Factors associated with neutropenia post heart transplantation.

Background: Neutropenia is a serious complication following heart transplantation (OHT); however, risk factors for its development and its association with outcomes is not well described. We sought to study the prevalence of neutropenia, risk factors associated with its development, and its impact on infection, rejection, and survival.

Methods: A retrospective single-center analysis of adult OHT recipients from July 2004 to December 2017 was performed. Demographic, laboratory, medication, infection, rejection, and survival data were collected for 1 year post-OHT. Baseline laboratory measurements were collected within the 24 hours before OHT. Neutropenia was defined as absolute neutrophil count ≤1000 cells/mm3. Cox proportional hazards models explored associations with time to first neutropenia. Associations between neutropenia, analyzed as a time-dependent covariate, with secondary outcomes of time to infection, rejection, or death were also examined.

Results: Of 278 OHT recipients, 84 (30%) developed neutropenia at a median of 142 days (range 81-228) after transplant. Factors independently associated with increased risk of neutropenia included lower baseline WBC (HR 1.12; 95% CI 1.11-1.24), pre-OHT ventricular assist device (1.63; 1.00-2.66), high-risk CMV serostatus [donor positive, recipient negative] (1.86; 1.19-2.88), and having a previous CMV infection (4.07; 3.92-13.7).

Conclusions: Neutropenia is a fairly common occurrence after adult OHT. CMV infection was associated with subsequent neutropenia, however, no statistically significant differences in outcomes were found between neutropenic and non-neutropenic patients in this small study. It remains to be determined in future studies if medication changes in response to neutropenia would impact patient outcomes.