We read with great interest the study by Cheng et al1 on cardiac troponin I (cTnI) surveillance integrated with symptom-based triaging in patients receiving immune checkpoint inhibitors (ICIs). Although the investigation provides important insights, several issues warrant further reflection.
First, the feasibility of this protocol is tightly bound to the presence of an institutional cardio-oncology response team. Although this structure is attainable at a tertiary referral center, most cancer care worldwide is delivered in settings that may lack this type of real-time expertise. Here, an isolated troponin elevation may serve as little more than a nonspecific trigger, and without expert interpretation, the result could lead to overtriage, unnecessary downstream testing, and inefficient use of limited resources.2 Future studies should therefore evaluate scalable models of care to make such surveillance practical beyond highly specialized centers.
Second, the study’s reliance on cTnI as the sole surveillance biomarker warrants closer scrutiny. The choice between cardiac troponin isoforms is not trivial and carries important clinical implications in the setting of immune-related adverse events. High-sensitivity troponin T may be elevated in patients with immune-related myositis, which frequently co-occurs with myocarditis, potentially leading to false positives. Conversely, cTnI may better reflect acute cardiac injury, yet reports exist in which cTnI remained normal despite evidence of myocardial inflammation while cardiac troponin T rose.3 These observations suggest that cardiac troponin T could be more sensitive in detecting disease reactivation, particularly during ICI rechallenge. A comprehensive surveillance strategy may therefore require a multibiomarker panel to differentiate myocarditis from myositis and to capture the full spectrum of immune-related cardiotoxicity.
Third, the 2-year follow-up period is insufficient to assess late toxicities. There can be delayed cardiac adverse events, including progressive heart failure and fibrosis.4 More concerning are reports of myocarditis recurrence even after the discontinuation of ICIs, suggesting the possibility of persistent subclinical inflammation.5 These long-term risks highlight the need for extended follow-up.
Finally, the value of surveillance lies not only in detecting myocarditis early but also in preventing high-cost complications. Formal cost-effectiveness analyses using established metrics are needed to justify routine implementation.
Footnotes
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
References
- 1.Cheng E., Ivanovic M., Chan A., et al. Cardiac troponin screening and clinical outcomes in patients receiving immunotherapy. JACC CardioOncol. 2025;7(6):708–721. doi: 10.1016/j.jaccao.2025.06.009. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Jacobs L.A., Shulman L.N. Cardio-oncology care delivery for all patients with cancer within academic and community settings. JACC CardioOncol. 2024;6(3):470–472. doi: 10.1016/j.jaccao.2023.10.010. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Barac A., Wadlow R.C., Deeken J.F., deFilippi C. Cardiac troponin I and T in ICI myocarditis screening, diagnosis, and prognosis. JACC CardioOncol. 2024;6(5):804–807. doi: 10.1016/j.jaccao.2024.07.001. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Dolladille C., Ederhy S., Allouche S., et al. Late cardiac adverse events in patients with cancer treated with immune checkpoint inhibitors. J Immunother Cancer. 2020;8 doi: 10.1136/jitc-2019-000261. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Bailly G., Robert-Halabi M., Vion P.A., et al. Rechallenge after severe immune checkpoint inhibitor myocarditis: venturing into the unknown. JACC CardioOncol. 2025;7(3):300–304. doi: 10.1016/j.jaccao.2025.02.004. [DOI] [PMC free article] [PubMed] [Google Scholar]