Mike: Hello, I'm Mike Clarke, podcast editor for the Cochrane Library. The Cochrane Heart Group’s reviews cover a very wide range of topics, including several relevant to cardiac surgery. In March 2024, their review of using prophylactic corticosteroids for cardiopulmonary bypass was updated. In this podcast, Carla Lucarelli from Imperial College London speaks with new lead author, Riccardo Abbasciano from the University of Leicester in the UK about this latest version of the review.

Carla: Hi Riccardo, thanks for joining us today. Let’s begin with why it was important to update this review for patients having cardiac surgery.

Riccardo: Hi Carla, thanks for having me. The use of steroids is still a fiercely debated topic in the cardiac surgery world and since the previous version, in 2011, several high quality, large trials have been published. This has changed the evidence base for the use of this class of drugs in clinical practice.

Carla: That’s interesting. So, what is the role of corticosteroids in the adult cardiac surgery setting?

Riccardo: Corticosteroids have been a promising drug for some time because of their effect to counteract inflammation. This is our body’s response to trauma, infection, and stress, and it’s common during and after a cardiac operation, in which we often use a heart-lung machine. Redirecting the blood flow to the machine can lead to an excess of inflammation, which might damage the heart itself but also the other organs, such as the lungs and kidneys. Corticosteroids are used in many other settings to reduce this type of response and might, therefore, have a role in preventing these injuries in patients having cardiac surgery.

Carla: And do they work as expected?

Riccardo: It’s tricky to give a clear answer, hence why this review was so important, and why we needed to update it with the recent research in adults.

Carla: Great! So how did you proceed to look for an answer to this tricky question?

Riccardo: First of all, we built a large team of researchers, with the support of the UK Society of Cardiothoracic Surgery, which supervised the initiative. Then, we were guided by Cochrane Heart and Cochrane Central who helped us to do this rigorous update, which now includes 72 studies with approximately 17000 participants. We just looked at adult patients, because although steroids also have a role in congenital and pediatric cardiac surgery, that’s very much a different context and is the topic of another review.

Carla: Of course! What kind of studies did you find?

Riccardo: Almost 90% of the randomised trials we assessed were done in patients undergoing low risk, first time coronary bypass grafting or valve surgery. These are the most common procedures performed in the world, so very relevant to everyday practice. However, there are some problems with the studies and very few, just four, managed to effectively reduce problems linked to the potential for bias.

Carla: I know that bias is a problem in many reviews and can affect the certainty of the results, which we’ll move onto now. What did you find?

Riccardo: As I mentioned, we did not come up with clear-cut answers. It seems as though corticosteroids may not reduce mortality around the time of the operation and there could be an increase in the risk of damage to the heart. However, the certainty of this finding is low, and there are issues related to how the damage was measured across the different studies. On the other hand, steroids might reduce damage to the lung, but again, the certainty of the finding is low.

Carla: That’s quite a challenging and conflicting set of results!

Riccardo: Indeed! There were also other effects that we had a look at. We could see a reduction in infection, a very small decrease in gastrointestinal bleeding and kidney damage, and possibly a reduction in the time spent in the hospital after the operation. Again, though, this comes with a lot of caution because the certainty of these findings is low or very low.

Carla: That’s a lot to take in. I suppose there are more details in the review itself.

Riccardo: Certainly. The review also explores whether the effects were different in specific settings, operations or group of patients. I would really encourage everyone interested to read it.

Carla: Thanks Riccardo. To finish then, and with that in mind, where can people get hold of the review?

Riccardo: Thanks Carla. It’s online at cochranelibrary.com and can be found with a search for “steroids and adult cardiac surgery”.