Cardiogenic shock (CS) due to acute right ventricular (RV) failure represents 7% of all shock cases and has a high 30-day mortality rate.1 The standard of care for acute RV failure includes fluids, vasoactive treatment and pacing. However, there are limited data identifying the best approach to managing these patients.
Dr Josiassen’s research compares the effects of a pharmacological vasoactive strategy to the Impella RP transvalvular RV mechanical support pump on end-organ perfusion and unloading of the heart in a porcine model of CS shock due to acute RV failure. RV CS induced by stepwise injection of polyvinyl alcohol microspheres into the right coronary artery presented as sustained reduction in cardiac output ≥50% with or without a >50% reduction in mixed venous oxygen saturation (SvO2) compared with baseline or an absolute SvO2 <30%. Echocardiogram confirmed dilation and dysfunction of the RV compared with baseline.
Pharmacological vasoactive treatment consisted of 0.1 µg/kg/min norepinephrine for 30 minutes, followed by 0.4 µg/kg/min milrinone for 150 minutes. Impella treatment consisted of implantation and activation of Impella RP at the highest performance level for 180 minutes. Impella treatment was supplemented with norepinephrine treatment if mean arterial pressure declined >50 mmHg in order to maintain coronary perfusion pressure. Pressure–volume area (PVA), cardiac workload and end-organ perfusion were monitored throughout the experiment. CS shock was successfully induced in 14 animals.
Impella RP treatment efficiently unloaded the failing RV, as measured by a reduced PVA (reflecting potential energy and stroke work) compared with vasoactive treatment. Compared with Impella RP, vasoactive treatment caused a greater increase in cerebral venous oxygen saturation. Both interventions increased renal perfusion to a similar degree. Limitations of the study include the use of healthy animals and the irreversible ischaemia and microcirculatory obstruction caused by microsphere use. Future directions include further analysis of echocardiography and biomarkers from this study, as well as future studies comparing extracorporeal membrane oxygenation (ECMO) alone versus Impella activation before vasoarterial-ECMO.
Dr Josiassen’s abstract presentation was a runner-up for an Acute Cardiac Unloading and REcovery Research Grant.