Comparison between optical coherence tomography and intravascular ultrasound in detecting neointimal healing patterns after stent implantation

Abstract

The amount of data comparing intravascular ultrasound (IVUS) and optical coherence tomography (OCT) for the detection of stent coverage in clinical settings is limited. To make a qualitative and quantitative assessment of the vascular healing patterns in patients after stent implantations visualised by both IVUS and OCT. Images were obtained in patients with clinical symptoms of angina, who had had a bare metal stent implanted in the previous 12 months. Angiography, IVUS and OCT were performed in 14 coronary arteries. Measurements of stent, lumen and neo-intima areas and dimensions were performed in stented regions and in both 10 mm references. IVUS, OCT, and angiographic data were compared in matched regions. Off-line analyses were performed by an independent core lab. 14 stents were imaged without any procedural complications. The nominal stent length was 28 ± 4.5 mm. OCT was the most accurate technique for assessing stent length (28.12 ± 6.8 mm), while QCA underestimated length due to foreshortening (22.16 ± 6.39 mm) and IVUS was vulnerable to random error due to discontinuous pullbacks and vessel movements (24.21 ± 7.90 mm). Minimum lumen area (MLA) and minimum lumen diameter (MLD) in reference sites were comparable in IVUS and OCT, whereas there were significant differences between these two modalities for MLA (3.30 ± 1.49 vs. 2.19 ± 1.30 mm², p = 0.0046) and for MLD (2.42 ± 0.51 vs. 1.58 ± 0.56 mm², p = 0.0023) in stented segments. There was a slight overestimation of lumen volume (130.18 ± 70.61 vs. 117.82 ± 67.02 mm³, p = 0.7256),a marked overestimation of stent volume (179.29 ± 97.58 vs. 226.46 ± 108.76 mm³, p = 0.0544) and a statistically significant difference in the neointima volume (49.11 ± 39.70 vs. 108.64 ± 43.77 mm³, p = 0.0060) by IVUS compared to OCT. Mean neointima burden in IVUS was much smaller than in OCT (20.79 ± 14.27% vs. 58.16 ± 18.25%, p = 0.0033). OCT can precisely quantify struts coverage and is more accurate than IVUS in the assessment of vascular healing in patients after stent implantation.