OCT or Angiography Guidance for PCI in Complex Bifurcation Lesions - OCTOBER

Contribution To Literature:

Highlighted text has been updated as of May 21, 2024.

The OCTOBER trial demonstrated that OCT-guided PCI of complex bifurcation lesions is superior to angiography-guided PCI for cardiovascular outcomes at 2 years.


The goal of the trial was to compare OCT-guided vs. angiography-guided PCI of bifurcation coronary lesions.

Study Design

Eligible patients were randomized in a 1:1 open-label fashion to either optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) (n = 600) or angiography-guided PCI (n = 601). A stepwise protocol was utilized in the OCT arm. In the angiography arm, intravascular ultrasound use was discouraged but could be pursued for left main (LM) PCI.

  • Total number of enrollees: 1,201
  • Duration of follow-up: 2 years
  • Mean patient age: 66.3 years
  • Percentage female: 21.1%

Inclusion criteria:

  • Stable angina, unstable angina, or non–ST-segment elevation myocardial infarction (NSTEMI)
  • True bifurcation lesion
  • Main branch reference ≥2.75 mm, stenosis ≥50%
  • Side branch reference ≥2.5 mm, stenosis ≥50% within 5 mm from the ostium of the side branch
  • Main branch with functional significance (physiologically) or angiographic severity ≥80%

Exclusion criteria:

  • STEMI within 72 hours
  • Cardiogenic shock
  • Previous coronary artery bypass grafting to a target vessel, or the procedure was planned
  • Estimated glomerular filtration rate <50 ml/min/1.73 m2
  • Expected survival <2 years
  • Left ventricular ejection fraction (LVEF) <30%
  • Heart failure symptoms more serious than New York Heart Association class II
  • Angiographic exclusions:
    • Severe tortuosity of the coronary artery at the target bifurcation lesion
    • Presence of a chronic total occlusion
    • Large thrombus in the LM coronary artery

Other salient features/characteristics:

  • Indication: Stable angina: 54%, NSTEMI: 13%
  • Median EF: 58%
  • Prior PCI: 41.7%
  • Renal failure: 2.2%
  • Left main bifurcation treated: 18.9%
  • One-stent strategy: 35%

Principal Findings:

The primary endpoint, major adverse cardiovascular events (MACE; cardiac death, target lesion myocardial infarction, or ischemia-driven target lesion revascularization) at 2 years for OCT-guided vs. angiography-guided PCI, was: 10.1% vs. 14.1% (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.50–0.98, p = 0.035).

  • Cardiac death: 1.4% vs. 2.6% (HR 0.53, 95% CI 0.22–1.25)
  • Ischemia-driven target lesion revascularization: 2.8% vs. 4.6% (HR 0.60, 95% CI 0.32–1.13)
  • Target lesion myocardial infarction: 7.8% vs. 8.5% (HR 0.90, 95% CI 0.60–1.34)

Secondary outcomes for OCT-guided vs. angiography-guided PCI:

  • All-cause mortality: 2.4% vs. 4.0% (HR 0.56, 95% CI 0.28–1.10)
  • Stent thrombosis: 2.1% vs. 3.0% (p > 0.05)
  • Contrast volume use: 300 vs. 200 cc
  • Procedure duration: 113 vs. 80 minutes

Unintended stent deformation (USD) and abluminal wiring: USD was identified in 9.3% of cases by core-lab analysis of OCT scans performed during the procedure or as the final step. The median length of deformed segments was 2.5 mm (interquartile range, 1.6; 3.5 mm) and the proximal stent edge was the most frequent location, typically due to guide catheter collision. The incidence of USD in left main coronary artery (LMCA) and non-LMCA treated cases were 27/146 (18.5%) and 28/443 (6.3%), respectively. USD was corrected by operators in 40% of cases. In the 5.1% of cases with untreated USD by final OCT, the MACE rate at 2 years was 23.3%, vs. 9.4% for the rest of the cases (p = 0.005).

The total incidence of accidental abluminal rewiring was 5.4%, as identified by core-lab analysis. Accidental abluminal rewiring was identified by physicians and corrected during the procedure in 55% of cases. Accidental abluminal rewiring left unnoticed resulted in subsequent USD in 15/15 cases (100%).


The results of this trial indicate that OCT-guided PCI of complex bifurcation lesions is superior to angiography-guided PCI for cardiovascular outcomes at 2 years. Numerically, the biggest reduction was noted in ischemia-driven target lesion revascularization but other important endpoints such as stent thrombosis also favored an OCT-guided approach. This came at the expense of greater contrast use and longer procedural duration of PCI. The approach was beneficial for both LM and non-LM bifurcation PCI.

Interestingly, unidentified stent deformation was noted in 9.3% and accidental abluminal rewiring in 5.4% (unrecognized abluminal rewiring resulted in USD in 100% of cases). USD was noted in 18.5% of left main PCIs and was most commonly at the proximal edge, usually due to guide catheter collision. MACE rates were higher among those with untreated USD compared with other PCIs.

These are important data and add to the available evidence supporting image-guided PCI for PCI, especially for complex PCI such as involving a coronary bifurcation. Greater contrast use with OCT did not appear to influence cardiovascular outcomes although may be a consideration for patients with advanced chronic kidney disease. OCT findings regarding USD and accidental abluminal wiring are important and may be particularly important for large vessels such as LM PCI.


Andreasen LN, Neghabat O, Laanmets P, et al. Unintended Deformation of Stents During Bifurcation PCI: An OCTOBER Trial Substudy. JACC Cardiovasc Interv 2024;17:1106-15.

Editorial Comment: Stankovic G, Lassen JF. Improving Stent Optimization in Bifurcation Stenting: Revealing the Unseen. JACC Cardiovasc Interv 2024;17:1116-8.

Holm NR, Andreasen LN, Neghabat O, et al., on behalf of the OCTOBER Trial Group. OCT or Angiography Guidance for PCI in Complex Bifurcation Lesions. N Engl J Med 2023;389:1477-87.

Editorial: Dauerman HL. Optical Coherence Tomography — Light and Truth. N Engl J Med 2023;389:1523-5.

Presented by Dr. Lene Nyhus Andreasen at the European Society of Cardiology Congress, Amsterdam, Netherlands, August 27, 2023.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: Coronary Angiography, ESC Congress, ESC23, Percutaneous Coronary Intervention, Stents, Tomography, Optical Coherence

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