Cardiac energetics and end-organ perfusion with veno-arterial extracorporeal membrane oxygenation versus ecmella for cardiogenic shock in a large animal model

Abstract

Abstract Background The use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is in severe cases of left ventricular (LV) failure associated with pulmonary edema due to inadequate LV emptying. In clinical practice VA-ECMO may be combined with Impella CP (ECMELLA), to unload the LV. We hypothesized that ECMELLA improves cardiac energetics without compromising end-organ perfusion compared to VA-ECMO alone in a porcine model of cardiogenic shock (CS). Methods Land-race pigs (weight 70 kg) were instrumented, including a LV conductance catheter and a carotid artery Doppler flow probe. Arterial blood samples were analyzed for lactate level. CS was induced with embolization in the left main coronary artery and was defined as a reduction of 50% or more in cardiac output (CO) or mixed oxygen saturation (SvO2) or a SvO2 < 30%. VA-ECMO was initiated at CS and embolization was continued until arterial pulse pressure was below 10 mmHg. At this point, Impella CP was placed in the ECMELLA arm. Support was maintained for four hours. Results CS was induced in 15 pigs (VA-ECMO n=7, ECMELLA n=8) and at CS the CO declined from 6.1 L/min (0.8) to 2.5 L/min (1.1) in the VA-ECMO arm and from 5.2 L/min (SD: 0.6) to 2.0 L/min (SD: 0.7) in the ECMELLA arm. The pressure-volume area (PVA) was comparable at CS, but significantly higher with VA-ECMO compared to ECMELLA after four hours (9567 SD: 1733 versus 6921 SD: 0536 mmHg*mL, p=0.014). Carotid blood flow increased from CS and was similar in VA-ECMO and ECMELLA (239 mL/min SD: 97 versus 213mL/min SD: 133) at four hours p=0.6. Arterial lactate was equally elevated in both groups at four hours (VA-ECMO 5.2 SD: 3.4 versus 4.2 SD: 2.9 mmol/l for ECMELLA), p=0.5). Conclusion In a porcine model of CS, we found lower PVA with the ECMELLA configuration compared to VA-ECMO, yet similar lactate levels after four hours of mechanical circulation. These findings indicate that ECMELLA better cardiac energetics without compromising systemic perfusion.Central hemodynamicsEnd-organ perfusion