Historical Aspects of Mechanical Circulatory Support

Establishing the Concept

In the 1930s, Carrel and Lindbergh developed an in vitro artificial heart-like apparatus for keeping organs alive outside the body. They removed the hearts, kidneys, ovaries, adrenal glands, thyroid glands, and spleens of small animals to watch them develop and function over the course of several days. Acute animal studies in Russia and the United States followed in the 1940s. However, the meaningful origin of the modern era of mechanical circulation support (MCS) can be traced to the development of the heart-lung machine by Gibbon ( Table 1.1 ) and its first successful clinical use in 1953. The device was developed for cardiopulmonary bypass so that surgical cardiac procedures that require hours of circulatory support could be performed. The success of the device and the need for prolonged circulatory support for patients who could not be weaned from the heart-lung machine or whose hearts could recover with longer durations of support provided the initial impetus for developing devices that could provide long-term circulatory support. The optimism in the 1950s and 1960s that circulation could be successfully supported for extended periods by an artificial heart spurred its development by pioneers such as Kolff, Akutsu, DeBakey, Liotta, and Kantrowitz. In 1963, DeBakey and Lederberg testified before the US Congress on the need for an artificial heart in very different domains: for patients otherwise healthy except for their failed heart and for isolated travelers on long space journeys. These hearings coincided with the debate about the implications of the Russian Sputnik Program and unbridled national enthusiasm for taking on large technologic challenges such as the program to put the first man on the moon, which had begun just a few years earlier.

In 1964, with special congressional approval, the National Heart Advisory Council established the mission-oriented Artificial Heart Program (AHP) to design and develop devices to assist a failing heart and to rehabilitate heart failure (HF) patients. In the initial planning stages of the program, cardiology and surgery experts recommended that clinical systems be capable of a cardiac output of 10 L/min, be able to maintain normal blood pressure, and be “biocompatible” (a vague physiological term then and now). These and other physiological parameters represented the defined design goals of the first generation of MCS systems. Despite this limited set of design inputs, engineers, biologists, and clinicians created teams and collaborations and used them, when appropriate, as quantifiable engineering design inputs to achieve the physiological goals in the early MCS systems.

Important progress on these early MCS systems resulted from the cooperation and collaboration fostered by the National Heart, Lung, and Blood Institute (NHLBI). In 1977, following a recommendation from the Cardiology Advisory Committee, the NHLBI Devices and Technology Branch (DTB) started the annual Contractors Meeting. The primary purpose of the meeting was to provide a public forum for showcasing the progress of the contract research projects. The DTB viewed the meeting as an opportunity for gathering the branch grantees and contractors together to share ideas and network with other teams. After a decade of successful annual meetings sponsored by the NHLBI, the meeting was moved to Louisville, Kentucky, as the “Cardiovascular Science and Technology: Basic and Applied” meeting under the leadership of Jack Norman, then to Washington, DC, with the guidance of Hank Edmunds, and was finally integrated into the Annual Meeting of the American Society of Artificial Internal Organs by then President Bob Eberhart (1993). This progression has preserved the spirit of collaboration of the original Contractors Meeting, which also includes the highly regarded Hastings Lecture dedicated to the memory of Dr. Frank Hastings, the first chief of the NHLBI Artificial Heart Program.

The annual meetings emphasized the importance of developing collaborative venues for the field to share results, both positive and negative, and develop a common language across disciplines with procedural guidelines, which improve the comparability of data between research teams.

During the early period of the program, spanning from 1963 to 1980, progress on implantable, long-term ventricular assist systems outpaced similar work on the more widely publicized total artificial heart (TAH) systems. In fact, short-term ventricular assist systems were being fabricated for use in initial clinical trials in the late 1970s. The Institute of Medicine Committee report to “Evaluate the NHLBI Artificial Heart Program” contains a useful chronology of research and related important events from 1963 to 1991.

The first generation (1980) of implantable MCS systems was designed to meet a 2-year operational goal during benchtop reliability testing. Next followed the NHLBI Readiness Program. This program aimed to ensure the functional reliability of the MCS systems that demonstrated the greatest promise. Each awarded contractor placed 12 MCS systems on “Mock Circulations” to assess their function during a simulated cycle of daily life for 2 years without interruption or maintenance. Success was completing the test with no more than one system failure at 2 years.