Should advanced age be a limiting factor in providing therapeutic hypothermia to cardiac arrest survivors? A single-center observational study.

As octogenarians represent the fastest growing segment of the elderly population and the incidence of out-of-hospital cardiac arrest (OHCA) increases with age, the outcome benefit of therapeutic hypothermia (TH) in comatose cardiac arrest survivors is of great interest. The first randomized controlled trials of TH excluded all patients older than 75 years and there exists considerable uncertainty whether the positive findings from these studies apply to older patients. This is a retrospective study of all unconscious OHCA survivors from 2002 to 2008 treated with TH in our intensive care unit who fulfilled the Hypothermia After Cardiac Arrest study inclusion criteria (witnessed, shockable OHCA receiving bystander-cardiopulmonary resuscitation (CPR), interval from collapse to ambulance arrival <15 minutes, and return of spontaneous circulation [ROSC] within 60 minutes) but with no upper age limit. Good cerebral outcome was defined as a Glasgow-Pittsburgh Cerebral Performance Category 1-2. The median age of the 113 OHCA survivors studied was 62 years (18-89 years), and 77% were men. Median time from collapse to ROSC was 15 minutes (3-50 minutes). Bystander CPR was performed in 76% and immediate postresuscitation coronary angiography in 63%. The overall good outcome rate was 70%. Both lower age and shorter time to ROSC, as well as bystander CPR and the time period after implementation of the ERC 2005 guidelines were associated with good outcome. Still, 54% of all patients aged >75 years achieved good outcome. Although age seems to influence outcome, we found that more than half of comatose OHCA survivors above 75 years showed a favorable outcome. Hence, our data do not support a limitation of postresuscitation TH based on age alone but highlights the need for more clinical trials of TH in the advanced age group.