Cluster analysis of patients with chronic rhinosinusitis and asthma after endoscopic sinus surgery

Background: Patients with chronic rhinosinusitis with nasal polyps and asthma (CRSwAS) are highly heterogenous in severity and prognosis. The clinical phenotypes and inflammatory endotypes of CRSwAS and their association with outcomes of endoscopic sinus surgery (ESS) have not been fully studied yet.

Objective: We aimed to find out the clinical phenotypes of CRSwAS and explore their relationship with ESS outcomes using cluster analysis.

Methods: We recruited 103 consecutive adult patients with CRSwAS who had undergone ESS and been followed up for more than 1 year. For cluster analysis, we collected the data from 63 variables pertaining to demographic characteristics, preoperative disease status, surgical techniques, postoperative medical treatment, and outcomes. Eosinophilic CRS was defined as greater than or equal to 10 eosinophils/high-power field, and sinus computed tomography was evaluated by Lund-Mackay sinus computed tomography score (LM score).

Results: We screened 92 eligible patients and 13 preoperative variables for balanced iterative reducing and clustering using hierarchies cluster analysis. Patients with CRSwAS were divided into 4 clusters with distinct ESS outcomes: (1) cluster 1, characterized by aspirin-exacerbated respiratory disease, eosinophilic CRS, high preoperative LM score, moderate-to-severe asthma, and uncontrolled CRS after ESS; (2) cluster 2, characterized as having female dominance (66.67%), non-aspirin-exacerbated respiratory disease, eosinophilic CRS, high preoperative LM score, moderate-to-severe asthma, and uncontrolled CRS after ESS; (3) cluster 3, characterized as having female dominance (95.83%), noneosinophilic CRS, low preoperative LM score, moderate asthma, and controlled CRS after ESS; and (4) cluster 4, characterized as men-only, smoker, noneosinophilic CRS, low preoperative LM score, mild asthma, and controlled CRS after ESS.

Conclusion: CRSwAS has distinct clusters, each corresponding to unique clinical and inflammatory characteristics and ESS outcomes.