A Valveless Pulsatile Pump for Heart Failure with Preserved Ejection Fraction: Hemo- and Fluid Dynamic Feasibility

Abstract

Treatment of heart failure with preserved ejection fraction (HFpEF) remains a major unmet medical need. An implantable valveless pulsatile pump with a single cannula—the CoPulse pump—may provide beneficial hemodynamic support for select HFpEF patients when connected to the failing ventricle. We aimed to demonstrate hemodynamic efficacy and hemocompatible design feasibility for this novel assist device. The hemodynamic effect of the pump was investigated with an in vitro circulatory mock loop and an ex vivo isolated porcine heart model. The hydraulic design was optimized using computational fluid dynamics (CFD), and validated by 4D-flow magnetic resonance imaging (MRI). The pump reduced left atrial pressure (> 27%) and increased cardiac output (> 14%) in vitro. Ex vivo experiments revealed elevated total stroke volume at increased end-systolic volume during pump support. Asymmetric cannula positioning indicated superior washout, decreased stagnation (8.06 mm2 vs. 31.42 mm2), and marginal blood trauma potential with moderate shear stresses (< 24 Pa) in silico. Good agreement in flow velocities was evident among CFD and 4D-flow MRI data (r > 0.76). The CoPulse pump proved hemodynamically effective. Hemocompatibility metrics were comparable to those of a previously reported, typical pulsatile pump with two cannulae. The encouraging in vitro, ex vivo, and hemocompatibility results substantiate further development of the CoPulse pump.

Video‐based valve motion combined with computational fluid dynamics gives stable and accurate simulations of blood flow in the Realheart total artificial heart

“…25 Maximum Re in the ventricle chamber, based on a flow rate given by motion of the atrioventricular plane piston, was 1740. Two-equation turbulence models, such as the SST k-ω model, sometimes chosen for artificial hearts, 19,28 are parameterized for fully turbulent flows and so are not necessarily better than a laminar assumption 16 which is chosen by other authors. 21,29,30 This can be seen in the results from the FDA CFD Benchmark medical device study, 31 in which the two-equation turbulence models gave good velocity predictions in some regions, but in other regions the laminar assumption gave better velocity predictions, and for several cases, the laminar assumption gave better pressure predictions.…”

Device-Based Solutions to Improve Cardiac Physiology and Hemodynamics in Heart Failure With Preserved Ejection Fraction

“…Although the use of HFrEF MCS devices that support the pumping action of the left ventricle is not recommended in HFpEF, due to reported risks of atrial suction and intraventricular thrombosis ( 86 , 172 , 182 , 185 , 186 , 187 , 188 ), analogous solutions that are specific for HFpEF are currently under development to reduce LAP, enhance LV filling, and restore cardiac output. In this context, a variety of in silico and in vitro studies have been conducted on a number of proposed approaches to investigate their feasibility ( 22 , 175 , 176 , 177 , 178 , 179 ). To date, however, animal experimentation for MCS for HFpEF remains minimal, and no clinical testing has yet been conducted.…”

“…The design and feasibility of a valveless pulsatile pump (CoPulse) for the treatment of HFpEF were recently described by Granegger et al ( 175 ) and Escher et al ( 176 ). Designed for implantation at the apex of the heart, the CoPulse device is composed of 1 blood chamber and 1 air chamber divided by a flexible polyurethane membrane.…”

“…Recently, Escher et al ( 176 ) developed a prototype of the CoPulse pump and tested its hydraulic characteristics by using computational fluid dynamics and 4-dimensional flow magnetic resonance imaging. The ex vivo results from the isolated porcine heart model revealed improved HFpEF hemodynamics by reducing LAP and increasing cardiac output.…”

Left atrial assist device for heart failure with preserved ejection fraction: initial results with torque control mode in diastolic heart failure model

“…The only example of adding LV volume to the LV is the CoPulse, a valveless pulsatile pump with a single cannula connected to the LV apex [33,34]. This pump can add around 30 mL to each LV stroke volume with the pump chamber and create pulsatile flow synchronized with the LV cardiac cycle by using the LV pressure as a signal.…”