The risk factors and implications of noninfectious fever after surgery for acute type A aortic dissection

Postoperative fever is common after aortic surgery and often leads to concerns about infection. However, fever may also arise from noninfectious inflammatory responses. The aim of this study was to identify the risk factors and implications of noninfectious fever in patients undergoing surgery for acute type A aortic dissection (AD).

This retrospective analysis examined 636 patients who underwent aortic replacement for acute type A AD between 2003 and 2024. Patients were excluded if they had pre- or postoperative infections. The remaining 545 patients were divided into a "Non-fever" group and a "Noninfectious fever" group. Patient demographics, surgical details, and outcomes were compared. Multivariable logistic regression was performed to identify independent predictors of noninfectious fever.

Patients with noninfectious fever were younger (63.3±14.8 vs. 55.7±16.0 years, P<0.001) and had longer cardiopulmonary bypass (CPB) and operation times (P=0.005 and P=0.04, respectively). In the multivariable analysis, independent risk factors for noninfectious fever were age [odds ratio (OR): 0.973, 95% confidence interval (CI): 0.959-0.988, P<0.001], longer CPB time (OR: 1.008, 95% CI: 1.003-1.012, P=0.002), and complete false lumen thrombosis (OR: 2.169, 95% CI: 1.074-4.007, P=0.01). Noninfectious fever was not associated with increased risk of 30-day mortality (OR: 0.537, 95% CI: 0.222-1.297, P=0.17).

Younger age, longer CPB time, and complete false lumen thrombosis were independent risk factors for noninfectious postoperative fever following type A AD surgery. Recognizing this benign response could help to avoid unnecessary testing and antibiotics, which would improve postoperative care and resource utilization.