Regular hours include weekdays, 7 AM to 5 PM.
Off-hours include weekdays 5 PM to 7 AM and
all times on the weekend days. American College of Cardiology and the American
Heart Association guidelines recommend that door-to-drug times be 30 minutes
or less; and door-to-balloon times be 90 minutes or less.15
Door-to-data refers to the time interval from hospital arrival to electrocardiogram
(ECG) completion. Data-to-drug refers to the time interval from ECG completion
to administration of fibrinolytic therapy. Data-to-catheterization laboratory
(cath lab) refers to the time from ECG completion to arrival at the catheterization
laboratory. Catheterization laboratory to balloon refers to the time from
cardiac catheterization laboratory arrival to balloon inflation. Regular hours
include weekdays, 7 AM to 5 PM. Off-hours include
weekdays 5 PM to 7 AM and all times on the weekend
Customize your JAMA Network experience by selecting one or more topics from the list below.
Magid DJ, Wang Y, Herrin J, et al. Relationship Between Time of Day, Day of Week, Timeliness of Reperfusion,
and In-Hospital Mortality for Patients With Acute ST-Segment Elevation Myocardial
Infarction. JAMA. 2005;294(7):803–812. doi:10.1001/jama.294.7.803
Author Affiliations: Clinical Research Unit,
Kaiser Permanente, Denver (Dr Magid) and Departments of Emergency Medicine
and Preventive Medicine and Biometrics, University of Colorado Health Sciences
Center, Denver (Dr Magid); Department of Internal Medicine, Section of Cardiovascular
Medicine (Drs Herrin, McNamara, Curtis, Krumholz, and Wang), Division of Health
Policy and Administration, Department of Epidemiology and Public Health (Drs
Bradley and Krumholz), and Robert Wood Johnson Clinical Scholars Program,
Yale University School of Medicine, and Center for Outcomes Research and Evaluation,
Yale–New Haven Health, New Haven, Conn (Drs Krumholz and Bradley); Pennsylvania
Hospital, Philadelphia (Dr Pollack); Harbor/University of California Los Angeles
Medical Center, Torrance (Dr French); and Genentech, South San Francisco,
Calif (Dr Blaney).
Context Understanding how door-to-drug and door-to-balloon times vary by time
of day and day of week can inform the design of interventions to improve the
timeliness of reperfusion therapy.
Objective To determine the pattern of door-to-drug and door-to-balloon times by
time of day and day of week and whether this pattern may affect mortality.
Design, Setting, and Participants Cohort study of 68 439 patients with ST-segment elevation myocardial
infarction (STEMI) treated with fibrinolytic therapy and 33 647 treated
with percutaneous coronary intervention (PCI) from 1999 through 2002. We classified
patient hospital arrival period into regular hours (weekdays, 7 AM-5 PM) and off-hours (weekdays 5 PM-7 AM and weekends).
Main Outcome Measures Geometric mean door-to-drug time for fibrinolytic therapy and door-to-balloon
time for PCI and all-cause in-hospital mortality. All outcomes were adjusted
for patient and hospital characteristics.
Results Most fibrinolytic therapy (67.9%) and PCI patients (54.2%) were treated
during off-hours. Door-to-drug times were slightly longer during off-hours
(34.3 minutes) than regular hours (33.2 minutes; difference, 1.0 minute; 95%
confidence interval [CI], 0.7-1.4; P<.001). In
contrast, door-to-balloon times were substantially longer during off-hours
(116.1 minutes) than regular hours (94.8 minutes; difference, 21.3 minutes;
95% CI, 20.5-22.2; P<.001). A lower percentage
of patients met guideline recommended times for door-to-balloon during off-hours
(25.7%) than regular hours (47%; P<.001). Door-to-balloon
times exceeding 120 minutes occurred much more commonly during off-hours (41.5%)
than regular hours (27.7%; P<.001). Longer off-hours
door-to-balloon times were primarily due to a longer interval between obtaining
the electrocardiogram and patient arrival at the catheterization laboratory
(off-hours, 69.8 minutes vs regular hours, 49.1 minutes; P<.001). This pattern was consistent across all hospital subgroups
examined. Furthermore, patients presenting during off-hours had significantly
higher adjusted in-hospital mortality than patients presenting during regular
hours (odds ratio, 1.07; 95% CI, 1.01-1.14; P = .02).
