Sudden cardiac death risk prediction in heart failure with preserved ejection fraction

Background: Sudden cardiac death (SCD) comprises 25% of deaths in patients with heart failure with preserved ejection fraction. Objective: We sought to validate a SCD risk prediction model in patients who participated in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist Trial. Methods: Of the 3445 Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist Trial participants, 615 (18%) had data on all 6 variables—age, sex, history of myocardial infarction, history of diabetes mellitus, presence of bundle branch block on the electrocardiogram, and N-terminal pro-brain natriuretic peptide level—of the SCD risk prediction model. Those with a 5-year predicted risk of SCD ≥10% were categorized as high risk patients. Results: Over a mean follow-up of 2.9 ± 1.3 years, there were 23 SCDs (3.7%) and 63 deaths from other causes (10.2%). The rate of mortality from SCD and other causes were 13 (95% confidence interval [CI] 9–19) and 35 (95% CI 28–45) per 1000 person-years of follow-up, respectively. A total of 216 participants (35.1%) were categorized as high risk by the SCD risk model. The estimated 5-year cumulative incidence of SCD was 15.2% (95% CI 6.6%–27.2%) in those classified as high risk vs 2.8% (95% CI 1.2%–5.5%) in those classified as low risk. In competing risk analysis, patients predicted to have high SCD risk had a 3.7-fold higher risk of SCD (hazard ratio 3.7; 95% CI 1.6–8.7; P = .003) than did those predicted to have low risk. The SCD risk model yielded a Harrell's C index of 0.74. Conclusion: A SCD risk prediction model including 6 widely available variables can identify patients with heart failure with preserved ejection fraction who had a high risk of SCD.