Abstract 12408: Fragmented QRS is Independently Predictive of Long-Term Adverse Clinical Outcomes in Asian Patients Hospitalized for Heart Failure: A Retrospective Cohort Study

Abstract

Introduction: Fragmented QRS (fQRS) results from myocardial scarring and predicts cardiovascular mortality and ventricular arrhythmia (VA). We evaluated the prevalence and prognostic value of fQRS in Asian patients hospitalized for heart failure. Hypothesis: fQRS is predictive of adverse clinical outcomes. Methods: This was a retrospective cohort study of adult patients hospitalized for heart failure between 1st January 2000 and 31st December 2019 at a tertiary center in Hong Kong. The baseline ECG was analysed. QRS complexes (<120 ms) with fragmented morphology in ≥2 contiguous leads were defined as fQRS. The primary outcome was a composite of cardiovascular mortality, VA, and sudden cardiac death (SCD). The secondary outcomes were the components of the primary outcome, myocardial infarction, and new-onset atrial fibrillation. Results: In total, 2192 patients were included, of whom 179 (8.20%) exhibited fQRS. The follow-up duration was 5.63±4.09 years. fQRS in any leads was associated with a higher risk of the primary outcome (adjusted hazard ratio (HR) 1.541 [1.185, 2.004], p=0.001; Figure A), but not myocardial infarction or new-onset atrial fibrillation. fQRS in >2 contiguous leads was an independent predictor of the primary outcome (HR 1.841 [1.119, 3.029], p=0.016; Figure B), driven by a higher risk of SCD (adjusted HR 2.679 [1.252, 5.729], p=0.011). In patients without ischaemic heart disease (N=1396), fQRS in any leads remained predictive of VA and SCD (adjusted HR 3.336 [1.343, 8.282], p=0.009, and 1.928 [1.135, 3.278], p=0.015, respectively), but not cardiovascular mortality (adjusted HR 1.049 [0.662, 1.662], p=0.839). Conclusions: fQRS is an independent predictor of cardiovascular mortality, VA, and SCD. Higher fQRS burden increased SCD risk. The implications of fQRS in heart failure patients without ischaemic heart disease require further studies.