1Herzzentrum der Universität zu Köln Klinik für Kardiologie, Angiologie, Pneumologie und Internistische Intensivmedizin Köln, Deutschland; 2Herzzentrum der Universität zu Köln Klinik III für Innere Medizin Köln, Deutschland; 3Universitätsmedizin der Johannes Gutenberg-Universität Mainz Zentrum für Kardiologie Mainz, Deutschland; 4Krankenhaus der Augustinerinnen, Akademisches Lehrkrankenhaus Klinik für Kardiologie und internistische Intensivmedizin Köln, Deutschland; 5St. Antonius Krankenhaus Medizinische Klinik & Kardio-Diabetes-Zentrum Köln Köln, Deutschland; 6Ev. Krankenhaus Köln-Kalk Kardiologie & Internistische Intensivmedizin Köln, Deutschland; 7Krankenhaus Porz am Rhein gGmbH Klinik für Kardiologie, Elektrophysiologie u. Rhythmologie Köln, Deutschland; 8St. Vinzenz-Hospital Innere Medizin III - Kardiologie Köln, Deutschland; 9Kliniken der Stadt Köln gGmbH, Krankenhaus Merheim Medizinische Klinik II Köln, Deutschland; 10Universitätsklinikum Köln Klinik III für Kardiologie, Angiologie, Pneumologie und Internistische Intensivmedizin Köln, Deutschland
Background: ST-segment myocardial infarction (STEMI) is associated with high morbidity and mortality burden. Type of first medical contact (FMC) has been proposed as a predictor of STEMI outcomes. Historical studies showed divergent results, but mainly indicated worse survival and patient-related treatment delay in walk-in patients compared to those who alerted emergency medical service (EMS) directly. Public awareness campaigns to overcome this gap were implemented, but effects of these interventions are uncertain.
Objective: This study evaluated the impact of FMC (walk-in vs. EMS treated patients) in an all-comer, metropolitan STEMI cohort.
Methods: The registry includes STEMI patients treated between January 2005 and December 2020. Patients presenting to a non-PCI hospital with inter-hospital transfer were excluded, as these underlie an inherent system-related treatment delay. The remaining patients were divided in walk-in and EMS cohort. Primary outcome was in-hospital all-cause mortality. Data were analyzed using Student’s t- and Chi square test.
Results: 3836 patients including 571 walk-in (14.9%) and 3265 EMS treated patients (85.1%) were eligible. Walk-in patients were significantly younger (60.9 vs. 63.7 years, mean, p<0.001). Conventional STEMI was the predominant ECG diagnosis, left bundle branch block was present in 5.4% and 8.2%, respectively (p=0.019). Diagnostic accuracy of ECG was 99.8% in walk-in patients, compared to 97% in EMS cohort (p<0.001).
During the pre-interventional course, walk-in patients less frequently required intubation (3.4 vs. 14% p<0.001) or vasopressors (4.4 vs. 13.6%, p<0.001). Correspondingly, sustained cardiogenic shock had a higher prevalence in the EMS group (7.6 vs. 17.1%, p<0.001). Both groups were equally referred for angiography (99.6 vs. 99.1%, p=0.173).
Symptom-to-FMC time was significantly increased in walk-in patients (447.8 [±745] vs. 268.9 [±608], mean, p<0.001, see figure). Door-to-balloon time was significantly higher in walk-in cohort compared to EMS cohort (88.5 [±98.8] vs. 59.4 [±64.1], mean, p<0.001).
Walk-in patients had a significantly lower rate of TIMI 0 flow (9.2% vs. 13.9%, p=0.003), and were more often treated with stent implantation (88.8 vs 82.2%, p<0.001). Walk-in patients had a lower incidence of procedural-related complications (7.0 vs. 10.2%, p=0.017). Incidence of re-infarction, stroke and episodes of ventricular fibrillation were comparable between the groups. In-hospital mortality was significantly lower in walk-in cohort (5.4 vs. 10.1%, p<0.001).
Conclusion: The present STEMI registry analysis still demonstrates a disturbing patient- and system-related treatment delay in walk-in patients. Even though this did not translate into worse in-hospital survival compared to the more morbid EMS cohort, strategies to overcome these domains of treatment delay in STEMI are required.
Streamlining of in-hospital diagnosis and transfer to catheterization should be targeted to minimize the alarmingly higher door-to-balloon time in walk-in patients. Awareness campaigns with precise instructions to activate EMS might be a tool to address patient-related delay.