The Tradeoff between Travel Time from Home to Hospital and Door to Balloon Time in Determining Mortality among STEMI Patients Undergoing PCI

BackgroundIn ST-segment elevation myocardial infarction (STEMI), even in presence of short door to balloon time (DTBT), timely reperfusion with percutaneous coronary intervention (PCI) is hampered by pre-hospital delays. Travel time (TT) constitutes a relevant part of these delays and may contribute to worse outcomes.ObjectiveTo evaluate the relationship between TT from home to hospital and DTBT on 30-day mortality after PCI among patients with STEMI.MethodsWe enrolled a cohort of 3,608 STEMI patients with a DTBT within 120 minutes who underwent PCI between years 2009 and 2013 in Lazio Region (Italy). We calculated the minimum travel time from residential address to emergency department where the first medical contact occurred. We defined system delay as the sum of travel time and DTBT time. Logistic regression models, including clinical and demographic characteristics were used to estimate the effect of TT and DTBT on mortality.ResultsAmong patients with 0–90 minutes of system delay, TT above the median value is positively associated with mortality (OR = 2.46; P = 0.009). Survival benefit associated with DTBT below the median results only among patients with TT below the median (OR for DTBT below the median = 0.39; P = 0.013), (OR for interaction between TT and DTBT = 2.36; p = 0.076).ConclusionTT affects survival after PCI for STEMI, even in the presence of health care systems compliant with current guidelines. Results emphasize the importance of health system initiatives to reduce pre-hospital delay. Utilization of TT can contribute to a better estimate of patient mortality risk in the evaluation of quality of care.研究背景：在ST段抬高型心肌梗死（ST-segment elevation myocardial infarction）患者中，即便首诊至球囊扩张时间（door to balloon time, DTBT）较短，及时行经皮冠状动脉介入治疗（percutaneous coronary intervention, PCI）实现再灌注仍会受到院前延迟的阻碍。出行时间（travel time, TT）是此类延迟的重要组成部分，可能会导致不良预后。 研究目的：评估ST段抬高型心肌梗死患者的居家至医院出行时间与首诊至球囊扩张时间，及其与经皮冠状动脉介入治疗后30天死亡率之间的关联。 研究方法：本研究纳入2009年至2013年间意大利拉齐奥大区接受经皮冠状动脉介入治疗的3608例首诊至球囊扩张时间≤120分钟的ST段抬高型心肌梗死队列患者。研究人员计算了患者居住地址至首次医疗接触急诊部门的最短出行时间，并将系统延迟定义为出行时间与首诊至球囊扩张时间之和。通过纳入临床与人口统计学特征的逻辑回归模型，评估出行时间与首诊至球囊扩张时间对死亡率的影响。 研究结果：在系统延迟为0~90分钟的患者中，出行时间高于中位数水平与死亡率呈正相关（优势比OR=2.46，P=0.009）。仅在出行时间低于中位数水平的患者中，首诊至球囊扩张时间低于中位数水平方能带来生存获益（首诊至球囊扩张时间低于中位数的优势比OR=0.39，P=0.013）；出行时间与首诊至球囊扩张时间的交互项优势比OR=2.36，P=0.076。 研究结论：即便所在医疗体系符合现行指南要求，出行时间仍会影响ST段抬高型心肌梗死患者经皮冠状动脉介入治疗后的生存结局。本研究结果强调了医疗体系采取措施缩短院前延迟的重要性，同时指出在医疗质量评估中，利用出行时间可更精准地估算患者的死亡风险。