[Clinical phenotyping of acute aortic dissection patients: a latent class analysis based on a multicenter retrospective cohort study].

<b>Objective:</b> To investigate the clinical subtypes of acute aortic dissection (AAD) through latent class analysis. <b>Methods:</b> This study was a multicenter retrospective cohort study. Patients with AAD admitted to five hospitals, including Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Henan Provincial People's Hospital, Central China Fuwai Hospital of Zhengzhou University (Fuwai Central China Cardiovascular Hospital), the Third Affiliated Hospital of Xinxiang Medical University and the Second Affiliated Hospital of Chongqing Medical University, between August 2010 and December 2021 were enrolled. Based on clinical and biological characteristics, latent class analysis (models with 2 to 5 latent classes) was conducted to classify the enrolled patients. The optimal classification scheme was determined using model fitting evaluations, including log-likelihood (LL), entropy, Lo-Mendell-Rubin adjusted likelihood ratio test and so on. Clinical data of different subtypes were compared, and in-hospital mortality was analyzed across the entire population and among subgroups receiving different treatments. <b>Results:</b> A total of 2 689 AAD patients, aged 54 (46, 63) years were included, with 1 305 (48.5%) having DeBakey type Ⅰ, 156 (5.8%) type Ⅱ, and 1 228 (45. 7%) type Ⅲ dissections. The cohort comprised 2 134 (79.4%) males. The overall in-hospital mortality rate was 22.8% (613/2 689). Latent class analysis indicated that a two-class model was optimal (LL=147 413.242, entropy=0.812, and <i>P</i>_LMRT<0.001). Patients were classified into two subtypes, named clinical subtype 1 and clinical subtype 2. Compared to clinical subtype 1, clinical subtype 2 had a higher proportion of females, was older, had more dissections involving the ascending aorta, and exhibited higher rates of organ dysfunction (elevated alanine aminotransferase and creatinine levels) and inflammatory response (neutrophilia) (all <i>P</i><0.05). Clinical subtype 2 also showed higher in-hospital mortality compared to subtype 1 (26.3% (238/905) vs. 21.0% (375/1 784), <i>P</i>=0.002). Among patients undergoing surgical treatment, clinical subtype 2 had higher mortality than subtype 1 (40.1% (67/167) vs. 30.0% (101/337), <i>P</i>=0.027). However, no significant differences in mortality were observed between the two subtypes among patients receiving medical therapy or endovascular and hybrid procedures (all <i>P></i>0.05). <b>Conclusions:</b> Comprehensive latent class analysis identifies two subtypes of AAD with distinct clinical characteristics and treatment responses. These findings provide new insights into individualized clinical decision-making and prognostic evaluation for AAD patients.