Survival of patients with and without diabetes following out-of-hospital cardiac arrest: A nationwide Danish study

Background:Research regarding out-of-hospital cardiac arrest (OHCA) survival of diabetes patients is sparse and it remains unknown whether initiatives to increase OHCA survival benefit diabetes and non-diabetes patients equally. We therefore examined overall and temporal survival in diabetes and non-diabetes patients following OHCA. Methods: Adult presumed cardiac-caused OHCAs were identified from the Danish Cardiac Arrest Registry (2001-2014). Associations between diabetes and return of spontaneous circulation upon hospital arrival and 30-day survival were estimated with logistic regression adjusted for patient- and OHCA-related characteristics. Results: In total, 28,955 OHCAs were included of which 4276 (14.8%) had diabetes. Compared with non-diabetes patients, diabetes patients had more comorbidities, same prevalence of bystander-witnessed arrests (51.7% vs. 52.7%) and bystander cardiopulmonary resuscitation (43.2% vs. 42.0%), more arrests in residential locations (77.3% vs. 73.0%) and were less likely to have shockable heart rhythm (23.5% vs. 27.9%). Temporal increases in return of spontaneous circulation and 30-day survival were seen for both groups (return of spontaneous circulation: 8.8% in 2001 to 22.3% in 2014 (diabetes patients) vs. 7.8% in 2001 to 25.7% in 2014 (non-diabetes patients); and 30-day survival: 2.8% in 2001 to 9.7% in 2014 vs. 3.5% to 14.8% in 2014, respectively). In adjusted models, diabetes was associated with decreased odds of return of spontaneous circulation (odds ratio 0.74 (95% confidence interval 0.66-0.82)) and 30-day survival (odds ratio 0.56 (95% confidence interval 0.48-0.65)) (interaction with calendar year p=0.434 and p=0.243, respectively). Conclusion:No significant difference in temporal survival was found between the two groups. However, diabetes was associated with lower odds of return of spontaneous circulation and 30-day survival.