Cardiotoxicity of BRAF/MEK Inhibitors Mimicking Apical Hypertrophic Cardiomyopathy

Cardio-oncology is a new and fast-evolving collaborative subdiscipline of cardiology whose goal is to increase the quality and length of the lives of oncological patients with precise prophylactic and therapeutical interventions. Novel targeted therapies present a challenge to recognize and treat rare adverse cardiovascular effects, usually without any evidence-based guidance. Therefore, scrupulous descriptions of clinical cases and drafting trials for real-world safety are paramount. We present a case of a 50-year-old Caucasian female who was diagnosed with cancer therapy-related cardiac dysfunction caused by combined BRAF and MEK inhibition in the treatment of malignant melanoma. The patient presented atypically with isolated severe fatigue without other specific cardiovascular symptoms. The findings of echocardiography and cardiac magnetic resonance indicated apical hypertrophic cardiomyopathy (AHCM), which is rare in our region. We stopped the oncological therapy and treated the patient with an ACE inhibitor, a beta-blocker, and an SGLT-2 inhibitor with a satisfactory effect. During the upcoming six months, the patient's state improved, and the control echocardiography ruled out an AHCM. As the patient's state rapidly improved after the withdrawal of BRAF and MEK inhibitors and the morphological finding was reversible, it can be theorized that the cardiotoxicity caused by the aforementioned drugs mimicked the phenotype of AHCM.