Targeted therapies alone or combined with chemotherapy have improved response rates as well as the progression-free survival and overall survival in several solid tumors. Trastuzumab is a monoclonal antibody with a revolutionary effect on tumoral breast cells, but also on the myocardium, as has been identified recently, following the inherent cascade signaling shared between both cells. Instead of decreasing the use of trastuzumab, investigations based on the results of Metastatic and Adjuvant Breast Cancer Trials tend to develop monitoring schemes as well as risk factor identification and prophylactic applications in order to improve the number of patients receiving full treatment instead of restricting it. Moreover, the largely reversible trastuzumab effect (different from anthracyclines) allows its reintroduction or its later withdrawal with cardiologic directed therapy. In conclusion, every action is aiming at optimizing trastuzumab's application instead of abandoning.