Peripheral Eosinophil Count Is Associated With the Prognosis of Patients With Type B Aortic Dissection Undergoing Endovascular Aortic Repair: A Retrospective Cohort Study

BACKGROUND: Eosinophil count (EOS) has been proposed to provide prognostic information in multiple cardiovascular disorders. However, few researchers have investigated the predictive value of EOS for patients with type B aortic dissection who had thoracic endovascular repair. METHODS AND RESULTS: The authors reviewed the records of 912 patients with type B aortic dissection who were treated with thoracic endovascular repair in Changhai Hospital, Shanghai. By using receiver operating characteristic curve analysis, patients were divided into 2 groups based on the admission EOS cutoff value (<7.4×10(6)/L [n=505] and ≥7.4×10(6)/L [n=407]). To reduce selection bias, propensity score matching was applied. Multivariable regression analysis and Kaplan–Meier curves were performed to assess the association between EOS and long‐term outcomes. Furthermore, we investigated nonlinear correlations between EOS and outcomes using general additive models with restricted cubic splines. In the matched population, lower EOS was associated with significantly higher 30‐day mortality (4.1% vs 0%, P=0.007). There was no statistically difference in 30‐day adverse events between the 2 groups (all P>0.05). Kaplan–Meier analysis revealed that patients with an EOS <7.4×10(6)/L had a higher incidence of 1‐year all‐cause death (7.95% vs. 2.34%, P=0.008) and aortic‐related death (5.98% vs 1.81%, P=0.023) than those with higher EOS. Multivariable Cox analysis showed that continuous EOS was independently associated with 1‐year mortality (hazard ratio, 3.23 [95% CI, 1.20–8.33], P=0.019). In addition, we discovered a nonlinear association between EOS and 1‐year outcomes. CONCLUSIONS: Lower admission EOS values predict higher short‐ and long‐term mortality after thoracic endovascular repair.