背景：主动脉夹层是一种致死率极高的危重症心血管类疾病。主动脉夹层术后患者不适症状多，自我管理不佳，生活质量差。体力活动作为心脏康复的重要组成部分，可以降低心血管事件风险和死亡率，减少复发和再次入院，改善心肺功能、生活质量和预后，且对主动脉夹层术后患者预后有益，与其生活质量及健康状况密切相关。出院过渡期一般持续至出院后的三个月，是心脏康复的关键时期。国内外均有研究表明主动脉夹层术后患者对体力活动认识不足，存在不正确的观念及行为。主动脉夹层术后患者运动康复起步较晚，目前越来越受重视，然而对于主动脉夹层术后患者体力活动量缺少指南或共识推荐。同时，既往研究多关注术前体力活动对患者发病的影响，少有系统地探究主动脉夹层术后患者体力活动水平及其影响因素，且未有纵向研究探索不同主动脉夹层术后患者体力活动变化趋势以及群体异质性。

目的：描述主动脉夹层术后患者住院前（T0时期）和出院后1、2、3个月（T1-T3时期）的体力活动水平及发展趋势；分析一般人口学、疾病相关因素、社会心理因素对主动脉夹层术后患者出院后3个时期（T1、T2、T3）体力活动的影响；探究主动脉夹层术后患者从住院前至出院后3个月4个时期的体力活动变化轨迹是否存在群体异质性，拟合相应的轨迹类别并分析影响因素。

方法：本研究为纵向研究，选取就诊于中国医学科学院阜外医院，确诊为主动脉夹层并进行开胸手术或介入手术治疗的患者。采用一般资料调查表、国际体力活动问卷长卷、心脏病患者运动恐惧量表、主动脉夹层术后患者康复期不适症状自评量表、心脏康复锻炼自我效能量表、锻炼社会支持量表简版收集患者信息，并进行出院后三个月的随访。采用SPSS26.0软件进行描述和统计分析，采用Mplus8.3软件分析主动脉夹层术后患者4个时期体力活动轨迹，并分析不同轨迹的影响因素。

结果：（1）共纳入165例主动脉夹层术后患者。四个时间总体力活动中位数分别为2874MET-min/w、189MET-min/w、394MET-min/w、779MET-min/w；从各个维度上来看，T0时期以工作相关体力活动为主，T1-T3时期以休闲相关体力活动为主；从体力活动分级上来看，T0-T4时期，人数占比最多的分别是中水平体力活动（49.1%）、低水平体力活动（87.9%）、低水平体力活动（65.5%）、中水平体力活动（49.7%）。统计结果表明，随着时间变化，体力活动总水平及各维度水平存在显著差异（P＜0.05），总体力活动T1＜T2＜T3＜T0。（2）二元Logistic逐步回归结果显示，年龄、手术方式是影响主动脉夹层术后患者出院后第一个月体力活动水平的重要因素；年龄、手术方式、运动恐惧是影响主动脉夹层术后患者出院后第二个月体力活动水平的重要因素；年龄、文化程度、运动恐惧、锻炼自我效能是影响主动脉夹层术后患者出院后第三个月的重要因素。（3）采用潜类别增长模型（LCGM）确定了四组不同轨迹，根据轨迹变化特点分别命名为：高水平稳定增长达标组（类别1）、低水平快速增长达标组（类别2）、低水平缓慢增长达标组（类别3）、低水平缓慢增长不达标组（类别4）。（4）多分类Logistic逐步回归结果显示，以类别4为参照组，类别1影响因素为年龄、运动恐惧、手术相关症状；类别2影响因素为；年龄、运动恐惧、锻炼社会支持、手术相关症状；类别3影响因素为：年龄。

结论：（1）主动脉夹层术后患者出院后2个月内大部分为低水平体力活动患者，出院后第三个月主要为中水平体力活动患者。T0-T3时期体力活动整体呈现先下降后上升趋势，T3时期体力活动水平始终低于T0时期。（2）年龄、手术方式是影响主动脉夹层术后患者出院后第一个月体力活动水平的重要因素；年龄、手术方式、运动恐惧是影响主动脉夹层术后患者出院后第二个月体力活动水平的重要因素；年龄、文化程度、运动恐惧、锻炼自我效能是影响主动脉夹层术后患者出院后第三个月的重要因素。（3）主动脉夹层术后患者不同时期体力活动水平变化情况存在群体异质性，可分为四种轨迹：高水平稳定增长达标组、低水平快速增长达标组、低水平缓慢增长达标组、低水平缓慢增长不达标组。（4）年龄越大、运动恐惧水平越高、锻炼社会支持水平越低、手术相关症状越严重是低水平缓慢增长不达标组的阻碍因素。医护人员应该早期识别这类患者，并采取针对性干预措施，已达到改善主动脉夹层术后患者出院后体力活动水平的目的。

Background: Aortic dissection is a serious cardiovascular disease with an extremely high fatality rate. Patients after aortic dissection surgery have many discomfort symptoms, poor self-management and poor quality of life. Physical activity, as an important component of cardiac rehabilitation, can reduce the risk of cardiovascular events and mortality, decrease recurrence and readmission, improve cardiopulmonary function, quality of life and prognosis, and is beneficial to the prognosis of patients after aortic dissection surgery, closely related to their quality of life and health status. The discharge transition period usually lasts until three months after discharge and is a critical period for cardiac rehabilitation. Studies both at home and abroad have shown that patients after aortic dissection surgery have insufficient understanding of physical activities and have incorrect concepts and behaviors. Exercise rehabilitation for patients after aortic dissection surgery started relatively late and is receiving increasing attention at present. However, there are no guidelines or consensus recommendations for the amount of physical activity of patients after aortic dissection surgery. Meanwhile, previous studies have mostly focused on the impact of preoperative physical activity on the onset of the disease in patients. Few have systematically explored the physical activity levels and influencing factors of patients after aortic dissection surgery, and there have been no longitudinal studies to explore the changing trends of physical activity and population heterogeneity in patients after different aortic dissection surgeries.

