Totally artificial heart implant extends life in research breakthrough

Risks of leaving a diseased heart in situ are eliminated after US university team’s artificial heart breakthrough.

An artificial device implanted in the chest of one Mississippi man kept him alive until a matching donor heart was found. 57-year-old Tim Lowell was in the final stages of congestive heart failure when the SynCardia Total Artificial Heart was used to buy him time after the Vanderbilt University Medical Center removed his diseased heart. Tim was kept alive for nearly three months by the mechanical replacement heart [1] before the medical team matched him with a donor heart and performed successful heart transplant surgery.

Longevity.Technology: Although the implanted device is not intended to function as a permanent replacement, this is a significant breakthrough in the field of bio-cybernetics. It allowed the medical team to mitigate the dangerous risks of congestive heart failure – serious or permanent damage to the lungs, kidneys, liver and eyes, among others – by completely removing the failing heart. Patient-matched replacement hearts will, in the future, be grown in pigs which take six months to reach maturity – this interim technology will form a big part of the Longevity care pathway.  

The TRL score for this Longevity.Technology domain is currently set at: ‘Late proof of concept demonstrated in real life conditions.’
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The TRL score for the technology addressed in this article is: ‘Technology completes late stage trials and has all evidence to prove safety and efficacy.’

Professor Ashish Shah, Chair of Cardiac Surgery at Vanderbilt said: “Our ability to take care of the truly complicated patients with either complex structural heart problems or problems that are just not solved by conventional technologies, can now be treated with this approach.” [2]

The Total Artificial Heart works by using pneumatics, pulses of air, to drive two ventricles that pump the blood. Four artificial valves control the blood-flow. The external driver is worn as a small backpack and is battery-driven, as well as plugging into any standard electrical outlet. All the housings, diaphragms and connectors in the mechanism are constructed from a highly-specialised polyurethane; this plastic is designed to be fatigue-resistant and strong, as well as biocompatible, thus preventing the artificial heart from being rejected by the patient’s body. The two ventricles are attached using Velcro, which means the surgical team can refine the position of the artificial heart inside the chest cavity until it is at the optimum placement [3].

Approximately 5.7 million adults in the US suffer from heart failure and research has found that one in nine deaths in 2009 had heart disease as a contributory factor. Half the people who develop heart failure in the US, die within 5 years of their diagnosis [4]. The outlook is equally bleak in the UK: over 900,000 people are living with heart disease and heart and circulatory diseases are responsible for more than 25% of all deaths; this works out as 170,000 deaths each year, or one death every three minutes [5].

The need for replacement hearts is obvious and the Total Artificial Heart is a promising step in the right direction, especially as it can function in the patient without the original heart and prevent further damage. Worldwide, there were 7435 heart transplants in 2017 [6] and as with all transplants, there are many more organs needed than are donated. As well as buying patients more time, the Total Artificial Heart paves the way into researching permanent bio-cybernetic replacement organs.

Image: bibiphoto /