Increased Risk of Stroke and Death in Ventricular Assist Device Patients Varies by ISHLT Infection Category: An INTERMACS Analysis
The Journal of Heart and Lung Transplantation 4/1/19
Ventricular assist device (VAD) patients experience infections, which increase the risk of stroke and mortality. We aimed to characterize key differences in clinical outcomes for VAD patients based on the ISHLT categorization of infections: VAD-specific (e.g. pump component related), VAD-related (e.g. bloodstream infection, BSI) and non-VAD infections (e.g. pneumonia).
Query of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) identified 16,597 continuous-flow VAD recipients. Categories of infection were tested in multivariate models to determine the risk of stroke and death.
After implant, 7,046 patients (42%) developed an infection at a median of 69 days (IQR: 12-272). A majority were non-VAD infections (49%) followed by VAD-related (26%) and VAD-specific infections (25%). Non-VAD and VAD-related infections had an incidence of 0.83 events/patient-year (EPPY) compared to 0.64 EPPY for VAD-specific infections (p<0.001). BSIs were the most common form of a VAD-related infection (92%) and the majority (59%) had no associated infection. After infection, 15% (0.13 EPPY) of patients suffered a stroke with lowest incidence after a VAD-specific infection (0.09 EPPY) compared to VAD-related (0.13 EPPY) and non-VAD infections (0.12 EPPY, p<0.001). The cumulative incidence of stroke was highest after a VAD-related infection (Figure). Hemorrhagic strokes were more common than ischemic strokes in infection patients, with the highest event rate after a VAD-related infection (0.12 EPPY, p<0.001). One-year survival after an infection was 87% in VAD-specific infections, compared to VAD-related (71%) and non-VAD infections (72%, p<0.001).
The ISHLT categorization of VAD infections unveils notable differences in associated risk of stroke and mortality. A re-assessment of transplant prioritization for eligible infected VAD patients may be useful to increase transplant related survival benefit.