Patients who develop signs and symptoms of congestive heart failure will be taken off treatment, but continued in the study for disease follow-up. Management of asymptomatic decreases in LVEF. Patients experiencing asymptomatic absolute decrease in LVEF < 20 percentage points from baseline, will continue on study as long as 1) the LVEF remains within the normal limits of the institution, and 2) their treating oncologist continues trastuzumab treatment. Patients with an asymptomatic decrease in LVEF of ≥ 20 percentage points (even if within the normal limits of the institution) or an ejection fraction below the range of normal limits, will be taken off treatment, but remain in the study for disease follow-up. Hematologic Toxicity and Neutropenic Infections. In prior clinical trials, an increased incidence of anemia was observed in patients receiving trastuzumab plus chemotherapy compared with patients receiving chemotherapy alone. The 18 Protocol: 2014-0443 Version 2.1 Version Date: 11 April 2016 majority of these anemia events were mild or moderate in intensity and reversible; none resulted in discontinuation of trastuzumab therapy. In the clinical trials, the per-patient incidences of moderate to severe neutropenia and of febrile neutropenia were higher in patients receiving trastuzumab in combination with myelosuppressive chemotherapy as compared to those who received chemotherapy alone. In the post-marketing setting, deaths due to sepsis in patients with severe neutropenia have been reported in patients receiving trastuzumab and myelosuppressive chemotherapy, although in controlled clinical trials (pre- and post-marketing), the incidence of septic deaths was not significantly increased. The pathophysiologic basis for exacerbation of neutropenia has not been determined. Secondary acute leukemia or myelodysplastic syndrome has been reported in 4 of approximately 1200 patients who participated in trastuzumab clinical trials. Patients treated with chemotherapeutic agents are known to be at increased risk for secondary leukemia. The observed incidence of leukemia among trastuzumab-treated patients appears to be consistent with the expected incidence of leukemia among patients treated with chemotherapy for metastatic breast cancer. Therefore, the contribution of trastuzumab to the etiology of acute leukemia or myelodysplastic syndrome in these cases is unclear. Management of Hematologic Toxicities.