Conclusions Presentation during off-hours was common and was associated with substantially
longer times to treatment for PCI but not for fibrinolytic therapy. To achieve
the best outcomes, hospitals providing PCI during off-hours should commit
to doing so in a timely manner.
Reperfusion therapy with either fibrinolytic therapy or percutaneous
coronary intervention (PCI) reduces mortality for eligible ST-segment elevation
myocardial infarction (STEMI) patients.1-8 The
shorter the time from symptom onset to treatment, the greater the survival
benefit with either therapy.3,9-14 The
choice between therapies should take into account reperfusion treatment times.15 Although prior studies16-18 have
shown that door-to-balloon times for PCI are longer on evenings, nights, and
weekends than on weekday days, several important questions remain. Prior studies
neither assessed whether such variation was common to all types of hospitals
nor did they determine where in the PCI process the delays occurred. In addition,
these studies did not evaluate the impact of delayed door-to-balloon times
on adherence to guideline recommended treatment times. Finally, previous studies
focused on PCI and did not evaluate whether door-to-drug times for fibrinolytic
therapy also varied by patient arrival period. Understanding the reasons for
variation in reperfusion treatment times by patient arrival period, and whether
such variation is common to all hospitals and to both fibrinolytic therapy
and PCI, can inform the design and targeting of interventions to improve timely
To determine whether patient hospital arrival period is associated with
door-to-drug and door-to-balloon times, we examined the relationship between
time of day and day of week and reperfusion treatment times for STEMI patients
treated with fibrinolytic therapy or PCI. Because fibrinolytic therapy is
generally administered in emergency departments, which are continuously staffed,
we hypothesized that door-to-drug times would not vary substantially by patient
arrival period. In contrast, because most hospitals do not staff their cardiac
catheterization laboratory around-the-clock, we hypothesized that door-to-balloon
times would be longer during evenings, nights, and weekends than on weekday
days. In addition, we examined whether the pattern of door-to-drug and door-to-balloon
times by time of day and day of week varied according to hospital characteristics.
Our primary data source was the National Registry of Myocardial Infarction
(NRMI), a voluntary prospective database of patients admitted with acute myocardial
infarction (AMI). Characteristics of the NRMI registry, data-gathering procedures,
and reliability have been described.19 This
study used data for patients enrolled in the NRMI 3 or NRMI 4 registries from
January 1, 1999, through December 31, 2002. All patient-level data and hospital-specific
annual reperfusion volumes were obtained from the NRMI registry. Additional
hospital characteristics were obtained from the American Hospital Association
Annual Survey of Hospitals and the Health Facility Master File (SMG Inc, Chicago,
We conducted a retrospective cohort study of patients who presented
acutely to the hospital within 12 hours of symptom onset who had an initial
electrocardiogram (ECG) demonstrating ST-segment elevation or presumably new
left bundle-branch block. To focus on primary reperfusion, we only included
patients administered fibrinolytic therapy or PCI within 6 hours after hospital
The NRMI registry contains data on 830 473 AMI hospitalizations
during the study period. We excluded 177 468 transfer patients who received
their initial care at another hospital and 431 281 patients with neither
ST-elevation nor left bundle-branch block on their initial ECG. We also excluded
patients whose AMI symptoms developed after admission (n = 5088);
patients without chest pain and whose symptom onset time was unknown (n = 20 415);
patients whose first ECG was nondiagnostic (n = 17 066); patients
whose diagnostic ECG time was missing, invalid, or more than 6 hours after
hospital arrival (n = 6335); and patients who were not administered
fibrinolytic therapy or PCI (n = 62 635).
