Occurrence and Impact of Time Delay to Primary Percutaneous Coronary Intervention in Patients With ST-Segment Elevation Myocardial Infarction.

Background: The aim of the study was to evaluate the occurrence, duration and impact of time delays to primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI).

Methods: A total of 357 consecutive STEMI patients enrolled in the prospective Special Program University Medicine ACS (SPUM-ACS) cohort were included. In order to identify the causes behind a possible treatment delay, we constructed four different time points which included: 1) symptom onset to hospital arrival, 2) hospital arrival to arrival in the catheterization laboratory, 3) hospital arrival to first balloon inflation, and 4) time from arrival in the catheterization laboratory to first balloon inflation in addition to total ischemic time. Patients were stratified according to a delay > 3 h, > 30 min, > 90 min and > 1 h, respectively and major adverse events at 0, 30 and 365 days were analyzed.

Results: Resuscitated STEMI patients (23 patients) and STEMI patients presenting at weekends (101 patients) and to lesser extent at night hours (100 patients) experienced more time delays than stable patients and those presenting at office hours. Median door-to-balloon time averaged 93 min in resuscitated, but 65 min in stable patients. Median door-to-balloon time at weekends and public holidays was 89 min, but 68 min at office hours. Median time from hospital arrival to cathlab arrival at weekends and public holidays was 30 min, but 15 min during office hours. Corresponding times for resuscitated patients was 45 and 15 min in stable patients. Of note, resuscitated patients were late presenters as regards time from symptoms onset to hospital arrival with a median time of 180 min compared to 155 min in stable patients. Median total ischemic time was 225 min for all patients, 223 min at day hours, 239 at night hours, 244 min at weekends, 233 min at office days, 220 min in stable patients and 273 min in resuscitated patients. Patients with STEMI who arrived > 3 h after symptom onset had a higher rate of myocardial infarction (MI) at 1 year (1.6% vs. 9% in < 3 h; P = 0.008). Furthermore, STEMI patients who had a delay of > 1 h from cathlab arrival to first balloon inflation had a higher rate of in hospital reinfarction at 0 day (0.6% vs. 0% in < 1 h; P = 0.007), MI at 30 days (0.8% vs. 0% in < 1 h; P = 0.001) and MI at 1 year (1.4% vs. 1.1% in < 1 h; P = 0.012). Similarly, in these patients, cardiac deaths at 0 day (0.8% vs. 0.6% in < 1 h; P = 0.035) and at 30 days (0.8% vs. 0.6% in < 1 h; P = 0.035) were higher as were major adverse cardiovascular events (MACCE) at 0 day (1.4% vs. 0.8% in < 1 h; P = 0.004).

Conclusion: Resuscitated STEMI patients and those presenting at weekends and to lesser extent at night hours experienced more time delays and longer ischemic time than stable patients and those presenting at office hours. In STEMI patients, any delay in treatment increased their risk of MACCE. Efforts should focus on improving patient's awareness along with minimizing in-hospital transfer to the catheterization laboratory especially at weekends and in resuscitated patients.