Abstract Body: Introduction: The neuroprotective benefit of hypothermic temperature control (TC) has not consistently translated into clinical practice. We previously defined high quality (HQ) TC induction based on treatment-related factors. We set out to evaluate TC quality across three institutions and evaluate the association between TC quality and clinical outcomes.

Methods: Retrospective analysis of institutional registry data collected between 2021-2024 in unresponsive out-of-hospital cardiac arrest (OHCA) survivors across three academic centers with established cardiac arrest programs. Eligible patients included those ≥18 years of age, treated with hypothermic TC (33-36°C), and admitted to an intensive care unit. A TC quality score was assigned for each patient (Figure 1). The primary outcome was survival to hospital discharge. The secondary outcome was good neurologic outcome at hospital discharge, defined as a Cerebral Performance Category score of 1-3. Univariate and multivariate logistic regression analyses were performed to assess the relationship between quality of TC, binarized as HQ (≥ 3) or low-quality (LQ) TC (≤2), and outcomes.

Results: Our cohort included 217 patients treated with TC. Patients were predominantly male (N=146, 67.3%) with a mean (standard deviation) age of 55.6 (15.9) years, suffered a non-shockable rhythm arrest (N=151, 69.6%) and received bystander CPR (N=118, 54.4%). The median [IQR] Pittsburgh Cardiac Arrest Category score was 4 [3,4], mean (SD) lactate 8.6 (7.6) mmol/L, and pH 7.14 (0.16). The median [IQR] pre-induction time was 3.2 [2.1, 5.2] hours and 88 (40.6%) were treated with early neuromuscular blockade. The median [IQR] TC score was 3 [2, 4]; 139 (64.1%) received HQ TC. Frequency of HQ TC by center was 68.8% (N=66), 53.5% (N=46), and 77.1% (N=27). Demographics and arrest-related variables were similar between quality groups (Table 1). Adjusting for confounders in the multivariable model, HQ TC was associated with improved survival to hospital discharge and good neurologic outcome OR (95% CI) 4.22 (1.64-11.97) and 2.90 (1.05-8.69), respectively. The direction and magnitude of effect were consistent across centers.

Conclusion: In unresponsive OHCA survivors, HQ TC was associated with improved survival and good neurologic outcome at hospital discharge. Lack of standardization in TC parameters may influence efficacy, and practice variability likely contributes to the translational gap seen with hypothermia.