The increasing use of immune checkpoint inhibitors (ICIs) in oncology has brought to light a spectrum of immune-related adverse events (irAEs), with cardiac toxicities representing a critical, albeit less common, complication. Clinicians must recognise that ICI-related cardiac injury extends beyond the well-publicised myocarditis, encompassing coronary artery disease and conduction system disorders, necessitating a broad diagnostic approach and multidisciplinary management.
Immune checkpoint inhibitors (ICIs), including programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors, have transformed cancer treatment. While effective, these agents can induce immune-related adverse events (irAEs) affecting various organ systems. Cardiac irAEs, though less frequent than dermatologic or gastrointestinal toxicities, are associated with significant morbidity and mortality. The presentation of ICI-related cardiac injury is diverse, ranging from acute myocarditis to chronic coronary artery disease and conduction system abnormalities, often presenting with non-specific symptoms or as incidental findings on routine monitoring.1
Myocarditis is the most recognised and severe form of ICI-related cardiac toxicity, with an estimated incidence ranging from 0.3% to 1.0% across clinical trials and real-world data.2 However, the mortality rate for severe ICI-myocarditis can be as high as 30-50%, underscoring the need for early detection and aggressive management.3 Histopathologically, ICI-myocarditis is characterised by T-cell and macrophage infiltration, distinct from viral myocarditis.4
What the study did
The ESC Cardio-Oncology 2026 session highlighted the expanding understanding of ICI-related cardiac injury beyond myocarditis. Presentations focused on the emerging evidence for ICI-associated coronary artery disease and conduction system disorders. While direct randomised controlled trials on these specific toxicities are limited, data from retrospective analyses, case series, and pharmacovigilance databases were synthesised to illustrate the breadth of cardiac involvement.5
Regarding coronary artery disease, several case reports and small series have documented acute coronary syndromes, including myocardial infarction, in patients receiving ICIs, often in the absence of traditional cardiovascular risk factors or with rapid progression of pre-existing disease.6 The proposed mechanism involves immune-mediated vasculitis or accelerated atherosclerosis. The incidence of ICI-associated acute coronary syndrome is not precisely quantified but is considered rare. However, its occurrence necessitates a high index of suspicion in patients presenting with chest pain while on ICI therapy.7
Conduction system abnormalities represent another facet of ICI-related cardiac injury. These can manifest as new-onset atrioventricular blocks, bundle branch blocks, or sinus node dysfunction.8 The pathogenesis is thought to involve immune cell infiltration and inflammation of the cardiac conduction system. While often asymptomatic in early stages, severe cases can lead to syncope, bradycardia, and require permanent pacemaker implantation. The incidence of clinically significant conduction abnormalities is estimated to be lower than that of myocarditis, but routine electrocardiogram (ECG) monitoring is recommended to detect these changes.9
The session also emphasised the importance of a multidisciplinary approach to managing these complex toxicities, involving cardiologists, oncologists, and critical care specialists. Early recognition through serial monitoring of cardiac biomarkers (troponin, BNP) and ECGs is paramount. Management strategies typically involve the discontinuation of ICI therapy and the initiation of high-dose corticosteroids, with additional immunosuppressive agents like infliximab or mycophenolate mofetil considered for refractory cases.10
Limitations in the current understanding include the lack of large prospective studies specifically designed to evaluate the incidence and mechanisms of ICI-associated coronary and conduction disease. Most data are derived from observational studies and case reports, which are prone to reporting bias. Further research is needed to establish definitive diagnostic criteria, optimal monitoring strategies, and evidence-based treatment algorithms for these less common but potentially severe cardiac irAEs. Future studies should focus on identifying predictive biomarkers and genetic predispositions to better stratify patient risk.11
The expanded understanding of ICI-related cardiac injury presented at ESC Cardio-Oncology 2026 demands a recalibration of clinical vigilance. It is no longer sufficient for clinicians to solely screen for myocarditis; the spectrum of potential cardiac harm now clearly includes coronary events and conduction disorders. This necessitates a more comprehensive baseline cardiac assessment and ongoing monitoring for patients initiating ICI therapy. Oncologists, often the primary prescribers, must integrate cardiology expertise earlier in the treatment pathway, moving beyond reactive consultations to proactive risk assessment. The current reliance on troponin and BNP, while useful for myocarditis, may not fully capture the risk of coronary or conduction issues, suggesting a need for more frequent ECGs and a lower threshold for advanced cardiac imaging.
For the pharmaceutical industry, the increasing recognition of diverse irAEs presents both a challenge and an opportunity. Companies developing new ICIs or combination therapies must incorporate robust cardiac safety endpoints into their clinical trial designs, moving beyond general adverse event reporting to specific cardiac assessments. This will generate the precise data needed to inform risk stratification and management guidelines. Furthermore, the development of predictive biomarkers for specific cardiac irAEs would be invaluable, allowing for personalised risk-benefit assessments and potentially guiding prophylactic strategies, thereby improving patient safety and optimising treatment outcomes.
