Hemodynamics and Vasopressor Support During Targeted Temperature Management at 33\ub0C Versus 36\ub0C After Out-of-Hospital Cardiac Arrest: A Post Hoc Study of the Target Temperature Management Trial

Abstract

OBJECTIVE:: To investigate the hemodynamic profile associated with different target temperatures and to assess the prognostic implication of inotropic/vasopressor support and mean arterial pressure after out-of-hospital cardiac arrest. There is a lack of information how different target temperatures may affect hemodynamics. DESIGN:: Post hoc analysis of a prospective randomized study. SETTING:: Thirthy-six ICUs in 10 countries. PATIENTS:: Nine hundred twenty patients (97%) with available vasopressor data out of 950 patients from the Target Temperature Management trial randomly assigned patients to a targeted temperature management at 33\ub0C or 36\ub0C. INTERVENTIONS:: None. MEASUREMENTS AND MAIN RESULTS:: Mean arterial pressure, heart rate, and lactate were registered at prespecified time points. The population was stratified according to cardiovascular Sequential Organ Failure Assessment = 4 defining the high vasopressor group and cardiovascular Sequential Organ Failure Assessment less than or equal to 3 defining the low vasopressor group. The targeted temperature management 33 (TTM33) group had a hemodynamic profile with lower heart rate (-7.0 min [95% confidence limit, -8.7, -5.1]; pgroup < 0.0001), similar mean arterial pressure (-1.1 mm Hg [95% confidence limit, -2.3, 0.2]; pgroup = 0.10), and increased lactate (0.6 mmol/L [95% confidence limit, 0.3, 0.8]; pgroup < 0.0001) compared with the targeted temperature management 36 (TTM36) group. A cardiovascular Sequential Organ Failure Assessment score = 4 was recorded in 54% versus 45%, p = 0.03 in the TTM33 and the TTM36 group, respectively. The high vasopressor group carried a 53% mortality rate when compared with a 34% in the low vasopressor group, plog-rank less than 0.0001, with an adjusted hazard ratio of 1.38 (95% CI, 1.11-1.71; p = 0.004). There was no interaction between vasopressor group and allocated target temperature group (p = 0.40). An inverse relationship between mean arterial pressure and mortality was identified (p = 0.0008). CONCLUSIONS:: Targeted temperature management at 33\ub0C was associated with hemodynamic alterations with decreased heart rate, elevated levels of lactate, and need for increased vasopressor support compared with targeted temperature management at 36\ub0C. Low mean arterial pressure and need for high doses of vasopressors were associated with increased mortality independent of allocated targeted temperature managemen