Preoperative lymphopenia is a predictor of postoperative adverse outcomes in children with congenital heart disease

Objective: Lymphopenia is a predictor of adverse clinical outcomes in adults with various systemic diseases. We hypothesized that preoperative absolute lymphopenia (absolute lymphocyte count of less than 3000 cells/μL) is associated with adverse postoperative outcomes in children with congenital heart disease undergoing corrective or palliative surgery on cardiopulmonary bypass during the first 2 years of life. Methods: A retrospective single center cohort study was performed. Categorical variables were analyzed with the χ² test. Preoperative variables were analyzed with logistic and linear regression analysis to determine whether they were associated with adverse outcomes. Results: Analysis was performed on 280 patients, of whom 124 were female and 156 were male. Seventy-one patients were neonates (≤30 days) at the time of the operation. Ninety patients had an absolute lymphocyte count of less than 3000 cells/μL before the operation. Regression models showed that RACHS-1 categories 5 and 6, age, and preoperative lymphopenia were significantly associated with postoperative mortality (P < .0006). Within RACHS-1 groups, lymphopenia remained a significant predictor of mortality for patients in RACHS categories 3 and 4. Lymphopenia and age were associated with longer length of stay and length of mechanical ventilation within RACHS categories 1 to 4 (P < .05). Preoperative lymphopenia was the only predictor of use of postoperative nitric oxide (P < .05). Conclusions: Preoperative lymphopenia is a predictor of adverse postoperative outcomes in children with congenital heart disease who undergo a corrective or palliative procedure with cardiopulmonary bypass during the first 2 years of life.