How Close Are We To The Dream Of An Artificial Heart?

The quest for a complete artificial heart has been a decades-long journey in the medical field. Along with the efforts of developing methods to supplement the lives of patients with end-stage heart failures, challenges, innovations, and breakthroughs have occurred. The total artificial heart (TAH) is at the forefront of artificial heart technology, providing hope for patients with limited alternatives. 

The Rise of Mechanical Circulatory Support: 

Heart failure is a significant global health challenge, with cardiovascular diseases accounting for a third of all deaths. Despite the optimal standard treatment being heart transplantation, the number of available donor hearts has remained stagnant for the past decade, unable to meet the increasing demand. This setback has fueled the exponential growth in the use of mechanical circulatory support devices like the TAH and the more prevalent left ventricular assist device (LVAD). 

While most patients find sufficient treatment with LVADs, a smaller group faces challenges, such as concurrent right ventricular failure or structural barriers to LVAD placement. For these cases, the TAH is a crucial therapeutic option, providing relief to those with significant biventricular dysfunction. 

Exploring the TAH’s History: 

The TAH’s history is a sequence followed through with continuation despite failures and pioneering efforts. Willem Kolf and his team laid the groundwork, performing the first successful animal TAH implant in 1957. Early human trials, however, were hindered by ethical controversies and poor post-implantation survival rates. 

As heart transplantation outcomes improved in the 1980s, the focus shifted from permanent TAH implants to using them as a bridge to transplantation. Copeland’s success with the CardioWest TAH in 1985 marked a turning point, leading to clinical trials and, eventually, FDA approval.

Today, the portable Freedom Driver allows patients to await transplants outside the hospital, highlighting the device’s evolution. 

Patient Selection and Surgical Procedures: 

Compared to the widespread use of LVADs, the TAH is reserved for a select group of patients, with the SynCardia TAH being the sole FDA-approved device in the United States. Patient selection is meticulous, focusing on those unsuitable for LVADs due to factors such as central venous pressures, ventricular function, and anatomical constraints. 

Surgical implantation involves intricate procedures, requiring median sternotomy, cannulation of major vessels, and excision of native ventricles. The TAH, with its polyurethane ventricles and mechanical valves, mimics the natural heart’s function, providing hemodynamic support through external pumping. 

Navigating Complications and Outcomes: 

While the TAH has proven successful in bridging patients to transplantation, complications are inherent. Strokes, infections, bleeding, and thrombosis are among the challenges, demanding a multi-faceted approach to long-term anticoagulation. Ongoing research explores the potential use of novel anticoagulants to enhance patient outcomes. 

Long-term complications, though still under scrutiny, reveal promising insights. Data shows that the TAH’s role may extend beyond transplantation, with the FDA approving a study for its use as destination therapy. Smaller device versions are also in development, challenging traditional chest size constraints and expanding possibilities for a broader range of patients to children as well. 

Looking Ahead To A Future of Hope: 

As TAH continues to pave the path in mechanical circulatory support, its role in destination therapy is as follows. With the FDA approving studies for this novel application, the potential for the TAH to revolutionize care for those ineligible for transplantation is within reach. 

The journey toward the artificial heart exemplifies the synergy between medical innovation and human resilience. The TAH stands as a testament to the advances we’ve made in combating end-stage heart failure, offering not just a bridge to transplantation but a lifeline for those previously considered beyond help.

By. Hayoung Kim