Predictors of transportation delay in patients with suspected ST-elevation-myocardial infarction in the VIENNA-STEMI network

Bernhard Jäger,Edita Piackova,Günter Christ,Kurt Huber,Alfred Kaff,Wolfgang Schreiber,Georg Delle-Karth,Gerhard Maurer,Thomas Stefenelli,Franz Weidinger,Paul Michael Haller

doi:10.1007/s00392-019-01520-z

Abstract

ObjectiveThe emergency medical service (EMS) provides rapid pre-hospital diagnosis and transportation in ST-elevation myocardial infarction (STEMI) systems of care. Aim of the study was to assess temporal and regional characteristics of EMS-related delays in a metropolitan STEMI network.MethodsPatient call-to-arrival of EMS at site (call-to-site), transportation time from site to hospital (site-to-door), call-to-door, patient’s location, month, weekday, and hour of EMS activation were recorded in 4751 patients referred to a tertiary center with suspicion of STEMI.ResultsMedian call-to-site, site-to-door, and call-to-door times were 9 (7–12), 39 (31–48), and 49 (41–59) minutes, respectively. The shortest transportation times were noted between 08:00 and 16:00 and in general on Sundays. They were significantly prolonged between midnight and 04:00, whereby the longest difference did not exceed 4 min in median. Patient’s site of call had a major impact on transportation times, which were shorter in Central and Western districts as compared to Southern and Eastern districts of Vienna (p < 0.001 between-group difference for call-to-site, site-to-door, and call-to-door). After multivariable adjustment, patient’s site of call was an independent predictor of call-to-site delay (p < 0.001). Moreover, age and hour of EMS activation were the strongest predictors of call-to-site, site-to-door, and call-to-door delays (p < 0.05).ConclusionIn our Viennese STEMI network, the strongest determinants of pre-hospital EMS-related transportation delays were patient’s site of call, patient’s age, and hour of EMS activation. Due to the significant but small median time delays, which are within the guideline-recommended time intervals, no impact on clinical outcome can be expected.Graphic abstract

Highlights

Reperfusion therapy is the cornerstone of successful treatment for ST-elevation myocardial infarction (STEMI) and is known to improve patient’s outcome [1,2,3]
The study population consisted of 4751 consecutive patients within a previous period of 8 years who called into the Viennese ambulance service due to ongoing chest pain, in whom STEMI was suspected after the initial onsite ECG, who were immediately transferred to a tertiary hospital for primary percutaneous coronary intervention (PCI), and in whom all necessary variables had been collected
Transportation times were recorded in 4751 patients with suspected STEMI [3093 males (65.1%), mean age 64.5 years]

Summary

Introduction

Reperfusion therapy is the cornerstone of successful treatment for ST-elevation myocardial infarction (STEMI) and is known to improve patient’s outcome [1,2,3]. Specific STEMI networks, consisting of an emergency ambulance medical system (EMS) staffed with emergency physicians or paramedics and tertiary hospitals with the capability of primary percutaneous coronary intervention (PCI), have been developed and established to shorten system-related delay in urban as well as in rural areas [4, 5]. The greatest benefits can be achieved by shortening the pre-hospital delay, as it usually accounts for the largest proportion of total ischemic time in STEMI [6]. To the best of our knowledge, no comprehensive analysis of the association of the patient’s site (city district) and transportation delay has been performed so far in a large-scale cohort of urban STEMI patients

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Discussion

Conclusion