Intravascular versus surface cooling for targeted temperature management after out-of-hospital cardiac arrest: an analysis of the TTH48 trial

Abstract

Background The aim of this study was to explore the performance and outcomes for intravascular (IC) versus surface cooling devices (SFC) for targeted temperature management (TTM) after out-of-hospital cardiac arrest. Methods A retrospective analysis of data from the Time-differentiated Therapeutic Hypothermia (TTH48) trial (NCT01689077), which compared whether TTM at 33 °C for 48 h results in better neurologic outcomes compared with standard 24-h duration. Devices were assessed for the speed of cooling and rewarming rates. Precision was assessed by measuring temperature variability (TV), i.e., the standard deviation (SD) of all temperature measurements in the cooling phase. Main outcomes were overall mortality and poor neurological outcome, including death, severe disability, or vegetative status. Results A total of 352 patients had available data and were included in the analysis; of those, 218 (62%) were managed with IC. A total of 114/218 (53%) patients with IC and 61/134 (43%) with SFC were cooled for 48 h ( p = 0.22). Time to target temperature (≤ 34 °C) was significantly shorter for patients treated with endovascular devices (2.2 [1.1–4.0] vs. 4.2 [2.7–6.0] h, p < 0.001), but temperature was also lower on admission (35.0 [34.2–35.6] vs. 35.3 [34.5–35.8]°C; p = 0.02) and cooling rate was similar (0.4 [0.2–0.8] vs. 0.4 [0.2–0.6]°C/h; p = 0.14) when compared to SFC. Temperature variability was significantly lower in the endovascular device group when compared with SFC methods (0.6 [0.4–0.9] vs. 0.7 [0.5–1.0]°C; p = 0.007), as was rewarming rate (0.31 [0.22–0.44] vs. 0.37 [0.29–0.49]°C/hour; p = 0.02). There was no statistically significant difference in mortality (endovascular 65/218, 29% vs. others 43/134, 32%; p = 0.72) or poor neurological outcome (endovascular 69/218, 32% vs. others 51/134, 38%; p = 0.24) between type of devices. Conclusions Endovascular cooling devices were more precise than SFC methods in patients cooled at 33 °C after out-of-hospital cardiac arrest. Main outcomes were similar with regard to the cooling methods.

Effect of different methods of cooling for targeted temperature management on outcome after cardiac arrest: a systematic review and meta-analysis

“…1). Of those, 24 were excluded after a full-paper analysis (Additional file 1: Table S2); a total of 22 studies [12–19, 23–37], including 8027 patients, were eventually included for meta-analysis.

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“…The characteristics of the selected studies are summarized in Table 1 and Additional file 1. We identified 4 RCTs (high quality of evidence for two [12, 33] and moderate for two [13, 24]; Additional file 1: Table S3), four prospective studies (low level of evidence [16, 27, 35, 37] with an additional one comparing a prospective cohort with historical controls (very low quality of evidence [36]), and 13 retrospective studies (very low quality of evidence [15, 17, 23, 25, 26, 28–32, 34]), with two of them being a secondary post hoc analysis of RCTs (low quality of evidence [14, 19]). The risk of bias (RB) was low in one study [14] and high for all the others (Tables 2 and 3).…”

“…This approach may have reduced the number of eligible citations; however, other reference libraries have a higher proportion of non-English citations, with probably smaller cohorts of patients for the TTM setting. However, as one study was already accepted for publication at that moment [19], the literature search was extended up to 22 February 2019.…”

Effects of endovascular and surface cooling on resuscitation in patients with cardiac arrest and a comparison of effectiveness, stability, and safety: a systematic review and meta-analysis

“…All were the contrast between EC and SC; however, the selection of equipment differed among the studies. In terms of EC, 16 studies used the Coolgard/Thermogard system [15] to compare with surface cooling, and the remaining 4 studies [24,28,35,37] did not indicate specific endovascular cooling equipment used. In terms of SC, 6 studies [30,35,36,38,39,41] selected ArcticSun equipment [45] for surface cooling, and other studies included ice packs, cooling blankets, cold liquid infusions, and intracavity perfusion cooling.…”

“…There were 16 cohort studies [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] and 4 RCTs [38][39][40][41]. The analysis included 14 single-center studies and 6 multicenter studies [23,31,33,[35][36][37]. Eleven studies included IHCA patients and OHCA patients, and 9 studies only included OHCA patients.…”