Abstract: Background　Patients presented to hospital during off-hours may experience poorer quality of care and clinical outcomes.However，in China，few studies examined the variations in clinical processes and outcomes across presentation times and days in patients with acute myocardial infarction（AMI）.Objective　This study aimed to comparatively analyze the impact of daytime and nighttime presentations and workday and off-day presentations on treatment efficiency and in-hospital mortality in AMI patients.Methods　We consecutively enrolled 2 109 AMI patients admitted to 11 tertiary general hospitals in Chengdu with accreditation as chest pain centers during January 2017 to June 2019.Patients were stratified into daytime group （n=1 235） and night-time group （n=874） according to admission time，while were divided into workday group （n=1 442） and off-day group （n=667） according to admission date.Clinical characteristics，treatment efficiency of STEMI patients with emergent PCI （including S-to-B time，S-to-D time，FMC-to-B time，D-to-B time，compliance rate of FMC-to-B time and D-to-B time），and in-hospital mortality were investigated between different groups.Multivariate regression analysis was used to analyze the influencing factors of in-hospital mortality.Results　Compared to STEMI patients with emergent PCI in daytime group，those in nighttime group had dramatically longer average S-to-B，FMC-to-B and D-to-B time，and much lower compliance rates of D-to-B and FMC-to-B time（P<0.05），while there was no obvious difference in the treatment efficiency between such patients in workday group and off-day group（P>0.05）.In-hospital mortality of AMI patients，non-STEMI patients，and STEMI patients underwent emergent PCI in nighttime group was significantly higher than that of those in daytime group （P<0.05）.But the in-hospital mortality was similar in AMI patients in workday and off-day groups，and so was that in non-STEMI patients，STEMI patients，and STEMI patients with and without emergent PCI in the two groups（P>0.05）.Multivariate Logistic regression analysis revealed that age 〔OR=1.051，95%CI（1.023，1.080）〕，diagnosis〔OR=2.820，95%CI（1.163，6.841）〕，cardiogenic shock 〔OR=7.463，95%CI（4.066，13.697）〕，sudden cardiac arrest 〔OR=5.729，95%CI（1.616，20.314）〕，multi-vessel disease 〔OR=1.889，95%CI（1.080，3.303）〕，and nighttime presentation 〔OR=1.788，95%CI（1.036，3.087）〕 were influencing factors of in-hospital death in AMI patients.Conclusion　It was proved that there was circadian difference but not workday and off-day difference in the treatment of AMI patients in Chengdu in our study.AMI patients admitted at night-time had more in-hospital treatment delays，longer total ischemic time，and higher in-hospital mortality when compared with those admitted during daytime.

Key words: Myocardial infarction, Institutional practice, Day＆ night, Night-time, In-hospital mortality, Treatment efficiency

摘要： 背景　在非正常工作时间入院就诊的患者，其救治质量和预后可能会较正常工作时间入院就诊患者差。而目前中国缺少关于急性心肌梗死（AMI）救治效率在不同就诊时间和就诊日期的差异性的研究。目的　比较夜间就诊和日间就诊、工作日就诊和非工作日就诊的AMI患者的救治效率和院内死亡率。方法　纳入2017年1月—2019年6月就诊于成都地区的11家已建立胸痛中心的三级综合医院的2 109例AMI患者。根据患者就诊时间分为日间组
（1 235例）和夜间组（874例）；根据就诊日期分为工作日组（1 442例）和非工作日组（667例）。比较两组AMI患者的临床特征、行急诊经皮冠状动脉介入治疗（PCI）的ST段抬高型心肌梗死（STEMI）患者早期救治效率〔症状发作至球囊开通的时间（S-to-B），症状发作至到达医院大门的时间（S-to-D），首次医疗接触至球囊开通时间（FMC-to-B），到达医院大门至球囊开通的时间（D-to-B），D-to-B达标率，FMC-to-B达标率〕和AMI患者院内死亡率，并分析患者院内死亡的影响因素。结果　夜间组行PCI的STEMI患者S-to-B、FMC-to-B、D-to-B长于日间组，D-to-B达标率、FMC-to-B达标率低于日间组（P<0.05）。工作日组和非工作日组S-to-B、S-to-D、FMC-to-B、D-to-B、D-to-B达标率、FMC-to-B达标率比较，差异均无统计学意义（P>0.05）。夜间组AMI患者院内死亡率、非ST段抬高型心肌梗死（NSTEMI）患者院内死亡率、行急诊PCI的STEMI患者院内死亡率高于日间组（P<0.05）。工作日组和非工作日组AMI患者院内死亡率、NSTEMI患者院内死亡率、STEMI患者院内死亡率、行急诊PCI的STEMI患者院内死亡率、未行急诊PCI的STEMI患者院内死亡率比较，差异均无统计学意义（P>0.05）。多因素Logistic回归分析结果显示，年龄〔OR=1.051，95%CI（1.023，1.080）〕、诊断疾病〔OR=2.820，95%CI（1.163，6.841）〕、心源性休克〔OR=7.463，95%CI（4.066，13.697）〕、院内心搏骤停〔OR=5.729，95%CI（1.616，20.314）〕、多支血管病变〔OR=1.889，95%CI（1.080，3.303）〕、夜间就诊〔OR=1.788，95%CI（1.036，3.087）〕是AMI患者院内死亡的影响因素（P<0.05）。结论　成都地区AMI的救治不存在工作日和非工作日就诊之间的差异，但存在昼夜差异。相对于日间来院就诊的AMI患者，夜间来院就诊的AMI患者院内救治延误更严重，心肌总缺血时间更长，且院内死亡率更高。

关键词: 心肌梗死, 院内诊疗, 昼夜, 夜间, 院内死亡率, 救治效率