What is the rate of a cardiac events that you quote to a patient with preexisting heart disease going on trastuzumab for metastatic Her2+ breast cancer?

I tell patients that it depends on their baseline risk factors and that some have reported rates as high as 25-28%. I discuss that if they have had prior anthracycline therapy, borderline baseline LVEF (50-54%), age > 65, and other cardiac risk factors like hypertension, that they could fall into this 25% group. These patients are excellent candidates for SWOG S1501 which is specifically enrolling high risk patients to 1) better define the risk of cardiac toxicity in patients at high risk for cardiac dysfunction and cardiac events and 2) evaluate the benefit of carvedilol for prevention of cardiac toxicity.