Division of Cardiology, Department of Medicine, University of Alberta, Alberta, Canada.
Am Heart J. 2011 Sep;162(3):436-43. doi: 10.1016/j.ahj.2011.06.011. Epub 2011 Aug 9.
Contemporary non-ST-elevation myocardial infarction-acute coronary syndrome guidelines emphasize early-risk stratification and optimizing therapy including an invasive strategy in high-risk patients. To assess the feasibility of initiating this strategy in the prehospital environment, we examined how such patients are transported to hospital, their risk profile, and the proportion potentially eligible for such a strategy.
Consecutive patients with ST-segment elevation myocardial infarction admitted in Edmonton were studied between September and November 2008 and divided according to their mode of transport to hospital: emergency medical services (EMS) versus self-presenting. Baseline characteristics, GRACE Risk Score, blinded core laboratory electrocardiogram analysis, cardiac biomarkers, in-hospital procedures, and outcomes were analyzed.
Thirty-five percent (93/263) of patients presented via EMS and often to percutaneous coronary intervention hospitals, that is, 64.5% versus 44.1% (P = .0016). They were older (75 vs 62 years, P < .001), more often female (43% vs 28.1%, P < .001), diabetic (34.4% vs 22.9%, P = .045), and hypertensive (72.0% vs 57.1%, P = .017) and had higher GRACE Risk Scores (median 166 vs 130, P < .001). Electrocardiogram analysis revealed more baseline Q waves (38.8% vs 25.5%, P = .031) and ST depression ≥2 mm (P = .027) in EMS-transported patients. Fewer EMS patients underwent cardiac catheterization (60.2% vs 88.2%, P < .001), and a paradoxical relationship existed between catheterization rates and GRACE Risk Score in the total cohort (low-risk: 93.4% vs high-risk: 59.3%, P < .001). The composite of death/re-myocardial infarction/congestive heart failure/shock was greater in EMS patients (unadjusted odds ratio 3.96, 95% CI 1.80-8.69, P = .001); these differences were attenuated after GRACE Risk Score adjustment.
Regional strategies using risk-based triage, early medical therapy, and timely triage to percutaneous coronary intervention centers represents an unrealized opportunity to enhance ST-segment elevation myocardial infarction care.
当代非 ST 段抬高型心肌梗死-急性冠状动脉综合征指南强调早期风险分层和优化治疗，包括高危患者的介入策略。为了评估在院前环境中启动这一策略的可行性，我们研究了这些患者如何被送往医院，他们的风险状况，以及有多少患者可能符合这种策略的条件。
连续纳入 2008 年 9 月至 11 月在埃德蒙顿因 ST 段抬高型心肌梗死住院的患者，并根据其到医院的交通方式进行分组：急救医疗服务（EMS）与自行就诊。分析基线特征、GRACE 风险评分、盲法核心实验室心电图分析、心脏生物标志物、院内治疗和结局。
35%（93/263）的患者通过 EMS 就诊，而且通常送往经皮冠状动脉介入治疗医院，即 64.5%比 44.1%（P =.0016）。他们年龄更大（75 岁比 62 岁，P <.001），女性更多（43%比 28.1%，P <.001），糖尿病（34.4%比 22.9%，P =.045）和高血压（72.0%比 57.1%，P =.017），GRACE 风险评分更高（中位数 166 比 130，P <.001）。心电图分析显示，EMS 转运患者的基线 Q 波更多（38.8%比 25.5%，P =.031）和 ST 段压低≥2mm（P =.027）。EMS 转运患者行心脏导管术的比例较低（60.2%比 88.2%，P <.001），而且在整个队列中，导管术率与 GRACE 风险评分之间存在一种矛盾关系（低危：93.4%比高危：59.3%，P <.001）。EMS 患者的死亡/再心肌梗死/充血性心力衰竭/休克复合终点发生率更高（未经调整的优势比 3.96，95%可信区间 1.80-8.69，P =.001）；这些差异在调整 GRACE 风险评分后有所减弱。
采用基于风险的分诊、早期药物治疗和及时分诊至经皮冠状动脉介入治疗中心的区域策略，代表了提高 ST 段抬高型心肌梗死治疗效果的一个未被充分利用的机会。
