Abstract 14990: Sudden Death in Patients with Heart Failure and Preserved Ejection Fraction

Abstract

Introduction: Severely reduced left ventricular ejection fraction (EF) is an established risk factor for sudden cardiac death (SCD), but has limited sensitivity and specificity. We evaluated the contribution of heart failure (HF) with preserved ejection fraction toward risk of SCD in the general population. Hypothesis: We hypothesized that HF would predict risk of SCD, even among patients with preserved EF. Methods: Subjects from an ongoing community-based study of SCD in the northwest US (pop. approx. one million) were included if age ≥18 (2002 - 2012) with clinical history and assessment of EF. Clinical history of heart failure (HF) was determined by physician report. Ejection fraction (EF) was determined from echocardiogram, angiogram, or multigated acquisition scan, and categorized as EF <20%, 20-34%, 35-44%, 45-54%, and ≥55%. Laboratory values of brain natriuretic peptide (BNP) were obtained from routine clinical laboratory testing for a subset of patients. Results: Cases (n=628, mean age 69.9, 65% male) were more likely than controls (n = 580, mean age 66.8, 66% male) to have a history of clinically-recognized HF (58% vs. 24%, p<0.0001) and to have an EF ≤ 35% (27% vs. 12%, p<0.0001). At each EF level above 20%, HF was approximately twice as prevalent in cases compared to controls (Figure, p≤0.002). Median BNP levels were significantly higher for patients with HF vs. those without, across EF categories. Adjusting for age and sex, each category of decreasing EF was associated with an increased risk of SCD (OR 1.4, 95% CI 1.3 - 1.6, p<0.0001), but the association was diminished by adjustment for HF, and for BNP. Odds of SCD were 4-fold higher (p<0.0001) in the presence HF, adjusting for age and sex, across all categories of EF. Conclusions: In this population, the significant role of HF with preserved EF in SCD was confirmed by BNP level trends. Improvements in SCD prevention will require focused investigation of high risk SCD markers in patients with heart failure and preserved EF.