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LETTER TO THE EDITOR | |
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Artificial heart transplantation
Abdul Mannan Khan Minhas1, Salman Assad2
1 Department of Internal Medicine, Orange Park Medical Center, Florida, USA
2 Department of Medicine, Shifa Tameer-e-Millat University, Islamabad, Pakistan
Date of Web Publication | 16-Jun-2017 |
Correspondence Address:
Salman Assad
Department of Medicine, Shifa Tameer.e.Millat University, Islamabad
Pakistan
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/amhs.amhs_34_17
How to cite this article: Minhas AM, Assad S. Artificial heart transplantation. Arch Med Health Sci 2017;5:142-3 |
Sir,
Heart failure has a fair share in disease burden worldwide. A very large portion with advanced heart failure has a very poor prognosis despite being on optimized medical therapy. Unfortunately, there is a huge mismatch in demand and supply for heart donors and recipients. For the patients awaiting cardiac transplantation, mechanical circulatory support has been widely utilized in the form of left ventricular assist device (LVAD) or total artificial heart (TAH). Both TAH and LVAD have been approved for the use as a bridge to transplantation; however, only LVAD has been approved for use as the destination therapy.[1] Currently, a trial is underway to support the use of TAH as the destination therapy. Most of the patients benefit from LVADs; however, the use of TAH is more appropriate in the patients who have concurrent right heart failure or other structural abnormalities.
Until now, almost 1600 TAHs have been transplanted. SynCardia temporary TAH is currently the only Food and Drug Administration (FDA), and Health Canada approved artificial heart commercially available in the market that is being used in over 50 centers in the world. A trial for Cardio West TAH (now being marketed as SynCardia TAH) was conducted between 1993 and 2002. Eighty-one patients were implanted with the device. At the end of the study, the rate of survival to transplantation was 79%, and 1- and 5-year survival rates after transplantation were 86% and 64%.[2]
SynCardia TAH consists of two artificial ventricles, each made of semirigid polyurethane. Each ventricle consists of two single leaflet mechanical valves, which regulate the blood flow. This pulsatile device is capable of generating up to 9.5 L/min of blood flow. Both the ventricles are attached to pneumatic drivelines, which are connected to the back of the external console. The console includes a monitoring computer that provides noninvasive diagnostic information. The device is surgically implanted after the removal of both the ventricles and four valves. It can only be placed in the patients with large enough body habitus that can accommodate its positioning.
A study of 47 patients evaluating the safety of device showed that patients who were supported on SynCardia TAH for more than 1 year had the following complications: systemic infections in 25 patients (53%), driveline infections in 13 patients (27%), thromboembolic events in 9 patients (19%), and hemorrhagic events in 7 patients (14%).[3]
FDA has already approved a clinical study for 19 patients to evaluate the effectiveness of SynCardia as the destination therapy.[4] Smaller SynCardia has also been designed for the use in patients with smaller body habitus and pediatric population. Moreover, the use of portable freedom driver allows the mobility of the patients and safe discharge from the hospital.[5] More clinical trials are needed to evaluate the efficacy of artificial hearts for their utilization in destination therapy. Awareness is needed about these devices in the medical community that would eventually prompt the government agencies to promote research in this area.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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