The total artificial heart: An existential transformation beyond technology

Abstract

The concept of the total artificial heart (TAH) has long fascinated humanity, between the quest for immortality and the fear of dehumanization. Previous generations of TAH were marred by thrombotic and haemorrhagic complications, tethering patients to the hospital,¹ offering at best a few weeks of reprieve.

The new generation Aeson TAH (Carmat SA, Vélizy, France) is now a lifesaving and life-changing therapeutic option for end-stage heart failure patients with severe irreversible biventricular dysfunction. With the shortage of organ donors and the growing number of end-stage heart failure patients, a machine capable of replicating the complex function of the human heart, tireless and silent, automated but innervated, capable of adapting to the needs of the human body is a transformative advance in care. Conceptually disruptive and audacious, the Aeson TAH has been the subject of scientific studies, media coverage and financial analyses so far, with a reflection based on clinical outcomes, statistics and economic profitability. However, being implanted with a TAH cannot merely reflect this scientific revolution. It is a profound intimate transformation that raises existential, societal, and ethical questions. Amid the technology, data, and parameters, who thinks about the lives of these women and men now living without a natural heart? What do these patients think of this transhumanist dream they are turning into reality? What are the impacts for patients, society, and humanity?

The Aeson TAH stands out for its unique features. Designed to mimic the structure of the human heart it now fits in the hand, is pulsatile, haemocompatible, and self-regulating.² A decade ago, Alain Carpentier reported the initial experience with the first two prototypes implanted in patients with end-stage heart failure.³ Preliminary results were deemed insufficient and the quest for the ideal machine continued. Today, more than 90 patients worldwide have received the Aeson TAH, including over 60 since programme restart in 2022. Forty of these patients are part of the French EFICAS trial, aiming to demonstrate the safety and efficacy of Aeson TAH as a bridge to transplantation, focusing on stroke-free survival at 6 months (ClinicalTrials.gov ID NCT04475393). Results from the full cohort are anticipated in 2025. However, initial analyses in critically ill patients with cardiogenic shock requiring extracorporeal life support are highly encouraging, demonstrating a 6-month survival rate of 90%. This survival is accompanied by significant improvements in functional capacity and quality of life (Martin A.C., unpublished data). Through its embedded sensors, Aeson TAH can instantly adjust cardiac output to life intensity, decreasing it at rest and increasing it during exertion, replicating the natural circadian variations in response to changes in venous return. It is designed for a return to life, offering mobility and autonomy. And it succeeds: patients live again, work, do exercise, fall in love. In our experience, patients express a unanimous feeling of gratitude for receiving this device, coupled with the realization that life is possible once again despite its burdens: the cumbersome exoskeleton, limited battery autonomy, the ever-present hum, and occasional, piercing alarms. These sentiments echo those reported in the early days of left ventricular assist devices (LVADs) in 1997: ‘eventually, many of these patients are able to leave the hospital, return to their families, and go back to their jobs…’.⁴ The challenge is met, Aeson TAH is a revolution.

Patients express unwavering confidence in the machine, assured and convinced of its performance and reliability. They articulate neither fear nor doubt. Yet, in the intimacy of our discussions, they reveal a troubling and bewildering existential disorientation, crystallized around a single question: the absence of a heartbeat. Although the arterial pressure waveform generated by the Aeson TAH is indistinguishable from that of a natural heart, the machine cannot recreate the heartbeat itself. Not just the audible beat that reassures us of life, but the palpable apex beat that connects us to a shared human experience. The heartbeat is a universal symbol of life and temporality. As French philosopher Alain wrote, ‘the feeling of self arises from a heartbeat’. Instead, implanted patients hear the constant hum of an artificial heart—automatic, ceaseless, operating at about a hundred beats per minute, regulated by flow variations but denervated and disconnected, unresponsive to emotions. Anger, sadness, desire, fear—none of these human emotions alter its unfaltering rhythm. This loss of a heartbeat, which not only severs an emotional tether but also disrupts a metaphysical connection to time and the essence of life itself, raises profound questions about identity. Can one still experience the essence of ‘being’ when stripped of such an elemental biological connection? How do patients reconcile the mechanization of their most intimate organ—the heart—within the framework of their identity, their human experience, and their relationship with others? Yet, despite this acknowledged dissonance, patients, whether consciously or unconsciously, refer to their ‘new heart’ rather than to a prosthetic device or an intruder. This linguistic choice—perhaps an act of acceptance, affective tolerance or a subconscious reclamation of identity—underscores the resilience of the human brain to overcome even radical transformation.

