Validation of Myocardial Perfusion and Extracellular Volume Assessment Using Photon-Counting Computed Tomography (PCCT) Compared With Cardiac Magnetic Resonance (CMR) in Patients Undergoing Transcatheter Aortic Valve Implantation (TAVI)

August 28, 2026 updated by: Raquel Themudo, Karolinska University Hospital

Validering av genomblödning Och extracellulärvolym i hjärtmuskeln Med datortomografiundersökning Hos Patienter Som Ska genomgå Perkutan Aortaklaffbyte (TAVI)

Cardiovascular diseases are the leading cause of death worldwide, responsible for about 30% of all deaths. This substantial burden highlights the need for accurate diagnostic tools that help doctors detect heart disease early and understand it more fully. Recent advances in medical imaging offer promising opportunities to improve how heart conditions are diagnosed and treated.

One important development in computed tomography (CT), a widely used imaging technique, is photon counting computed tomography (PCCT). PCCT produces clearer and more detailed images of the heart while using lower radiation doses and smaller amounts of contrast agent, the dye injected into the bloodstream to make body tissues more visible. As PCCT is still a relatively new technology, its full potential in clinical heart imaging has not yet been fully explored.

This study includes patients with narrowing of the aortic valve, a condition that reduces blood flow from the heart and often requires treatment. These patients undergo cardiac CT before receiving a minimally invasive valve replacement procedure called transcatheter aortic valve implantation (TAVI). The study evaluates two diagnostic applications of PCCT:

Functional assessment: Blood flow to the heart muscle is examined during stress imaging, when the heart works harder, to determine whether narrowed coronary arteries significantly limit blood supply.

Tissue characterization: The heart muscle is analyzed to detect scarring or fibrosis by measuring the extracellular volume (ECV), the space between cells.

If successful, PCCT could provide detailed anatomical, functional, and tissue information in a single non invasive examination, offering a "one stop shop" for comprehensive heart assessment.

Study Overview

Study Type

Observational

Enrollment (Estimated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Stockholm County
      • Huddinge, Stockholm County, Sweden, 141057

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients with severe aortic valve stenosis referred for computed tomography angiography (CTA) as part of routine preprocedural evaluation for transcatheter aortic valve implantation (TAVI).

Description

Inclusion Criteria:

  • Patients referred for TAVI planning CTA. Both sexes are eligible; equal sex distribution is not required. Age ≥ 60 years.

Exclusion Criteria:

- Hemodynamic or rhythm related conditions: Systolic blood pressure < 90 mmHg. Bradycardia: < 45 beats/min. Persistent AV block II-III. Sick sinus syndrome. Prolonged QT interval. Atrial fibrillation. Severe heart failure: NYHA class IV.

Contrast or kidney relaterad factors: Previous allergic reaction to iodinated or gadolinium contrast or history of contrast induced nephropathy. Impaired renal function: eGFR < 45 mL/min/1.73 m².

Implants or devices: Metallic implants or devices in the imaging area, e.g., pacemaker. Medication: Persantin (dipyridamole), Theophyllamine, Fevarin (fluvoxamine).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Agreement Between Photon-Counting CT and Cardiac Magnetic Resonance for Extracellular Volume Quantification
Time Frame: At baseline imaging assessment
At baseline imaging assessment
Agreement Between Photon-Counting CT and Cardiac Magnetic Resonance for Myocardial Perfusion Assessment
Time Frame: At baseline imaging assessment
At baseline imaging assessment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 10, 2025

Primary Completion (Estimated)

August 31, 2027

Study Completion (Estimated)

December 31, 2027

Study Registration Dates

First Submitted

August 28, 2026

First Submitted That Met QC Criteria

August 28, 2026

First Posted (Actual)

September 2, 2026

Study Record Updates

Last Update Posted (Actual)

September 2, 2026

Last Update Submitted That Met QC Criteria

August 28, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • K 2026-5796

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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