Factors associated with time delay to angiography in acute ST-elevation myocardial infarction - A retrospective cohort study in Northern Finland

BACKGROUND: The delay of percutaneous coronary intervention increases the risk of heart failure and mortality in STEMI. The aim of this study was to examine the time intervals of EMS and the factors associated with the time delay to angiography in patients with STEMI. METHODS: The present study was conducted in Northern Ostrobothnia, Finland in 2014-2016. All patients transported to the hospital by EMS who were diagnosed with STEMI and underwent a primary angiography within 24 h of arrival were included. Angiography was defined as delayed if it was performed over 120 min of the first medical contact (FMC). RESULTS: 310 patients met the inclusion criteria during the study period. Time from the FMC to angiography was less than 120 min in 231 patients (74.5%). In multivariate analysis, the factors associated with delayed angiography were the absence of chest pain (OR 2.46 (1.18-5.13),p = 0.016), dyspnea (OR 3.11 (1.54-6.28),p = 0.002), the treatment protocol violations by EMS (OR 2.41 (0.99-5.80),p = 0.050), treatment initiation at a primary health care center (OR 3.64 (1.39-9.48),p = 0.008), and the distance to hospital of over 100 km (OR 11.87 (6.14-22.93),p < 0.001). CONCLUSION: In our study, treatment protocol violations, non-specific symptoms, and the distance to hospital of over 100 km were associated with primary angiography in patients with STEMI transported to the hospital by EMS.