CONGRESS ABSTRACT

Background: Non-ischemic cardiomyopathy (NICM) with reduced ejection fraction poses significant challenges for risk stratification regarding adverse life-threatening events. This study investigated the prognostic role of cardiac magnetic resonance (CMR) parameters in predicting events in this population. Methods: This is a retrospective, observational study involving 57 consecutive patients newly diagnosed  with NICM (68.4% male, mean age 62.5±11.4 years,) with reduced left ventricular ejection fraction (LVEF 42±9%) who underwent CMR imaging. The imaging protocol included cine-, T1-weighted-, contrasted- and multi-parametric mapping images. The composite endpoint comprised sudden cardiac death (SCD), major arrhythmic events, and heart failure hospitalization, over a 543 days of mean follow-up period.   Results: During follow-up, 18 patients (31%) were reported to have adverse outcomes. Only higher native T1 values (1076 [1025-1120] vs. 999 [990-1037] ms, p<0.001), higher extracellular-volume (34±6% vs. 28±4%, p<0.001) and lower RVEF (48±13% vs. 59±10%, p=0.03) significantly correlated with SCD and major arrhythmic events. A T1 threshold exceeding 1018 ms showed 77.8% sensitivity and 81.8% specificity, with a odds ratio (OR, 95,0% CI) of 6.2 for the composite endpoint and 5.39 for SCD/arrhythmic events. An extracellular-volume greater than 28% demonstrated remarkable predictive power (OR 18.0 for composite endpoint; OR 77.0 for SCD/arrhythmic events).   Conclusions: CMR tissue characterization, particularly T1 mapping and ECV quantification, provides robust prognostic information in NICM patients. These parameters identify high-risk individuals for arrhythmic events more effectively than conventional measures, supporting their integration into risk stratification protocols.