RecruitingNAINTERVENTIONAL

A Single Centre Study Comparing Continuous Interstitial Fluid Lactate Detection to Standard Measurements of Lactate in Patients Undergoing Elective Coronary Artery Bypass Graft Surgery and/or Valve Replacement.

This study is testing a new wearable device that continuously measures lactate levels in patients undergoing heart surgery at Barts Hospital, specifically for coronary artery bypass grafts or valve replacements. Lactate is a chemical in the body that doctors can monitor to check on a patient's health. Currently, this requires frequent blood tests. Researchers want to see if this new device, worn on the arm, can accurately track these levels compared to standard blood tests. The hope is that if the device works well, it could make recovery more comfortable by reducing the number of blood tests needed. It might also help doctors make quicker diagnoses in emergency situations, especially for people with chest pain, leading to better and faster care.

At a glance

Status

Recruiting

Phase

Sponsor

Queen Mary University of London

Enrolment target

Start

20 May 2025

Estimated completion

01 May 2026

Coronary Artery Bypass Coronary Artery Bypass Graft Coronary Artery Bypass Graft Surgery (CABG)Valve Replacement Valve Surgery Cardiovascular CABG

What is this study about?

This study is looking into a new way to monitor your body's health during and after major heart surgery, specifically coronary artery bypass grafts (CABG) or valve replacements. When you have surgery, especially on your heart, doctors keep a close eye on various body signals to make sure you're recovering well. One important signal is lactate levels, which can tell doctors how your body is coping. Currently, the most common way to check lactate is by taking blood samples, which can be frequent and sometimes uncomfortable for patients.

The main goal of this study is to test a new wearable device that could measure lactate levels continuously, right through your skin. Think of it like a patch you wear on your arm. The researchers want to see if the readings from this device are as accurate and reliable as the usual blood tests. If it works well, it could be a real game-changer. It might mean fewer needle sticks for patients, making your recovery journey a bit smoother and more comfortable.

Beyond just making recovery easier, accurate and continuous readings could also help doctors in emergency situations. For example, if someone comes into the hospital with chest pain, quickly knowing their lactate levels could help doctors understand their condition faster and make more informed decisions about treatment. This study is a step towards improving how medical care is delivered, using technology to provide quicker information and potentially better outcomes for patients in the future.

Key takeaways

Testing a new wearable device for continuous lactate measurement.
Aims to reduce frequent blood tests for heart surgery patients.
Could help with quicker diagnoses in emergencies.
Involves wearing sensors on the arm and hourly blood samples for comparison.
Study takes place at Barts Hospital for planned heart surgeries.
Participation is voluntary and won't affect your medical care.

Who may be eligible?

To be able to take part in this study, you would need to be having a planned coronary artery bypass graft (CABG) and/or valve replacement surgery at Barts Hospital. You must be aged between 18 and 90 years old and be able to understand and agree to take part.

There are some reasons why you might not be able to join the study. For example, if you've already had a coronary artery bypass graft before, or if you've recently had a heart attack (within the last four weeks). You would also not be able to take part if you have severe kidney or liver problems, certain blood conditions like severe anaemia, or if you are pregnant.

Additionally, if you have a skin condition on your upper arm where the sensor would be placed, or if you have certain medical devices implanted like a pacemaker, or if you have specific allergies to materials in the sensor, you wouldn't be able to participate. The research team will carefully check all these points with you to ensure your safety and suitability for the study.

Quick self-check

Are you having planned coronary artery bypass graft (CABG) or valve replacement surgery?
Are you aged between 18 and 90 years old?
Do you have severe kidney problems (eGFR below 30)?
Have you had a heart attack in the last 4 weeks?
Do you have a severe skin condition on your upper arm where a patch would go?
Do you have an implanted medical device like a pacemaker?

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, a research nurse or doctor will explain everything thoroughly and obtain your consent. Up to five days before your surgery, two small lactate sensors will be placed on your upper arm. These sensors will need about 24 hours to warm up before they start continuously measuring your lactate levels. You'll also have a medical check-up, including blood pressure, heart rate, and an ECG, and some baseline blood samples will be taken, which is standard before your surgery.

You will then have your planned heart surgery as usual. During and after surgery, for up to 14 hours, hourly blood samples will be taken through the tubes that are already in place for your surgery. This is to compare with the continuous readings from the sensors on your arm. Your blood pressure, heart rate, and breathing rate will also be monitored hourly, and any changes in your medication will be noted. The sensors will then be removed from your arm within 48 hours after your surgery.

Potential risks and benefits

Taking part in this study could help advance medical understanding and improve care for future heart surgery patients, potentially leading to more comfortable monitoring with fewer blood tests. However, there are no direct health benefits for you personally from participating beyond the excellent care you would already receive. The main inconvenience would be the placement and removal of the sensors, and the additional hourly blood samples taken for a short period after surgery, which are used to validate the new device. You might also experience mild skin irritation from the sensor adhesive. Your safety is paramount, and you are free to withdraw from the study at any time without affecting your medical care.

Locations (1)

Barts Health
London, United Kingdom· Recruiting

Common questions

What is lactate and why do doctors measure it?

Lactate is a chemical in your blood that doctors can measure to understand how well your body and organs are functioning, especially during and after surgery.

What is a wearable device in this study?

It's a small patch-like sensor that sticks to your skin on your upper arm, designed to continuously measure your lactate levels without needing a blood sample.

Will taking part in the study affect my planned surgery?

No, your planned heart surgery will go ahead exactly as scheduled and your medical care will not be affected by your participation in the study.

Will I get any results from the device?

While the study aims to collect data for research, the device readings are for research purposes and will not directly guide your immediate treatment decisions. Your medical team will continue to rely on standard measurements and tests for your care.

How long will the sensors stay on my arm?

The sensors will be applied up to five days before your surgery and removed within 48 hours after your surgery.

How to find out more

Prof Anthony Mathur

a.mathur@qmul.ac.uk 02037658740 Official trial record

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