Current Status of Emergency Care for ST-Elevation Myocardial Infarction in an Urban Setting in Japan

BACKGROUND: The door-to-balloon time (DTB) is an important predictor of the outcome for patients with ST-elevation myocardial infarction (STEMI). In Japan, percutaneous coronary intervention (PCI) can be performed at many hospitals, and the predominant strategy for reperfusion therapy is primary PCI. However, it remains unclear how rapidly reperfusion is achieved at these hospitals. METHODS AND RESULTS: The study group comprised 369 patients with STEMI who presented within 12 h of symptom onset to a tertiary emergency center (TEC) or at 11 community hospitals (CHs) in 2006 and underwent emergency coronary angiography. Median DTB was shorter in the TEC (63 vs 104 min, P<0.001), and the rate of DTB within 90 min was higher in the TEC (96% vs 39%, P<0.001). Lateral myocardial infarction, presentation during off-hours, and non-cardiologist as the first-contact physician were significantly associated with a prolonged DTB in CHs. There was a trend toward lower 30-day mortality from all causes in the TEC (2.0% vs 4.8%, P=0.08). Multiple logistic regression analysis demonstrated that prolonged DTB (>90 min) was an independent predictor of 30-day mortality (odds ratio 12.6; 95% confidence interval 1.85-86.2, P=0.01). CONCLUSIONS: Establishment of emergency cardiac care systems with the goal of DTB within 90 min is required in PCI-capable hospitals to improve clinical outcomes.