Status, Indications, and Use of Cardiac Replacement Therapy in the Era of Multimodal Mechanical Approaches to Circulatory Support: A Scoping Review

Abstract

The aim of this review is to describe the current use, indications, and outcomes of the Syncardia temporary total artificial heart (TAH) (Syncardia Systems, Tucson, AZ, USA), the only TAH currently approved as a bridge-to-transplant strategy in Canada, the United States, and Europe. With more than 1700 implantations worldwide, the Syncardia temporary TAH is the most commonly used pump. Globally, it represents 2% of the long-term mechanical circulatory support devices implanted, with a recent decrease in its use. The main candidates for TAH are heart transplant candidates suffering from acute or decompensated chronic irreversible biventricular failure at high risk of imminent death and for whom a suitable donor is not available. Most patients receiving a TAH are acutely ill, characterized by an INTERMACS profile of 1 or 2, and 20% are under extracorporeal membrane oxygenation. The TAH provides efficient circulatory support and allows the end-organ to recover from the initial hypoperfusion injury. More than 60% of patients implanted with a Syncardia TAH will later undergo transplantation, with a 1-year survival rate of 70% after transplantation, compared with a 1-year survival rate of ∼ 42% in nontransplant patients. Bleeding, infection, stroke, and acute kidney injury are the most common complications in this critically ill population. The new miniaturization of the console (Freedom Portable Driver) facilitates the recovery of TAH recipients by allowing ambulation, aggressive physiotherapy, and, eventually, hospital discharge. This last aspect is one of the main benefits of TAH compared with other biventricular assist devices. In conclusion, the Syncardia temporary TAH is a reasonable bridge-to-transplant option for selected patients with either biventricular failure or special anatomic conditions.