Infectious complications after pulsatile-flow and continuous-flow left ventricular assist device implantation

Infection is a significant source of morbidity and mortality after left ventricular assist device (LVAD) implantation. Newer generation continuous-flow (CF) LVADs are smaller, requiring smaller pump pockets and drive-line exit sites as compared with pulsatile-flow (PF) devices. With their recent adoption, CF device patients benefit from improved provider experience in the detection and treatment of infectious complications. Given these advances in design and experience, we examined the incidence of infectious complications in patients receiving CF and PF devices.

We reviewed patients who received CF or PF LVADs (June 2000 to May 2009) at our institution. Incidences and timing of systemic infections (bacteremia, sepsis, severe sepsis, septic shock), device-associated infections (drive-line, LVAD pocket, sternal wound) and non-device-associated infections (catheter-related bloodstream, pneumonia, urinary tract) were compared between devices. Primary outcomes were sepsis, severe sepsis, a composite of drive-line and LVAD pocket infection, and catheter-related bloodstream infection.

Of 133 LVADs, 86 were CF. CF patients had lower pre-operative risk, more recent device implantation, and longer LVAD support time. Device type was highly correlated with reduced infections; however, on multivariate analysis, implantation date appeared to drive this association. Kaplan-Meier estimates of freedom from all primary outcomes were improved with more recent implantation (p < 0.05). On multivariate analysis, implantation date was predictive of all primary outcomes except severe sepsis, for which advanced age and worse Seattle Heart Failure Model score were predictive.

In this institutional review of post-LVAD infections, a decrease in infectious complications in CF patients was likely related to increased provider experience associated with a more recent date of implantation.