Impact of Impella RP Versus Vasoactive Treatment on Right and Left Ventricular Strain in a Porcine Model of Acute Cardiogenic Shock Induced by Right Coronary Artery Embolization

Abstract

Background The response of the left ventricle to cardiogenic shock (CS) caused by right ventricular (RV) infarction and the effect of treatment with either vasoactive treatment or Impella RP are not well described. We sought to determine RV and left ventricular longitudinal strain (LS) by echocardiography after initiation of either Impella RP or vasoactive treatment for CS induced by right coronary artery embolization. Methods and Results CS was induced with microsphere embolization in the right coronary artery in 20 pigs. Shock was defined as a reduction in cardiac output of ≥50% and/or an SvO 2 <30%. At the time of CS either Impella RP or vasoactive treatment (norepinephrine and milrinone) was initiated. Echocardiography and conductance measures were obtained at baseline, when CS was present, and 30, 90, and 180 minutes after induction of CS. Of 20 animals, 14 completed the protocol and were treated with either vasoactive treatment (n=7) or Impella RP (n=7); 6 animals died (3 in each group). In the RV there was a significantly higher LS with the vasoactive treatment compared with Impella RP (−7.6% [4.5] to −6.0% [5.2] vs −4.5% [6.6] to –14.2% [10.6]; P <0.006). Left ventricular LS improved with both treatments compared with shock, but with a larger effect (−9.4% [3.2] to −17.9% [3.6]) on LS with vasoactive treatment than Impella RP (−9.8% [3.1] to −12.3% [4.6]; P <0.001). We found a significant correlation between stroke work and RV LS (r=−0.60, P <0.001) and left ventricular LS (r=−0.62, P <0.001). Conclusions We found significantly higher hemodynamic effects with vasoactive treatment compared with Impella RP in both the RV and left ventricular but at a cost of increased stroke work.