Objective: Describe the physical activity levels and development trends of patients after aortic dissection surgery before hospitalization (T0 period) and 1, 2, and 3 months after discharge (T1-T3 period); To analyze the effects of general demographics, disease-related factors, and psychosocial factors on physical activity in patients after aortic dissection surgery at three periods (T1, T2, and T3) after discharge; To explore whether there is population heterogeneity in the physical activity change trajectories of patients after aortic dissection surgery from before hospitalization to 3 months after discharge in four periods, fit the corresponding trajectory categories and analyze the influencing factors.

Methods: This study was a longitudinal study. Patients who visited Fuwai Hospital, Chinese Academy of Medical Sciences, were diagnosed with aortic dissection and underwent thoracotomy or interventional surgery were selected. Patients' information was collected using the General Information Questionnaire, the long International Physical Activity Questionnaire, the Exercise Phobia Scale for Patients with Heart Disease, the Self-rating Scale of Discomfort Symptoms in the Rehabilitation Period of Patients after Aortic Dissection Surgery, the Self-Efficacy Scale of Cardiac Rehabilitation Exercise, and the Short version of the Exercise Social Support Scale. A follow-up was conducted three months after discharge. The SPSS26.0 software was used for description and statistical analysis. The Mplus8.3 software was used to analyze the physical activity trajectories of patients after aortic dissection surgery in four periods, and the influencing factors of different trajectories were analyzed.

Results: (1) In this research, 165 patients post - aortic dissection surgery were recruited. The median total physical activity at four times was 2874 MET-min /w, 189 MET-min /w, 394 MET-min /w, and 779 MET-min /w respectively; From various dimensions, during the T0 period, it was mainly work-related physical activities, while during the T1-T3 period, it was mainly leisure-related physical activities. From the perspective of physical activity classification, during the T0-T4 period, the largest proportions of participants were moderate physical activity (49.1%), low physical activity (87.9%), low physical activity (65.5%), and moderate physical activity (49.7%), respectively. The statistical results show that with the change of time, there are significant differences in the total level of physical activity and the levels of each dimension (P < 0.05), and the total physical activity T1 < T2 < T3 < T0. (2) The results of binary Logistic stepwise regression showed that age and surgical method were important factors affecting the physical activity level of patients after aortic dissection surgery in the first month after discharge. Age, surgical method and exercise phobia are important factors affecting the physical activity level of patients after aortic dissection surgery in the second month after discharge. Age, educational level, exercise phobia and exercise self-efficacy are important factors affecting patients after aortic dissection surgery in the third month after discharge. (3) Four different trajectories were determined by using the latent Class Growth Model (LCGM), and they were respectively named according to the characteristics of trajectory changes as follows: high-level stable growth reaching the standard group (Category 1), low-level rapid growth reaching the standard group (Category 2), low-level slow growth reaching the standard group (Category 3), and low-level slow growth not reaching the standard group (Category 4). (4) The results of multi-class Logistic stepwise regression showed that with category 4 as the reference group, the influencing factors of category 1 were age, exercise phobia, and surgery-related symptoms; The influencing factors of category 2 were age, exercise phobia, social support for exercise, surgery-related symptoms; The influencing factor of category 3 was age.

Conclusions: (1) Within 2 months after discharge, most patients after aortic dissection surgery were of low level of physical activity, and in the third month after discharge, they were mainly of moderate level of physical activity. During the period from T0 to T3, the overall physical activity showed a trend of first decreasing and then increasing. The level of physical activity during the T3 period was always lower than that during the T0 period. (2) Age and surgical methods are important factors affecting the physical activity level of patients after aortic dissection surgery in the first month after discharge; Age, surgical method and exercise phobia are important factors affecting the physical activity level of patients after aortic dissection surgery in the second month after discharge. Age, educational level, exercise phobia and exercise self-efficacy are important factors affecting patients after aortic dissection surgery in the third month after discharge. (3) There is population heterogeneity in the changes of physical activity levels in patients after aortic dissection surgery at different periods, which can be divided into four trajectories: high-level stable growth reaching the standard group, low-level rapid growth reaching the standard group, low-level slow growth reaching the standard group, and low-level slow growth not reaching the standard group. (4) Older age, higher level of exercise phobia, lower level of social support for exercise, and more severe surgery-related symptoms are the obstructive factors for the low-level slow growth non-compliant group. Medical staff should identify such patients at an early stage and take targeted intervention measures to achieve the goal of improving the physical activity level of patients after aortic dissection surgery after discharge.