RecruitingNAINTERVENTIONAL

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.

This research investigates whether special ultrasound contrast agents, which are tiny bubbles, can be used to accurately estimate the pressures inside your heart. Currently, these pressures are measured using a thin tube called a catheter, which is inserted into your heart. The study aims to see if there's a strong link between the signal from these bubbles and the heart pressures, and how to convert the bubble signal into a pressure reading. Participants will have a standard heart catheterisation and receive the bubble contrast through a drip in their arm. They will then have special ultrasound scans of their heart (with and without the bubbles) to compare the new method against the traditional catheter measurements. The goal is to find a less invasive way to assess heart conditions like heart failure.

At a glance

Status

Recruiting

Phase

Sponsor

King's College London

Enrolment target

Start

01 Feb 2026

Estimated completion

01 Mar 2027

HFpEF - Heart Failure With Preserved Ejection Fraction Cardiac Catheterisation Heart Disease

What is this study about?

Imagine your heart needing a health check-up, especially to understand the pressures inside its chambers. Traditionally, doctors have used a 'catheter' – a thin, flexible tube inserted into a blood vessel and guided into the heart – to get these precise pressure readings. While very effective, this can be an uncomfortable and slightly more involved procedure.

This study is looking for a kinder, less invasive way to do this. We're investigating if tiny, safe bubbles, commonly used in special ultrasound heart scans, can give us the same important information about your heart's pressures. These bubbles are given through a simple drip in your arm, making it much less intrusive than a catheter. The main aim is to see if the signals from these bubbles accurately match the pressure readings from a catheter.

If successful, this new method could mean that in the future, people needing their heart pressures assessed might not always need a catheter procedure. This could make diagnosing and monitoring heart conditions like heart failure (specifically 'Heart Failure with Preserved Ejection Fraction' or HFpEF, where the heart pumps well but is stiff) much easier and more comfortable for patients. It's about finding smart, gentle ways to understand your heart's health.

Key takeaways

Exploring a less invasive way to measure heart pressures.
Compares tiny bubbles (contrast agents) with traditional catheters.
All study activities happen on the day of your planned heart catheterisation.
Aims to improve diagnosis for conditions like heart failure (HFpEF).
Could make heart assessments more comfortable in the future.

Who may be eligible?

This study is looking for adults aged between 21 and 81 who are already scheduled to have a heart catheterisation procedure as part of their routine medical care. It's important that you are able to understand and agree to take part in the study, and that doctors can get a clear view of your heart with an ultrasound scan while you lie flat.

However, there are reasons why you might not be able to join. For example, if you have ever had an allergic reaction to the contrast agent called SonoVue (or any of its ingredients like sulphur hexafluoride or PEG), or if you have certain existing heart or lung conditions like a hole in your heart, very high blood pressure in your lung arteries, or uncontrolled high blood pressure. Also, if you are pregnant, have moderate to severe heart valve problems, or have recently had certain serious heart events, this study may not be suitable for you.

We also can't include you if you're currently taking a heart medicine called dobutamine, or if you're taking part in another drug trial or research that would make your catheterisation procedure much longer and more tiring.

Quick self-check

Am I already scheduled for a heart catheterisation procedure?
Am I aged between 21 and 81?
Can I lie flat and get clear heart ultrasound scans?
Have I ever had an allergic reaction to SonoVue or its ingredients?
Do I have a known hole in my heart or severe lung pressure?
Am I pregnant or could I be?

This is a guide only — the research team will confirm whether you can take part.

What does participation involve?

If you decide to take part, all study activities will happen on the same day as your planned heart catheterisation, meaning no extra hospital visits. During your catheterisation, you will have a small amount of extra X-ray exposure to help guide the catheter (a thin tube) into your heart, so we can get precise pressure readings – these are the 'gold standard' measurements we will compare against.

You will also receive a special liquid called an 'ultrasound contrast agent' (tiny bubbles) through a drip in your arm, at a standard, safe dose. While this liquid is working, you'll have specific ultrasound scans of your heart, both with and without the contrast, to see how the bubbles help us measure pressure. The entire process is designed not to prolong your day at the hospital or add extra burden.

Potential risks and benefits

Taking part in this study could potentially help advance medical knowledge, leading to more comfortable ways to assess heart health for future patients. However, there are some small risks, such as a tiny amount of extra X-ray exposure for guiding the catheter, and potential (though rare) side effects from the ultrasound contrast agent, which will be given at a standard clinical dose. You may also feel slightly more tired due to the extra scans performed during your catheterisation. You are free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

King's College Hospital
London, United Kingdom· Recruiting

Common questions

What are these 'tiny bubbles'?

They are a special, safe liquid called an ultrasound contrast agent. They are very small bubbles that help doctors see your heart more clearly during an ultrasound scan.

Will taking part mean more hospital visits?

No, all the study steps will happen on the same day as your planned heart catheterisation. No extra appointments are needed.

Is the catheter still necessary if you're testing the bubbles?

Yes, for this study, the catheter is essential. It provides the accurate, traditional pressure measurements we need to compare with the new bubble method.

What is 'Heart Failure with Preserved Ejection Fraction' (HFpEF)?

It's a type of heart failure where your heart pumps out blood well, but its chambers are stiff and don't fill properly with blood. It’s a common condition this study hopes to help diagnose better.

Can I stop participating if I change my mind?

Absolutely. You are free to withdraw from the study at any time, and it will not affect your medical care.

How to find out more

Amanda Nio, PhD

amanda.nio@kcl.ac.uk +44 (0)20 7836 5454 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.