With the remaining 110 185 patients, we developed 2 cohorts based
on the reperfusion therapy administered (fibrinolytic therapy, n = 73 422
or PCI, n = 36 763). We excluded 512 patients from the fibrinolytic
cohort and 891 patients from the PCI cohort because reperfusion treatment
time could not be determined. Patients were assigned to the group of the first
therapy they received. We excluded 13 patients from the fibrinolytic cohort
initially treated with PCI and 507 patients from the PCI cohort initially
treated with fibrinolytic therapy. We excluded 4436 patients from the fibrinolytic
cohort admitted to hospitals administering fibrinolytic therapy in fewer than
20 cases and 1718 patients from the PCI cohort admitted to hospitals performing
fewer than 20 PCI procedures over the 4-year study period. From the fibrinolytic
cohort, we excluded an additional 22 patients who were admitted to non-US
hospitals. The final cohorts included 68 439 patients administered fibrinolytic
therapy at 1015 hospitals and 33 647 patients treated with PCI at 421
The primary outcome was reperfusion treatment time. For the fibrinolytic
cohort, treatment time was defined as the time from hospital arrival to the
initiation of fibrinolytic therapy (door-to-drug time). For the PCI cohort,
treatment time was defined as the time from hospital arrival to first balloon
inflation (door-to-balloon time). We also determined the proportion of patients
administered fibrinolytic therapy within the American College of Cardiology/American
Heart Association (ACC/AHA) guideline–recommended 30-minute door-to-drug
time15 and the proportion with prolonged door-to-drug
times (>45 minutes). Similarly, we assessed the proportion of patients receiving
PCI within the ACC/AHA guideline–recommended 90-minute door-to-balloon
time15 and the proportion with prolonged door-to-balloon
times (>120 minutes).
The primary independent variable, patient arrival period, was defined
by categorizing the week into 2 workday groups: weekday (Monday-Friday) and
weekend (Saturday-Sunday), and 3 daily shifts: day (7 AM-5 PM), evening (5 PM-12 AM) and night
(12 AM-7 AM). Shift times were determined by
consideration of typical emergency department and catheterization laboratory
workshifts and inspection of the distribution of the dependent variable by
hour. In the primary analysis, patient arrival period was dichotomized into
regular hours (weekdays, 7 AM-5 PM) and off-hours
(weekdays, 5 PM-7 AM and weekends). In secondary
analyses, we categorized off-hours into 5 periods: weekday-evening, weekday-night,
weekend-day, weekend-evening, and weekend-night.
Additional patient covariates included baseline sociodemographic and
medical history factors and characteristics of the clinical presentation.
Hospital covariates included US Census division, ownership status, cardiac
interventional capabilities, teaching status, reperfusion volume, reperfusion
specialization, and urban vs rural location (Table 1, Table 2, Table 3, and Table
In this study, race was used to control for potential confounding in
multivariable regression analysis. Patient race or ethnicity was coded as
a set of dummy variables indicating patients’ racial or ethnic group,
which was abstracted from the medical records using the following categories:
white, African American/black, Hispanic, Asian/Pacific Islander, American
Indian or Alaska native, and other or unknown race or ethnicity. Because
the number of patients categorized as Asian/Pacific Islander or American Indian
or Alaska native was small, these patients were grouped into the “other”
category during the analysis. Admission or triage staff recorded race or ethnicity
as the patient was registered, and in NRMI, patients were assigned to only
1 racial or ethnic category.
For both the fibrinolytic and PCI cohorts, time to reperfusion was treated
as a continuous variable, log transformed to correct for skewness.22 The geometric means for door-to-drug and door-to-balloon
times were reported among the categories of patient arrival period. We constructed
multivariable hierarchical models for each cohort to assess the relationship
between patient arrival period and reperfusion time adjusted for all patient
and hospital characteristics.23 The outcome
variable for all models was logarithm of reperfusion treatment time. We also
included calendar time in all models to account for secular trends and staggered
reporting periods by hospitals; random effects were specified for the main
intercept and the coefficient of calendar time in all models.24 To
facilitate clinical interpretation, we retransformed model results to natural
units (ie, minutes) using simulation.25 We
also assessed the relationship between patient arrival period and reperfusion
treatment time in subgroups defined by hospital characteristics.
