A study to prevent heart damage that some chemotherapy drugs for breast cancer and non-Hodgkin lymphoma can cause (PROACT)

This study showed that enalapril did not stop heart damage caused by anthracycline chemotherapy for breast cancer and non-Hodgkin lymphoma.

Results
The research team hoped that about 170 people would join this study. But they found it harder than they expected to find people to take part in this study. This was partly due to the COVID-19 pandemic. The research team agreed that at least 106 people would be needed for the study.

A total of 111 people took part in the study. They were put into 1 of 2 groups at random. There were:

• 56 people in the group who had enalapril and chemotherapy (enalapril group)
• 55 people in the in the group who had chemotherapy as usual (standard care group)

PROACT Study Diagram

The researchers were able to analyse the results for most people who took part.

They looked at the levels of cardiac troponin in the blood of people taking part, 1 month after anthracycline chemotherapy. 

They found cTnT was increased in:

• 42 out of 54 people (78%) in the enalapril group
• 45 out of 54 people (83%) in the standard care group

They also found that cTnI was increased in:

• 25 out of 53 people (47%) in the enalapril group
• 24 out of 53 people (45%) in the standard care group

The researchers looked at the cardiac function of people taking part. This means how well the heart works. They used an echocardiogram scan to check this.

First, they looked at how well the heart muscle works. They found it worked less well in:

• 10 out of 47 people (21%) in the enalapril group
• 9 out of 41 people (22%) in the standard care group

They also looked at how well the heart pumps blood. They found it was pumping less blood in:

• 2 out of 49 people (4%) in the enalapril group
• no one in the standard care group

The results from the tests and scans also showed that people in both groups had heart damage related to chemotherapy that did not give any symptoms. This was:

• 42 out of 49 people (86%) in the enalapril group
• 44 out of 48 people (92%) in the standard care group

Side effects
In total, 95 out of the 111 people (85%) had at least one side effect caused by the chemotherapy:

• 50 out of 56 people (89%) in the enalapril group
• 45 out of 55 people (82%) in the standard care group

21 out of 56 people (38%) had side effects related to enalapril. The most common were:

• a cough
• dizziness
• headaches
• low blood pressure
• feeling sick

9 people in the research group stopped taking enalapril before completing chemotherapy. This was because:

• 2 had a cough
• 2 had low blood pressure
• 4 couldn’t continue with chemotherapy
• 1 developed sudden swelling (angioedema)

Enalapril did not cause any serious side effects.

Conclusion
The study team concluded that adding enalapril to anthracycline chemotherapy for breast cancer and non-Hodgkin lymphoma did not stop heart damage.

Sometimes trials show a treatment to prevent side effects from chemotherapy isn’t useful. But these trials still add to our knowledge and understanding of the side effects of treatment.

More detailed information
There is more information about this research in the reference below. 

Please note, the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.

Preventing Cardiac Damage in Patients Treated for Breast Cancer and Lymphoma: The PROACT Clinical Trial
D Austin and others
Journal of the American College of Cardiology (JACC): CardioOncology, 2024. Volume 6, issue 5, pages 684-696.

Where this information comes from    
We have based this summary on the information in the article above. This has been reviewed by independent specialists (peer reviewed ) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active and the article is free and available to view.