Background: Time delay between onset of symptoms and primary percutaneous coronary intervention (PCI) is a important prognostic factor in patients with ST-segment elevation acute myocardial infarction (STEMI). We reviewed time delay in patients with STEMI and analyzed the relationship between symptom-to-balloon time and clinical outcomes.
Methods: From the Korea Acute Myocardial Infarction Registry, 3,399 patients with STEMI who were undergoing primary PCI within 12hours (61.4짹12.8 years, 25.6% women) were enrolled between January 2005 and December 2008. The patients were divided into two groups according to symptom-to-balloon time: group I (<3 hours, n=955) and group II (>3 hours, n=2444). In hospital mortality rates and 1-month major adverse cardiac event (MACE) rates were compared between the groups.
Results: The mean time interval from the onset of symptoms to the arrival at the emergency room (ER) (pre-hospital delay) was 188.0짹133.6 (median: 152) minutes. The mean time interval from the ER to reperfusion (door-to-balloon time) was 97.8짹67.9 (median 80) minutes. The mean time interval from the onset of symptoms to reperfusion therapy (symptom-to-balloon time) was 285.8짹146.2 (median: 250) minutes. In-hospital mortality rates were significantly lower in group I (3.6%, 34/955) than group II (5.2%, 127/2444, p=0.044) and 1-month MACE rates were also significantly lower in group I (2.1%, 17/813) than group II (3.5%, 73/2085, p=0.049)
Conclusions: This study demonstrates that there is a significant pre-hospital time delay in patients with STEMI and this time delay is associated with the adverse clinical outcomes.
Key Words: Myocardial infarction; Prognosis; Time factors