Ventricular assist devices (VADs) and a Total Artificial Hearts (TAHs) are mechanical pumps that are surgically implanted alongside (VAD), or in replacement of (TAH), the heart of patients with severe heart failure (HF). They effectively work to restore the flow of blood around the body.
Currently, VADs are usually designed to support only one side of the heart, the left, which is responsible for pumping blood to the entire body. However, up to 30% of HF patients also require
support to their right heart, helping them pump blood through their lungs to collect vital oxygen. This necessitates the complete removal of the diseased heart and implantation of a TAH to assume the function of both sides of the heart, or alternatively, the implantation of a second VAD alongside the right heart to provide biventricular assistance (BiVAD). This latter approach, however, creates problems with regard to finding space to fit a second device within the chest cavity, as well as difficulties in controlling the devices to work together to balance both blood flows.
VADs and TAHs are often used instead of drugs to support HF patients until a heart transplant becomes available (bridge to transplant – BTT), or as a permanent treatment (destination therapy – DT). These approaches have been shown to prolong and improve patient quality of life above and beyond optimal medical therapy. In some cases, VADs have also been used until the failing heart recovers (bridge to recovery – BTR).
Originally, these devices used wear prone compressing sacs to replicate the pulsatile nature of the native heartbeat (first generation), however newer, smaller, and more reliable rotary turbo pumps (second and third generation) have been recently shown to produce superior results when used as a VAD. This has led to the US Food and Drug Administration (FDA) to approve this technology for use in BTT (2008) and DT (2010) applications. TAH technology on the other hand still relies on pulsatile devices, with the FDA approving their use for BTT in 2004. However, poor durability and adverse events associated with this older pulsatile technology are limiting their use for DT.
The BiVACOR® artificial heart is a revolutionary rotary turbo pump that can be used for patients that require support to pump blood to their body and lungs. The BiVACOR® is used as a BiVAD (BV Assist) if a chance of heart recovery is anticipated, whilst patients identified as having no chance of heart recovery can have the device implanted as a TAH (BV Replace). Since the BiVACOR® is a single compact device; it will fit inside the chest of most patients. Furthermore, its double-sided magnetically levitated (MAGLEV) disc is continuously co-operating to provide blood flow to the body and lungs. Durability and flow balancing issues are therefore eliminated, opening the door for use in BTT or DT applications as either a VAD or TAH.
 Rose E, Gelijns A, Moskowitz A, Heitjan D, Stevenson L, Dembitsky W, et al. Long-Term Use of A Left Ventricular Assist Device for End Stage Heart Failure. N Engl J Med. 2001;345:1435-43.
 Slaughter MS. Long-Term Continuous Flow Left Ventricular Assist Device Support and End-Organ Function: Prospects for Destination Therapy. J Card Surg. 2010;25:490-4.
 Thoratec Corporation (2010), Heartmate® II Pivotal Clinical Trial Fact Sheet, (Online), Available from: http://www.thoratec.com/downloads/HeartMate-II-Pivotal-Clinical-Trial-Fact-Sheet-2711.pdf [Accessed: 19th May 2010]