Predictors and Outcomes of Sudden Cardiac Arrest in Heart Failure With Preserved Ejection Fraction: A Nationwide Inpatient Sample Analysis

Sudden cardiac arrest (SCA) is the leading cause of cardiovascular mortality in heart failure with preserved ejection fraction (HFpEF), contributing to around 25% of deaths observed in pivotal HFpEF trials. However, predictors and outcomes of in-hospital SCA in HFpEF have not been well characterized. We queried the Nationwide Inpatient Sample (2016 to 2017) to identify adult hospitalizations with a diagnosis of HFpEF. Patients with acute or chronic conditions associated with SCA (e.g., acute myocardial infarction, acute pulmonary embolism, sarcoidosis) were excluded. We ascertained whether SCA occurred during these hospitalizations, identified predictors of SCA using multivariate logistic regression, and determined outcomes of SCA in HFpEF. Of 2,909,134 hospitalizations, SCA occurred in 1.48% (43,105). The mean age of the SCA group was 72.3 ± 12.4 years, 55.8% were women, and 66.4% were White. Presence of third-degree atrioventricular block (odds ratio [OR] 5.95, 95% confidence interval [CI] 5.31 to 6.67), left bundle branch block (OR 1.96, 95% CI 1.72 to 2.25), and liver disease (OR 1.87, 95% CI 1.73 to 2.02) were the leading predictors of SCA in HFpEF. After excluding patients with do-not-resuscitate status, the SCA group versus those without SCA had higher mortality (25.9% vs 1.6%), major bleeding complications (4.1% vs 1.7%), increased use of percutaneous coronary intervention (2.5% vs 0.7%), and mechanical circulatory assist device (1.2% vs 0.1%). These observational inpatient data suggest identifiable risk factors for SCA in HFpEF including cardiac arrhythmias. Further research is warranted to identify the best tools to risk-stratify patients with HFpEF to implement targeted SCA prevention strategies.

Sudden cardiac death in heart failure with preserved ejection fraction: an updated review

Despite the advances in medical and device therapies for heart failure (HF), sudden cardiac death (SCD) remains a tremendous global burden in patients with HF. Among the risk factors for SCD, HF has the greatest impact. Previous studies focusing on patients with systolic dysfunction have found several predictive factors associated with SCD, leading to the subsequent development of strategies of primary prevention, like placement of implantable cardioverter-defibrillator (ICD) in high-risk patients. Although patients with HF with preserved ejection fraction (HFpEF) were less prone to SCD compared to patients with HF with reduced ejection fraction (HFrEF), patients with HFpEF did account for a significant proportion of all HF patients who encountered SCD. The cutoff value of left ventricular ejection fraction (LVEF) to define the subset of HF did not reach consensus until 2016 when the European Society of Cardiology proposed a new classification system by LVEF. There is a great unmet need in the field of SCD in HFpEF regarding risk stratification and appropriate device therapy with ICD implantation. In this article, we will approach SCD in HFpEF from HFrEF subsets. We also aim at clarifying the mechanisms, risk factors, and prevention of SCD in HFpEF.