Time to treatment in patients with STEMI.

n engl j med 369;10 nejm.org september 5, 2013 889 20 to 30 minutes of ischemia, it takes several hours for transmural myocardial necrosis to develop. The goal of reperfusion therapy with fibrinolytic drugs or primary percutaneous coronary intervention (PCI) is to restore blood flow to ischemic, but still viable, myocardium and reduce infarct size. Reducing the time to treatment and maximizing myocardial salvage — in keeping with the mantra that “time is muscle” — pre sent a logistic challenge. Early randomized trials of fibrinolytic therapy established the direct relationship between symptom duration, myocardial infarct size, and mortality. At the time, however, treatment delays were prolonged because of the lack of prehospital and in-hospital systems of care to facilitate timely STEMI therapy. To address this problem, the National Heart, Lung, and Blood Institute launched the National Heart Attack Alert Program in 1991. Four critical time points in the emergency department (ED) were identified and dubbed the “4Ds”: “door,” the time of arrival in the ED; “data,” the time of acquisition of an electrocardiogram (ECG); “decision,” the time of ordering of fibrinolytic therapy; and “drug,” the time of initiation of fibrinolytic drug infusion. Within 3 years, by reducing ED delays, participating hospitals had doubled the percentage of patients treated within the door-to-needle goal of 30 minutes. The treatment goal is the same today, but less than half of patients in the United States are treated within 30 minutes, perhaps because fibrinolytic therapy is used so infrequently. Primary PCI has replaced fibrinolytic therapy as the preferred reperfusion strategy, despite the delays inherent in transferring the patient from the ED to the cardiac catheterization laboratory and then performing the procedure (see the figure). The Centers for Medicare and Medicaid Services and the Joint Commission began using door-to-balloon time as a performance measure for public reporting in 2002. In 2006, the American College of Cardiology (ACC) launched the Door-to-Balloon Alliance with a goal of providing treatment within 90 minutes after arrival for at least 75% of patients with STEMI who present directly to a PCI-capable hospital.1 Several strategies were promoted, including activation of the cardiac catheterization laboratory with a single call by the Time to Treatment in Patients with STEMI