AuthorisedTherapeutic use (Phase IV)Interventional

Platelet function testing in outpatients after heart transplantation on aspirin therapy

This study aims to understand how well aspirin works in people who have had a heart transplant. Aspirin is often given to prevent blood clots. Researchers are interested in finding out if some people might have 'aspirin resistance,' meaning the aspirin isn't working as well as it should. They will use a special blood test called Multiplate® ASPI to check this. They'll also look at other health factors like age, whether someone smokes, and cholesterol levels. The results could help doctors give the best possible care to heart transplant patients. This is a Phase IV study, meaning it's looking at a medicine already in use.

At a glance

Status

Authorised

Phase

Therapeutic use (Phase IV)

Sponsor

Medical University Of Vienna

Enrolment target

100

Start

25 May 2026

Patients who have undergone heart transplantation.

What is this study about?

This research is focused on people who have received a new heart through a transplant and are taking a daily aspirin. Aspirin is a very common medicine prescribed after heart transplants to help prevent blood clots, which can be very serious. Sometimes, however, aspirin doesn't work as well as expected in some people; this is called 'aspirin resistance.' This study wants to find out how common aspirin resistance is in heart transplant patients once they have gone home from the hospital.

The main goal is to see if a specific blood test, called a Multiplate® ASPI test, can easily tell if someone's aspirin is working properly. Researchers will also be looking at many other things that might affect how aspirin works or a person's health more generally. This includes things like your age, whether you smoke, if you have conditions like diabetes or high blood pressure, and even how active you are.

By gathering all this information, doctors hope to get a clearer picture of how heart transplant patients respond to aspirin. This knowledge is important because it could help them give better, more personalised care in the future. If they can identify patients for whom aspirin isn't working as well, they might be able to adjust their treatment to keep them healthier and reduce the risk of serious problems like strokes.

Key takeaways

Aims to understand aspirin's effectiveness in heart transplant patients.
Checks for 'aspirin resistance' using a special blood test.
Focuses on patients already taking aspirin after their transplant.
Could help doctors give better care to heart transplant patients.
Eligible participants are adults (18+) who have had a heart transplant.
You would continue your usual aspirin treatment.

Who may be eligible?

To be part of this study, you need to be an adult, 18 years old or older, who has had a heart transplant. The study is open to both men and women.

Basically, if you're an adult who has received a new heart and you're taking aspirin, you might be able to take part. There aren't any other specific health conditions mentioned that would stop you from joining, but the research team will check all your details carefully.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you 18 years old or older?
Have you had a heart transplant?
Are you currently taking aspirin as prescribed by your doctor?
Are you willing to have blood tests as part of the study?

Answer every question to see your result.

What does participation involve?

This study is considered a 'Phase IV' study. This typically means it’s looking at a medicine (in this case, aspirin) that is already approved and used by many people. Your involvement would likely primarily focus on assessing how well your aspirin is working through blood tests. There might be one or more clinic visits where blood samples are taken. They will be checking for 'aspirin resistance,' which means seeing how your blood reacts to the aspirin you're already taking. You wouldn't be given a new or experimental medicine in this study; you would continue with your current aspirin dose. The research team would also collect information about your general health, such as your age, sex, and other medical conditions you might have. The total duration would depend on the study design, but Phase IV studies often involve fewer visits than earlier phases.

Potential risks and benefits

Potential benefits from taking part might include a deeper understanding of how your body responds to aspirin after your heart transplant. This information could eventually help doctors improve treatment for other heart transplant patients. As for risks, taking part in a study always carries some. The main risk would likely be discomfort or bruising from blood draws, which are common and usually minor. You are always free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

—
Unverified
Austria

Common questions

What is 'aspirin resistance'?

Aspirin resistance means that the aspirin you're taking isn't working as well as expected to prevent blood clots in your body.

Will I have to stop taking my aspirin for this study?

No, you will continue with your current aspirin treatment as prescribed by your doctor. This study is about checking how well it's working.

What kind of tests will I have?

You'll most likely have blood tests to see how your blood reacts to aspirin. They'll also collect some general health information.

Is this a new medicine?

No, this study is looking at aspirin, which is a medicine already in use. It's not testing a brand-new drug.

Who can join this study?

Adults aged 18 and over who have had a heart transplant are eligible to take part in this study.