We examined reperfusion treatment time subintervals for fibrinolytic
therapy and PCI using the same analytic approach. The door-to-drug time was
divided into 2 subintervals: door-to-data (hospital arrival to ECG completion),
and data-to-drug (ECG completion to fibrinolytic therapy administration).
The door-to-balloon time was divided into 3 subintervals: door-to-data, data-to-catheterization
laboratory (ECG completion to catheterization laboratory arrival), and catheterization-laboratory-to-balloon
(catheterization laboratory arrival to balloon inflation).
To determine whether mortality differed between patients presenting
during off-hours vs regular hours, we constructed a multivariable hierarchical
model adjusted for all patient characteristics. To address the potential selection
bias arising from differential use of therapies by patient arrival period,
we compared the in-hospital mortality for all patients administered reperfusion
(PCI plus fibrinolytic therapy) during regular hours and off-hours. To assess
the degree to which any mortality differences could be explained by variation
in reperfusion treatment time, we subsequently added reperfusion treatment
time to the multivariable model. Since this model included patients treated
with either PCI or fibrinolytic therapy, we standardized reperfusion treatment
times based on the therapy administered. We used the same analytic approach
to determine whether mortality differed among patients presenting during off-hours
vs regular hours in the PCI cohort and the fibrinolytic therapy cohort, respectively.
Mortality data for the entire hospitalization episode was not available for
transfer-out patients (defined as patients who present initially to one hospital
but who are subsequently transferred to a second institution prior to hospital
discharge). Because mortality data were available only from the first hospital
for these transfer-out patients they were assumed to be alive in the analysis.
Statistical analyses were performed using SAS version 8.2 (SAS Institute
Inc, Cary, NC), Stata version 8.0 (Stata Corp, College Station, Tex), and
HLM version 5 (SSI, Lincolnwood, Ill). P <.05 was considered
statistically significant. The Yale University School of Medicine Institutional
Review Board determined that this protocol was exempt from review because
we used secondary data that had no patient identifiers.
The characteristics of the fibrinolytic and PCI cohorts stratified by
patient arrival period are presented in Table
1 and Table 3. Patient and
hospital characteristics were generally similar for different arrival periods.
However, patients in the fibrinolytic and PCI cohorts who came to the hospital
during off-hours were younger, more likely to be smokers, and less likely
to have had a prehospital ECG than patients who came to the hospital during
regular hours. Compared with patients who presented during regular hours,
patients in the fibrinolytic cohort who presented during off-hours were more
likely to be admitted to hospitals with cardiac surgery capability but less
likely to be admitted to hospitals that used fibrinolysis for more than 90%
of reperfusion cases. Finally, patients in the PCI cohort presenting during
off-hours were more likely to be admitted to high-volume PCI centers and hospitals
that used PCI for more than 90% of reperfusion cases than patients presenting
during regular hours.
Overall 46 450 patients (67.9%) administered fibrinolytic therapy
presented during off-hours while 21 989 (32.1%) presented during regular
hours. The adjusted mean door-to-drug times were longer during off-hours (34.3
minutes) than regular hours (33.2 minutes), but the absolute difference was
small (1.0 minutes 95% confidence interval [CI], 0.7-1.4; P<.001). Door-to-drug times ranged from 0.3 to 2.0 minutes longer
for each off-hour period compared with regular hours: weekday evening (35.2
minutes), weekday night (33.5 minutes), weekend daytime (33.8 minutes), weekend
evening (34.6 minutes), and weekend night (34.0 minutes). This pattern was
consistent across all hospital subgroups (Table
The proportion of patients with door-to-drug times less than 30 minutes
and more than 45 minutes did not vary substantially by patient arrival period
(Figure 1). A slightly lower proportion
of patients were administered fibrinolytic therapy within 30 minutes during
off-hours (41.2%) compared with regular hours (43.9%; difference, 2.7%; 95%
CI, 1.9%-3.5%; P<.001). A similar proportion of
patients had door-to-drug times more than 45 minutes during off-hours (30.3%)
compared with regular hours (28.8%; difference, 1.5%; 95% CI, 0.8%-2.3%; P<.001).
