Effectiveness of 3-1-5 Model in ST-Elevation Myocardial Infarction (STEMI) Patients in Bangkok Heart Hospital

Abstract

OBJECTIVES: To assess treatment timeliness using the 3-1-5 model in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) and to identify factors associated with delayed reperfusion and adverse clinical outcomes.

MATERIALS AND METHODS: This retrospective observational study included adults (≥18 years) with STEMI undergoing primary PCI between June 2020 and December 2023. Patients who declined reperfusion, required interhospital transfer, or died before PCI were excluded. After Institutional Review Board approval, data were collected using a standardized case record form. Timeliness was assessed using the 3-1-5 model (≤ 90 minutes from first medical contact (FMC) to PCI). Outcomes included in-hospital and 30-day mortality and hospital readmission. RESULTS: Among 52 patients (mean age 59.83 ± 10.97 years; 88.46% male), FMC-to-device time ≤ 90 minutes was achieved in 69.23%. In-hospital mortality was 3.85%, with no mortality at 30 days or 6 months. Complications included cardiogenic shock (7.69%), arrhythmia, and intra-aortic balloon pump use (3.85%). Hospital readmission within 6 months occurred in 7.50%. The median door-in–door-out time was 35 minutes, exceeding the recommended 30 minutes. Delays were mainly attributed to system- and patient-related factors, including atypical or absent chest pain, delayed diagnosis, poor communication, and hemodynamic instability.

CONCLUSION: Although the key performance indicator (KPI) for achieving coronary reperfusion time within 90 minutes was not met, this study identified key contributors to treatment delays, particularly during the door-in door-out (DIDO) time. These delays were related to both system delay and patient delay. The door in door out interval is a critical early phase that directly affects timely diagnosis and subsequent reperfusion. System delay improvements in triage, diagnostic workflows and continuous training of healthcare personnel may help optimize this process and facilitate timely care across subsequent stages. In addition, enhancing public awareness of STEMI symptoms and the importance of early hospital presentation may reduce patient delay.