Off-Hours STEMI Care on Target, But Room for Improvement

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The quality of care for patients with ST-segment-elevation myocardial infarction (STEMI) is high regardless of when patients present to the hospital, but door-to-balloon (D2B) times and in-hospital mortality remain higher for those presenting outside of regular business hours, according to a registry study published online July 29, 2014, ahead of print in Circulation: Cardiovascular Quality and Outcomes.

“Short D2B times and early invasive strategies have proven to reduce cardiovascular events in patients presenting with STEMI. Thus, there is an impetus to provide timely care to all patients with STEMI, regardless of the time of presentation,” Jorge F. Saucedo, MD, of NorthShore University Health System (Evanston, IL), and colleagues write. They add, however, that the difference in D2B times between patients presenting during on- vs off-hours cannot fully explain the disparity in mortality.

Methods
 The researchers examined data from the American Heart Association’s Mission: Lifeline program, which is available via the Acute Coronary Treatment and Intervention Outcomes Network-Get With The Guidelines (ACTION-GWTG) registry. The analysis included 15,972 patients with STEMI who presented on-hours (weekdays 8 AM to 6 PM) and 27,270 who presented off-hours (at night, on the weekend, or on a holiday) to 447 US centers between January 2007 and September 2010.

Baseline characteristics were generally similar between groups, although those presenting off-hours were slightly younger (59 vs 61 years; < .0001) and more likely to be a current or recent smoker (46.3% vs 42.0%; P < .001). 


Quality of Care Slightly Better On-Hours

Use of recommended medications was high overall, regardless of when patients arrived at the hospital. Aspirin, for example, was given to 99% of patients in both groups. Other metrics also were similar in the 2 groups including door-to-ECG times of 10 minutes or less and door-to-needle times of 30 minutes or less. 

There were some differences between the groups, however. Of the patients undergoing primary PCI (97.1% of the cohort), those presenting on-hours had shorter median D2B time (56 vs 72 minutes) and were more likely to undergo the procedure in 90 minutes or less (87.8% vs 79.2%; P < .0001 for both). 

Despite an in-hospital mortality rate of 4.2% in both groups, after risk adjustment the likelihood of dying was elevated in those presenting off-hours (OR 1.13; 95% CI 1.02-1.26). That relationship was weakened when the analysis was restricted to patients undergoing primary PCI (OR 1.12; 95% CI 1.00-1.25) and was no longer statistically significant after exclusion of nonsystem reasons for delay (OR 1.10; 95% CI 0.95-1.27). 

Does D2B Time Explain Mortality Gap?

In a telephone interview with TCTMD, Dr. Saucedo said that the longer D2B time in the off-hours group was related to the lack of a fully staffed, 24-hour cath lab at most centers; the delay resulting from staff members having to travel to the hospital when the STEMI system was activated.

Having cath labs staffed 24/7 at all centers would address that problem, he said. “We think there needs to be a conversation in that regard,” Dr. Saucedo said. “But… it’s probably not cost-effective. It would be a tremendous cost to an institution to have a team of at least 4 individuals, including the nurse, the technicians, and the physician, available at all hours.”

Even if D2B times could be equalized between the on-hours and off-hours cohorts, that would not necessarily narrow the difference in outcomes, he added. He pointed to the possibility that factors not captured in the registry could explain the higher mortality in the patients presenting off-hours.

Improvements Over Time in Both Groups

Jeffrey W. Moses, MD, of Columbia University Medical Center/Weill Cornell Medical Center (New York, NY), agreed that the difference in D2B times was not sufficient to explain the mortality gap, also pointing to unmeasured confounders.

Median D2B times in both groups were “very good,” he noted in a telephone interview with TCTMD, describing the time in the off-hours group as “pretty impressive.” He questioned whether it would be worth putting additional resources into bringing the D2B times down any further after multiple national initiatives aimed at doing so have proven so successful.

“It’s not clear that an hour is better than 90 minutes or that 90 minutes is better than 120 minutes,” Dr. Moses said. 

Instead, he said, efforts are being directed at identifying patients and getting them to the hospital faster. “I think there’s more bang for your buck there,” he commented, adding that “the quality initiatives have actually squeezed the systems down to a point where it’s time to start looking at other measures of increased efficacy instead of just perseverating on the old ones.”

Dr. Saucedo highlighted the low rate of in-hospital mortality, in addition to the lower D2B times, in the current study compared with analyses conducted using older data. In prior studies, the proportion of patients with STEMI presenting off-hours who achieved D2B times of 90 minutes or less ranged from 26% to 31%, far below the 79.2% observed in the current study.

“If you come in off-hours, 80% of the time you’re going to have your angioplasty done within 90 minutes,” Dr. Saucedo said. “In my opinion, that’s a powerful message.”

 


Source: 
Dasari TW, Roe MT, Chen AY, et al. Impact of time of presentation on process performance and outcomes in ST-segment-elevation myocardial infarction: a report from the American Heart Association: Mission Lifeline program. Circ Cardiovasc Qual Outcomes. 2014;Epub ahead of print. 

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Todd Neale is the Associate News Editor for TCTMD and a Senior Medical Journalist. He got his start in journalism at …

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Disclosures
  • Dr. Saucedo reports no relevant conflicts of interest.
  • Dr. Moses reports serving as a consultant for Boston Scientific.

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