Cardiac monitoring during adjuvant trastuzumab therapy: Guideline adherence in clinical practice.

BACKGROUND: Cardiotoxicity is an important adverse effect of adjuvant breast cancer treatment with trastuzumab and three monthly left ventricular ejection fraction (LVEF) monitoring is considered mandatory. The purpose of this study was to gain insight into LVEF monitoring during adjuvant trastuzumab treatment in clinical practice. MATERIAL AND METHODS: In a multicenter retrospective study encompassing 328 patients, of which 171 patients were actually treated with trastuzumab, we analyzed the frequency and mode of LVEF monitoring and compared it with LVEF monitoring guidelines. RESULTS: The results indicated poor guideline adherence. In 9% of patients trastuzumab was started in spite of a low LVEF (< 55%). In 24% of patients no valid baseline LVEF value was available. LVEF measurements during treatment at three, six and 12 months were only performed in, respectively, 53%, 40% and 30% of patients. CONCLUSION: A significant proportion of patients are treated with trastuzumab, while LVEF monitoring is not adequately performed. More attention should be paid to the implementation of (cardiac assessment) guidelines in clinical practice.