Innovations in cardiac transplantation

[Heart failure: ventricular assist devices and cardiac transplantation : A review of current surgical innovations]

BACKGROUND

End-stage heart failure is one of the leading causes of death in Germany. Cardiac transplantation is still considered the gold standard for the treatment of terminal heart failure; however, there is a discrepancy between patients on the waiting list and yearly performed transplantations. As an alternative, ventricular assist devices have achieved a high level of importance but treatment is still associated with challenges. Novel systems as well as innovative surgical techniques contribute to improving the safety and effectiveness of the treatment.

OBJECTIVE

To generate an overview of current surgical innovations in cardiac transplantation and mechanical circulatory support.

MATERIAL AND METHODS

A Medline search was conducted regarding innovations in cardiac transplantation and mechanical circulatory support.

RESULTS AND CONCLUSION

Not only the number of yearly performed cardiac transplantations has changed but also recipient profiles. While in the pioneering era of transplantation the typical candidate was young, not previously operated on and with lower levels of comorbidities, today's patients are significantly older, have been fitted with ventricular assist devices and have increased operative risk profiles. Modern methods of organ preservation enable longer transportation and operation times as well as an improved assessment of graft function and perspectives for graft optimization in the future. In the area of ventricular assist devices, advances in the reduction of the stroke rate seem to have been achieved by the latest generation devices. From a surgical perspective, less invasive surgical techniques with promising initial results have been established at numerous centers.

Heart re-transplantation in Eurotransplant

Internationally 3% of the donor hearts are distributed to re-transplant patients. In Eurotransplant, only patients with a primary graft dysfunction (PGD) within 1 week after heart transplantation (HTX) are indicated for high urgency listing. The aim of this study is to provide evidence for the discussion on whether these patients should still be allocated with priority. All consecutive HTX performed in the period 1981-2015 were included. Multivariate Cox' model was built including: donor and recipient age and gender, ischaemia time, recipient diagnose, urgency status and era. The study population included 18 490 HTX, of these 463 (2.6%) were repeat transplants. The major indications for re-HTX were cardiac allograft vasculopathy (CAV) (50%), PGD (26%) and acute rejection (21%). In a multivariate model, compared with first HTX hazards ratio and 95% confidence interval for repeat HTX were 2.27 (1.83-2.82) for PGD, 2.24 (1.76-2.85) for acute rejection and 1.22 (1.00-1.48) for CAV (P < 0.0001). Outcome after cardiac re-HTX strongly depends on the indication for re-HTX with acceptable outcomes for CAV. In contrast, just 47.5% of all hearts transplanted in patients who were re-transplanted for PGD still functioned at 1-month post-transplant. Alternative options like VA-ECMO should be first offered before opting for acute re-transplantation.

Machine perfusion of thoracic organs

This article summarizes recent knowledge and clinical advances in machine perfusion (MP) of thoracic organs. MP of thoracic organs has gained much attention during the last decade. Clinical studies are investigating the role of MP to preserve, resuscitate, and assess heart and lungs prior to transplantation. Currently, MP of the cardiac allograft is essential in all type DCD heart transplantation while MP of the pulmonary allograft is mandatory in uncontrolled DCD lung transplantation. MP of thoracic organs also offers an exciting platform to further investigate downregulation of the innate and adaptive immunity prior to reperfusion of the allograft in recipients. MP provides a promising technology that allows pre-transplant preservation, resuscitation, assessment, repair, and conditioning of cardiac and pulmonary allografts outside the body in a near physiologic state prior to planned transplantation. Results of ongoing clinical trials are awaited to estimate the true clinical value of this new technology in advancing the field of heart and lung transplantation by increasing the total number and the quality of available organs and by further improving recipient early and long-term outcome.