CONGRESS ABSTRACT

A 71-year-old man with a family history of dilated cardiomyopathy (CMD) and a history of dual-chamber pacemaker implantation for sick sinus syndrome was diagnosed with HER2-positive metastatic adenocarcinoma of the distal esophagus. He was selected for treatment with FOLOFOX chemotherapy (CT) and Trastuzumab. Due to the potential cardiotoxicity associated with the planned regimen, a preliminary cardio-oncology evaluation was performed revealing a significant left ventricular dysfunction (LVEF <30%). The patient was asymptomatic with laboratory results showing normal troponin and NTproBNP values. A subsequent coronary angiography demonstrated a chronic total occlusion of the proximal circumflex artery and moderate-to-severe stenosis in the mid-distal left anterior descending artery. Multidisciplinary discussions concluded that the patient's hypokinetic dilated cardiomyopathy, likely of mixed etiology (familial and ischemic), could complicate access to oncological therapy. Given the low likelihood of cardiac function recovery after percutaneous coronary intervention and the high hemorrhagic risk for the patient, a medical therapy-based strategy was recommended. The patient's cardioactive therapy was optimized following the "four pillars" approach for heart failure management. Due to the LVEF still < 35%, Trastuzumab was initially deferred, given the absence of safety data for its use in such cases. Instead, 75% of the planned dose of 5-fluorouracil was initiated under inpatient observation to monitor for potential coronary spasms and microvascular damage. After a month of optimized medical therapy, the LVEF was 36%. However, considering the potential prognostic impact of anti-HER2 therapy, initiating treatment with close laboratory and echocardiographic monitoring was decided. The patient subsequently completed six full-dose CT cycles alongside four Trastuzumab cycles. Follow-up CT scans revealed partial regression of the neoplasm. Subsequent serial cardiological reevaluation indicated significant clinical and functional improvements. The patient is now asymptomatic and hemodynamically stable, with normal NT-proBNP levels and last echocardiography shows decreased LV volumes and an improved LVEF of 46%. This case exemplifies the value of a multidisciplinary approach in managing a complex cardio-oncology patient, emphasizing the importance of careful monitoring and tailored interventions to address both oncological and severe cardiac conditions.