Article

Abstract: Right Ventricular Energetic Efficiency Improvement During Left Ventricular Unloading in Post-MI Pigs

Abstract

Published online:

Citation:Interventional Cardiology Review 2021;16(Suppl 2):20–1.

Support: The development of this supplement was funded by Abiomed.

Open access:

This work is open access under the CC-BY-NC 4.0 License which allows users to copy, redistribute and make derivative works for non-commercial purposes, provided the original work is cited correctly.

Thirty per cent of heart failure patients experience right ventricular (RV) overloading, dilation and subsequent RV failure after left ventricular (LV) unloading by a mechanical support device, such as Impella. The Ishikawa lab presented data at the 2019 Acute Cardiac Unloading and REcovery (A-CURE) symposium demonstrating flow-dependent RV dilatation after LV Impella support in pigs with MI.

The impact of acute LV unloading with Impella on RV energetic efficiency remains unclear.

Dr Kariya’s hypothesis is that myocardial oxygen consumption (MVO2) efficiency improves in the loaded RV during Impella LV support in post-MI pigs. Female Yorkshire pigs (n=3) received LV Impella CP support 1 week after induction of MI. The impact of LV Impella support on RV energetics was studied using a Millar pressure–volume catheter in the right ventricle. The RV MVO2 rate was studied by measuring the blood oxygen content difference between the right coronary artery and coronary vein on the RV free wall surface (by surgical approach). Regional myocardial perfusion was assessed using fluorescently labelled microspheres.

Impella support reduced LV pressure and volume while increasing RV stroke work, stroke work (SW) over 1 minute (SW × heart rate), pressure–volume area (PVA), and PVA over 1 minute (PVA × heart rate). MVO2 as a function of stroke work over 1 minute also significantly decreased in all pigs, indicating improved energy efficiency in loaded RV during LV Impella support. Future directions include repeating the study with additional animals and in silico mechanistic investigations into how Impella LV support affects the behaviour of sarcomeric proteins in the RV wall.

Dr Kariya’s abstract presentation was a runner-up for an A-CURE Research Grant.