Comparative outcomes in patients with preexisting heart failure to those without heart failure after out-of-hospital cardiac arrest: A nationwide registry study

Background: The knowledge of prognosis following out -of -hospital cardiac arrest (OHCA) in patients with heart failure heart failure (HF) is sparse. The objective of this study was to compare the outcome after OHCA among patients with and without HF. Methods: We studied 45,293 patients who were included for the Danish cardiac arrest registry between 2001 and 2014. Patients were stratified into two groups based on the presence of HF prior to cardiac arrest. The primary outcome was 30-day survival and secondary outcome was anoxic brain damage or permanent nursing home admission at 1 -year among 30-day survivors. Results: Among the final 28,955 patients included, 6675 (23%) patients had prior HF and 22,280 (77%) patients had no prior HF. At 30 days, 616 (9.2%) patients survived among the patients with HF and 1916 (8.6%) among the patients without HF. There was a significant interaction between atrial fibrillation (AF) and HF for primary outcome and therefore it was assessed separately between the two study groups stratified based on AF. Among patients without AF a significantly higher odds of 30-day survival were observed among patients with HF (OR 2.69, 95% CI 2.34-3.08, P < 0.001), but no difference was observed among the patients from two study groups with no AF. No significant difference in risk for secondary outcome was observed among the two study groups. In multivariable average treatment effect modeling, all the results largely remain unchanged. Conclusions: Outcome following OHCA among patients with and without HF is found to be similar in this large Danish OHCA registry.