150 Imaging arrhythmias in congenital heart disease 11.6±7.7%, respectively. During 8 years of follow-up, 20 patients met the com- posite endpoint. Reduced global longitudinal and circumferential strain showed trends towards worse prognosis (HR 1.15/%, 95% CI 1.00–1.32 and 1.12/%, 95% CI 0.98–1.27). Reduced LS over the free wall was associated with adverse events (HR 1.15/%, 95% CI 1.04–1.28). In 35% of patients, free wall LS was >-12, which predicted poor prognosis (HR 5.31, 95% CI 2.09–13.50, p<0.001). Event-free survival by free wall strain Conclusion: Reduced longitudinal strain in the sRV free wall is associated with poor prognosis in patients with TGA. Currently, we are analyzing more patients to make our findings more robust. Acknowledgement/Funding: This work was supported by a grant from the Dutch Heart Foundation and was carried out in the context of the Parelsnoer Institute. P735 | BEDSIDE Utility of 18F-FDG PET/CT imaging in detecting aortic wall inflammation of adult patients after successful coarctation repair A.S. Antonopoulos 1 , S. Brili 1 , E. Oikonomou 1 , I. Cutajar 1 , N. Pianou 2 , G. Spyrou 2 , E. Athanasiadis 2 , A. Georgakopoulos 2 , P. Kafouris 1 , G. Siasos 1 , C. Anagnostopoulos 1 , D. Tousoulis 1 . 1 Hippokration General Hospital, 1st Cardi- ology Department, Athens Medical School, Athens, Greece; 2 Academy of Athens Biomedical Research Foundation, Athens, Greece Background: Inflammation is involved in the mechanisms of premature atherosclerosis development of patients with successful surgical repair of coarc- tation of aorta (SCR). The role of positron emission tomography/computed to- mography (PET/CT) imaging for evaluating aortic wall inflammation in subjects with SCR remains poorly explored. Purpose: To study aortic wall inflammation by PET/CT imaging in adult SCR patients and its associations with with systemic inflammation and arterial elastic properties. Methods: Eighteen subjects with SCR underwent evaluation of aortic wall inflam- mation by 18F-fluorodeocyglucose (FDG) PET/CT. Standardised uptake value and target to background ratio (TBR) for ascending (aorta AA, at the pre- coarctation site) and descending aorta (DA, at the post-coarctation site) were compared with that of 18 age- and sex-matched subjects undergoing PET/CT imaging for clinical purposes. SCR patients also underwent assessment of ar- terial elastic properties by Sphygmocor and measurement of plasma levels of interleukin-6 (IL-6), transforming growth factor-beta (TGF-b) and macrophage colony-stimulating factor (MCSF) by enzyme-linked immunosorbent assay. Results: Aortic 18F-FDG uptake was significantly higher in SCR compared to control subjects in both the pre- coarctation and post-coarctation aortic site (A-B). 18F-FDG uptake values in either the AA or DA were not related to plasma levels of IL-6 (C), MCSF (D) or TGF-b (p=NS, not shown). suggesting that subclinical aortic wall inflammation in these patients cannot be studied by systemic inflammatory markers. Similarly, there was no association between arterial stiffness properties, i.e. augmentation index (AIx, E) or carotid-femoral pulse wave velocity (c-f PWV, F) with aortic FDG uptake. Conclusions: Assessment of aortic wall inflammation by 18F-FDG PET/CT imaging detects aortic wall inflammation in both the pre- and post-coarctation sites during adult life in SCR patients. Our findings demonstrate that 18F-FDG PET/CT imaging of aorta is a sensitive marker of inflammation in adult SCR pa- tients. P736 | BEDSIDE Relative downregulation of septal function and metabolism in TGA patients with atrial switch P. Storsten 1 , J.G. Fjeld 2 , A.G. Sherwani 2 , E. Boe 1 , E.W. Remme 3 , O. Gjesdal 4 , G. Erikssen 4 , O.A. Smiseth 5 , H. Skulstad 6 on behalf of Integrated Cardiovascular Function. 