Sudden cardiac death after myocardial infarction: individual participant data from pooled cohorts

Niels Peek1,2, Gerhard Hindricks3,4, Artur Akbarov1

  • 1Division of Informatics, Imaging and Data Science, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.

European Heart Journal
|October 8, 2024
PubMed

Insights

Risk stratification for sudden cardiac death after myocardial infarction using left ventricular ejection fraction (LVEF) is unreliable. Current methods, including LVEF and other predictors, cannot accurately identify high- or low-risk patients for defibrillator therapy.

Area of Science:

  • Cardiology
  • Preventive Medicine
  • Medical Imaging

Background:

  • Sudden cardiac death (SCD) risk stratification post-myocardial infarction (MI) often relies on left ventricular ejection fraction (LVEF).
  • Accurate risk assessment across the entire LVEF spectrum is crucial for guiding defibrillator implantation decisions.
  • Existing methods may not adequately identify individuals who would benefit from or be harmed by defibrillator therapy.

Purpose of the Study:

  • To evaluate the predictive performance of LVEF and other clinical parameters for SCD risk stratification in post-MI patients.
  • To determine if multivariable models can improve risk prediction compared to LVEF alone.
  • To assess the generalizability of risk prediction models across different patient subgroups.

Main Methods:

  • Pooled analysis of 20 datasets comprising 140,204 post-MI patients.
  • Separate analyses for implantable cardioverter-defibrillator (ICD) patients (LVEF ≤ 35%), non-ICD patients (LVEF ≤ 35%), and non-ICD patients (LVEF > 35%).
  • Development and external validation of LVEF-only, parametric survival, and random forest survival models; performance assessed via meta-analysis.

Main Results:

  • LVEF demonstrated poor predictive ability for SCD in all analyzed subgroups (c-statistics 0.50–0.56).
  • Inclusion of additional clinical parameters did not enhance model calibration, discrimination, or generalizability.
  • Significant numbers of primary outcomes (SCD or appropriate defibrillator therapy) were observed across all patient groups.

Conclusions:

  • Accurate risk stratification for SCD in post-MI patients remains challenging, even with comprehensive data.
  • Neither LVEF alone nor multivariable models incorporating other predictors reliably identify low-risk individuals with reduced LVEF or high-risk individuals with preserved LVEF.
  • Current risk stratification tools are insufficient for optimizing defibrillator implantation decisions across the full LVEF range.
Abstract

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