Impact of time of presentation on process performance and outcomes in ST-segment-elevation myocardial infarction: a report from the American Heart Association: Mission Lifeline program

Background: Prior studies demonstrated that patients with ST-segment-elevation myocardial infarction presenting during off-hours (weeknights, weekends, and holidays) have slower reperfusion times. Recent nationwide initiatives have emphasized 24/7 quality care in ST-segment-elevation myocardial infarction. It remains unclear whether patients presenting off-hours versus on-hours receive similar quality care in contemporary practice.

Methods and results: Using Acute Coronary Treatment and Intervention Outcomes Network-Get With The Guidelines (ACTION-GWTG) database, we examined ST-segment-elevation myocardial infarction performance measures in patients presenting off-hours (n=27 270) versus on-hours (n=15 972; January 2007 to September 2010) at 447 US centers. Key quality measures assessed were aspirin use within first 24 hours, door-to-balloon time, door-to-ECG time, and door-to-needle time. In-hospital risk-adjusted all-cause mortality was calculated. Baseline demographic and clinical characteristics were similar. Aspirin use within 24 hours approached 99% in both groups. Among patients undergoing primary percutaneous coronary intervention (n=41 979; 97.1%), median door-to-balloon times were 56 versus 72 minutes (P<0.0001) for on-hours versus off-hours. The proportion of patients achieving door-to-balloon time ≤90 minutes was 87.8% versus 79.2% (P<0.0001), respectively. There were no differences attaining door-to-ECG time ≤10 minutes (73.4% versus 74.3%, P=0.09) and door-to-needle time ≤30 minutes (62.3% versus 58.7%; P=0.44) between on-hours versus off-hours. Although in-hospital all-cause mortality was similar (4.2%) in both groups, the risk-adjusted all-cause mortality was higher for patients presenting off-hours (odds ratio, 1.13; 95% confidence interval, 1.02-1.26).

Conclusions: In contemporary community practice, achievement of quality performance measures in patients presenting with ST-segment-elevation myocardial infarction was high, regardless of time of presentation. Door-to-balloon time was, however, slightly delayed (by an average of 16 minutes), and risk-adjusted in-hospital mortality was 13% higher in patients presenting off-hours.