ABSTRACT: Background: Both the American Heart Association (AHA) and European Resuscitation Council (ERC) have strongly recommended targeted temperature management (TTM) for patients who remain in coma after return of spontaneous circulation (ROSC). However, the role of TTM, especially hypothermia, in cardiac arrest patients after TTM2 trials has become much uncertain. Methods: We searched four online databases (PubMed, Embase, CENTRAL, and Web of Science) and conducted a Bayesian network meta-analysis. Based on the time of collapse to ROSC and whether the patient received TTM or not, we divided this analysis into eight groups (<20 min + TTM, <20 min, 20-39 min + TTM, 20-39 min, 40-59 min + TTM, 40-59 min, ≥60 min + TTM and ≥60 min) to compare their 30-day and at-discharge survival and neurologic outcomes. Results: From an initial search of 3,023 articles, a total of 9,005 patients from 42 trials were eligible and were included in this network meta-analysis. Compared with other groups, patients in the <20 min + TTM group were more likely to have better survival and good neurologic outcomes (probability = 46.1 and 52.5%, respectively). In comparing the same time groups with and without TTM, only the survival and neurologic outcome of the 20-39 min + TTM group was significantly better than that of the 20-39 min group [odds ratio = 1.41, 95% confidence interval (1.04-1.91); OR = 1.46, 95% CI (1.07-2.00) respectively]. Applying TTM with <20 min or more than 40 min of collapse to ROSC did not improve survival or neurologic outcome [ <20 min vs. <20 min + TTM: OR = 1.02, 95% CI (0.61-1.71)/OR = 1.03, 95% CI (0.61-1.75); 40-59 min vs. 40-59 min + TTM: OR = 1.50, 95% CI (0.97-2.32)/OR = 1.40, 95% CI (0.81-2.44); ≧60 min vs. ≧60 min + TTM: OR = 2.09, 95% CI (0.70-6.24)/OR = 4.14, 95% CI (0.91-18.74), respectively]. Both survival and good neurologic outcome were closely related to the time from collapse to ROSC. Conclusion: Survival and good neurologic outcome are closely associated with the time of collapse to ROSC. These findings supported that 20-40 min of collapse to ROSC should be a more suitable indication for TTM for cardiac arrest patients. Moreover, the future trials should pay more attention to these patients who suffer from moderate injury. Systematic Review Registration: [https://inplasy.com/?s=202180027], identifier [INPLASY202180027].
