Diabetes in resuscitated comatose out-of-hospital cardiac arrest patients - A substudy of the randomized BOX trial

AIMS: This study aimed to assess mortality rates in resuscitated comatose out-of-hospital cardiac arrest (OHCA) patients with and without diabetes randomized to targets of blood pressure, oxygen, and duration of fever prevention.

METHODS AND RESULTS: Diabetic and non-diabetic patients from the BOX trial were compared. The BOX trial was a randomized, controlled, multicentre study comparing two mean arterial blood pressure targets (63 vs. 77 mmHg) in a double-blinded intervention and two open-labelled targets including a liberal and restrictive oxygenation (9-10 vs. 13-14 kPa) target and two regimes for length of fever control (36 vs. 72 h). The primary outcome for this substudy is 365-day survival. Multiple logistic regression models were used to adjust for factors known to be associated with outcome including age, sex, witnessed arrest (y/n), and time to return of spontaneous circulation (min). A total of 110 (14%) patients had pre-existing diabetes. Compared with the non-diabetic group, the patients with diabetes were older [median years (IQR) 67 (59; 73) vs. 63 (53; 72)] and had more comorbidities. The diabetic patients had an overall increased 365-day all-cause mortality (45% vs. 34%, P = 0.02). The logistic regression model adjusting for age and sex, witnessed arrest (y/n), and place of arrest gave an estimated adjusted odds ratio of 1.47 (0.93-2.30) (P = 0.10). No significant interactions were observed among interventions and outcomes related to diabetes status, P ranging from 0.10 to 0.80.

CONCLUSION: Pre-existing diabetes was associated with an increased crude 365-day mortality. No differences in outcome were observed among diabetic OHCA patients depending on the assessed blood pressure targets, oxygen levels, and durations of fever control.