Distinct mortality patterns and sudden cardiac death mechanisms in heart failure with a preserved ejection fraction

Fig. 1. Study Population Flowchart. From an initial cohort of 2989 patients admitted for worsening heart failure between 2008 and 2017, 2331 were categorized into three phenotypes based on the left ventricular ejection fraction: HFrEF (n = 1208), HFmrEF (n = 369), and HFpEF (n = 754).

Fig. 2. Distribution of the Causes of Death Across the Heart Failure Phenotypes. The proportions of cardiac and non-cardiac deaths are displayed for the patients with HFrEF, HFmrEF, and HFpEF. Significant differences were observed in the distribution, with cardiac deaths being more prevalent in HFrEF and HFmrEF, whereas non-cardiac deaths were dominant in HFpEF (p < 0.01).

Fig. 3. Cumulative Incidence Functions for Sudden Cardiac Death. Cumulative incidence functions for sudden cardiac death (SCD), stratified by HF phenotype, with non-SCD death treated as a competing event. Between-group differences were assessed using Gray’s test (p < 0.01).

Fig. 4. Modes of Sudden Cardiac Death by the Heart Failure Phenotype. The modes of SCD (asystole, ventricular arrhythmias) are shown for HFrEF, HFmrEF, and HFpEF. Asystole was most common in HFpEF (52.9%), while ventricular arrhythmias were predominant in HFrEF and HFmrEF (p < 0.01). Those findings highlight the distinct arrhythmic profiles among the heart failure phenotypes.