Combined model improves sudden cardiac death risk prediction
MedWire News: A risk model combining left ventricular ejection fraction (LVEF) with clinical risk factors is a better predictor of sudden cardiac death (SCD) in women with coronary artery disease (CAD) than LVEF alone, researchers suggest.
The study, published in the Archives of Internal Medicine, also found that SCD (defined as death of cardiac origin occurring within 1 hour of symptom onset) comprised the majority (54%) of cardiac deaths among postmenopausal women with CAD, and occurred at a rate of 0.79% per year.
The randomized, double-blind, placebo-controlled trial conducted by Rajat Deo (University of Pennsylvania, Philadephia, USA) and colleagues, involved 2763 women with an average age of 67 years.
Multivariate analysis revealed that myocardial infarction, heart failure, an estimated glomerular filtration rate below 40 ml/min/1.73 m2, atrial fibrillation, physical inactivity, and diabetes were independent clinical risk factors for SCD (with hazard ratios ranging from 1.44 to 2.10, all p<0.06).
Overall, SCD occurred at a rate of 0.3% per year among women with none of these risk factors, 0.5% among those with one, 1.2% among those with two, and 2.9% among those with more than three.
In a risk model combining LVEF and clinical risk factors, the C-statistic was 0.681, compared with 0.600 for a LVEF-only model, indicating that the combined model had greater discriminatory power. The net reclassification improvement of the combined model was 20% (p<0.001).
"Future projects should focus on combining studies to allow more robust estimates for established risk factors and to identify additional markers that augment the predictive ability of a SCD risk model," conclude the authors.
In a related commentary, Christine Albert (Brigham and Women's Hospital, Boston, Massachusetts, USA) described Deo and team's study as an important step toward future research into SCD risk prediction scores in broader populations.
"The discovery of novel [risk] markers… could ultimately lead to new therapeutic approaches for SCD prevention," she added.
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By Piriya Mahendra