1 Institute for Surgical Research and Center for Cardiological Innovation, Oslo University Hospital, Oslo, Norway; 2 Dep. of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway; 3 K.G. Jebsen Cardiac Research Centre and Inst. for Surgical Research, Oslo University Hospital, Oslo, Norway; 4 Dep. of Cardiology, Rikshospitalet, Oslo University Hospital, Oslo, Norway; 5 University of Oslo, Institute for Surgical Research, Oslo, Norway; 6 Dep. of Cardiology and Inst. for Surgical Research, Rikshospitalet, Oslo University Hospital, Oslo, Norway Background: In patients with transposition of the great arteries (TGA) and atrial switch, the right ventricle (RV) becomes the systemic ventricle. These patients have increased risk of heart failure. We have previously demonstrated reduced septal function by regional strain and work analyses. Purpose: To determine whether reduced septal function in TGA-patients is re- flected in reduced metabolism. Methods: We included 10 TGA patients, age (30±5 years mean±SD), operated with atrial switch (Senning/Mustard) shortly after birth. Myocardial shortening was measured as longitudinal strain by speckle tracking echocardiography. Myocar- dial glucose metabolism was measured by 18F-fluorodeoxyglucose PET imaging (FDG-PET) by standard protocol, using SUV body mass (SUV:Standardized Up- take Value) as unit. These SUV were also normalized to the highest SUV value. Values presented are average SUV from volumes of interest (VOI) from the basal and mid segments for septum and RV free wall for both absolute and relative SUV. Results: Septal longitudinal shortening was markedly reduced compared to the RV free wall (13±2 vs 20±3%,P<0.001) (Figure, panel A). Myocardial glucose metabolism, i.e. 18FDG-uptake, was also reduced in the septal segments com- pared to the RV free wall (SUV 5.1±1.8 vs 6.3±1.8,P<0.001). When SUV was normalised to the VOI with highest SUV, the septum had a mean of 0.75±0.09 vs 0.95±0.04 in the lateral wall (P<0.001) (Figure, panel B). In each patient, with no exception, the absolute value of SUV and strain were lower in the septum than in the RV free wall. In the typical example in panel C, there is normal metabolism in the RV free wall (homogenous red) and reduced metabolism is seen in the septum (pale red or yellow). Conclusions: TGA patients demonstrated markedly reduced septal function which was accompanied by reduction in septal metabolism. Global function of the systemic right ventricle was maintained due to preserved function of the RV free wall. The change in septal function and metabolism may be early markers of decompensation of the systemic ventricle. P737 | BEDSIDE Fontan patients with fenestration acquire low central-venous pressure but hold poor cardiac performances Y. Hamamichi, T. Matsui, S. Kuwata, Y. Horimoto, T. Kobayashi, M. Saitou, T. Ishii, A. Inage, T. Ueda, S. Yazaki, T. Yoshikawa. Sakakibara Heart institution, Pediatric cardiology, Tokyo, Japan Background: If we anticipate that pulmonary circulation is hard to hold good after Fontan, we bypass lungs with fenestration from conduit to systemic atrium on Fontan procedure (fenFon). We got the impression that fenFon patients gained low pressure of central vein but had cardiac performance inferior to non-fenFon patients. We investigated hemodynamic status in fenFon patients. Methods: The medical records of 39 fenFon patients were reviewed who under- went cardiac catheterization between 2010 and 2015. Control was 137 Fontan pa- tients without fenestration who had examinations likewise during the same period. Of 39 fenFon patients, 17 also had catheterization before Fontan bettween 2010 and 2015; of 137 non-fenFon, 29 also had catheterization before Fontan. First, we compared cardiac performances between 39 fenFon and 137 non-fenFon. Second, we compared changes of cardiac performances between preFontan and postFontan ((%) = postFon – preFon/preFon x 100). Results: There were significant difference in post-Fontan cardiac performances between 39 fenFon patients and 137 non-fenFon patients, such as ventricular volume on end-diastole (122% vs. 101%: p=0.0127), ventricular pressure on end- diastole (10.0 vs. 8.2 mmHg), capillary wedge pressure of pulmonary arteries (8.5 vs. 6.8 mmHg: p=0.029). However, central vein pressures were equivalent between two groups (12.6 vs. 12.2 mmHg); cardiac outputs were higher in fenFon (3.8 vs. 3.3 L/min/m 2 , p=0.0055). As for pre-Fontan, ventricular volumes on end- diastole and end-systole were almost same between patients with and without fenFon. Cardiac output was also not different. However, the decreasing rates for ventricular volumes were smaller in fenFon patients: end-diastolic volume (-24% vs. -38%: p=0.039), end-systolic volume (-21% vs. -39%: p=0.027). On the other Downloaded from https://academic.oup.com/eurheartj/article-abstract/38/suppl_1/ehx501.P736/4088030 by guest on 22 January 2019