Standardised pre-hospital care of acute myocardial infarction patients: MISSION! guidelines applied in practice

Abstract

Background. To improve acute myocardial infarction (AMI) care in the region 'Hollands-Midden' (the Netherlands), a standardised guideline-based care program was developed (MISSION!). This study aimed to evaluate the outcome of the pre-hospital part of the MISSION! program and to study potential differences in pre-hospital care between four areas of residency.Methods. Time-to-treatment delays, AMI risk profile, cardiac enzymes, hospital stay, in-hospital mortality, and pre-AMI medication was evaluated in consecutive AMI patients (n=863, 61±13years, 75% male) transferred to the Leiden University Medical Center for primary percutaneous coronary intervention (PCI).Results. Median time interval between onset of symptoms and arrival at the catheterisation laboratory was 150 (interquartile range [IQR] 101-280) minutes. The alert of emergency services to arrival at the hospital time was 48 (IQR 40-60) minutes and the door-to-catheterisation laboratory time was 23 (IQR 13-42) minutes. Despite significant regional differences in ambulance transportation times no difference in total time from onset of symptoms to arrival at the catheterisation room was found. Peak troponin T was 3.33 (IQR 1.23-7.04) μg/l, hospital stay was 2 (IQR 2-3) days and in-hospital mortality was 2.3%. Twelve percent had 0 known risk factors, 30% had one risk factor, 45% two to three risk factors and 13% had four or more risk factors. No significant differences were observed for AMI risk profiles and medication pre-AMI. Conclusions. This study shows that a standardised regional AMI treatment protocol achieved optimal and uniformly distributed pre-hospital performance in the region 'Hollands-Midden', resulting in minimal time delays regardless of area of residence. Hospital stay was short and in-hospital mortality low. Of the patients, 88% had ≥1 modifiable risk factor. (Neth Heart J 2010;18:408-15.).

Keywords: Angioplasty, Transluminal, Percutaneous Coronary; Myocardial Infarction/therapy; Prevention & Control; Time Factors.

Figure 1

Schematic map of the region ‘Hollands-Midden’ (the Netherlands) further subdivided into the four areas of residency: ‘Duin & Bollen’ (region 1), ‘Leiden’ (region 2), ‘Alphen’ (region 3), ‘Gouda’ (region 4). The star within ‘Leiden’ (region 2) represents the location of the PCI centre. Maximal travel time to each area of residency (minutes) and percentage of patients per area are shown in the bar graphs on the right. AMI=acute myocardial infarction, km=kilometers, Max.=maximal, PCI=percutaneous coronary intervention.

Figure 2

Time to treatment delay. Bar graphs showing patient delay defined as time from onset of symptoms to alert of emergency services (panel A); time interval from symptom onset to arrival at the catheterisation room (cath lab) (panel B) and hospital delay expressed as time from arrival at the hospital to arrival at the cath lab (panel C). Top of bar represents median time (minutes). Error bars indicate 25th and 75th percentile (minutes). Abbreviations as in figure 1.

Figure 3

Time from alert of emergency services to arrival at PCI centre. Bars represent time interval (median minutes) from 911 call to the arrival at PCI centre (represented by star) per region of residency. Abbreviations as in figure 1.