Heart transplantation and mechanical circulatory support

Abstract

Dr. O.P. Yadava, CEO and Chief Cardiac Surgeon, National Heart Institute, New Delhi, India, and Editor-in-Chief, Indian Journal of Thoracic and Cardiovascular Surgery, in conversation with Dr. Vivek Rao, Chief of Cardiovascular Surgery, Peter Munk Cardiac Centre, University of Toronto, discusses donation after circulatory death, role of pulsatility in mechanical circulatory support (MCS) and current status of MCS versus heart transplant as a destination therapy.

Electronic supplementary material

The online version of this article (10.1007/s12055-020-01044-6) contains supplementary material, which is available to authorized users.

Dr. Vivek Rao feels that India has the talent, capabilities and infrastructure to be world leaders in heart transplant. However, there are two major barriers:

1. Lack of organisational structure to identify donors and match them to the recipients and

2. Lack of public awareness and a poor public perception that heart transplantation is truly an act of benevolence and generosity.

Transplantation with donors after circulatory determination of death (DCD) is growing and has the potential to bridge the gap [1] between available organs and recipients by increasing the donor pool by 20–30%.

Commenting on the equivalence of mechanical circulatory support (MCS) as a destination therapy against heart transplant, Dr. Rao feels that the perioperative mortality rates of the two procedures are beginning to converge. However, quality of life is much better and near normal with heart transplants [2]. In MCS, there are problems with percutaneous drive lines. Even exposure to water is an issue and frequent change of battery too is cumbersome. However, with the advent of fully implantable systems, the gap is narrowing and ultimately the patients may have to make a choice of getting a mechanical circulatory support within days and weeks versus waiting for months for a heart transplant. On being asked, is pulsatility important or are the continuous flow device systems the way to go in the future, Dr. Rao candidly admits that he was surprised to see such good results with continuous flow systems [3, 4]. He believes in the importance of pulsatility for the vasculature [5]. New aortic regurgitation and gastrointestinal malformations leading to bleeding are probably related to non-pulsatile flow. Going forward, he thinks pulsatility will return to the mechanical circulatory support.

Biological hearts too are being developed and the French Company Carmat is one of them, but Dr. Rao is a little sceptical on the evolution of a bio-engineered heart and cell-based therapies [6]. It is difficult to make these cells cross-talk with each other, which is essential for these cells to contract in a synchronised fashion and at the same time not interfere with the working of the native cells. Cell-based therapies are pro-arrhythmogenic and that is another down side. He differentiates between the development of a ‘beating heart’ from a ‘functioning heart’, which is able to sustain end-organ perfusion, and the latter may be decades away.