Abstract 07: Percutaneous Ventricular Assist Devices In Refractory Cardiac Arrest: The Role Of Chest Compressions

Abstract

Background: Recent studies describe an emerging role for percutaneous ventricular assist devices (pVADs, Impella CP®, Abiomed) as rescue therapy for refractory cardiac arrest (CA). We hypothesized that continuing mechanical chest compressions (mCPR) after initiation of pVAD would improve hemodynamics by decompressing the right ventricle and augmenting pulmonary blood flow and left ventricular filling. We performed a pilot study to test this hypothesis using a swine model of prolonged cardiac arrest. Methods: Eight Yorkshire swine, anesthetized, intubated and instrumented for hemodynamic monitoring, were subjected to untreated ventricular fibrillation for 5.75 (SD 2.90) minutes followed by mCPR for a mean of 20.00 (SD 5.0) minutes before initiation of pVAD (Table 1). After pVAD initiation mCPR was stopped (n=4) or continued (n=4). Defibrillation was attempted 4, 8 and 12 minutes after initiating pVAD circulatory support, except for the first pilot animal where it was attempted at 2 minutes. The animals that achieved return of spontaneous heartbeat (ROSHB) were maintained on pVAD support for four additional hours. Results: There was no difference in the rate of ROSHB between groups (Table 1). The pVAD + mCPR group had significantly higher pVAD flow prior to ROSHB at four- and twelve-minutes after pVAD initiation, and significantly higher end tidal CO 2 (PetCO 2 ) at four- and eight-minutes after pVAD initiation, when compared with the pVAD alone group (Table 1). There was a trend toward higher carotid artery flow prior to ROSHB in the pVAD + mCPR group compared with the pVAD alone group after pVAD initiation, but the difference was not statistically significant (Table 1). Conclusion: The addition of mCPR to pVAD support during cardiac arrest may generate higher pVAD flow and cardiac output prior to ROSHB compared to pVAD alone. Further studies are needed to determine if this approach improves other hemodynamic parameters or outcomes after prolonged cardiac arrest.