Fibrinolytic treatment-time subintervals did not differ appreciably
by patient arrival period (Figure 2).
The geometric mean door-to-data subinterval was comparable for off-hours (7.5
minutes) and regular hours (7.4 minutes; difference, 0.1 minutes; 95% CI,
0-0.2; P = .04). The geometric mean data-to-drug
subinterval was also comparable for off-hours (25.5 minutes) and regular hours
(24.8 minutes; difference, 0.7 minutes; 95% CI, 0.4-1.0; P<.001).
Overall 18 228 patients (54.2%) received PCI during off-hours while
15 419 (45.8%) received PCI during regular hours. The adjusted mean door-to-balloon
time was longer during off-hours (116.1 minutes) than regular hours (94.8
minutes), and the absolute difference was large (21.3 minutes; 95% CI, 20.5-22.2; P<.001). Door-to-balloon times ranged from 17.0 to 30.7
minutes longer for each of the off-hour time periods compared with regular
hours: weekday evening (111.8 minutes), weekday night (118.3 minutes), weekend
daytime (115.9 minutes), weekend evening (116.4 minutes) and weekend night
(125.5 minutes). This pattern was consistent across all hospital subgroups
The proportion of patients with door-to-balloon times less than 90 minutes
and more120 minutes varied markedly by patient arrival period (Figure 1). Fewer patients received PCI within 90 minutes during
off-hours (25.7%) compared with regular hours (47.0%; difference, 21.3%; 95%
CI, 20.3%-22.3%; P<.001). Substantially more patients
experienced prolonged door-to-balloon times (>120 minutes) during off-hours
(41.5%) compared with regular hours (27.7%; difference, 13.8%; 95% CI, 12.8%-14.9%; P<.001).
To better understand the source of the variation in PCI treatment times,
we examined the relationship between PCI treatment time subintervals and patient
arrival period (Figure 2). The door-to-data
subinterval was the same for off-hours (7.9 minutes) and regular hours (7.9
minutes; difference, 0 minutes; 95% CI, −0.1 to 0.2; P = .6). The catheterization-laboratory-to-balloon subinterval
was also similar for off-hours (33.8 minutes) and regular hours (33.7 minutes;
difference, 0.1 minutes; 95% CI, −0.3 to 0.4; P = .7).
In contrast, the data-to-catheterization-laboratory subinterval was longer
during off-hours (69.8 minutes) than regular hours (49.1 minutes). This increase
in the time from ECG completion to catheterization laboratory arrival (20.8
minutes; 95% CI, 20.0-21.5; P<.001) accounted
for nearly all of the increased door-to-balloon times during off-hours.
To determine whether variation in reperfusion treatment times was also
associated with differences in mortality, we examined the in-hospital mortality
for patients presenting during off-hours compared with those presenting during
regular hours. Among 21 989 patients treated with fibrinolytic therapy
during regular hours, 963 (4.4%) died while among 46 450 treated during
off-hours, 2043 (4.4%) died. Among 15 419 patients who underwent primary
PCI during regular hours, 728 (4.7%) died while among 18 228 treated
during off-hours 859 (4.7%) died.
Overall, after adjusting for all patient covariates, patients presenting
during off-hours had significantly higher in-hospital mortality than patients
presenting during regular hours (OR, 1.07; 95% CI, 1.01-1.14; P = .02).
