Shockable Rhythms Are Common First Rhythms in Cardiac Arrests Involving Patient with Heart Failure with Preserved Ejection Fraction

Introduction: Sudden cardiac death (SCD) is responsible from 25% of the total mortality in patients with heart failure with preserved ejection fraction (HFpEF). Whether SCD in HFpEF is due to shockable or unshockable rhythms is unknown. Hypothesis: Cardiac arrests in HFpEF are due to ventricular tachycardia/ventricular fibrillation (VT/VF). Methods: We determined the initial rhythm in 286 consecutive in-hospital cardiac arrests at the Minneapolis VA Health Care system from 2011 through 2020. Clinical and survival information were obtained from electronic health records. According to their heart failure history, we categorized the patients as HFpEF, heart failure with reduced ejection fraction (HFrEF) or no heart failure (NoHF). Results: Of the 286 patients (mean age 70.2±9.0 years old and 97.5% male), 51 (17.8%) had HFpEF, 77 (26.9%) had HFrEF and 158 (55.2%) had NoHF. The initial rhythm was VT/VF in 47.1%, 39.0% and 22.2% of patients with HFpEF, HFrEF and NoHF respectively (p<0.001) (Figure). Return of spontaneous circulation (ROSC) after VT/VF arrest was similar amongst the three groups (66.7%, 73.3% and 74.3%, respectively; p=0.8) but the 30-day survival trended higher in HFpEF (54.2%) and NoHF (48.6%) when compared with HFrEF (26.7%) (p=0.08)(Figure). Among patients with HFpEF, 30-day survival was lower after cardiac arrests due to PEA/Asystole when compared to those due to VT/VF (18.5% vs. 54.2%, respectively, p=0.03). Conclusion: VT/VF was the initial rhythm in 47% of patients with HFpEF who had in-hospital cardiac arrest. The proportion of VT/VF and ROSC after in-hospital cardiac arrest was similar in HFpEF and HFrEF. These data provide one more piece of evidence that SCD could be a therapeutic target in HFpEF.