An observational study in Myocardial Diseases, Perfusion Imaging and Stress Perfusion, sponsored by Karolinska University Hospital. Recruiting at 1 site in Sweden. Open to participants aged 60 Years and older. Per ClinicalTrials.gov, last updated 2026-09-02.
Sponsored by Karolinska University Hospital · Observational
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.
553 studies on the registry are indexed under Cardiomyopathies; 152 are open to participants now.
This study's planned enrollment of 100 is below the median of 200 across 263 observational studies indexed under Cardiomyopathies.
Browse Cardiomyopathies studies →Karolinska University Hospital is the lead sponsor of 279 studies on the registry; 55 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients with severe aortic valve stenosis referred for computed tomography angiography (CTA) as part of routine preprocedural evaluation for transcatheter aortic valve implantation (TAVI).
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
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 . Atrial fibrillation. Severe heart failure: class IV.
Contrast or kidney relaterad factors: Previous allergic reaction to iodinated or gadolinium contrast or history of contrast induced nephropathy. Impaired renal function: \< 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).
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Photon-counting cardiac CT including adenosine stress myocardial perfusion imaging and extracellular volume (ECV) quantification performed in patients undergoing TAVI evaluation. Results are compared with cardiac magnetic resonance and invasive coronary angiography.
Agreement Between Photon-Counting CT and Cardiac Magnetic Resonance for Extracellular Volume Quantification
Time frame: At baseline imaging assessment
Agreement Between Photon-Counting CT and Cardiac Magnetic Resonance for Myocardial Perfusion Assessment
Time frame: At baseline imaging assessment
Plan to share: No
No publications or documents are linked to this record.
Started Jun 2025 (actual). Primary completion is estimated for Aug 2027, 26 months after the start.
Of 119 non-industry observational studies under Cardiomyopathies, half reached primary completion within 87 months of starting (the median), counting those still running; a quarter within 34. This study's planned 26 months is below that.
Counting every sponsor, half of 140 studies reached it within 83 months; a quarter within 34.
How these figures are worked out, and which studies are left out of them.
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