Working formulation for the standardization of definitions of infections in patients using ventricular assist devices

In 2009, the International Society for Heart and Lung Transplantation (ISHLT) recognized the importance of infectionrelated morbidity and mortality in patients using ventricular assist devices (VADs) and the growing need for a consensusbased expert opinion to provide standard definitions of infections in these patients. The aim of these standard definitions is to improve clinical-investigator communication, allowing meaningful comparison in practice and outcomes between different centers and different VAD devices. In 2010, a core group of experts, including infectious diseases specialists, cardiologists, pathologists, radiologists, and cardiothoracic surgeons, formed an ISHLT Infectious Diseases Working Group to develop agreed criteria for definitions of infections in VAD patients. These definitions have been created by adapting and expanding on existing standardized definitions, which are based on the pathophysiology of equivalent infectious processes in prosthetic devices, such as cardiac prosthetic valve infections, intravascular catheter-related infections, and prosthetic joint infections. These definitions have been divided into 3 sections: VAD-specific infections, VAD-related infections, and non-VAD infections. Owing to the constant shortage of donor organs, new allocation systems, and improved medical therapies for congestive cardiac failure, the overwhelming trend in cardiac transplantation has been toward listing principally the most critically ill patients, that is, those requiring inpatient inotropic therapy for mechanical circulatory support (MCS). The ventricular assist device (VAD) has an expanding role in the management of these patients, both as a bridge to transplantation and as a destination therapy (ie, alternative to transplantation). According to United Network of Organ Sharing (UNOS) registry data, 9,000 transplant candidates have undergone MCS since 1999, comprising 33% of all listed patients and 75% of all listed inpatients. 1