Clinical Indications for Implantation of the Total Artificial Heart

Abstract

The total artificial heart (TAH) is effective for bridging patients with biventricular heart failure (BiVHF) to transplantation. It consists of two pneumatic pumps with four mechanical valves that replace nearly the entire myocardium, thus also making it effective therapy for heart failure from alternative (ALT) anatomical and pathophysiological causes that preclude left ventricular assist device (LVAD). This report reviews the clinical indications and outcomes for TAH implantation at our institution from 2006 to 2012. We sought to characterize and compare survival to transplant for patients with BiVHF to those with ALT indications. The overall survival to transplant for all patients was 86% (57/66). There was a trend towards decreased survival to transplantation in the ALT group compared with the BiVHF group (77% vs. 93%, HR 0.42 [95% confidence interval 0.1, 1.7], log-rank test: p = 0.2). This was likely driven by certain high risk subgroups of allograft failure, LVAD failure, and acute postinfarct shock.

Airway complications of total artificial heart

“…The TAH has been approved by Food and Drug Administration as a bridge to transplant in patients awaiting cardiac transplantations. [ 1 2 3 4 5 ] Risk of early bleeding is not uncommon in patients with total artificial heart and therefore delayed sternal closure is preferred in many centers. [ 1 ] Other complications such as mediastinal tamponade and renal failure could occur due to altered physiology.…”

The ongoing quest for the first total artificial heart as destination therapy

“…The risk of post-transplantation complications increases with prolonged TAH support 128 . The most frequently reported causes of death during support with a SynCardia device are multiorgan failure (40%), thromboembolic complications (13%) and infection (10%) 129,130,131,132,133,134,135,136 . Although minor device malfunctions are frequently described in the literature, severe device malfunctions that lead to death are rare (<2% of the deaths during SynCardia support) 129,130,131,132,133,134,135,136 .…”

“…The most frequently reported causes of death during support with a SynCardia device are multiorgan failure (40%), thromboembolic complications (13%) and infection (10%) 129,130,131,132,133,134,135,136 . Although minor device malfunctions are frequently described in the literature, severe device malfunctions that lead to death are rare (<2% of the deaths during SynCardia support) 129,130,131,132,133,134,135,136 . The hydraulic TAH developed by Carmat received CE approval as bridge to transplantation therapy in 2020, but the company is continuing clinical research with the aim of ultimately using the Carmat TAH as destination therapy 56 .…”

“…The percutaneous drivelines of both TAHs are associated with low quality of life and a high risk of infection 128 . Long-term support with the SynCardia TAH is associated with serious risks such as stroke and multiorgan failure 128,129,130,131,132,133,134,135,136 .…”

Mechanical Circulatory Support

“…There have been multiple studies looking at outcomes for patients who undergo total artificial heart as a bridge to transplant. The Virginia Commonwealth University Medical Center published data for 66 patients; mean time of support was 87.5 days, 76% were successfully bridged to transplant, 15% were discharged home on Freedom Driver, 11% were still awaiting transplantation, and 14% died on the device (34). Similar results were found by Copeland et al (35); 101 patients were supported for a mean of 87 days, 68% successfully bridged to transplant, and 32 patients died.…”