For some patients with acute coronary syndromes (ACS), the strategy of immediate intervention at a medical center does not appear to result in differences in outcomes compared with an intervention performed the next day, according to results of the ABOARD trial published in the Sept. 2 issue of Journal of the American Medical Association.
"The optimal intervention in the treatment strategy of patients presenting with ACS without ST-segment elevation (NSTE-ACS) has been debated for years," the authors wrote. "Numerous studies, randomized trials and meta-analyses have investigated the potential benefits of invasive over conservative strategies, and most have suggested a prolonged advantage of an invasive approach for the prevention of death of MI, particularly among high-risk patients."
Gilles Montalescot, MD, PhD, of the Institut de Cardiologie, Centre Hospitalier Universitaire Pitie-Sapetriere in Paris, and colleagues from the ABOARD (Angioplasty to Blunt the Rise of Troponin in Acute Coronary Syndromes Randomized for an Immediate or Delayed Intervention) study evaluated data from 352 patients with ACS at 13 high-volume medical centers in France with 24-hour facilities for treatment of primary PCI from August 2006 through September 2008.
The investigators randomized patients, all of whom had ACS without ST-segment elevation, to undergo an immediate invasive strategy or an invasive strategy scheduled on the next working day. The primary endpoint was the peak troponin value during hospitalization. The key secondary endpoint was the composite of death, MI or urgent revascularization at one-month follow-up.
They found time from randomization to sheath insertion was 70 minutes with immediate intervention vs. 21 hours with delayed intervention.
"Troponin I release, as reflected by peak value collected during hospitalization, did not differ between the two strategies in the immediate and delayed intervention groups. The probability of MI as measured by the curves of troponin peak values was similar with either strategy," they wrote.
Montalescot and colleagues also found that "the key secondary endpoint was observed in 13.7 percent of the group assigned to receive immediate intervention and 10.2 percent of the group assigned to receive delayed intervention. The other endpoints, as well as major bleeding, did not differ between the two strategies."
The authors noted that hospital stay was significantly reduced with the immediate strategy compared with the delayed intervention strategy.
"This study demonstrates the feasibility of immediate catheterization and revascularization in patients who present with NTSE-ACS but does not show that this strategy is superior to catheterization scheduled on the next working day," the authors concluded. "Thus, rapid or urgent catheterization appears preferable in high-risk or unstable patients, while the benefit in other situations may be limited to practicality and length of hospital stay.”