ERBB2 and breast cancer: The SAFE-HeaRt (Cardiac Safety Study in Patients With HER2+ Breast Cancer) trial, which enrolled HER2-positive patients with asymptomatic LV dysfunction (LVEF 40%-49%) who were candidates for trastuzumab, pertuzumab, or trastuzumab emtansine,13 demonstrated that it is safe to use HER2-targeted therapies in select asymptomatic patients with LV dysfunction.