Related Experiment Video
Updated: Sep 19, 2025
Integration of Brain Tissue Saturation Monitoring in Cardiopulmonary Exercise Testing in Patients with Heart Failure
Published on: October 1, 2019
Incremental Prognostic Value of Hippocampal Metabolic Activity for Sudden Cardiac Death in Patients With Heart
Zhiyong Shi1, Mingkai Yun1, Binbin Nie2
1Department of Nuclear Medicine, Molecular Imaging Lab, Beijing Anzhen Hospital Capital Medical University Beijing China.
Insights
Hippocampal metabolic activity (HMA) predicts sudden cardiac death (SCD) in heart failure patients. Impaired HMA, especially with myocardial scarring, increases SCD risk, partly through corrected QT interval changes.
Area of Science:
- Cardiology
- Neurology
- Nuclear Medicine
Background:
- Heart failure with reduced ejection fraction (HFrEF) is linked to cognitive issues and cardiac events.
- The predictive role of hippocampal metabolic activity (HMA) for sudden cardiac death (SCD) in HFrEF patients is not well understood.
- Mechanisms linking HMA to SCD in HFrEF require further investigation.
Purpose of the Study:
- To assess the independent and incremental predictive value of HMA for SCD-related events in HFrEF patients.
- To evaluate HMA's predictive capacity relative to myocardial scar burden.
- To explore the potential mechanisms underlying the association between HMA and SCD.
Main Methods:
- Prospective study of 270 HFrEF patients using SPECT and 18F-FDG PET imaging.
- Evaluation of HMA and myocardial scarring.
- Analysis of SCD-related events using survival analysis (log-rank, Cox model) and reclassification metrics.
- Mediation analysis to investigate the role of left ventricular electrical instability.
Main Results:
- 34 patients (12.6%) experienced SCD-related events during a median 4.3-year follow-up.
- Both myocardial scarring and HMA were significantly associated with SCD-related events (P<0.01).
- HMA provided significant incremental prognostic value, improving risk discrimination (C-statistic 0.760 vs 0.715) and reclassification (NRI 25.6%).
- HMA was linked to SCD-related events via the corrected QT interval.
Conclusions:
- Functional myocardial scarring and HMA are strong independent predictors of SCD-related events in HFrEF.
- HMA offers incremental prognostic value beyond myocardial scarring assessment.
- HMA impairment may contribute to SCD in HFrEF, potentially mediated by corrected QT interval prolongation.
Background:
Hippocampal injury is linked to cognitive impairment and cardiac events in patients with heart failure with reduced ejection fraction. However, the predictive value of hippocampal metabolic activity (HMA) for sudden cardiac death (SCD) and the underlying mechanisms remain unclear. This study aimed to evaluate the independent and incremental predictive value of HMA over myocardial scar for SCD-related events in patients with heart failure with reduced ejection fraction and to explore the potential mechanism.
Methods:
This prospective study included 270 patients with heart failure with reduced ejection fraction undergoing gated single-photon emission computed tomography and brain/cardiac 18F-fluorodeoxyglucose positron emission tomography. HMA and myocardial scarring were evaluated. The independent and incremental predictive values of HMA for SCD-related events were explored via the log-rank test, Cox model, C statistic, global χ2 test, and net reclassification improvement. Mediation analysis was used to examine the direct and indirect effects of HMA on SCD-related events by setting left ventricular electrical instability as a mediator.
Results:
Overall, 34 (12.6%; median follow-up, 4.3 years) patients experienced SCD-related events. Functional myocardial scarring and HMA were strongly associated with SCD-related events (all P<0.01). HMA resulted in significant incremental improvements in prognostic value (χ2 increased by 6.598), discrimination (C statistics of 0.760 versus 0.715), and reclassification (net reclassification improvement, 25.6%) for SCD-related events. HMA was associated with SCD-related events via corrected QT interval.
Conclusions:
Functional myocardial scarring and HMA had strong independent prognostic value in the risk stratification of SCD-related events in patients with heart failure with reduced ejection fraction. Additionally, HMA had incremental prognostic value based on myocardial scarring. HMA impairment may induce SCD-related events, partly mediated by corrected QT interval.
More Related Videos
07:02Utilizing the Modified T-Maze to Assess Functional Memory Outcomes After Cardiac Arrest
Published on: January 5, 2018
08:35Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction
Published on: August 17, 2022
