Temporal trends in survival after out-of-hospital cardiac arrest in patients with and without underlying chronic obstructive pulmonary disease.

Abstract

Survival after out-of-hospital cardiac arrest (OHCA) has tripled during the past decade in Denmark as a likely result of improvements in cardiac arrest management. This study analyzed whether these improvements were applicable for patients with chronic obstructive pulmonary disease (COPD). Patients ≥18 years with OHCA of presumed cardiac cause were identified through the Danish Cardiac Arrest Registry, 2001-2011. Patients with a history of COPD up to ten years prior to arrest were identified from the Danish National Patient Register and compared to non-COPD patients. Of 21,480 included patients, 3056 (14.2%) had history of COPD. Compared to non-COPD patients, COPD patients were older (75 vs. 71 years), less likely male (61.2% vs. 68.5%), had higher prevalence of other comorbidities, and were less likely to have: arrests outside private homes (17.7% vs. 28.3%), witnessed arrests (48.7% vs. 52.9%), bystander cardiopulmonary resuscitation (25.8% vs. 34.8%), and shockable heart rhythm (15.6% vs. 29.9%), all p<0.001; while no significant difference in the time-interval from recognition of arrest to rhythm analysis by ambulance-crew; p=0.24. From 2001 to 2011, survival upon hospital arrival increased in both patient-groups (from 6.8% to 17.1% in COPD patients and from 8.2% to 25.6% in non-COPD patients, p<0.001). However, no significant change was observed in 30-day survival in COPD patients (from 3.7% to 2.1%, p=0.27), in contrast to non-COPD patients (from 3.5% to 13.0%, p<0.001). Despite generally improved 30-day survival after OHCA over time, no improvement was observed in 30-day survival in COPD patients.