RecruitingOBSERVATIONAL

Differential Regulation of RAAS-axis in Patients Undergoing Cardiac Surgery

This study is investigating differences in hormone levels during heart surgery. Specifically, we're looking at a group of hormones called the RAAS-axis that help control blood pressure. When people have heart surgery, sometimes their blood vessels relax too much, leading to low blood pressure, a condition called vasoplegia. There are two main types of heart bypass surgery: 'on-pump' where a heart-lung machine takes over, and 'off-pump' where the heart continues to beat. We want to understand if using the heart-lung machine changes these hormone levels, and if that could explain why some patients develop vasoplegia after surgery. By understanding this better, doctors hope to improve care for patients undergoing heart surgery.

At a glance

Status

Recruiting

Sponsor

Universität Münster

Enrolment target

Start

24 Aug 2023

Estimated completion

01 Aug 2025

Vasoplegia Vasoplegic Shock

What is this study about?

When people need certain heart surgeries, like a bypass, doctors sometimes use a special machine called a heart-lung machine. This machine temporarily takes over the job of circulating blood and adding oxygen to it, allowing the surgeons to operate on a still heart. This is known as 'on-pump' surgery. Another way to do it is 'off-pump' surgery, where the heart continues to beat during the operation.

A common issue that can happen after heart surgery is called vasoplegia. This is when your blood vessels become too relaxed, leading to a sudden drop in blood pressure. It can be quite serious. Your body has a complex system of hormones, often called the RAAS-axis, that plays a big role in controlling your blood pressure and how tense your blood vessels are. The lungs are actually quite important in activating some of these hormones.

This study is trying to understand if using the heart-lung machine during 'on-pump' surgery changes how these important hormones behave, compared to 'off-pump' surgery. Researchers believe that bypassing the lungs with the machine might affect these hormone levels, and this could be a reason why some patients develop vasoplegia. By studying these hormone differences, doctors hope to learn more about what causes vasoplegia and how to better prevent or treat it for people having heart surgery.

Key takeaways

This study explores why some patients experience low blood pressure (vasoplegia) after heart surgery.
It compares hormone levels in patients having 'on-pump' vs. 'off-pump' heart bypass surgery.
The research aims to understand if using a heart-lung machine affects these hormone levels.
Participation involves giving extra blood samples during and after your surgery.
The study does not involve new medicines or changes to your treatment.
Findings could help improve care for future heart surgery patients.

Who may be eligible?

To be part of this study, you must be an adult patient having coronary artery bypass graft surgery. This means you'll be having a common type of heart bypass operation. You also need to be able to understand the study and agree to take part by signing a consent form.

There are several reasons why you might not be able to join the study. These include if you need emergency surgery for a sudden heart problem, or if you're taking certain blood pressure medicines (like ACE-inhibitors or AT1-receptor blockers) that weren't stopped on the day of your surgery. You also can't participate if you have severe kidney disease, serious long-term lung conditions like severe emphysema or lung fibrosis, or ongoing high blood pressure in your lungs.

Additionally, pregnant or breastfeeding women cannot join. If you are dependent on the researchers or work for the institution conducting the study, or if you are in an institution by a legal order, you also wouldn't be eligible. The study is open to both men and women aged 18 and older.

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 an adult aged 18 or over?
Are you having a coronary artery bypass graft (heart bypass) surgery?
Do you have severe kidney disease or serious long-term lung problems?
Are you currently pregnant or breastfeeding?
Are you taking specific blood pressure medications that were not stopped before surgery?

Answer every question to see your result.

What does participation involve?

The study involves collecting blood samples at specific times during and after your heart surgery. These samples will be used to measure the levels of certain hormones related to blood pressure. There are no additional visits beyond your standard surgical care and recovery. You will not receive any new or experimental medications as part of this study; it's purely observational, meaning we are just monitoring and taking measurements. Your participation will last for a short period around the time of your surgery and initial recovery.

Potential risks and benefits

A potential benefit of joining this study is helping doctors understand more about why some people get low blood pressure after heart surgery. This knowledge could lead to better ways of caring for future patients. The main risk involves the extra blood samples taken, which might cause minor discomfort, bruising, or a small risk of infection at the needle site, similar to any routine blood test. Your standard medical care will not be affected. You are free to withdraw from the study at any time without any impact on your medical treatment.

Locations (2)

Deutsches Herzzentrum der Charité
Verified postcode
Berlin, Germany· Recruiting
University Hospital Münster; Department of Anesthesiology, Intensive Care Medicine and Pain Medicine
Verified postcode
Münster, Germany· Recruiting

Common questions

What is vasoplegia?

Vasoplegia is when your blood vessels relax too much, causing your blood pressure to drop significantly. It can happen after heart surgery.

What's the difference between 'on-pump' and 'off-pump' surgery?

'On-pump' uses a heart-lung machine during surgery, while 'off-pump' means your heart keeps beating without the machine.

Will I receive new medicines in this study?

No, this study is just observing and taking measurements. You will not receive any new or experimental medications.

How many extra blood samples will be taken?

Extra blood samples will be taken at specific times during and after your surgery for research purposes.

Can I leave the study if I change my mind?

Yes, you can choose to leave the study at any time without it affecting your medical care.

How to find out more

Alexander Zarbock, MD

aki@anit.uni-muenster.de +492518347255 Official trial record

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