基于故障树理论的我国主动脉夹层死亡风险预测模型构建及管理策略

Aortic Dissection (AD) is one of the most complex and dangerous cardiovascular diseases in China. It has high mortality rates due to the acute onset, rapid proceeding, various initial symptom, high misdiagnosis rate, high referral rate, high missed diagnosis rate, and bad prognosis. In addition, the AD patients are getting younger, which put a great threat to population health. A bundle of studies have investigated the mortality risk factors and disease management methods of AD in hospital. However, little is known about some risk factors throughout the disease, such as pre-hospital factors, social and self-management factors. We have previously investigated the clinical characteristics of AD, the pre-hospital delay of acute myocardial infarction, and the continued nursing for discharged patients. Based on previous researches, the mortality risk factors of AD will be sorted out using the fault tree theory, which will be recorded during patient follow-up, as well as their survive time after definite diagnosis of AD. After that, all risk factors will be weighted and a death risk predicting model for AD patients will be established to predict the death risk so as to improve the alertness of AD high-risk groups. At the same time, we will explore the health promotion model of AD patients develop and the whole process management strategies of AD, including standardized diagnosis and treatment procedures, follow-up mechanism, comprehensive prevention and control measures. The purpose of our program is to provide the basis for the establishment of the AD evaluation system for the health administration department as well as theoretical support for the macro-policy of national health care. Finally, it will reduce the mortality of AD patients and promote the health of the population.

主动脉夹层（AD）是我国最复杂、最凶险的心血管疾病之一。其起病急、进展快、症状多样、漏诊误诊及转诊率高、预后差所致的高死亡率及发病年轻化，严重威胁人群健康。目前国内外对AD风险因素探索等疾病管理多局限于院内，在医院、社会、自我管理、院外等全程风险因素的探索有待深入。本项目在AD临床特点、急性心梗院前延迟、出院病人延续性护理等研究基础上，通过故障树理论逐层分析AD患者自发病到死亡各环节的危险因素。在前瞻性追踪随访结果的基础上，应用层次分析法对各危险因素的权重进行比较，建立Cox死亡风险模型和人工神经网络模型，综合比较探索出最优模型，并对AD患者死亡风险进行预测，提高AD高危人群的警觉性。同时探索AD人群的健康促进模式，制定规范化诊疗程序、随访机制和综合防治措施等疾病管理策略，为卫生行政部门制定AD评估体系提供依据，为国家制定医疗保健宏观政策提供理论支撑，最终降低AD患者死亡率，促进人群健康。

主动脉夹层潜在风险人群大、发病呈年轻化趋势、死亡率高，严重威胁人群健康。目前对主动脉夹层患者的管理主要集中于院内阶段，且尚未建立主动脉夹层患者全程管理可推广的大样本死亡风险预测模型。本项目对全国两地的1011名主动脉夹层患者进行了调查随访，患者1年生存率为89.59%，构建了主动脉夹层患者死亡风险故障树理论模型和死亡风险预测模型，并制定了健康促进方案及策略。在构建主动脉夹层死亡风险故障树理论模型时，课题组从院前、院内、随访三个阶段探讨了主动脉夹层死亡风险因素，形成了13个中间事件34个底事件的故障树模型：院前阶段探讨了院前时间、正向转诊及急救绿色通道对患者预后的影响，并基于上述3个方面囊括了院前死亡风险因素，包括症状（大汗、持续性疼痛）、旁观者反应、转诊（转诊前是否确诊、收入院方式、经治医院数、转诊距离），以及医务人员认知和能力；院中阶段明确血压波动性和四肢血压对患者死亡风险具有显著性影响，其中四肢血压中踝臂指数≤0.9，臂见收缩压差≥10mmHg，踝间收缩压差≥13mmHg对主动脉夹层的发生有预测作用；踝臂指数≤0.8，踝间收缩压差≥20mmHg是主动脉夹层患者死亡预测的风险阈值，自我管理（吸烟、饮酒）、疾病史（肾功能不全、高血压）、撕裂假腔范围评分、规范诊疗（血液透析、麻醉方式、体外循环）为影响因素；随访阶段从患者自我管理依从性着手，风险因素包括居住地、出院带药和规律复查。主动脉夹层死亡风险预测模型构建中以急性主动脉夹层为例，对Lasso回归后筛选出的9个变量分别建立了Cox死亡风险预测模型和BP神经网络模型，模型比较中Cox回归模型与BP神经网络的AUC值分别为0.920（0.893-0.947），0.912（0.866-0.957）；交叉验证后AUC值分别为0.897（0.790-1.000），0.899（0.824-0.975）；Brier评分分别为0.236，0.120；AIC值分别为-33.020，-425.138。基于上述研究结果，本项目明确了死亡风险关口前移的重要性，构建了主动脉夹层患者健康管理方案，并从区域性院前救治机制、信息化平台及随访机制，及四肢血压作为主动脉夹层患者死亡早期预警机制等方面提出了策略及建议，为重大疾病的风险及死亡预警提供了理论及实践依据。