System-Wide Effort Produces Lasting Improvement in D2B Times for STEMI Transfers

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With coordinated effort and several specific initiatives, a regional health care system in North Carolina has established an ST-segment elevation myocardial infarction (STEMI) network with sustained reductions in door-to-balloon (D2B) time over 4 years. However, the gains have failed to make a dent in in-hospital mortality and length of stay, reports a paper published online September 18, 2013, ahead of print in JACC: Cardiovascular Interventions.   

B. Hadley Wilson, MD, of Carolinas Medical Center (Charlotte, NC), and colleagues compared 101 STEMI patients transferred in 2007, before the program began, with 442 transferred from 2008 to 2011, after 5 key strategies had been put into place by 9 referral hospitals. These initiatives created: 

• A hospital referral system 
• A transfer protocol with time-oriented performance goals 
• Expedited transport via ambulance or helicopter within 60 minutes 
• Standard protocols enabling the transfer hospital physician to activate the PCI hospital cath lab 
• An online tracking system to give feedback to referring hospitals about transfer times and patient outcomes 

Between the 2 periods, there were reductions in several measures of treatment delay, whereas transport times held steady. In-hospital mortality or length of stay showed no improvement (table 1).   

Table 1. Performance Measures Before vs. After Start of STEMI Network

   

“The implementation of multiple system-wide initiatives for [the transfer of STEMI patients] along with advanced transport protocols and patient-level feedback can achieve durable first D2B times within 90 minutes for a transfer STEMI network [while maintaining] transport times consistently within 60 minutes,” Dr. Wilson and colleagues conclude.   

“Because our total ischemia times could not be assessed and compared,” they add, “this may explain the lack of improvement in length of stay and mortality despite the well-established fact that most transport time reductions usually lead to reduced mortality (mainly in those with infarctions of less than 3-hour duration. . . . Future efforts for systems of care improvements should concentrate on reducing total ischemia time by public education of early signs and symptoms of heart attack, as well as calling 911 rather than using private vehicle transport to emergency departments.” 

Cooperation Required to Improve Patient Care   

Christopher Granger, MD, of Duke University (Durham, NC), told TCTMD in a telephone interview that the success of the Charlotte-based STEMI network is unsurprising given the health care system’s longstanding participation in the Regional Approach to Cardiovascular Emergencies (RACE) program.   

“It’s not just chance. This is an important study, because it shows what can be done by top-performing systems,” he said, adding that the experience serves as an example of how competing hospitals can coordinate their efforts. “We went to Charlotte and got people together and brokered a strategy where . . . the focus could be on improving patient care. Now, I think Charlotte may in fact be the best place in the country in terms of caring for STEMI.”   

Though there were many contributors toward faster treatment, “the single biggest thing is that the door-in/door-out at the non-PCI hospitals is so good there,” Dr. Granger commented, adding that “transportation time is something you can’t and shouldn’t try to accelerate, because that would mean speeding, and we don’t want to encourage that.”  

Why No Impact on Mortality?  

Even though another recent paper, published earlier this month in the New England Journal of Medicine, also showed no mortality benefit from shorter D2B times, Dr. Granger was not dissuaded.   

“There is no principle that’s better established based on incontrovertible evidence than rapid reperfusion saves lives in STEMI,” he stressed. “We have hundreds of thousands of patients in randomized studies showing that’s the case, and that faster treatment saves more myocardium and more lives. None of these observational studies—which are relatively small and highly confounded by changes in measured and unmeasured baseline characteristics—should challenge that principle.”   

He explained that “if sicker patients are now able to enter the system, then lack of an apparent decrease in mortality is misleading.”   

But Daniel S. Menees, MD, of the University of Michigan (Ann Arbor, MI), first author of the NEJM paper, said he believes that the lack of effect on morality and length of stay is genuine.   

“While it is easier for hospitals and physicians to measure and improve both transfer and DTB times, both of these factors are only individual components of the total ischemic time, which is likely the bigger issue,” Dr. Menees said. “As transfer times and DTB times decrease, the portion of total ischemic time that they comprise becomes ever shorter, and thus they are less likely to produce any further benefits.”   

He further noted: “What is not yet clear is whether or not improved times are affecting other clinical factors further downstream, such as long term mortality, CHF, or quality of life. And while improvements in D2B time have not yet been shown to improve short term patient outcomes, there are likely improvements in systems-based care that may not be as easily measured.” 

    

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Source:
Wilson BH, Humphrey AD, Cedarholm JC, et al. Achieving sustainable first door-to-balloon times of 90 minutes for regional transfer ST-segment elevation myocardial infarction. J Am Coll Cardiol Intv. 2013;Epub ahead of print. 

  

  

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