Abstract 17497: Natural History of the Left Ventricular Ejection Fraction in Heart Failure and Sudden Cardiac Death

Abstract

Background: A clinical diagnosis of heart failure (HF) is associated with increased risk of sudden cardiac death (SCD), but only HF with severely reduced LV ejection fraction (HFrEF, EF ≤35%) is utilized for risk stratification. Guideline-directed medical therapy and heart disease processes may improve or reduce the LVEF. Hypothesis: There is significant variation of LVEF over time among HF patients with SCD. Methods: From a large, prospective population-based study of SCD in the Northwest US (catchment population 1 million, 2002-2018), we identified all consecutive patients with a diagnosis of HF and prior assessment of LVEF. The sub-group of patients with at least 2 prior LVEF evaluations (earliest and latest in relation to SCD) was determined. Results: A total of 1622 individuals suffered SCD with a known diagnosis of HF (65% male, age 72±14) of which 434 had 2 LVEF evaluations at least 1 yr apart prior to their SCD. At earliest evaluation, 100 (23%) had HFrEF (73% male, age 67±13), 88 (20%) had HF with moderately reduced EF (HFmrEF, 35<ef<50) (71% male, age 72±12), and 246 (57%) had hf with preserved ef (hfpef, ef≥50) (57% 72±12). comparing the earliest latest assessment of lvef, mean lvef in hfref increased by 9±14 percentage points (p<0.001) from 27±6 to 36±14; hfmref decreased over time -4±14 (p="0.003)" 43±4 39±14; hfpef -8±13, 62±7 54±14. each subtype changed substantially (mean 2.9±1.5 yrs), sizeable proportions re-classified into different subtypes (Figure). Overall, the HF LVEF subtype was unchanged in 58% and altered in 42% (p<0.001). Conclusions: Based on the LVEF, at least 40% of HF sub-types were re-classified prior to SCD and risk assessment would be variable depending on when LVEF was measured. These findings highlight the limitations of using the LVEF as the only risk predictor of SCD.