Recognition of the cardiac effects of many immunotherapies has led to increasing attention to toxicity. A particular problem has been myocarditis. In this video, , director of cardio-oncology at Vanderbilt University in Nashville, talks about tests for detecting cardiotoxicity and the threshold for when oncologists should reach out to cardiologists.
Following is a transcript of his remarks:
As many people know, immunotherapies have revolutionized cancer therapy. But we and several investigators have shown that a small percentage of patients who get immunotherapies, especially when the drugs are used in combination, develop an inflammation of the heart called myocarditis, which can be detrimental, and fatal in some of the patients. We are working hard to understand what the incidence of this is. Our group at Vanderbilt is collaborating with the FDA, and when you use the drugs, immunotherapies, in combination, the incidence of myocarditis is about 1%.
The big question in the field now is trying to determine what the characteristics are of the patients who get immunotherapy-associated myocarditis -- better identifying who's at risk of developing myocarditis and forming preventive and potentially treatment protocols for these patients.
I think it's very important for the treating oncologist to be aware of this toxic effect, myocarditis, that can result from immunotherapies. One key issue for oncologists to remember is to have a high vigilance with respect to this presenting. Some of the important tests to consider for the oncologist include troponin, a biomarker that looks at myocardial damage, and electrocardiogram, which looks for arrhythmias -- which is how these myocarditis cases many times present -- and some form of imaging and/or possibly endomyocardial biopsy to help diagnose this.
Diagnosis is key. The most critical thing I would say with oncologists is identify a cardiologist who is interested in this area who treats cancer patients near you. Because you can reach out to them for help, and that's a critical message for the treating oncologists.
The threshold for identifying a cardiologist or reaching out for help to a cardiologist should be very low. Part of the reason we've created the website is for this ability to occur very quickly, where the treating oncologist sends information about the patient in a de-identified fashion, tells what the blood pressure is, and tells what the EKG looks like; there is at least then some help coming from a cardiologist, even though they may be thousands of miles away, in order to kind of say, "This is urgent." Reach out to a cardiologist and get the patients seen quickly.
That has hopefully facilitated that for the oncologist to be able to know which are the critical cases and which are not.
I actually think there's been enough educational possibilities for oncologists that they are actually becoming more and more aware of this. One thing we are trying to understand is whether there are other forms of cardiac complications other than myocarditis: Are there increased bread-and-butter heart attacks or heart failure that result from immunotherapies? I think it's really important for oncologists to be aware of cardiac complications from immunotherapies, and again, reach out for help as quickly as you can using the website or using a cardiologist near you for help.
One other thing to stress is that as a community we have to work together to better identify who's at risk of developing myocarditis as well as understanding better the mechanisms behind this toxicity. We are working on developing a number of preclinical models using laboratory models such as mice to better understand myocarditis, develop models that one can potentially use to test what are the key drugs that could help treat this condition. I think that will help later on in order to better inform the treating physician about how to treat this condition.