Detection of Profound Myocardial Damage by Cardiac MRI in a Patient with Severe Cardiotoxicity Induced by Anti-HER2 Therapy.

Anti-HER2 therapy has greatly improved the long-term prognosis of patients with HER2-positive breast cancer. Meanwhile, by interfering with the protective effects of neuregulin-1/HER2 signaling on stressed cardiomyocytes, anti-HER2 therapy occasionally induces reversible cancer therapeutics-related cardiac dysfunction (CTRCD). Cardiac magnetic resonance (CMR) parametric mapping or myocardial feature-tracking, in combination with late gadolinium enhancement (LGE) imaging, has the potential to detect changes in the myocardium in anti-HER2 therapy-related cardiac dysfunction. Here we report a breast cancer patient who experienced life-threatening CTRCD after treatment with trastuzumab plus pertuzumab. This case showed multiple transmural LGE-positive myocardial lesions in CMR imaging and high native T1 and T2 values in CMR parametric mapping, which was apparently more extensive than those observed in most patients with anti-HER2 therapy-related cardiac dysfunction. Consistent with profound myocardial damage indicated by CMR, her cardiac function was not fully restored despite intensive care and cardioprotective drug therapy. These findings suggest the potential usefulness of LGE imaging and parametric mapping by CMR for the assessment of myocardial injury to determine the clinical severity of anti-HER2 therapy-related cardiac dysfunction.