Wang Henry E, Marroquin Oscar C, Smith Kenneth J
Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Ann Emerg Med. 2009 Feb;53(2):233-240. doi: 10.1016/j.annemergmed.2008.07.020. Epub 2008 Sep 18.
One potential strategy in the emergency medical services (EMS) care of acute ST-segment elevation myocardial infarction (STEMI) is to bypass the nearest community hospital in favor of a more distant specialty center able to perform primary percutaneous coronary intervention. We seek to determine whether EMS transport of out-of-hospital STEMI patients directly to more distant specialty percutaneous coronary intervention centers will alter 30-day survival compared with transport to the nearest community hospital fibrinolytic therapy.
This decision analysis used parameter values and ranges from meta-analyses and North American clinical studies of STEMI and chest pain care published after 2001. The primary hypothetical interventions were primary percutaneous coronary intervention versus community hospital-delivered fibrinolytic therapy. We defined total STEMI treatment time as the sum of symptom duration, EMS response time, EMS scene time, EMS transport time to the nearest community hospital, additional EMS transport time to a more distant percutaneous coronary intervention center, and door-to-drug or door-to-balloon time. We related total STEMI treatment time to the primary outcome 30-day post-STEMI survival. We assumed that the closest specialty percutaneous coronary intervention centers were located farther than the nearest community hospital and that patients would receive primary percutaneous coronary intervention at specialty centers and fibrinolytic therapy at community hospitals. We assumed the use of ground transportation only and excluded situations with fibrinolytic therapy contraindications. We examined standard risk and best-case scenarios for each intervention, as well as changes in predicted risk with parameter value variations.
Baseline total treatment times (chest pain onset to intervention) were percutaneous coronary intervention 188 minutes (range 41 to 447 minutes) and community hospital fibrinolytic therapy 118 minutes (range 51 to 267 minutes). Thirty-day survival was higher for standard percutaneous coronary intervention than standard community hospital fibrinolytic therapy (95.8% versus 93.8%; relative risk [RR] 1.021; number needed to treat 50) but lower when compared to best-case community hospital fibrinolytic therapy (95.8% versus 97.8%; RR 0.980; number needed to harm 50). Best-case percutaneous coronary intervention was equivalent to best-case community hospital fibrinolytic therapy (RR 1.000). In 1-way sensitivity analyses, best-case community hospital fibrinolytic therapy versus standard percutaneous coronary intervention was sensitive to treatment time parameter variations. Probabilistic sensitivity analysis favored standard percutaneous coronary intervention over standard community hospital fibrinolytic therapy (RR=1.020; 95% probability range 1.002 to 1.045) but did not indicate a favored strategy for the other scenarios.
In select out-of-hospital STEMI care scenarios, EMS transport of acute STEMI patients directly to percutaneous coronary intervention centers may offer small but uncertain survival benefits over nearest community hospital fibrinolytic therapy.
在急性ST段抬高型心肌梗死（STEMI）的紧急医疗服务（EMS）中，一种潜在策略是绕过最近的社区医院，转而将患者送往距离更远但能够进行直接经皮冠状动脉介入治疗的专科中心。我们试图确定，与将院外STEMI患者转运至最近的社区医院进行溶栓治疗相比，将其直接转运至距离更远的专科经皮冠状动脉介入治疗中心是否会改变30天生存率。
本决策分析使用了2001年后发表的关于STEMI和胸痛护理的荟萃分析及北美临床研究中的参数值和范围。主要的假设干预措施为直接经皮冠状动脉介入治疗与社区医院溶栓治疗。我们将STEMI总治疗时间定义为症状持续时间、EMS响应时间、EMS现场时间、转运至最近社区医院的EMS运输时间、转运至距离更远的经皮冠状动脉介入治疗中心的额外EMS运输时间以及门到用药或门到球囊时间之和。我们将STEMI总治疗时间与主要结局即STEMI后30天生存率相关联。我们假设距离最近的专科经皮冠状动脉介入治疗中心比最近的社区医院更远，且患者将在专科中心接受直接经皮冠状动脉介入治疗，在社区医院接受溶栓治疗。我们假设仅使用地面交通，并排除有溶栓治疗禁忌证的情况。我们研究了每种干预措施的标准风险和最佳情况，以及参数值变化时预测风险的变化。
基线总治疗时间（胸痛发作至干预），直接经皮冠状动脉介入治疗为188分钟（范围41至447分钟），社区医院溶栓治疗为118分钟（范围51至267分钟）。标准直接经皮冠状动脉介入治疗的30天生存率高于标准社区医院溶栓治疗（95.8%对93.8%；相对危险度[RR]1.021；需治疗人数50），但与最佳情况的社区医院溶栓治疗相比更低（95.8%对97.8%；RR 0.980；需伤害人数50）。最佳情况的直接经皮冠状动脉介入治疗与最佳情况的社区医院溶栓治疗相当（RR 1.000）。在单因素敏感性分析中，最佳情况的社区医院溶栓治疗与标准直接经皮冠状动脉介入治疗对治疗时间参数变化敏感。概率敏感性分析显示，标准直接经皮冠状动脉介入治疗优于标准社区医院溶栓治疗（RR = 1.020；95%概率范围1.002至1.045），但未表明其他情况的首选策略。
在某些院外STEMI护理场景中，将急性STEMI患者通过EMS直接转运至经皮冠状动脉介入治疗中心，与在最近社区医院进行溶栓治疗相比可能带来微小但不确定的生存益处。
