myocardial dysfunction in breast cancer patients receiving chemotherapy, and future studies are needed to determine its prognostic and therapeutic implications. 408 COMBINED THREE-DIMENSIONAL MYOCARDIAL STRAIN AND NON-CONTRAST TISSUE MAPPING BY CARDIAC MAGNETIC RESONANCE IMAGING IDENTIFIES EARLY CARDIOTOXICITY IN PATIENTS RECEIVING ANTHRACYCLINE-BASED CHEMOTHERAPY A Satriano, Y Mikami, B Blume, NA Nixon, C Sheppard, J Chartrain, AG Howarth, CP Lydell, B Heydari, JD McMeekin, D Stewart, J Henning, NM Fine, B Clarke, JA White Calgary, Alberta BACKGROUND: Up to 20% of cancer survivors may be affected by cardiotoxicity, a chronic disease associated with elevated mortality. While surveillance strategies are engaged during chemotherapy, current practice relies on significant drops in left ventricular ejection fraction (LVEF), a point where myocardial injury has already occurred. In this study we investigate the feasibility and preliminary findings of a non-contrast MRI protocol in patients receiving Anthracycline-based chemo- therapy aimed at validating upstream markers of cardiotoxicity that are evident prior to significant reductions in LVEF. METHODS: Nineteen patients planned for Anthracycline-based chemotherapy (14 Breast cancer and 5 Lymphoma) were recruited. Cardiac magnetic resonance (CMR) imaging was performed at baseline, 3 and 6-months using a protocol in- clusive of multi-planar cine imaging and short-axis T1 map- ping. T1 maps, LV volumes, and LV mass were quantified using commercially available software (cvi 42 , Circle Cardio- vascular Imaging Inc, Calgary Canada). Three-dimensional strain analysis was performed using custom in-house software (GIUSEPPE) using a 4D feature tracking algorithm. Global and segmental values for principal, circumferential, radial and longitudinal strain, strain rate (SR) and time to peak (TTP) strain were calculated. RESULTS: The mean age was 49.0Æ12.3 years with 16 (84%) being female. Cumulative Anthracycline dose exposure at 6 months was 534Æ120 mg/m 2 . The mean baseline LVEF was 61.3Æ5.6% with no significant reduction at 6 months (-3.5Æ8.8%, p¼0.14). Both LVEDV and LVESV indexed to BSA showed significant elevations at 6 months (13.1Æ16.1%, p¼0.0015, and 12.8Æ23.1%, p¼0.0050, respectively). Sig- nificant reductions (p<0.05) were identified in global strain for circumferential and longitudinal directions at 6 months along with corresponding elevations in longitudinal, minimum prin- cipal and maximum principal TTP strain. SR was significantly reduced at 6 months for circumferential (p¼0.0002), longitu- dinal (p¼0.0003), radial (p¼0.021), minimal principal (p¼0.002) and maximal principal (p¼0.007) directions (Figure 1). Segmental analysis showed geographic reductions in strain measures, as shown in figure 1. Non-contrast T1 rose signifi- cantly at 6 months (5.5Æ8.9%, p¼0.03) without alteration in T2 values (1.3Æ5.9%, p¼0.41). CONCLUSION: Cardiac MRI revealed significant alterations in LV volumes, myocardial strain and myocardial T1 over the first 6 months of Anthracycline exposure despite no appre- ciable change in the LVEF. These findings suggest tissue injury and adverse remodelling occurs prior to an overt reduction in conventional parameters of global systolic func- tion. The utility of cardiac MRI for cardiotoxicity surveillance in this population warrants further investigation. 409 MYOCARDIAL 2D STRAIN AND STRESSES INDICES IN THE DETECTION OF CARDIOTOXICITY IN CANCER SURVIVORS M Aissiou, F Cheriet, D Curnier, M Friedrich, C Laverdiere, G Andelfinger, M Krajinovic, D Sinnett, D Perie Montréal, Québec BACKGROUND: Doxorubicin-based chemotherapy is an effec- tive treatment for cancer, however its successes are hindered by its alterations of myocardial physiology at multiple stages. From molecular scale up to morphological and functional scale, the induction of multiple cardiotoxicities is reported. Accurate estimation of myocardial strains and stresses requires accurate tracking of myocardial displacements. However, the heart is relatively complex to track since it has much fewer Abstracts S299