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

Introduction: Despite 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 10 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 and cerebral and myocardial lesions following CPR. We hypothesized that iCPR would result in 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 mmHg vs. 9 +/- 5 mmHg, P = 0.01, 1 minute after start of CPR; 20 +/- 11 mmHg vs. 10 +/- 7 mmHg, P = 0.03, 2 minutes after start of CPR), resulting in high ROSC rates (100% in iCPR vs. 50% in sCPR animals; P = 0.03). iCPR animals showed significantly lower serum S100 levels at 10 and 30 minutes following ROSC (3.5 +/- 0.6 ng/ml vs. 7.4 +/- 3.0 ng/ml 30 minutes after ROSC; P = 0.01), as well as superior clinical outcomes based on overall performance categories (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 six of the remaining eight 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.