Transcriptome and metabolome after porcine hemodynamic-directed CPR compared with standard CPR and sham controls

Abstract

Objective: The effect of cardiac arrest (CA) on cerebral transcriptomics and metabolomics is unknown. We previously demonstrated hemodynamic-directed CPR (HD-CPR) improves survival with favorable neurologic outcomes versus standard CPR (Std-CPR). We hypothesized HD-CPR would preserve the cerebral transcriptome and metabolome compared to Std-CPR.

Design: Randomized pre-clinical animal trial.

Setting: Large animal resuscitation laboratory at an academic children's hospital.

Subjects: Four-week-old female piglets (8-11 kg).

Interventions: Pigs (1-month-old), three groups: 1) HD-CPR (compression depth to systolic BP 90 mmHg, vasopressors to coronary perfusion pressure 20 mmHg); 2) Std-CPR and 3) shams (no CPR). HD-CPR and Std-CPR underwent asphyxia, induced ventricular fibrillation, 10-20 min of CPR and post-resuscitation care. Primary outcomes at 24 h in cerebral cortex: 1) transcriptomic analysis (n = 4 per treatment arm, n = 8 sham) of 1727 genes using differential gene expression and 2) metabolomic analysis (n = 5 per group) of 27 metabolites using one-way ANOVA, post-hoc Tukey HSD.

Measurements and main results: 65 genes were differentially expressed between HD-CPR and Std-CPR and 72 genes between Std-CPR and sham, but only five differed between HD-CPR and sham. Std-CPR increased the concentration of five AA compared to HD-CPR and sham, including the branched chain amino acids (BCAA), but zero metabolites differed between HD-CPR and sham.

Conclusions: In cerebral cortex 24 h post CA, Std-CPR resulted in a different transcriptome and metabolome compared with either HD-CPR or sham. HD-CPR preserves the transcriptome and metabolome, and is neuroprotective. Global molecular analyses may be a novel method to assess efficacy of clinical interventions and identify therapeutic targets.

Institutional protocol number: IAC 16-001023.

Keywords: Cardiac arrest; Cardiopulmonary resuscitation; Metabolomics; RNA sequence; Transcriptome.

Fig. 1

Schematic of Experimental Protocol. Definitions of abbreviations: CPR cardiopulmonary resuscitation; ETT = endotracheal tube; VF = ventricular fibrillation; Std = Standard, CPR = cardiopulmonary resuscitation; HD = hemodynamic-directed; SBP = systolic blood pressure; AP = anterior–posterior; CoPP = coronary perfusion pressure; ROSC = return of spontaneous circulation.

Fig. 2

Transcriptome of HD-CPR following asphyxia CA global RNA expression is similar to sham animals that did not undergo cardiac arrest, while Std-CPR animals exhibited distinct RNA expression. A. PCA loading plot for the first two principal components of the RNA expression indicate HD-CPR and sham animals are similar to one another, but distinct from Std-CPR animals. B. Venn Diagram illustrating RNA transcripts differentially expressed between treatment arms. Of those analyzed, there are five genes differentially expressed between HD-CPR and sham, 72 between Std-CPR and sham, and 65 between Std-CPR and HD-CPR. Three of the five genes differentially expressed between HD-CPR and sham were also different between Std-CPR and HD-CPR. Similarly, 14 genes differentially expressed between Std-CPR and HD-CPR were also different between Std-CPR and sham. C. Volcano plot of RNA transcripts between Std-CPR and HD-CPR. Red values indicate transcripts with increased expression in Std-CPR versus HD-CPR. Blue values indicate decreased expression in Std-CPR versus HD-CPR. D. Volcano plot of RNA transcripts between Std-CPR and sham. Red values indicate transcripts with increased expression in Std-CPR versus sham. Blue values indicate decreased expression in Std-CPR versus sham. E. Volcano plot of RNA transcripts between HD-CPR and sham. Red values indicate transcripts with increased expression in HD-CPR versus sham. Blue values indicate decreased expression in HD-CPR versus sham.

Fig. 3

Cerebral cortex metabolite profiles of animals receiving HD-CPR are similar to sham animals that did not undergo cardiac arrest, while Std-CPR animals exhibited a distinct metabolite profile. A. PCA loadings plot for the first two principal components for all metabolite expression indicate HD-CPR and sham are similar to one another, but distinct from Std-CPR animals. B. Assembly of major metabolic pathways in the brain with differentially expressed metabolites shaded. Branched chain amino acid metabolic pathway is altered in Std-CPR animals. C. Std-CPR animals exhibited an increase in all branched chain amino acids compared to both HD-CPR and sham animals in cerebral cortex at 24 h after CA.