CONGRESS ABSTRACT

Background. Persistently reduced left ventricular ejection fraction (LVEF) is associated with an increased risk of sudden cardiac death with an indication for an implantable cardioverter-defibrillator (ICD) after 3 months of optimal medical therapy (OMT) during which it is not clear how to prevent SCD and how to distinguish patients with a transient SCD risk from those with an early indication for ICD therapy. Methods. Patients with newly diagnosed heart failure with reduced LVEF underwent a comprehensive baseline characterization including coronary angiography and cardiac magnetic resonance imaging (CMRi). Provided with a wearable defibrillator (WCD), all patients received OMT and underwent clinical and echocardiographic follow-up. Patients with LVEF 33-38% at 3 months continued follow-up with life vest. We compared the patients meeting definitive indication for ICD therapy to the ones undergoing LVEF recovery. Multivariable models were built to identify the predictors of the need for ICD therapy. Results. A total of 128 patients with 27±8% LVEF were included in the analysis, of which 36% with ischemic etiology and 67% with non-ischemic cardiomyopathy. No appropriate intervention of WCD was observed. Patients undergoing ICD implantation were 26%. With respect to those recovering LVEF, patients recieving ICD had more frequently ischemic heart disease (53 vs 30%), diabetes, and chronic kidney disease (all p<0.05), despite comparable age, sex prevalence, LVEF, and coronary anatomy. CMRi revealed higher indexed left ventricular end-diastolic volume (LV-EDVi) and higher fibrosis burden at late gadolinium enhancement (LGE score 6.9 (0.8-9.1) vs 4.1 (0-4.6), p<0.05). A subgroup of 33 (26%) patients with borderline LVEF at 3 months were followed-up for 1-3 extra months, allowing the detection of LVEF recovery in 30 (90%). The predictors of the need for ICD were LV-EDVi, presence of diabetes, LGE score, and kidney function. Conclusions. Baseline CMRi indices of fibrosis and remodeling (LGE, LV-EDVi), diabetes, and kidney function can help identify patients more likely to have persistently low LVEF. Longer follow-up might avoid untimely ICD therapy in a significant number of patients with late recovery (>3 months). This strategy can help reduce the use of definitive ICD with better quality of life and reduced healthcare costs.