Angioplasty to Blunt the Rise of Troponin in Acute Coronary Syndromes Randomized for an Immediate or Delayed Intervention - ABOARD


The goal of the trial was to evaluate a strategy of catheterization and revascularization immediately after admission for non–ST-elevation acute coronary syndrome (NSTE-ACS).


A strategy of catheterization and revascularization immediately after admission for NSTE-ACS would be safe and effective.

Study Design

Patients Enrolled: 352
Mean Follow Up: 1 month
Mean Patient Age: 65 years
Female: 28%

Patient Populations:

  • Presence of at least two of the following: ischemic symptoms, electrocardiographic abnormalities in at least two contiguous leads, or positive troponin
  • TIMI score ≥3


  • Hemodynamic or arrhythmic instability requiring urgent catheterization
  • Chronic oral anticoagulation
  • Thrombolytic therapy in the preceding 24 hours

Primary Endpoints:

  • Peak troponin-I

Secondary Endpoints:

  • Composite of death, MI, or urgent revascularization at 1 month
  • Composite of death, MI, urgent revascularization, or refractory ischemia
  • Major bleeding
  • Minor bleeding
  • Major or minor bleeding

Drug/Procedures Used:

Patients with NSTE-ACS were randomized to immediate (n = 175) or next-day (n = 177) catheterization and revascularization.

Concomitant Medications:

For the immediate and delayed catheterization groups: aspirin (99%, 100%), clopidogrel (97%, 99%), abciximab (65%, 57%), beta-blockers (87%, 85%), statins (94%, 96%), and angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker (85%, 80%), respectively

Principal Findings:

A total of 352 patients were randomized. Baseline characteristics were fairly similar between the two arms. Median time to catheterization was 70 minutes in the immediate catheterization group and 21 hours in the delayed catheterization group. Percutaneous coronary intervention (PCI) was performed in 80% of patients in the immediate catheterization group and 70% of patients in the delayed catheterization group. Culprit vessel was the left anterior descending artery in 47% of the patients, right coronary artery in 25%, and left circumflex artery in 27%. Three-vessel disease was noted in approximately 25% of the patients, and coronary artery bypass grafting was performed in 11% of patients.

There was no difference in the primary endpoint of peak troponin-I between the immediate and delayed groups (median 2.1 vs. 1.7 ng/ml, p = 0.70). Furthermore, there was no difference in the composite endpoints of death, myocardial infarction (MI), or urgent revascularization at 30 days (13.7% vs. 10.2%, p = 0.31) and death, MI, urgent revascularization, or refractory ischemia at 30 days (21.1% vs. 21.5%, p = 0.94). None of the individual endpoints were significantly different either, including mortality (2.9% vs. 1.1%, p = 0.28), MI (9.1% vs. 4.5%, p = 0.09), or urgent revascularization (3.4% vs. 5.6%, p = 0.32). Major bleeding at 30 days was also similar between the two arms (4.0% vs. 6.8%, p = 0.25). Length of stay was significantly shorter in the immediate catheterization group (median: 55 vs. 77 hours, p


The benefit of an early invasive strategy in NSTE-ACS has been established in the FRISC II, TACTICS-TIMI 18, and RITA-3 trials. However, ABOARD represents the first randomized study to evaluate an immediate invasive strategy, such as that used in primary PCI for ST elevation MI, in NSTE-ACS. Results are similar to those noted in the recently published, and significantly larger TIMACS study, where NSTE-ACS patients were randomized to an early versus delayed PCI (median times 14 and 50 hours, respectively). No significant difference was noted in the primary endpoint of death, MI, or stroke.

Although ABOARD did not demonstrate a difference in the primary efficacy endpoint, there was a significantly reduced length of hospital stay in patients undergoing an immediate invasive strategy. However, whether such a strategy is cost-effective in the management of NSTE-ACS remains unclear.


Montalescot G, Cayla G, Collet JP, et al. Immediate vs delayed intervention for acute coronary syndromes: a randomized clinical trial. JAMA 2009;302:947-54.

Immediate Versus Next Day Catheterization in Non-ST Elevation Acute Coronary Syndrome: Results of the Multicenter Randomized ABOARD Study. Presented by Dr. Gilles Montalescot at ACC.09/i2, Orlando, FL, March 2009.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Aortic Surgery

Keywords: Myocardial Infarction, Stroke, Troponin I, Catheterization, Coronary Disease, Coronary Artery Bypass, Stents, Percutaneous Coronary Intervention, Length of Stay

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