Predicting sudden cardiac death after a heart attack may be impossible—for now
It may be impossible to accurately predict when heart attack survivors are going to experience sudden cardiac death later in life, according to a new analysis published in European Heart Journal.[1] That could change in the future, of course, but it does not seem to be feasible with our current knowledge base.
Left ventricular ejection fraction (LVEF) is currently used to anticipate sudden cardiac death in these patients, but room for significant improvement remains. The study’s authors attempted to crack the code, exploring data from more than 140,000 patients who survived a myocardial infarction in the United States, Europe or Israel.
While 7,543 patients were equipped with an implantable cardioverter-defibrillator (ICD), 25,058 had a LVEF ≤ 35% and the remaining 107,603 had an LVEF > 35%.
The primary outcome—sudden cardiac death in non-ICD patients or appropriate defibrillator therapy in ICD patients—occurred in 1,326 ICD patients, 1,193 patients with an LVEF ≤ 35% and 1,567 patients with an LVEF > 35%. In each subgroup, researchers determined that LVEF was a poor predictor of sudden cardiac death. They then tested alternative parameters—specific demographics, prior medical history, imaging results and much more—and found that nothing they tried was more accurate.
“The current analysis did not yield a tool that predicted the individual sudden cardiac death risk with satisfactory accuracy across a wide range of geographically dispersed datasets,” wrote first author Niels Peek, PhD, a professor with the University of Cambridge England, and colleagues. “Whether this result is related to the nature of sudden cardiac death or to inherent limitations of respective datasets cannot be answered. But the finding is consistent with mounting evidence that it is not possible to develop universally valid prediction models.”
Peek added that advanced artificial intelligence algorithms could potentially help with predictions in the future, especially if they can identify new biomarkers that researchers have not previously studied.
Peek et al. also wondered if ICD implantation in patients with LVEF ≤ 35% provides enough value to continue being treated as a sound treatment strategy.
“Considering the declining risk for sudden death, the effect of recently introduced heart failure drugs, the fact that non-sudden deaths account for the large majority of deaths in this population, and the still considerable complication rate of the devices, a re-evaluation of the benefit of routine prophylactic defibrillator implantation in patients with LVEF ≤ 35% appears necessary,” the group wrote.
Click here to read the full study in European Heart Journal, a European Society of Cardiology journal.
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.