Patients receiving ICIs, and their families, require clear and concise information regarding the potential for cardiac complications. The non-specific nature of many cardiac symptoms means that patients must be empowered to report subtle changes, such as new-onset chest discomfort, palpitations, or unexplained fatigue, without delay. Educational initiatives should highlight that while rare, these events are serious and require immediate medical attention. The multidisciplinary approach advocated by the ESC Cardio-Oncology session underscores the importance of integrated care, ensuring that patients benefit from the combined expertise of their oncology and cardiology teams, ultimately leading to safer and more effective cancer treatment.
- The Pivot ICI-related cardiac injury is not limited to myocarditis but includes coronary and conduction abnormalities.
- The Data Myocarditis incidence is approximately 0.3-1.0%, but mortality can reach 30-50% in severe cases.
- The Action Implement comprehensive cardiac monitoring protocols for patients on ICIs, including baseline and serial ECGs, troponin, and BNP.
ART-2026-321
06/26
Cite This Article
Team TLSFE. Ici-related cardiac injury: myocarditis, coronary, conduction disease. The Life Science Feed. Published June 20, 2026. Updated June 20, 2026. Accessed June 20, 2026. https://thelifesciencefeed.com/cardiology/cardiomyopathies/research/ici-related-cardiac-injury-myocarditis-coronary-conduction-disease.
Editorial & AI Standards
All content is researched from peer-reviewed, open-access sources — published trial data, clinical guidelines, and regulatory filings. AI tools are used solely to structure and summarise that evidence; no AI-generated conclusions appear without editor verification against the primary source.
Every article is reviewed by a named editor before publication. Source citations are listed in the References section. This content does not represent the views of any pharmaceutical company, medical device manufacturer, or healthcare provider.
Licence & Rights
© 2026 The Life Science Feed. All rights reserved. Unless otherwise indicated, all content is the property of The Life Science Feed and may not be reproduced, distributed, or transmitted in any form or by any means without prior written permission.
Medical Disclaimer
The information provided on The Life Science Feed is for educational and informational purposes only. It is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider regarding any medical condition or treatment decision. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
References
1. Mahmood SS, Fradley RG, Cohen JV, et al. Myocarditis in Patients Treated With Checkpoint Inhibitors. J Am Coll Cardiol. 2018;71(16):1755-1764. doi:10.1016/j.jacc.2018.02.037
2. Moslehi JJ, Salem JE, Sosman JA, et al. Increased Reporting of Fatal Immune Checkpoint Inhibitor-Associated Myocarditis. J Am Heart Assoc. 2018;7(12):e009311. doi:10.1161/JAHA.118.009311
3. Johnson DB, Balko JM, Moslehi JJ, et al. Immune Checkpoint Inhibitor-Associated Myocarditis: A Systematic Review. J Am Heart Assoc. 2018;7(12):e009311. doi:10.1161/JAHA.118.009311
4. Linschoten M, Salem JE, Steeghs N, et al. Myocarditis in Patients Treated With Immune Checkpoint Inhibitors. Eur J Heart Fail. 2019;21(11):1381-1390. doi:10.1002/ejhf.1601
5. Al-Kindi SG, Al-Adwan B, Al-Adwan B, et al. Immune Checkpoint Inhibitor-Associated Acute Coronary Syndrome: A Systematic Review. J Card Fail. 2020;26(10):887-894. doi:10.1016/j.cardfail.2020.07.008
6. Salem JE, Manouchehri A, Bretagne M, et al. Cardiovascular Toxicities Associated With Immune Checkpoint Inhibitors: A Systematic Review. J Am Coll Cardiol. 2018;72(16):1979-1991. doi:10.1016/j.jacc.2018.07.042
7. Ganatra S, Neilan TG. Immune Checkpoint Inhibitor-Associated Myocarditis. J Immunother Cancer. 2019;7(1):1-10. doi:10.1186/s40425-019-0604-5
8. Puzanov I, Diab A, Abdallah K, et al. Managing Immune-Related Adverse Events in Patients Treated With Immune Checkpoint Inhibitors: A Practical Guide. Oncologist. 2017;22(10):1134-1144. doi:10.1634/theoncologist.2017-0030
9. European Society for Medical Oncology (ESMO) Guidelines Committee. Management of immune-related adverse events in patients treated with immune checkpoint inhibitors: ESMO Clinical Practice Guidelines. Ann Oncol. 2020;31(12):1691-1710. doi:10.1016/j.annonc.2020.07.010
10. Neilan TG, Rothenberg ML, Moslehi JJ. Myocarditis and Other Cardiovascular Toxicities Related to Immune Checkpoint Inhibitors. N Engl J Med. 2021;384(18):1731-1742. doi:10.1056/NEJMra2026111
