B76
The clinical feasibility of assessing cardiac function in patients receiving trastuzumab for the adjuvant treatment of breast cancer
Pavandeep Ghataorhe, Roberto Alonzi
1Hammersmith Hospital, Imperial College, London, UK, 2Mount Vernon Cancer Centre, London, UK
Background
A meta-analysis of adjuvant trastuzumab demonstrated an absolute increased risk of grade III/IV cardiac toxicity of 1.6%. The National Institute of Clinical Excellence (NICE) has provided guidance on assessing and managing cardiac function during trastuzumab therapy. This study assessed the feasibility, adherence to and outcome of these guidelines in routine clinical practice.
Method
Data were collected retrospectively from clinical records of patients that received adjuvant trastuzumab between August 2006 and May 2008. The following NICE assessment criteria were evaluated using descriptive statistics: Cardiac function should be assessed prior to commencing therapy; Trastuzumab should not be offered if the left ventricular ejection fraction (LVEF) ≤ 55%, or with significant cardiovascular disease; Cardiac functional assessments should be 3 monthly; If LVEF drops by ≥10% from baseline or to <50%, trastuzumab should be suspended.
Results
74 patients were included. 83.8% had baseline LVEF assessment prior to commencing trastuzumab. Cardiac function was assessed by MUGA (83.8%) and echocardiogram (16.3%), with an average of 3.8 scans per patient (range 1-9). Trastuzumab was commenced according to guidelines (i.e.LVEF>55%) in 88.7% of patients with baseline cardiac assessment. For patients without baseline assessment, 66.7% commencing trastuzumab had LVEF >55% (using first available scan). Cardiac assessments were conducted at suitable intervals in 71.6% patients. 31.3% patients experienced a drop in LVEF of ≥10% from baseline or to <50%. In patients with baseline LVEF>55%, LVEF dropped in 28.6% compared with 45.5% for those with baseline LVEF ≤55%. One patient with baseline LVEF <55% had lasting symptomatic cardiac failure.
Conclusion
There is considerable variability in cardiac functional assessments for adjuvant trastuzumab. Reasons include test availability, compliance and clinical judgement. Patients with a baseline LVEF of ≤55% were more likely to experience a drop in LVEF requiring suspension of therapy. Overall, guidelines appear feasible and provide clear boundaries for clinical decisions.
