Off-hour presentation and outcomes in patients with acute myocardial infarction: systematic review and meta-analysis
Sorita A, Ahmed A, Starr SR et al.

KEYWORDS
STEMI; Door to balloon time; Mortality

OBJECTIVE - To assess the association between off-hour (weekends and nights) presentation, door to balloon times, and mortality in patients with acute myocardial infarction.

DATA SOURCES - Medline in-process and other non-indexed citations, Medline, Embase, Cochrane Database of Systematic Reviews, and Scopus through April 2013.

STUDY SELECTION - Any study that evaluated the association between time of presentation to a healthcare facility and mortality or door to balloon times among patients with acute myocardial infarction was included.

DATA EXTRACTION - Studies' characteristics and outcomes data were extracted. Quality of studies was assessed with the Newcastle-Ottawa scale. A random effect meta-analysis model was applied. Heterogeneity was assessed using the Q statistic and I(2).

RESULTS - 48 studies with fair quality, enrolling 1,896,859 patients, were included in the meta-analysis. 36 studies reported mortality outcomes for 1,892,424 patients with acute myocardial infarction, and 30 studies reported door to balloon times for 70,534 patients with ST elevation myocardial infarction (STEMI). Off-hour presentation for patients with acute myocardial infarction was associated with higher short term mortality (odds ratio 1.06, 95% confidence interval 1.04 to 1.09). Patients with STEMI presenting during off-hours were less likely to receive percutaneous coronary intervention within 90 minutes (odds ratio 0.40, 0.35 to 0.45) and had longer door to balloon time by 14.8 (95% confidence interval 10.7 to 19.0) minutes. A diagnosis of STEMI and countries outside North America were associated with larger increase in mortality during off-hours. Differences in mortality between off-hours and regular hours have increased in recent years. Analyses were associated with statistical heterogeneity.

CONCLUSION - This systematic review suggests that patients with acute myocardial infarction presenting during off-hours have higher mortality, and patients with STEMI have longer door to balloon times. Clinical performance measures may need to account for differences arising from time of presentation to a healthcare facility.