Impact of time of presentation on the care and outcomes of acute myocardial infarction.
BACKGROUND
Prior studies have demonstrated an inconsistent association between patients' arrival time for acute myocardial infarction (AMI) and their subsequent medical care and outcomes.


RESULTS
Using a contemporary national clinical registry, we examined differences in medical care and in-hospital mortality among AMI patients admitted during regular hours (weekdays 7 am to 7 pm) versus off-hours (weekends, holidays, and 7 pm to 7 am weeknights). The study cohort included 62,814 AMI patients from the Get With the Guidelines-Coronary Artery Disease database admitted to 379 hospitals throughout the United States from July 2000 through September 2005. Overall, 33 982 (54.1%) patients arrived during off-hours. Compared with those arriving during regular hours, eligible off-hour patients were slightly less likely to receive primary percutaneous coronary intervention (adjusted odds ratio [OR], 0.93; 95% confidence interval [CI], 0.89 to 0.98), had longer door-to-balloon times (median, 110 versus 85 minutes; P<0.0001), and were less likely to achieve door-to-balloon < or = 90 minutes (adjusted OR, 0.34; 95% CI, 0.29 to 0.39). Arrival during off-hours was associated with slightly lower overall revascularization rates (adjusted OR, 0.94; 95% CI, 0.90 to 0.97). No measurable differences, however, were found in in-hospital mortality between regular hours and off-hours in the overall AMI, ST-elevated MI, and non-ST-elevated MI cohorts (adjusted OR, 0.99; 95% CI, 0.93 to 1.06; adjusted OR, 1.05; 95% CI, 0.94 to 1.18; and adjusted OR, 0.97; 95% CI, 0.90 to 1.04, respectively). Similar observations were made across most age and sex subgroups and with an alternative definition for arrival time (weekends/holidays versus weekdays).


CONCLUSIONS
Despite slightly fewer primary percutaneous coronary interventions and overall revascularizations and significantly longer door-to-balloon times, patients presenting with AMI during off-hours had in-hospital mortality similar to those presenting during regular hours.
Jneid
Hani
H
Division of Cardiology, Massachusetts General Hospital, 55 Fruit St, GRB 800 Boston, MA 02114. jneid.hani@mgh.harvard.edu.
Fonarow
Gregg C
GC
Cannon
Christopher P
CP
Palacios
Igor F
IF
Kilic
Teoman
T
Moukarbel
George V
GV
Maree
Andrew O
AO
LaBresh
Kenneth A
KA
Liang
Li
L
Newby
L Kristin
LK
Fletcher
Gerald
G
Wexler
Laura
L
Peterson
Eric
E
D039602:After-Hours Care / Q000592:standards*; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000628:therapy*; D009204:Myocardial Revascularization / Q000706:statistics & numerical data; D010818:Practice Patterns, Physicians'; D044469:Racial Groups; D012042:Registries; D013997:Time Factors; D016896:Treatment Outcome