BACKGROUND: This article reports, the cardiac toxicity according to 6- versus 
12-month durations of adjuvant trastuzumab in PHARE randomised trial 
(NCT00381901).
PATIENTS AND METHODS: Cardiac follow-up and Left Ventricular Ejection Fraction 
(LVEF) assessment by echocardiography or multigated acquisition scan were 
performed every 3 months while patients received trastuzumab and after 
completion of treatment over the first 2 years and every 6 months afterwards. 
The primary cardiac end-point was Cardiac Heart Failure (CHF) defined as New 
York Heart Association (NYHA) class III or IV. The secondary cardiac end-points 
were: cardiac events, cardiac dysfunctions defined by NYHA class I and II; LVEF 
decreases, cardiac recoveries. The cardiac subcommittee reviewed cardiac events 
and assessed if patients had favourable outcomes or not on the basis of trends 
from LVEF measurements.
RESULTS: Among 3380 patients the cardiac dysfunction assessment included 14,055 
and 13,218 LVEF measurements in the 12- and 6-month arms. The overall incidences 
of CHF were 0.65% (11/1690) and 0.53% (9/1690) in the 12 and 6 month arms, 
respectively (p>0.05). Cardiac dysfunction occurred in 5.9% (100/1690) and 3.4% 
(58/1690) of patients in the 12 and 6 month arms, respectively (p=0.001). 
Recoveries were observed for the majority patients and 0.79% (27/3380) of 
patients experienced an unfavourable cardiac outcome.
CONCLUSION: PHARE confirm that the incidence of cardiac end-points remains low 
and mostly reversible after trastuzumab. Identification at baseline of cardiac 
risk categories of patients should be of interest to provide an optimal 
adaptation of adjuvant modalities and a shorter duration might be an option.