy of contrast-enhanced MR angiography and unenhanced proton MR imaging compared with CT pulmonary angiography in chronic thromboembolic pulmonary hypertension. Eur Radiol. 2012 Feb;22(2):310-7. doi: 10.1007/s00330-011-2252-x. Epub 2011 Sep 2.

    PubMed 21887483
  • Dong C, Zhou M, Liu D, Long X, Guo T, Kong X. Diagnostic accuracy of computed tomography for chronic thromboembolic pulmonary hypertension: a systematic review and meta-analysis. PLoS One. 2015 Apr 29;10(4):e0126985. doi: 10.1371/journal.pone.0126985. eCollection 2015.

    PubMed 25923810

Questions about this trial

What is this clinical trial studying?

An observational study of Chronic Thromboembolic Pulmonary Hypertension, run by University of Sheffield.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: status not confirmed, as of the sponsor's last update on 12 Feb 2019. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

Contact Andy J Swift, PhD (0114 2159595, a.j.swift@sheffield.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Assessment of the diagnostic performance of CT-LSIM for evaluation of pulmonary perfusion in patients with known or suspected chronic thromboembolic pulmonary hypertension (CTEPH) (time frame: 12 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03806907, which also lists 6 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Feb 2019.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in