A less-invasive left atrial assist device concept for diastolic heart failure: First in vitro and in vivo assessment

Chihiro Miyagi; Taiyo Kuroda; Barry D Kuban; Shengquiang Gao; Christine R Flick; Anthony R Polakowski; Jamshid H Karimov; Kiyotaka Fukamachi

doi:10.1016/j.xjon.2024.08.011

A less-invasive left atrial assist device concept for diastolic heart failure: First in vitro and in vivo assessment

JTCVS Open. 2024 Aug 28:21:180-190. doi: 10.1016/j.xjon.2024.08.011. eCollection 2024 Oct.

Authors

Chihiro Miyagi¹, Taiyo Kuroda¹, Barry D Kuban^{1

2}, Shengquiang Gao¹, Christine R Flick^{1

2}, Anthony R Polakowski^{1

2}, Jamshid H Karimov^{1

3

4}, Kiyotaka Fukamachi^{1

3

4}

Affiliations

¹ Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.
² Medical Device Solutions, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.
³ Kaufman Center for Heart Failure, Heart, Vascular, and Thoracic Institute, Cleveland Clinic, Cleveland, Ohio.
⁴ Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio.

Abstract

Objective: A less-invasive left atrial assist device (LAADx) is a novel and implantable, extracardiac blood pump concept, intended for the treatment of diastolic heart failure, represented by heart failure with preserved ejection fraction.

Methods: A mixed-flow pump was used as the working LAADx model. Its performance was evaluated at 3 speeds, using an in vitro pulsatile mock circulatory loop, with a pneumatic pump that can simulate diastolic heart failure conditions by adjusting the diastolic drive pressure. The LAADx model was implanted in 4 healthy calves. The pump's inflow and outflow cannulas were inserted into the left atrium (LA) and left ventricle (LV), respectively, without cardiopulmonary bypass. The LAADx was operated at 3 speeds, and diastolic heart failure-like conditions were induced by inflating a balloon, inserted into the LV.

Results: With the in vitro study, diastolic heart failure-like conditions were successfully induced, exhibiting decreased cardiac output and aortic pressure as well as increased mean LA pressure both mitigated with the LAADx support. With regard to the in vivo study, simulated diastolic heart failure conditions showed a decrease in aortic pressure and an increase in LA pressure and LV end-diastolic pressure, which were again mitigated by the LAADx. Echocardiography showed good positioning of the outflow cannula and neither cardiac dysfunction nor mitral interference was observed.

Conclusions: Initial in vitro and in vivo results confirmed that the LAADx model, a device concept driven by creating an extracardiac route from the LA to LV, has the potential to mitigate high LA pressure and improve LV filling of heart failure with preserved ejection fraction pathology.

Keywords: blood pump; heart failure with preserved ejection fraction; large animal model; mechanical circulatory support; minimally invasive cardiac surgery.