Does Co-registration of OCT and Angiography Reduce Geographic Miss of Stent Implantation?

Background: When a stent fails to fully cover the lesion, it is termed "geographic miss" (GM). Optical coherence tomography (OCT) is an intracoronary imaging modality that has higher resolution than conventional intracoronary ultrasound. Although OCT allows identification of the location of the culprit lesion and side branch using automated measures, it is sometimes difficult to identify the exact segment corresponding to angiography. Recently, co-registration of OCT and angiography has become available; however, whether this reduces the incidence of GM during stenting is unknown.

Hypothesis: OCT reduces GM during percutaneous coronary intervention.

Objectives:

1. Determine the incidence of GM defined as residual disease* and significant edge dissection† at proximal and distal reference
2. Determine the incidence of stent dislocation (distance between planned and actual stented place)
3. Determine procedural findings (additional stent, total fluoro time, total contrast volume)

• Minimum lumen area <4.0 mm2 in the presence of significant residual plaque within 5 mm distal and proximal to the stent edge.
• A flap of vessel wall of >60° is seen in ≥2 consecutive cross-section image within 5 mm distal and proximal from stent edge Study Design and Methods: Single-center, prospective, randomized study. Consented subjects who are to undergo percutaneous coronary intervention are divided into 2 groups randomly (OCT with co-registration vs OCT without co-registration). After stent deployment guided by OCT, dissection, residual disease at the stent edge, and distance between planned and actual stent location are assessed using OCT or angiography. Additional stent deployment, procedure time, total fluoroscopy time, and total contrast volume are also evaluated.

Sample size considerations: OCT with co-registration: 100, OCT without co-registration: 100 (α＝0.05, β ＝0.2). In a retrospective evaluation, the incidence of residual disease (lumen area <4.0 mm2 in the presence of significant residual plaque) or significant stent edge dissection was 36% (18/50, 34% [17/50] with residual stenosis, 4% [2/50] with significant edge dissection). Under the assumption that GM occurs in 36% of patients without co-registration and 18% of patients with co-registration, a group of 190 patients yields a power 80% (with a 2-sided α=0.05) to detect a difference in GM between patients with and without co-registration. In order to account for patient drop out and non-evaluable OCT recordings (5%), a total of 200 patients will be enrolled.