When we also adjusted for reperfusion treatment time in the regression model,
the difference in mortality between the regular hours and off-hours periods
was attenuated and was no longer statistically significant (OR, 1.04; 95%
CI, 0.98-1.11; P = .18). After adjusting for all patient
covariates, those treated with PCI presenting during off-hours had higher
in-hospital mortality than patients presenting during regular hours but the
difference was not statistically significant (OR, 1.05; 95% CI, 0.95-1.16; P = .30). When we also adjusted for reperfusion treatment
time in the regression model, the difference in mortality between the regular
hours and off-hours periods was attenuated (OR, 1.02; 95% CI, 0.92-1.13; P = .74). After adjusting for all patient covariates, patients
treated with fibrinolytic therapy presenting during off-hours had higher in-hospital
mortality than patients presenting during regular hours but the difference
was not statistically significant (OR, 1.06; 95% CI, 0.98-1.15; P = .13).
Adjusting for reperfusion treatment time in the regression model did not alter
the magnitude of the difference in mortality between the regular hours and
off-hours period (OR, 1.06; 95% CI, 0.98-1.14; P = .15).
Almost two thirds of the 102 086 STEMI patients administered reperfusion
therapy in this study were treated during off-hours. Door-to-balloon times
for PCI were longer during off-hours than regular hours while door-to-drug
times for fibrinolytic therapy did not differ appreciably by patient arrival
period. Patients who received PCI during off-hours had a 21-minute longer
door-to-balloon times and were treated within the guideline-recommended time
45% less often than patients seen during regular hours. Increases in the time
from ECG completion to catheterization laboratory arrival accounted for nearly
all of the delay in door-to-balloon times during off-hours. Patients treated
with reperfusion therapy during off-hours had a higher mortality rate than
patients treated during regular hours. This mortality difference was attenuated
by 43% when we adjusted for differences in reperfusion treatment times, suggesting
that the higher off-hours mortality was due in part to longer reperfusion
Although differences in PCI treatment times by patient arrival period
have been previously noted,16-18 our
study advances existing research in several respects. This study is the first
to demonstrate that PCI reperfusion times are greater during off-hours than
regular hours although fibrinolytic reperfusion times are similar for all
times of the day and days of the week. In addition, this study demonstrates
that delays to PCI during off-hours are common to all types of hospitals,
including high-volume PCI centers. Finally, this is the first study to suggest
that higher off-hours in-hospital mortality rates may be partly due to longer
off-hours reperfusion times.
We found that increases in the time interval from ECG completion to
catheterization laboratory arrival accounted for nearly all of the increases
in door-to-balloon times during off-hours. The major clinical processes that
occur during this subinterval are (1) the diagnosis of the patient with a
reperfusion-eligible STEMI and (2) activation of the cardiac catheterization
laboratory. Because the diagnosis of a reperfusion-eligible STEMI is the same
whether the patient is treated with fibrinolytic therapy or PCI and because
door-to-drug times for fibrinolysis do not vary appreciably by patient arrival
period, it is unlikely that variations in the time to diagnosis contribute
significantly to the prolonged PCI treatment times during off-hours. However,
activation of the catheterization laboratory is likely to be longer during
off-hours, because catheterization laboratory personnel are frequently off
In contrast to our findings for PCI, door-to-drug times for fibrinolysis
did not vary appreciably during off-hours. One explanation is that the administration
of fibrinolytic therapy requires only emergency department personnel and the
emergency departments of most US acute care hospitals are staffed around the
clock.26 In contrast, the administration of
PCI requires a multidisciplinary team of emergency department and cardiac
catheterization laboratory personnel, and very few US hospitals provide onsite
staffing of their cardiac catheterization laboratory continuously.
