Treatment at a STEMI Center Boosts Cardiac Arrest Outcomes

Patients resuscitated after out-of-hospital cardiac arrest are more likely to achieve a good neurologic outcome if treated at a center with full-time PCI capabilities, according to a registry study published online June 14, 2015, ahead of print in the American Heart Journal.

Bryn E. Mumma, MD, MAS, of the University of California, Davis Medical Center (Sacramento, CA), and colleagues looked at 7,725 patients (mean age 67 years; 58% men) resuscitated after out-of-hospital cardiac arrest in California in 2011; data was mined from the California Office of Statewide Health Planning and Development database.

Approximately two-thirds (n = 5,202) of patients were treated at a STEMI center, including 3,340 at centers with at least 40 out-of-hospital cardiac arrest cases per year, and 24.2% had good neurologic recovery.

On univariate analysis, good neurological recovery was higher in patients treated at STEMI centers with a volume of 40 cases or more per year (OR 1.35; 95% CI 1.13-1.62), as well as at centers with less than 40 cases per year (OR 1.71; 95% CI 1.42-2.07), compared with treatment at non-STEMI centers.

These differences were maintained after adjustment for age, race, gender, ethnicity, insurance type, ventricular arrest rhythm, hospital size, trauma center designation, and teaching status. Additionally, increasing age was associated with decreased odds of good neurologic recovery, with similar but nonsignificant trends tied to female sex and treatment at a level 1 or 2 trauma center. Ventricular arrest rhythm was related to a greater likelihood of having a good recovery (table 1).

Increasing hospital volume of resuscitated patients was associated with lower odds of good neurologic recovery, but this difference did not remain when the highest-volume outlier hospital was removed from the analysis.

Hypothermia use was low among STEMI centers—regardless of whether they had a volume of 40 or more cases per year (6.3%) or fewer than 40 (7.8%)—and among non-STEMI centers (1.7%). Rates of cardiac catheterization were 22.0%, 27.1%, and 4.8%, respectively.

“Possible reasons for this low utilization include limited awareness of or agreement with the data supporting these interventions, perception of poor patient prognosis, lack of organized protocols, and concerns regarding cardiac catheterization outcome reporting,” Dr. Mumma and colleagues write.

Confounded, Yet Still Valid

“The findings are interesting, but the study lacks the clinical detail that you would like to have to understand what they are observing,” said Harlan M. Krumholz, MD, SM, of Yale University School of Medicine (New Haven, CT), in an email with TCTMD. “If this is true, rather than [thinking] we need to regionalize care, I would like to understand the mechanism. How are better results being achieved, and can they be adopted by non-STEMI centers, or are there interventions that are best done in the context of high volume?”

Similarly, Christopher Granger, MD, of Duke University Medical Center (Durham, NC), told TCTMD in a telephone interview that the study is “very confounded” and therefore urged caution in interpreting the data. “For example, let’s say a patient has an out-of-hospital cardiac arrest and they are being taken to a PCI center, and then they have another cardiac arrest in the ambulance so they go to a closer hospital…. That kind of information is not fully captured in these databases,” he said. “There may be reasons that people go to a non-PCI center that partially explain the worse outcome, other than the care that they get.”

Jeffrey W. Moses, MD, of Columbia University Medical Center, told TCTMD in a telephone interview that because the study was based on administrative data, “this is a very 10-, 20-thousand-foot view of the problem…. It’s impossible to really isolate the components that actually led to that better recovery. It raises as many questions as it answers.”

But the bottom line, according to Dr. Granger, is that the study “provides some support to the concept that patients seem to do better if they are taken to STEMI centers [for] out-of-hospital cardiac arrest. I think that makes perfect sense and that’s actually consistent with guidelines.”

Moreover, he said the study supports the need for regional systems of care for patients with out-of-hospital cardiac arrest, which should optimally include treatment at STEMI centers.

Mumma BE, Diercks DB, Wilson MD, Holmes JF. Association between treatment at an ST segment elevation myocardial infarction (STEMI) center and neurologic recovery following out-of-hospital cardiac arrest. Am Heart J. 2015;Epub ahead of print.

Related Stories:

• Regional STEMI Care Systems Improve Treatment Times
• Off-Hours STEMI Care on Target, But Room for Improvement
• Direct Transport to PCI Center Improves Outcomes in STEMI Patients