Abstract 18593: Predictors of Sudden Cardiac Arrest with Preserved Left Ventricular Systolic Function
Introduction: Though severely reduced left ventricular ejection fraction (EF) is proven to increase sudden cardiac arrest (SCA) risk, community-based studies indicate that most SCAs occur in individuals with normal LV systolic function.
Hypothesis: Determinants of SCA risk in the large subgroup of patients with coronary disease but normal LV systolic function can be identified from the general population.
Methods: In a large, ongoing community-based study in the northwestern US (Pop. approx. 1 million) a case-control design was used to compare clinical characteristics of SCA cases with coronary artery disease (CAD) to a control group from the same geographic region with documented CAD but no history of SCA. Subjects age ≥35 enrolled 2002 - 2008 with physician records and preserved LV ejection fraction (LVEF≥50%) were included. Chi-square and t-tests were used to evaluate univariate case-control associations; and a logistic regression model used to estimate adjusted odds ratios for each factor significant in univariate comparisons.
Results: Cases (n=171) were older than controls (n=149) (70 vs 68 y, p=0.009), and were more likely to have a history of stroke, atrial fibrillation (AF), left ventricular hypertrophy (LVH), chronic obstructive pulmonary disease (COPD), chronic renal insufficiency (p≤0.02), higher heart rate and longer corrected QT (QTc) interval (p<0.0001). In the multivariate model adjusting for age, there were 5 significant predictors of SCA: LVH (OR 3.7, 1.7-8.0), higher HR or longer QTc (OR 4.9, 2.5 - 9.9), AF (OR 2.3, 95% CI 1.1 - 4.9), chronic renal insufficiency (OR 2.5, 1.3 - 4.9), and COPD (OR 2.9, 1.6 - 5.4). Among control subjects, 58% had none of these five risk factors and <2% had three or more; among cases, 18% had none, 25% had two, and 18% had three or more (p<0.0001). In a regression model with age and number of risk predictors (0, 1, or ≥2), presence of one predictor quadrupled SCA odds (OR 3.9, 2.2-6.9), and presence of two or more increased risk 12-fold (OR 12.8, 6.5 - 25.3).
Conclusions: In this community-based study, LVH, higher heart rate or longer QTc, AF, chronic renal insufficiency and COPD were significant predictors of SCA with preserved LV systolic function.
- © 2010 by American Heart Association, Inc.