NEW YORK (Reuters Health) – In patients with high-risk acute coronary syndromes (ACS) without ST-segment elevation, delaying intervention until the next working day does not appear to pose any greater risk than immediate intervention.

According to lead author Dr. Gilles Montalescot from Centre Hospitalier Universitaire Pitie-Salpetriere in Paris, and his colleagues, “Little information is available regarding the optimal timing of coronary angiography and intervention” for patients with non-ST segment elevation ACS.

The Angioplasty to Blunt the Rise of Troponin in Acute Coronary Syndromes Randomized for an Immediate or Delayed Intervention (ABOARD) study was designed to answer these questions. Findings are reported in the September 2 issue of the Journal of the American Medical Association.

Included were 352 patients treated at 13 French centers. They were randomly assigned to immediate treatment (median 70 minutes from randomization to sheath insertion) or delayed intervention (median 21 hours; maximum, 60 hours after weekend admission).

The primary outcome, peak troponin I release during hospitalization, did not differ significantly between the two groups (median 2.1 ng/mL in the immediate intervention group and 1.7 ng/mL in the delayed group).

Results were similar across all major subgroups (age, gender, Thrombolysis in Myocardial Infarction score, or diabetes status). Similarly, groups did not differ significantly with regard to the secondary end point combining death, MI, or urgent revascularization at 1 month follow-up.

Hospital stay was significantly longer in the delayed intervention group (median 77 vs 55 hours, p < 0.001). Thus, Dr. Montalescot’s team concludes, “The hypothesis that reducing the waiting period for revascularization to a delay of primary percutaneous intervention would reduce MI is not confirmed.” Still, they recommend, “Rapid or urgent catheterization appears preferable I high-risk or unstable patients, while the benefit in other situations may be limited to practicality and length of hospital stay.” Reference:
JAMA 2009;302:947-954.