Poster session 6: Saturday 6 December 2014, 08:30-12:30 * Location: Poster area

Introduction: The increase of left auricular volume (LAV) is a robust cardiovascular event predictor. Despite that echochardiography is more often used, cardiac MRI is considered more accurate. Our objetives are to validate "fast" LAV measures by MRI vs the considered gold standard (GS) and to compare Echo and MRI in a wide spectrum of patients. Methods: In a non-selected popullation with MRI study previously realized, we measured LAV by biplane method (BPMR) and by area-length in 4 chamber view (ALMR) and compared them with biplane (BPe) and discs method (MDDe) in 4 chamber view in echo. To validate MRI measurements, we measured LAV in short axis slices (Simpson Method, SM) in a group of patients and considered it the GS. Results: 186 patients were included (mean age 51 ± 17 age; 123 male; 14 in AF) with clinical indication of cardiac MRI (Philips 1,5 T). In 24 patients SM was calculated. 29% of cardiac MRI were considered normal. Mean underlying pathologies were myocardiopathy (27%), Ischemic myocardiopathy (17%), myopericarditis (10%), prior to AF ablation (4%), valvular disease (6%) and miscellaneous (7%). Excellent correlation was obtained between "fast" MRI measurements and SM in MRI (SM vs BPMR interclass correlation coefficient ICC=0.965 and SM vs ALMR, ICC=0.958; P<0.05) with low interobserver variability (ICC=0.983 for SM; ICC=0.949 for BPMR; ICC=0.931 for ALMR). "Fast" measurements by MRI showed stadistical correlation between them (CCI=0.910) (Figure). Correlation between Echo and MRI measures was only moderate. (BPRM vs BPe CCI=0,469 mean difference -30 ml; ALMR vs MDDe ICC=0,456 mean difference -24 mL). Conclusions: ‘fast’ LAV measures by MRI are comparable with the MRI GS and also between them. Echo values seem to underestimate compared to MRI, so its use may not be suitable. <fig loc="float" id="CHAPTERsub90742F1"> <link locator="15209920140531125928"></fig>