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

Abstract

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.MethodsIn 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.ResultsiCPR 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.ConclusionsIn a model of prolonged cardiac arrest, the use of iCPR instead of sCPR improved CPP and doubled ROSC rates, translating into improved clinical outcomes.

Brief inhalation of nitric oxide increases resuscitation success and improves 7-day-survival after cardiac arrest in rats: a randomized controlled animal study

“…iNO is known to lower pulmonary artery pressure, hence enhancing transpulmonary blood flow. Indeed, dramatic increases in pulmonary artery pressure with concurrent reductions in pulmonary blood flow are well-documented during closed chest compressions in humans and animals [ 40 – 42 ]. Therefore it is conceivable that iNO-induced pulmonary vasodilation improved hemodynamics in our study by enhancing left ventricular filling leading to the improved ROSC rates.…”

Successful ECMO-cardiopulmonary resuscitation with the associated post-arrest cardiac dysfunction as demonstrated by MRI

“…A 60-min time-frame is often stated as the clinical accepted limit of low-flow (the period of standard CPR) before ECMO is established. In animals, without extracorporeal support the probability of successful ROSC decreases drastically when VF is untreated for more than 10–12 min, and it is almost impossible to achieve sustainable ROSC in pigs after 15 min of untreated VF [ 23 – 26 ]. In the present study, the 15 min duration of cardiac arrest followed by ECMO-CPR was chosen to allow early survival [ 23 , 27 – 30 ], but with a significant post-arrest cardiac dysfunction that could be examined by cardiac MRI in a stable state.…”

Beyond Reperfusion: Acute Ventricular Unloading and Cardioprotection During Myocardial Infarction

“…This clinical report verified the ability of the Impella device to maintain CO and perfusion pressure despite a non-pulsatile LV. Furthermore, several reports demonstrate Impella support safely bridging patients through ventricular tachycardia ablation procedures, acute right ventricular failure, and even cardiac arrest [ 89 – 92 ]. In a canine model of acute decompensated HF, Kawashima et al [ 44 ] demonstrate that Impella support led to superior ventricular unloading compared with ECMO, and hearts supported by Impella had a higher rate of successful defibrillation and recovery of sinus rhythm.…”