Mortality Following Durable Left Ventricular Assist Device Implant by Timing and Category of First Infection

Abstract

<h3>Purpose</h3> While infections are common following left ventricular assist device (LVAD) implant, the relationship between timing and category of first infection and mortality is less well understood. <h3>Methods</h3> STS Intermacs patients (>19 yrs) receiving a primary, durable continuous flow LVAD from 4/2012 to 5/2017 were included. The primary exposure was defined in 3 ways: any infection, timing of first post-implant infection (early: <90d, intermediate: 90-180d, late: >180d), and first infection category (VAD-specific, VAD-related, non-VAD). Cox proportional-hazards regression models were used to estimate the association between first infection and all-cause mortality, adjusting for comorbidities & post-implant stroke. <h3>Results</h3> A total of 12,957 patients (228,742 person-months of follow-up) were implanted (DT: 47.4%, BTT: 41.2%) at 166 centers. First infections were most often non-VAD (54.2%), followed by VAD-specific (25.4%) & VAD-related (20.4%). Rates of first infection (per 100 person-months) were highest in the early interval (10.7) vs intermediate (3.7) or late (2.7), p<0.001. Relative to patients without infection, patients with any infection had a significantly higher hazard of death (HR 3.46). First infection in the intermediate interval following implant was associated with the largest increase in hazard of death (HR 3.97), followed by late (HR 3.65) and early intervals (HR: 3.31). VAD-related infections were associated with the largest increase in hazard of death (HR 4.04) followed by non-VAD (HR 3.34), and VAD-specific infections (HR 3.23). <h3>Conclusion</h3> First infections were most often non-VAD-related and rates were highest early after implant. VAD-related infections and infections occurring in the intermediate interval were associated with the largest increase in hazard of death. A mixed-methods evaluation could explore these findings at the institutional level and why these patterns occur.