The Use of Shengmai San to Prevent Anthracycline Sequential Trastuzumab Therapy Related Cardiac Toxicity

This trial is testing whether Shengmai San — a traditional Chinese herbal formula — can protect the heart from damage caused by certain breast cancer treatments. Specifically, some chemotherapy drugs (anthracyclines) and the targeted therapy trastuzumab can reduce heart function over time. The study wants to see if this herbal medicine can prevent or reduce that cardiac side effect. **You may be eligible if...** - You have non-metastatic HER2-positive breast cancer (stages I to III) - You are planned to receive a chemotherapy regimen that includes anthracyclines followed by trastuzumab (with or without pertuzumab) - Your heart pumping function (ejection fraction) is at least 50% before starting chemotherapy - You are in good general health and able to follow the study plan **You may NOT be eligible if...** - You have heart disease classified as moderate or severe (NYHA Class II or above) - You have severe heart rhythm problems or other serious heart conditions - You are allergic to ginseng, Ophiopogon, or other ingredients in Shengmai San - There are medical reasons you cannot receive trastuzumab - You have conditions that would make the planned treatment unsafe Talk to your doctor to see if this trial is right for you.