Sharing primary percutaneous coronary intervention care: first experiences with South Limburg ST-elevation myocardial infarction network

Regional networks of hospitals, which are connected by emergency medical services (EMSs), are essential to treat ST-elevation myocardial infarction (STEMI) [1‐3]. These networks improve clinical outcomes by shortening the time until coronary artery reperfusion [4‐6]. Experienced centres and clear patient pathways are critical for these networks; thus, guidelines discourage the implementation of rotation models [1]. Still, some densely populated regions have proven that, under special circumstances, shared systems are effective and improve quality indicators [3, 7]. The region of South Limburg, the Netherlands has taken this rotation model a step further. To our knowledge, our network is the first to provide rotation of STEMI care at two locations, supported by the same team of interventional cardiologists.

Herein, we present the performance of our network in the light of contemporary revascularisation guidelines. With this analysis, we also aimed at a better understanding of the prevalence and impact of simultaneous admissions at two locations.

We set up a novel primary PCI network (SLIM network) and showed that, under special circumstances and with proper logistics, PCI centres can effectively share their interventional cardiologists and meet the quality criteria set by contemporary European Society of Cardiology (ESC) guidelines [1].

The quality and efficacy of STEMI systems are usually measured with key time indicators. They are patient- and system-related delays of STEMI care; the latter consists of prehospital delays (EMS and transportation delays) and in-hospital delays [1, 6]. These delays are important, as they correlate with short- and long-term outcomes of STEMI patients [5, 6]. To keep these delays as short as possible, the ESC emphasises the importance of transparent and effective STEMI networks and strongly recommends 24/7 on-call systems for primary PCI centres [1].

Regional peculiarities of geography, population density and hospital logistics have already led to unique solutions, such as centre rotations in the Vienna and Budapest regions [3, 7, 11, 12]. There are, however, significant differences between these networks and the SLIM network. Where both Vienna and Budapest are densely populated metropolitan areas with at least five PCI centres operating in their rotations, South-Limburg is an average-sized region with two PCI centres [7, 12]. Another important difference is the sharing of interventional cardiologists between the two Dutch centres. While the Austrian and Hungarian centres only work with their own interventional cardiologists, the MUMC+ and ZMC optimise their primary PCI rotations by sharing staff members.

Since more admissions occurred during out-of-office hours, we believe that the SLIM network evenly distributed the number of acute admissions between the regional centres (Tab. 2). This should lead to a balanced regional operator experience, with all interventional cardiologists easily meeting the national accreditation criteria (>30 PCIs/year). Since being on-call disrupts everyday life regardless of the actual number of calls, our colleagues also preferred the ‘rare and intense’ shifts over ‘balanced and mild’ rotations.

There are several options to measure the efficacy of STEMI systems, as proven by publications discussing changes in treatment availability, mortality and time delays [7, 11, 12]. Since primary PCI networks are well established in the Netherlands, it was less important to analyse treatment availability in the current study [3]. With synchronised medical protocols, shared personnel and matched PCI equipment, regional time delays remain the most relevant quality indicator as they correlate directly with mortality rates [5, 6]. Therefore, even though there are well-known difficulties with data registration, regional time delays were chosen to demonstrate the efficacy of the SLIM model [13].

Despite the lack of contemporary evidence, European guidelines have left the 120-minute time window for initial decision-making (PCI vs fibrinolysis) unchanged and still advise a maximum of 90 min for the diagnosis-to-reperfusion time [1]. In the present analysis, both the diagnosis-to-needle time (56 min (46–67)) and the system delay (EMS alert to needle time: 65 min (53–77)) were shorter in the SLIM network (Fig. 2) than the advised 90 min and were clearly below the 108–120 min threshold for increased mortality rates [1, 5, 6]. Although we analysed an ‘all-comer’ STEMI population, the median arrival time was close to 60 min, the time point when the next significant step down in mortality rates is expected [5, 6, 13].

Door-to-needle and door-to-balloon (reperfusion) times are an integral part of system delay and have a significant correlation with in-hospital and long-term mortality rates [14]. Still, the ESC does not offer clear recommendations on the maximum duration of these times. Presumably, as long as the diagnosis-to-reperfusion time recommendations of 90–120 min are respected, door-to-needle time remains a secondary indicator for STEMI networks [1]. Nevertheless, door-to-needle and door-to-balloon times are almost entirely PCI centre–dependent and are therefore important local quality indicators [13].

Although regional system delays and door-to-needle times complied with the contemporary revascularisation guidelines, we also noticed that ongoing procedures, out-of-office hours and delayed site activation had a negative influence on these key time indicators. As for the ongoing procedures, cath lab ‘jams’ were predominantly seen when patients were already being treated at the same location. Simultaneous site activation was rare and had no effect on the median delays.

Time delays are not only influenced by patient- and EMS-related factors, but also by cath lab availability. As customary in the Netherlands, our interventional cardiologists are not required to remain in the hospital during out-of-office hours, but they must be ‘ready to reperfuse’ within 30 min. Our interventional cardiologists live in different areas of South Limburg and have an estimated travel time of 5–25 min and a measured arrival time of 15 min (13–31). Regional EMS transport times resonate well with both the 30-minute deadline and the staff travel times. Our data also suggest that a delay in alerting the PCI centre, and consequently its personnel, could add several minutes to the local door-to-needle times. Optimising patient pathways based on the medical team’s actual location and availability is also essential to avoid unnecessary delays caused by travelling interventional cardiologists. Some medical emergencies and conditions (e.g. out-of-hospital cardiac arrest, cardiogenic shock and ruling out of potentially life-threatening secondary diagnoses) are difficult to generalise, but have contributed to median delays and outliers [13].

With its effective patient pathway management, the SLIM network was able to meet the time delay requirements set by contemporary European revascularisation guidelines.