Optical coherence tomography predictors of clinical outcomes after stent implantation: the ILUMIEN IV trial

Abstract

Background and aims: Observational registries have suggested that optical coherence tomography (OCT) imaging-derived parameters may predict adverse events after drug-eluting stent (DES) implantation. The present analysis sought to determine the OCT predictors of clinical outcomes from the large-scale ILUMIEN IV trial.

Methods: ILUMIEN IV was a prospective, single-blind trial of 2487 patients with diabetes or high-risk lesions randomized to OCT-guided versus angiography-guided DES implantation. All patients underwent final OCT imaging (blinded in the angiography-guided arm). From more than 20 candidates, the independent OCT predictors of 2-year target lesion failure (TLF; the primary endpoint), cardiac death or target-vessel myocardial infarction (TV-MI), ischaemia-driven target lesion revascularization (ID-TLR), and stent thrombosis were analysed by multivariable Cox proportional hazard regression in single treated lesions.

Results: A total of 2128 patients had a single treated lesion with core laboratory-analysed final OCT. The 2-year Kaplan-Meier rates of TLF, cardiac death or TV-MI, ID-TLR, and stent thrombosis were 6.3% (n = 130), 3.3% (n = 68), 4.3% (n = 87), and 0.9% (n = 18), respectively. The independent predictors of 2-year TLF were a smaller minimal stent area (per 1 mm2 increase: hazard ratio 0.76, 95% confidence interval 0.68-0.89, P < .0001) and proximal edge dissection (hazard ratio 1.77, 95% confidence interval 1.20-2.62, P = .004). The independent predictors of cardiac death or TV-MI were smaller minimal stent area and longer stent length; of ID-TLR were smaller intra-stent flow area and proximal edge dissection; and of stent thrombosis was smaller minimal stent expansion.

Conclusions: In the ILUMIEN IV trial, the most important OCT-derived post-DES predictors of both safety and effectiveness outcomes were parameters related to stent area, expansion and flow, proximal edge dissection, and stent length.

Keywords: Optical coherence tomography; Percutaneous coronary intervention; Prognosis; Stent.

Structured Graphical Abstract

The independent optical coherence tomography predictors of clinical outcomes in 2128 patients with a single treated lesion in the ILUMIEN IV trial are shown here. Minimal stent area is defined as the smallest stent area within the contiguous stent segment. Minimal stent expansion is defined as the minimal stent area divided by the average of proximal and distal reference lumen areas × 100. Intra-stent flow (lumen) area is defined as stent area minus intra-stent plaque protrusion or thrombus area. HR, hazard ratio; ID-TLR, ischaemia-driven target lesion revascularization; MSA, minimal stent area; MSE, minimal stent expansion; OCT, optical coherence tomography; TLF, target lesion failure; TV-MI, target-vessel myocardial infarction

Figure 1

Consort diagram. The present analysis included randomized patients with single lesion treatment and core laboratory analysable final optical coherence tomography images. OCT, optical coherence tomography; PCI, percutaneous coronary intervention

Figure 2

Distribution of optical coherence tomography-derived minimal stent area and its relationship with target lesion failure during 2-year follow-up. Top: Penalized spline analysis showing the 2-year target lesion failure rate (green line) and 95% confidence interval (green shading) in the pooled optical coherence tomography and angiography guidance groups for each post-percutaneous coronary intervention minimal stent area value as a continuous measure. The blue line and shading represents the penalized spline relationship of the hazard ratio and 95% confidence interval for target lesion failure for each minimal stent area value referenced to a hazard ratio of 1.0 for the median minimal stent area of 5.24 mm². Note that the hazard ratio is calculated from the actual continuous minimal stent area value, which ranged from 1.22 to 15.30 mm². In contrast, the target lesion failure rate is based on a rounding function such that minimal stent area of 1.22 is rounded to 1 and 15.30 is rounded to 15. As such, the curves appear slightly offset. Bottom: Histogram bars showing the numbers of patients in each randomized group (left y-axis) with minimal stent area in 1 mm increments centred around each whole number (e.g. the bars to the left and right of the 2 mm² minimal stent area tick mark includes minimal stent area values ranging from 1.5 to 2.5 mm²). The right y-axis shows the 2-year rate of target lesion failure (line graphs) for each associated minimal stent area grouping in patients randomized to optical coherence tomography guidance vs. angiography guidance. MSA, minimal stent area; OCT, optical coherence tomography; TLF, target lesion failure