We acknowledge that several issues merit consideration in the interpretation
of our study. Though the NRMI registry includes geographically diverse hospitals,
our results may not be generalizable to all US hospitals. The NRMI hospitals
tend to have greater AMI volumes and are more likely to be nonprofit than
nonparticipating hospitals. Nevertheless, NRMI is the largest and most current
database of AMI patients available, and our results were consistent in multiple
hospital subgroups. The quality of the NRMI time data collected during regular
hours vs off-hours was not assessed. We believe it is unlikely that variation
in documentation during off-hours would result in a differential bias and
doubt that such variation could account for the substantial increase in door-to-balloon
times noted during off-hours. A physician might choose to treat patients with
fibrinolytic therapy instead of PCI during off-hours when anticipated door-to-balloon
times are longer, potentially confounding the relationship between patient
arrival period and reperfusion treatment times. However, the effect of such
confounding would be to underestimate the association between off-hours and
longer door-to-balloon times. Finally, because mortality data for the entire
hospitalization episode were not available for transfer-out patients, they
were assumed to have survived to hospital discharge. Since patients treated
with fibrinolytic therapy are much more likely to be transferred than patients
treated with PCI, this assumption introduces a bias that likely underestimates
the mortality of patients treated with fibrinolytic therapy vs patients undergoing
PCI. Such a comparison was not an objective of our study, and it would be
inappropriate to draw any inferences about the mortality following PCI vs
fibrinolytic therapy from this analysis. However, the transfer-out issue does
not likely introduce a substantial bias for the regular hours vs off-hours
comparisons made separately for the PCI cohort and fibrinolytic therapy cohorts.
Furthermore, in the primary mortality analysis that included all patients
treated with reperfusion, the transfer-out issue introduces a small but conservative
bias, which underestimates the mortality during off-hours relative to regular
hours because a higher proportion of patients treated during off-hours than
during regular hours received fibrinolytic therapy.
Our study has implications for the delivery of reperfusion therapy during
off-hours. Because delays to PCI can result in lower survival rates for STEMI
patients,14 institutions providing PCI during
off-hours should commit to doing so in a timely manner. One way to improve
the timeliness of PCI during off-hours would be to provide onsite staffing
of the cardiac catheterization laboratory around-the-clock. However, the clinical
benefits of providing continuous in-house staffing of the cardiac catheterization
laboratory must be weighed against the extra cost of providing such coverage.
Another possible solution is to cross-train noncardiac catheterization laboratory
staff to assist with PCI during off-hours. However, the benefits of cross-training
staff may not be realized unless rapid access to interventional cardiologists
is also available. Still another approach would be to regionalize interventional
cardiac care, transporting off-hour patients to institutions with continuous
cardiac catheterization laboratory staffing and rapid door-to-balloon times.
However, this approach would only affect patients transported by emergency
medical services and the faster door-to-balloon times at regional centers
might be offset by prolonged transport times to these hospitals.
In conclusion, door-to-balloon times were longer during off-hours than
regular hours while door-to-drug times did not differ appreciably by time
of day or day of week. Increases in the time from ECG completion to catheterization
laboratory arrival mainly accounted for the longer door-to-balloon times during
off-hours. To achieve the best outcomes, hospitals providing PCI during off-hours
should commit to doing so in a timely manner.
Corresponding Author: Harlan M. Krumholz,
MD, SM, Cardiovascular Section, Yale University School of Medicine, 333 Cedar
St, PO Box 208088, New Haven, CT 06520-8088 (email@example.com).
Author Contributions: Dr Krumholz had full
access to all of the data in the study and takes responsibility for the integrity
of the data and the accuracy of the data analysis.
Study concept and design: Magid, Wang, Herrin,
McNamara, Pollack, Krumholz.
Analysis and interpretation of data: Wang,
Herrin, Magid, McNamara, Bradley, Curtis, Pollack, French, Blaney, Krumholz.
Drafting of the manuscript: Magid, Herrin.
Critical revision of the manuscript for important
intellectual content: Magid, Wang, McNamara, Bradley, Curtis, Pollack,
French, Blaney, Krumholz.
Statistical analysis: Wang, Herrin
Obtained funding: Krumholz.
Administrative, technical, or material support:
Study supervision: Krumholz.
Financial Disclosures: None reported.
Funding/Support: This research was supported
by grant R01 HL072575 of the National Heart, Lung, and Blood Institute.
Role of the Sponsor: The National Heart, Lung,
and Blood Institute had no involvement in the design or conduct of the study,
data management or analysis, or manuscript preparation, review, or authorization
for submission. Genentech approved the study and provided access to the NRMI
database at no charge; however, Genentech did not provide any direct support
for the study and was not involved in the study design and conduct, analysis
and interpretation of the data, and preparation of the manuscript.
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