Patients with TAH often face a disconnect between their lived experiences and societal perceptions. They struggle to reconcile their ‘new’ existence with the world around them. Feedback from patients re-entering daily life highlights the complexity of social reintegration. Some view them as figures from science fiction—bionic humans equipped with an artificial organ that replaces or even enhances natural functions, predictable and infallible. Others look at them as vulnerable, frail, diminished. Patients, however, challenge these polarized perceptions. They describe themselves as neither ‘augmented’ nor ‘less than human’. Instead, they see themselves as ‘repaired’ humans, striving to reconstruct their lives and identities, but humans in the making. While society may celebrate them as superheroes, their response is often humble: ‘If heroes we are, it is as reluctant heroes’. At present, patients with TAH are exceptional cases. This marginalization carries the risk of stigmatization, as patients may experience ‘dys-appearance’, where the body becomes a source of discomfort or alienation for the individual and society. As the number of patients implanted increases, society will need to move away from viewing them as outliers and instead embrace them as part of an evolving norm. The integration of individuals with TAH would necessitate significant societal adjustments, particularly in healthcare systems, to manage their unique medical, psychological, and technological needs. It would also require new social norms to accommodate the emergence of ‘everyday cyborgs’. This shift raises a fundamental question. Does the adoption of TAH mark a new form of humanity? If so, it challenges us to promote respect, diversity, and integration, ensuring these individuals are fully accepted as equal members of society, free from stigma and prejudice. This evolution requires us to rethink how we define humanity and our collective commitment to inclusion.

The Aeson TAH is currently an exceptional but costly therapy, limited to a few leading centres equipped with the necessary expertise and advanced facilities for cardiac assistance and transplantation programmes. Like other advanced heart failure therapies (LVADs, transplantation), the TAH raises significant ethical questions about equitable access to care. Currently approved as a bridge to transplantation, its use depends on strict inclusion criteria, requiring patients to meet eligibility thresholds for age, comorbidities, overall health, and social environment.

One of the most intriguing aspects of the Aeson TAH is its potential to serve as a permanent solution. In a near future, it may become possible to eliminate the need for external drivelines using transcutaneous battery chargers. Such technological improvements would make TAH far more acceptable as a destination therapy, replacing heart transplantation for older patients or those otherwise ineligible. This introduces a profound ethical dilemma: who decides which patients qualify for such life-extending therapies? What criteria should guide this decision? Should access to these expensive technologies be limited, and if so, to whom? Conversely, why restrict TAH access when it offers an additional therapeutic option that results in a net benefit of more lives saved? However, should life be preserved at all costs, even if it means living with a machine at the core of one's existence? If so, it challenges fundamental notions of life and death. While LVADs and transplantation are seen as sustainable solutions but with an inherent finitude, the TAH could be viewed as a life-extending therapy. What does it mean to die for a patient under mechanical ventilation, when the heart continues to beat and circulate oxygenated blood? Does death require the deliberate act of deactivating the machine? Conversely, is ‘technological’ death truly death? In this way TAH disrupts end-of-life definitions.

Definitely, the story of the Aeson TAH is not just about scientific and technological revolution; it is about integrating these advancements into the social and cultural fabric of humanity, compelling us to (re)think life itself. This endeavor can only succeed through interdisciplinary dialogue spanning philosophy, sociology, ethics, and technology. Such conversations are essential to understand the profound impact of living with a TAH and to ensure that technological progress respects dignity, autonomy, and humanity.

Conflict of interest: A.C.M. reports honoraria from Abbott, Alliance BMS-Pfizer, Bayer, Boehringer Ingelheim, Carmat, Medtronic, Novartis, and Sanofi. B.C. reports honoraria from Edwards Lifesciences, AOP Health, and Nordic Pharma.