Doubling survival and improving clinical outcomes using a left ventricular assist device instead of chest compressions for resuscitation after prolonged cardiac arrest: a large animal study (Critical Care)

IntroductionDespite improvements in pre-hospital and post-arrest critical care, sudden cardiac arrest (CA) remains one of the leading causes of death. Improving circulation during cardiopulmonary resuscitation (CPR) may improve survival rates and long-term clinical outcomes after CA. Methods: In a porcine model, we compared standard CPR (sCPR, n = 10) with CPR using an intravascular cardiac assist device without additional chest compressions (iCPR, n = 10) following ten minutes of electrically induced ventricular fibrillation (VF). In a separate crossover experiment, 10 additional pigs were subjected to 10 minutes of VF and 6 minutes of sCPR; the iCPR device was then implanted if a return of spontaneous circulation (ROSC) was not achieved using sCPR. Animals were evaluated in respect to intra- and post-arrest hemodynamics, survival, functional outcome, cerebral- and myocardial lesions following CPR. We hypothesized that iCPR would result in a more frequent ROSC and better functional recovery than sCPR. Results: iCPR produced a mean flow of 1.36 ± 0.02 L/min, leading to significantly higher coronary perfusion pressure (CPP) values during the early period of CPR (22 ± 10 vs. 9 ± 5 mmHg, p ≤ 0.01, one min post start of CPR; 20 ± 11 vs. 10 ± 7 mmHg, p = 0.03, two min post start of CPR), resulting in high ROSC rates (100% in iCPR vs. 50% in sCPR animals; p = 0.03). iCPR animals showed significantly lower S-100 serum levels at 10 and 30 minutes following ROSC (3.5 ± 0.6 vs. 7.4 ± 3.0 ng/mL 30 minutes post ROSC, p ≤ 0.01), as well as superior clinical outcomes based on overall performance categories (OPC) (2.9 ± 1.0 vs. 4.6 ± 0.8 on Day 1, p ≤ 0.01). In crossover experiments, 80% of animals required treatment with iCPR after failed sCPR. Notably, ROSC was still achieved in 6 of the remaining 8 animals (75%) after a total of 22.8 ± 5.1 minutes of ischemia. Conclusions: In a model of prolonged cardiac arrest, the use of iCPR instead of sCPR improved CPP and doubled ROSC rates, translating into improved clinical outcomes.