These abstracts have been selected for presentation in 4 sessions throughout the meeting. Please refer to the PROGRAM for more details. BEST ORAL ABSTRACTSMain Sessions | Landtagssaal Friday May 16 | 09:45-10:45 1167 Metabolic profiling using ex-vivo proton magic angle spinning magnetic resonance spectroscopy (1H-MAS-MRS) detects myocardial injury in experimental autoimmune myocarditis (EAM)Recently, breathing maneuvers have been shown to be associated with a similar vascular response as seen with vasodilatory agents like adenosine. Yet, there has been no data on its potential diagnostic utility in the presence of coronary artery stenosis. In swine, we investigated whether hyperventilation followed by a long breath-hold can detect an abnormal regional response in the presence of coronary artery stenosis. Eighteen anaesthetized swine were prepared with a blood flow probe on the left anterior descending coronary artery (LAD) and a femoral arterial catheter. In ten of these animals, a significant stenosis of the LAD was created with a hydraulic occluder and quantified by measuring the fractional flow reserve (FFR).Background: The cardiovascular magnetic resonance (CMR) derived native myocardial T1 is decreased in patients with Anderson Fabry disease (AFD) even before left ventricular hypertrophy (LVH) occurs and may be a first non-invasive measure of myocyte storage. The relationship of native T1 lowering prior to hypertrophy to other candidate early phenotype markers and its reproducibility as a clinical test are unknown. Methods: sixty-three pts, 34 (54%) female, mean age 43 + 15 years with confirmed (genotyped) AFD underwent CMR, ECG and echocardiographic assessment. LVH was absent in 25 (40%) of the pts. Native T1 mapping was performed with both Modified Look-Locker Inversionrecovery(MOLLI)and ashortenedversion (Sh-MOLLI)sequences ona1.5 Tesla magnet. Twenty-one patients underwent a second scan later on the same day to assess inter-study reproducibility. Results were compared with 63 healthyvolunteersmatched for gender and age. Results: The mean native T1 in AFD (LVH+), (LVH-) and healthy subjects (HS) was 853 + 50ms, 904 + 46ms and 968 + 32ms (for all p , 0.0001), Figure 1. Native T1 assessment showed high inter-study, intra-observer and inter-observer agreement with intra-class correlation coefficients (ICC) of 0.99, 0.98, 0.97 (ShMOLLI) and 0.98, 0.98, 0.98 (MOLLI). In AFD LVH-individuals, low native T1 was associated with reduced echocardiographicbased global longitudinal speckle tracking strain (-19 + 2% vs -21 + 2%, p ¼ 0.036) and early diastolic function impairment (E/E'¼ 7[6-8] vs 5[5-7], p ¼ 0.045), Figure 2. Conclusion: Native T1 mapping in AFD is a reproducible technique. T1 reduction prior to the onset of LVH is associated with early diastolic and systolic changes measured by echocardiography.