System Delays for STEMI Patients Linked to Subsequent Heart Failure Care

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In patients with ST-segment myocardial infarction (STEMI), delays in obtaining primary percutaneous coronary intervention (PCI) are associated with an increased need for subsequent care, both inpatient and outpatient, related to chronic heart failure (CHF). According to a paper published in the September 20, 2011, issue of Annals of Internal Medicine, the findings add to a large body of evidence that system delays, which are modifiable, can make a tremendous difference in patient outcome.

Researchers led by Christian Juhl Terkelsen, MD, PhD, of Aarhus University Hospital (Aarhus, Denmark), looked at 7,952 Danish STEMI patients who were transported via ambulance for primary PCI within 12 hours of symptom onset. The study assessed the period from January 1999 to February 2010.

Every Hour Counts

System delays ranged from 60 minutes or less to 360 minutes. Overall, the mean treatment delay was 4.2 ± 5.9 hours, including a mean patient delay of 2.3 ± 5.2 hours and a mean system delay of 2.2 ± 1.0 hour. Patient delays occurred between symptom onset and EMS call, while system delays occurred from EMS call to first catheterization during PCI.

At 1 year, the mortality rate was 9.2%. The proportion of patients readmitted or seen on an outpatient basis for CHF was 7.4%, with readmission accounting for 3.0% and outpatient visits for 4.4%. After a median of 3.1 years (interquartile range, 0.9-5.4 years), 17.5% of patients had died and 9.9% had been treated for CHF.

Cumulative incidence of readmission or outpatient contact due to CHF over the course of follow-up increased with increasing system delay times (P < 0.001; table 1).

Table 1. Rates of Treatment for CHF According to System Delay

≤ 60 Minutes
(n = 451)

61-120 Minutes
(n = 3,457)

121-180 Minutes
(n = 2,655)

181-360 Minutes
(n = 1,389)





On multivariable analysis, treatment delay as a whole independently predicted readmissions or outpatient visits for CHF treatment (adjusted HR 1.04 per hour increase; 95% CI 1.008-1.06; P = 0.012). However, separating treatment delay into its 2 components—patient delay and system delay—showed that only system delay was associated with CHF-related readmission or outpatient contact (table 2).

Table 2. Likelihood of CHF Treatment by Type of Delay


Adjusted HR (95% CI)a

P Value

System Delay

1.10 (1.02-1.17)


Patient Delay

1.00 (0.998-1.003)


a Per hour increase.

According to the study authors, the findings make sense because delayed reperfusion is associated with more extensive myocardial necrosis and reduced LVEF. They say that health care system delay is the ideal performance measure in triaging patients with STEMI for primary PCI because it:

  • Is objective
  • Is not prone to recall bias
  • Applies to all patients surviving until contact with the health care system
  • Is useful for both transferred patients and those triaged in the field
  • Has less uncertainty than estimates of patient delay

Christopher B. Granger, MD, of the Duke University School of Medicine (Durham, NC), told TCTMD in a telephone interview that while such information is important, the caveat with any observational study lies in interpreting whether the relationship is causative.

“One possibility is that the worse outcome is because of the delay. But the second possibility is that the worse outcome is related to the delay but not because of it,” he said. For example, older patients are at higher risk for problems that may be exacerbated by lags in treatment.

Still, Dr. Granger said the study adds to accumulating evidence “that even modest acceleration of treatment may be important in optimizing outcomes.”

One Strategy for All Not Best for Patients

But in an editorial accompanying the study, Paul W. Armstrong, MD, of the University of Alberta (Alberta, Canada), and William E. Boden, MD, of Buffalo General Hospital (Buffalo, NY), argue that too much emphasis on getting patients to primary PCI obscures the issue that timely use of reperfusion more generally—either primary PCI or fibrinolysis—should be the goal in treating all patients with STEMI.

“We contend that avoidance or delay in administering fibrinolysis to increase primary [PCI] for all patients has caused a STEMI treatment paradox,” Drs. Armstrong and Boden write. “This is especially true in the large proportion of patients presenting early after symptom onset. Of note, [primary] PCI-capable centers in the United States with the highest STEMI volume have longer [door-to-needle] times.”

The editorial suggests that STEMI patients are not being well-served by the promulgation of one reperfusion strategy over another. Instead, Drs. Armstrong and Boden point to the merits of an integrated approach using fibrinolysis and primary PCI, coupled with co-intervention in patients who initially receive fibrinolysis.

“We believe that we now have compelling evidence of suboptimal care for many patients with STEMI and that the time for a single therapeutic strategy is long past,” they write. “We contend that it is time to embrace an integrated therapeutic strategy, including more frequent, timely, and strategic fibrinolysis, for an inherently complex disorder.”


1. Terkelsen CJ, Jensen LO, Tilsted H-H, et al. Health care system delay and heart failure in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention: Follow-up of population-based medical registry data. Ann Intern Med. 2011;155:361-367.

2. Armstrong PW, Boden WE. Reperfusion paradox in ST-segment elevation myocardial infarction. Ann Intern Med. 2011;155:389-391.



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  • The study was funded by grants from the Arvid Nilsson Foundation, the Health Research Fund of Central Denmark Region, the Helga and Peter Korning Foundation, the Karl G. Andersen Foundation, the Research Foundation at Skejby University Hospital, and the Riisfort Foundation.
  • Drs. Terkelson, Armstrong, and Granger report no relevant conflicts of interest.
  • Dr. Boden’s information could not be accessed from the Annals of Internal Medicine Web site.