Association of Prehospital Rearrest With Outcome Following Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis of Observational Studies.

Objectives: Exposure to prehospital rearrest has previously been associated with mortality following out-of-hospital cardiac arrest (OHCA). Our objective was to conduct a systematic review and meta-analysis examining the association between prehospital rearrest and survival in adults following OHCA resuscitation.

Methods: We searched the PubMed, Scopus, and Web of Science bibliographic databases for observational studies that included adult OHCA patients who achieved return of spontaneous circulation in the prehospital setting following OHCA and reported survival to hospital discharge data stratified by rearrest status. The primary exposure was prehospital rearrest. The primary outcome for this study was survival to hospital discharge. Secondary outcomes included survival with a favorable neurological outcome and rearrest prevalence. We pooled data using inverse heterogeneity modeling and presented effect sizes for the survival outcomes as odds ratios with 95% confidence intervals. We quantified heterogeneity using Cochran's Q and the I² statistic and examined small study effects using Doi plots and the LFK index.

Results: Of the 84 publications screened, we included 7 observational studies containing 27,045 patients with survival to hospital discharge data. Rearrest was common (30% [18-43%]; n = 7 studies; Q = 1086.1, p < 0.001; I² = 99%; LFK index = 1.21) and associated with both decreased odds of survival to discharge (pooled aOR: 0.27 [0.22, 0.33]; n = 7 studies; Q = 32.2, p < 0.01, I² = 81%, LFK index = -0.08) and decreased odds of survival to discharge with a favorable neurological outcome (pooled aOR: 0.25, [0.22, 0.28]; n = 4 studies; Q = 3.5, p = 0.3; I² = 13%, LFK index = 1.30).

Conclusions: Rearrest is common and associated with decreased survival following OHCA. The pooled result of this meta-analysis suggests that preventing rearrest in five patients would be necessary to save one life.