Infectious complications during support with a ventricular assist system (VAS) can cause severe morbidity and mortality, affecting nearly one-half of all VAS recipients. Because of the lack of a uniform definition of
infection, the incidence of this complication is hard to determine accurately. It is approximately 50% for patients being supported by an implantable VAS as a bridge to
heart transplantation and 28% for patients supported by an external, short-term VAS.
Infections can be classified according to the involvement or noninvolvement of the implanted device and according to the severity of the
infection. Severe
infections involving the implanted device may preclude
heart transplantation for some patients, but numerous patients with milder
infections have undergone successful
transplantation. Numerous factors predispose VAS patients to
infection. Postoperative
bleeding necessitating re-operation is an important contributing factor. Endotracheal tubes, intravascular
catheters, and other indwelling tubes necessary for the care of postsurgical patients are also common routes of contamination. Control of
infection may be improved with new VAS designs,
antibiotic impregnated drivelines, and
innovative therapies such as
antibiotic beads. The next generation of VASs should be inherently less susceptible to
infection because of their smaller size, reduced thrombogenicity, and better flow characteristics. In addition to more effective
antibiotics, improved VAS designs that incorporate transcutaneous energy transmission systems may reduce infectious complications and allow safe, long-term VAS support.