Can Tiny Bubbles Offer an Alternative to Catheters for Assessing Pressures Inside the Heart? Investigating Ultrasound Contrast Agents as Pressure Sensors Against Gold Standard Catheter Pressures in Cardiac Catheterisation Patients. (SonoHeart)

February 10, 2026 updated by: King's College London

Intracardiac Pressures From Microbubbles Instead of a Catheter: First in Human Study and Signal Calibration

The goal of this clinical trial is to investigate if ultrasound contrast agents can be used to estimate filling pressures inside the heart in patients with suspected heart disease. The main questions it aims to answer are:

  • Is there a strong correlation between the contrast signal and filling pressures inside the heart?
  • What is the calibration approach to convert the contrast signal from dB to a measure of pressure in mmHg?

Researchers will compare the contrast signal with reference pressures measured using a catheter to see if it can be used to quantify filling pressures inside the heart.

Participants will:

  • Be exposed to a small amount of additional ionising radiation to guide a catheter in position inside the heart for reference pressures
  • Receive an ultrasound contrast agent at the clinically recommended dose and in line with clinical guidelines, via an intravenous line in their arm
  • Undergo contrast echocardiography - ultrasound scan of their heart with contrast
  • Undergo standard echocardiography - ultrasound scan of their heart without contrast

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study will record ultrasound contrast signals simultaneously with gold standard catheter pressure measurements inside the heart, to enable a direct comparison between the two methods. Complementary ultrasound data will be used to develop a personalised calibration solution to convert the contrast signal in dB to estimated pressure in mmHg. All study procedures will be completed on the same day as the participant's standard of care cardiac catheterisation and no additional study visits will be required.

Study Type

Interventional

Enrollment (Estimated)

10

Phase

  • Not Applicable

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

  • United Kingdom
      • London, United Kingdom, SE5 9RS
        • Recruiting
        • King's College Hospital

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

Description

Inclusion Criteria:

  • Participant is willing and able to give informed consent to participate in the study
  • Patients who require a cardiac catheterisation procedure as part of their standard medical care
  • Good acoustic windows for echocardiography when lying flat on their back

Exclusion Criteria:

  • Known previous allergy to SonoVue, used in ultrasound contrast scans
  • Known allergy to any of the components of SonoVue microbubbles, for example, sulphur hexafluoride or polyethylene glycol (PEG), also known as macrogol, which is in bowel preparations used during colonoscopy and certain laxatives
  • A hole in their heart that lets blood flow from the right side to the left, skipping the lungs
  • Very high blood pressure in the arteries of the lungs (severe pulmonary hypertension)
  • Uncontrolled high blood pressure (hypertension)
  • Adult respiratory distress syndrome (ARDS; where severe lung inflammation prevents enough oxygen from reaching the body)
  • Current use of the medicine dobutamine (used to treat heart failure), or have been advised not to take dobutamine
  • Moderate to severe heart valve disease that could affect the catheter measurements
  • Recent acute coronary syndrome or unstable ischaemic cardiac disease, where blood flow to the heart muscle is reduced
  • Pregnant or may be pregnant
  • Participation in a clinical trial of a medicine within the past four months, to avoid any possible interactions with SonoVue
  • Participating in other research that would prolong their cardiac catheterisation procedure, to ensure that the overall process does not become too tiring or burdensome

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

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Contrast echocardiography for intracardiac filling pressures
Other: Contrast Echocardiography
Simultaneous contrast echocardiography and cardiac catheterisation for intracardiac pressures in the cardiac catheterisation laboratory
Other Names:
  • Standard echocardiography
  • High frame rate contrast echocardiography

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation between the signal of the ultrasound contrast agent SonoVue and intracardiac pressure measured using a catheter
Time Frame: 20 minutes
The ultrasound signal of SonoVue at the subharmonic frequency will be compared with left ventricular filling pressures measured using a high-fidelity catheter.
20 minutes

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Intracardiac pressure estimated from the ultrasound signal of SonoVue, converted from dB to mmHg using an ultrasound-based calibration approach
Time Frame: 20 minutes
The signal of ultrasound contrast agents has to be calibrated to convert it from dB to mmHg for pressure. Ultrasound-based approaches involving standard echocardiography and high frame rate contrast echocardiography will be investigated as potential calibration approaches in this study.
20 minutes

Collaborators and Investigators

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

Sponsor

King's College London

Collaborators

King's College Hospital NHS Trust

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Estimated)

February 1, 2026

Primary Completion (Estimated)

March 1, 2027

Study Completion (Estimated)

March 1, 2027

Study Registration Dates

First Submitted

February 10, 2026

First Submitted That Met QC Criteria

February 10, 2026

First Posted (Actual)

February 18, 2026

Study Record Updates

Last Update Posted (Actual)

February 18, 2026

Last Update Submitted That Met QC Criteria

February 10, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 331447

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified data towards any publications and conference papers will be made publicly available on an online open access repository (e.g. Figshare) after the research output is accepted.

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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