Immune Checkpoint Inhibitor-Associated Myocarditis Mimicking Takotsubo Cardiomyopathy.
[BACKGROUND] Pembrolizumab-induced myocarditis is a rare but life-threatening immune-related adverse event.
APA
Hiromasa S, Ueda Y, et al. (2026). Immune Checkpoint Inhibitor-Associated Myocarditis Mimicking Takotsubo Cardiomyopathy.. JACC. Case reports, 31(2), 106131. https://doi.org/10.1016/j.jaccas.2025.106131
MLA
Hiromasa S, et al.. "Immune Checkpoint Inhibitor-Associated Myocarditis Mimicking Takotsubo Cardiomyopathy.." JACC. Case reports, vol. 31, no. 2, 2026, pp. 106131.
PMID
41240046
Abstract
[BACKGROUND] Pembrolizumab-induced myocarditis is a rare but life-threatening immune-related adverse event.
[CASE SUMMARY] A 72-year-old woman with stage IV EGFR exon 19 deletion-positive left lung adenocarcinoma received osimertinib as first-line therapy. After disease progression, she underwent pembrolizumab plus pemetrexed-carboplatin as second-line therapy, then docetaxel plus ramucirumab as third-line therapy. She presented with nausea and anorexia, and electrocardiograms revealed widespread ST-segment elevation. Coronary angiography revealed no significant stenosis; left ventriculography revealed an apical ballooning pattern. Although Takotsubo cardiomyopathy was suspected, endomyocardial biopsy confirmed pembrolizumab-induced myocarditis. High-dose corticosteroids improved her cardiac function; however, the underlying malignancy progressed.
[DISCUSSION] Immune checkpoint inhibitor-associated myocarditis can mimic atypical Takotsubo cardiomyopathy, with persistent changes on electrocardiograms or elevated biomarkers, warranting endomyocardial biopsy for diagnosis and treatment with steroids.
[TAKE-HOME MESSAGE] In patients receiving immune checkpoint inhibitors, consider myocarditis in atypical Takotsubo presentations; biopsy and early steroids improve outcomes.
[CASE SUMMARY] A 72-year-old woman with stage IV EGFR exon 19 deletion-positive left lung adenocarcinoma received osimertinib as first-line therapy. After disease progression, she underwent pembrolizumab plus pemetrexed-carboplatin as second-line therapy, then docetaxel plus ramucirumab as third-line therapy. She presented with nausea and anorexia, and electrocardiograms revealed widespread ST-segment elevation. Coronary angiography revealed no significant stenosis; left ventriculography revealed an apical ballooning pattern. Although Takotsubo cardiomyopathy was suspected, endomyocardial biopsy confirmed pembrolizumab-induced myocarditis. High-dose corticosteroids improved her cardiac function; however, the underlying malignancy progressed.
[DISCUSSION] Immune checkpoint inhibitor-associated myocarditis can mimic atypical Takotsubo cardiomyopathy, with persistent changes on electrocardiograms or elevated biomarkers, warranting endomyocardial biopsy for diagnosis and treatment with steroids.
[TAKE-HOME MESSAGE] In patients receiving immune checkpoint inhibitors, consider myocarditis in atypical Takotsubo presentations; biopsy and early steroids improve outcomes.