High versus low mean arterial pressure targets after out-of-hospital cardiac arrest: a meta-analysis of randomized controlled trials

Abstract Background Out-of-hospital cardiac arrest (OHCA) is a significant healthcare burden, with an average global incidence of 55 per 100,000 person-years among adults. OHCA patients require blood pressure support to maintain effective mean arterial pressure (MAP) for cerebral reperfusion, which is usually achieved by intravascular fluids and vasopressors in the intensive care unit (ICU). Targeting a specific MAP has been evaluated as a treatment strategy after OHCA; however, the current evidence lacks clear guidelines regarding the optimal MAP target after OHCA. Purpose We aim to evaluate the efficacy of targeting a high MAP (>70 mmHg) versus a low MAP target (< 65 mmHg) after OHCA resuscitation. Methods We conducted a systematic review and meta-analysis synthesizing randomized controlled trials (RCTs), which were retrieved by systematically searching: PubMed, EMBASE, Web of Science, SCOPUS, and Cochrane through January 18th, 2023. Continuous and dichotomous outcomes were pooled using mean difference (MD) and risk ratio (RR) along with confidence interval (CI), using Revman V. 5.4 software. Our review protocol was prospectively published on PROSPERO with ID: CRD42023395333. Results Four RCTs with a total of 1070 patients (531 in the high MAP target group and 534 in the low MAP target group) were included in our analysis. High MAP target was significantly associated with decreased ICU length of stay (MD: -0.78 with a 95 CI [-1.54, -0.02], P= .04) and mechanical ventilation duration (MD: -0.91 with a 95 CI of [-1.51, -0.31], P= .003). However, There was no difference between targeting a high MAP versus low MAP regarding all-cause mortality (RR: 1.07 with a 95% CI [0.91, 1.27], P= 0.4), favorable neurological recovery (cerebral categories scale (CPC) ≤ 2) (RR: 1.02 with a 95% CI [0.93, 1.13], P= 0.68), and neuron-specific enolase (NSE) at 48 hours (MD: 0.54 with 95% CI [-1.67, 2.75], P = 0.63), the incidence of adverse events, including any bleeding (RR: 0.89 with a 95% CI [0.69, 1.36], P= 0.39); arrhythmia (RR: 0.91 with a 95% CI [0.46, 1.82], P= 0.79), or acute kidney injury (RR: 0.80 with a 95% CI [0.36, 1.76] and P = 0.58). Conclusion In patients with OHCA who have been resuscitated, targeting a higher MAP significantly reduced the ICU length of stay and mechanical ventilation, implying potential clinical benefit with an acceptable safety margin. However, there was no difference between targeting a high MAP versus a low MAP regarding all-cause mortality, favorable neurological recovery, and NSE. Therefore, further RCTs are still warranted to elucidate the potential clinical benefit of targeting a high MAP after OHCA before endorsement in clinical practice.Figure 1Figure 2