Temporal trends in left ventricular ejection fraction before sudden death in patients with heart failure
Marita Knudsen Pope1, Harpriya Chugh2, Arayik Sargsyan2
1Center for Cardiac Arrest Prevention, Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California; Department of Cardiology, Oslo University Hospital, Ullevaal, and the Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
Background:
Risk stratification for sudden cardiac death (SCD) in heart failure (HF) patients is largely based on left ventricular ejection fraction (LVEF) of ≤35%. However, disease-related LV remodeling and medical treatment may change LVEF over time.
Objective:
This study aimed to evaluate the temporal trends in LVEF in patients with HF who experience an SCD.
Methods:
We performed 2 retrospective cohort studies (discovery and validation) of patients who experienced SCD after an established diagnosis of HF. Individuals were identified from 2 separate population-based studies of SCD in Oregon and California, if they underwent ≥2 echocardiographic evaluations performed at least 6 months apart.
Results:
The Oregon discovery cohort included 526 patients (male 63.9%; age 70.4 [13.2]), and the California validation cohort 191 patients (male 60.7%; age 74.6 [13.6]). In the discovery cohort, 45% of patients with LVEF of ≤35% on first assessment were reclassified to LVEF of >35% at final assessment (P < .001). Among patients with LVEF of 36%-49%, 66% were reclassified to either ≤35% or >50% (P < .001). In patients with LVEF of >50%, 32% were reclassified to LVEF of <50% (P < .001). Overall, 41.1% of patients in the discovery cohort were reclassified based on LVEF (P < .001). No distinguishing characteristics were identified between patients with an initial LVEF of ≤35% who improved or did not. Similar findings were observed in the validation cohort.
Conclusion:
LVEF category changed significantly over time, resulting in substantial reclassification of risk before the SCD event. These findings highlight the major limitation of using LVEF measured at a single time point as the main predictor of SCD risk.
