When every minute counts, delaying treatment can have enormous repercussions. An analysis of U.S. data finds that while door-to-balloon times have improved, many patients may still not receive care within the recommended 120 minutes, due in part to transfers to STEMI care centers.

Research published online Dec. 8 in JAMA: Internal Medicine revealed that when patients are transferred to a specialized facility with an estimated drive time of more than 30 minutes from the initial triage hospital, only 42.6 percent were treated with a first door-to-balloon time within 120 minutes.

Amit N. Vora, MD, MPH, of the Duke University Medical Center in Durham, N.C., and colleagues acquired patient data through the Acute Coronary Treatment and Intervention Outcomes Network Registry - Get with the (ACTION-GWTG) database. They analyzed times and outcomes for STEMI patients available between 2008 and 2012.

While 51.3 percent of all patients transferred had a primary PCI within 120 minutes, the proportion shifted based on mean drive times between the hospitals where patients presented with STEMI and hospitals that had the ability to provide PCI. If drives took longer than 60 minutes, only 29.6 percent of patients received primary PCI within the 120 minute window.

They also found that 52.7 percent of patients with drive times longer than 60 minutes received fibrinolysis, contrary to current guidelines.

In patients with a transfer between 30 and 120 minutes, 34.3 percent received pretransfer fibrinolysis. In the same time period, 65.7 were directly transferred for primary PCI, although only 43.7 percent of these patients had a door-to-balloon time within 120 minutes. Within these patients, they observed no difference between patients treated with fibrinolysis and primary PCI.

In general, however, pretransfer fibrinolysis had higher risk of major bleeding over primary PCI, even though incidence of intracranial hemorrhage was low.

An editorial response, Marc J Claeys, MD, PhD, of the department of cardiology at Antwerp University Hospital in Edegem, Belgium, wrote that while these findings add greater clarity to current practices, four factors should remain part of the decision process in providing patients with optimal reperfusion therapy. These factors include delay to balloon time due to distance between initial care facility and primary PCI providers, patient-related delays, patient bleeding risk and patient risk profiles.

Of particular concern to Claeys were patients who presented to hospitals early but ultimately required 60 to 90 minute transfers between hospitals. “Additional research is needed to better define this subgroup, and large-scale studies such as that by Vora et al provide helpful pieces of this information.”

Vora et al wrote that while these findings were nearly double that of previous reviews, “room for improvement remains in reperfusion performance in the United States because our study shows that neither fibrinolysis nor pPCI [primary PCI] is being optimally used to achieve guideline-recommended treatment targets.”