Turbocharging diseased hearts - 25 years of artificial hearts in Vienna

Vienna (25th May 2011) - For several decades, a research group at the Medical University of Vienna and the Ludwig Boltzmann Society has been playing a leading role worldwide in producing innovations in the field of artificial hearts. The Vienna artificial heart was implanted for the first time 25 years ago. Originally used as a stopgap until a heart became available for transplantation, an artificial heart is now even a long-term option for patients with serious heart conditions.

A human heart beats around three billion times over the course of a person's lifetime and, depending on demand, pumps between 5 and around 40 litres of blood around the body every minute. During this process, the blood is transported from the right-hand side of the heart to the lungs, enriched with oxygen and then pumped from the left-hand side of the heart to the body, where organs are supplied with the vital oxygen they need to function.

At rest, a heart has an output of around 1.5 Watt, rising to 10 Watt and more during exercise. When the heart fails, however, barely any more output than the basic minimum at rest can be achieved. The causes for this are varied and range from damage to the heart muscle as a result of a heart attack, inflammation of the cardiac muscle caused by leaking aortic valves or even as a result of untreated high blood pressure. The effects are the same: in the advanced stages of heart failure, even everyday activities such as simple walking can quickly lead to exhaustion and shortness of breath. With more than 10 million people affected by the condition, heart failure is one of the most commonly seen general medical complaints in Europe. A further almost 10 million people already have cardiac muscle weakness but do not show any symptoms. In severe forms, or if medication is insufficient, a heart transplant or the implantation of an artificial heart is required.

Turbocharger for a weak heart
One of the modern artificial hearts that the scientists in Vienna are working with is no bigger than a thumb. "An artificial heart is used like a turbocharger in the left ventricle of the weakened heart and takes over the majority of the pumping action. The assisted heart and the entire organism is therefore able to recover", explains Georg Wieselthaler, surgeon and clinical lead on the artificial heart programme at the MedUni Vienna, who has been contributing his expertise in the development of artificial hearts for 25 years. "This means we are able to prepare even severely ill and weakened patients for heart transplant surgery and bridge the time until the procedure." People who would have been terminally ill in the past are now able to lead largely normal lives, take moderate exercise and often even return to work. People with artificial hearts are only recognisable to those in the know by a battery bag on their hip.

Artificial heart instead of transplantation
 "An artificial heart is increasingly becoming a long-term treatment option for us", says Heinrich Schima, technical leader of the Vienna artificial heart programme. "We have developed control systems that adapt to the body's physiological demands, and we have successfully been able to constantly monitor the interaction between the remaining cardiac function and the implant. In a multi-centre study we are currently leading, we are investigating the safety and user-friendliness of these systems. We are also developing cannulas with special blood conservation for future systems that can be implanted using keyhole surgery."

All in all, the survival rate and quality of life of these patients have improved tremendously. Whereas 10 years ago a transplant was urgently needed, since fewer than 50% of patients survived for more than two years, the two-year survival rate in Vienna is currently at 85%, a top-class value worldwide.

Pioneering achievements in Vienna
35 patients are currently being provided with artificial hearts by the experts at the Medical University of Vienna at Vienna's General Hospital. All in all, more than 300 such implants have been carried out to date, some of which were pioneering achievements: The first use of the eponymous "New Vienna Heart" in 1986 was also the first successful bridging until a transplant procedure in Europe. The New Vienna Heart featured a pulsating membrane and valves, similar to a heart, and was implanted as a complete substitute for the patient's own heart. In 1999, a patient was discharged home - a world first - with a rotating blood pump that generated an even, regular flow of blood. In 2006, a rotating blood pump with a hydromagnetic, contactless bearing was implanted in Vienna - another world first. The latest innovations include automatic regulation which adapts the pump's output to the patient's physiological demands and the development of a technology that can be use to continuously monitor the remaining heart function.

Collaboration is the key to success
One crucial element of Vienna's success story is the interdisciplinary collaboration between experts from various specialties. The Ludwig Boltzmann Cluster for Cardiovascular Research, for example, includes physicists (Centre for Medical Physics and Biomedical Technology), experimental researchers (Department of Biomedical Research), surgeons (University Department of Surgery) and cardiologists (University Department of Internal Medicine II and Wilheminenspital) who work together on a translational basis in fundamental research and clinical research.

Wolfgang Schütz, Rector of the Medical University of Vienna says: "The goal of our research in this field is to develop reliable, long-term support systems. The experts at the MedUni Vienna are cooperating on a global scale with leading manufacturers and centres to do this, and are playing a crucial role in the latest developments. The results show that we are on the right path."

Claudia Lingner, Managing Director of the Ludwig Boltzmann Society: "As part of a major reform in 2005, the LBG successfully merged several institutions to form the LB Cluster for Cardiovascular Research. Today, we believe this move has been validated, since it was possible to bundle resources productively and encourage sustainability in one of LBG's core areas of activity, namely clinical research. The MedUni Vienna helped us do this, and has proven itself to be a valuable cooperation partner."