Study objective: American Heart Association/American College of Cardiology guidelines recommend door-to-balloon times of fewer than 90 minutes in patients with acute ST-segment-elevation myocardial infarction. We hypothesized that immediate activation of an interventional cardiology team (code H) would reduce the time to percutaneous coronary intervention by 1 hour and increase the proportion of patients undergoing percutaneous coronary intervention within 90 minutes of arrival.
Methods: Study design was a before-and-after trial in an academic suburban emergency department (ED) with a certified cardiac catheterization laboratory. Subjects were a consecutive sample of patients presenting to the ED with ST-segment-elevation myocardial infarction evident on the initial ECG. Patients without chest pain and refusing catheterization were excluded. The intervention was the use of a central paging system for activation of the interventional cardiology team (attending physician, fellow, nurse, technician) by emergency physicians in patients presenting to the ED with ST-segment-elevation myocardial infarction. Measures were demographic and clinical information collected with standardized data collection forms. Outcomes were door-to-balloon times and the proportion of patients undergoing percutaneous coronary intervention within 90 minutes of arrival. Groups were compared with chi2 and t tests.
Results: There were 97 patients included in the study; 43 were treated in the 2 years before implementation of the code H and 54 patients were treated the subsequent 2 years. Mean age (SD) was 56.9 years (13.7), 27% were women, and 86% were white. Groups were similar in age, sex, and race. Implementation of a code H reduced the median door-to-balloon time by 68 minutes (from 176 to 108 minutes; P<.001) and increased the proportion of patients undergoing percutaneous coronary intervention within 90 minutes from 2.8% to 29.0% (mean difference 26.5; 95% confidence interval 15.0 to 36.9). To determine whether further improvements occurred, 48 patients treated in 2006 showed a 20-minute further reduction in door-to-balloon time; 52% underwent angioplasty within 90 minutes of ED presentation.
Conclusion: Institutional implementation of a protocol that requires emergency physicians to activate an interventional cardiology team response in ED patients with ST-segment-elevation myocardial infarction reduces the door-to-balloon time and increases the proportion of patients undergoing percutaneous coronary intervention within 90 minutes.