Registering a Therapy in Evolution

The development of durable mechanical circulatory support systems paralleled the expansion of cardiac transplantation. The National Institutes of Health sponsored grants in the 1980s to develop implantable left heart assist systems; 20 years later, they contracted for a national registry, the Interagency Registry for Mechanical Assisted Circulatory Support, to track the clinical evolution of this new technology. The Interagency Registry for Mechanical Assisted Circulatory Support has refined the classification of New York Heart Association class IV heart failure, standardized adverse event definitions, and explored outcomes of device type, location, and strategy. The majority of mechanical circulatory support patients are between the ages of 50 and 70 years, and 90% of patients are in the highest levels of clinical instability before implantation. Six-month survival after device implant is 75%, but it increases to 80% among those not in shock at implantation. Patients who require biventricular support have decreased survival. As longer-term outcomes are analyzed, improved outcomes may justify triage of high-risk patients awaiting heart transplantation to chronic mechanical circulatory support.