INTRODUCTION: Although having high clinical efficacy in the treatment of human 
epidermal growth factor receptor-2 (HER2+) metastatic breast cancer, trastuzumab 
has been associated with cardiotoxicity, and the etiology and pathogenesis of 
this condition is currently under investigation.
METHODS: This paper reviews the cardiotoxicity, associated with trastuzumab use 
and discusses the risk assessment and management of cardiac dysfunction.
RESULTS: The increased risk of cardiotoxicity is lower when trastuzumab is given 
as monotherapy (3%-7%) compared with anthracyclines + trastuzumab therapy (27%). 
Type II cardiac changes occur in trastuzumab-treated patients, which do not 
appear to be dose-related, are not associated with histological changes, and are 
generally reversible. Several risk factors for cardiac events have been 
identified and assessing levels of troponin I and N-terminal pro-brain B-type 
natriuretic peptide before and after treatment with trastuzumab may allow early 
detection of cardiotoxicity. A symptomatic and functional evaluation scheme for 
patients indicated for treatment with trastuzumab has also been proposed to work 
alongside therapeutic options for the treatment of heart failure.
CONCLUSION: The risk of cardiac dysfunction associated with trastuzumab can be 
justified given the increase in overall survival. This risk is lower when 
trastuzumab is given as monotherapy. The paradigm for cardiologists remains the 
same: treat the cancer effectively whilst preventing cardiotoxicity.