Differences in clinical outcomes between pre- and post-marketing clinical study following paclitaxel-coated balloon catheter treatment for coronary in-stent restenosis: from the Japanese regulatory viewpoint.

In 2013, a drug-coated balloon catheter (DCB) (SeQuent Please) for the treatment of coronary in-stent restenosis (ISR) was approved in Japan. The pre-marketing Japan domestic NP001 study demonstrated better outcomes of the DCB (n = 138) compared to plain balloon angioplasty (n = 72). After the introduction to marketing, a post-marketing surveillance (PMS) (n = 396) was conducted to evaluate the safety and efficacy of the DCB in Japanese routine clinical practice. The aim of this paper was to assess differences between the pre-marketing NP001 study and the PMS. Compared to the NP001 study, more complex lesions were treated in the PMS (type B2/C: 69.0% vs 20.4%, total occlusion: 11.2% vs 0%, p < 0.001, respectively) and target lesion was more frequently ISR related to drug-eluting stent (DES) (79.5% vs 39.4%, p < 0.001). Regarding clinical outcomes, the rate of target lesion revascularization (TLR) was higher in the PMS than in the NP001 study (TLR: 12.9% at 7 months and 17.6% at 12 months vs 2.8% at 6 months, p = 0.001, p < 0.001, respectively). Multivariable logistic regression analysis revealed that DES-ISR was a risk factor of TLR after DCB treatment for ISR (odds ratio: 5.77, 95% CI 1.75-18.95, p = 0.004). Among representative published trials using DCB for ISR, clinical outcomes are often worse in DES-ISR trials than those in bare metal stent-ISR trials. The rates of TLR in previous DES-ISR trials are similar to that in the current PMS (TLR at 12 months: 22.1% for ISAR-DESIRE 3, 15.3% for PEPCAD-DES, and 13.0% for RIBS IV). The effectiveness and safety of DCB for coronary ISR have been confirmed in the Japanese real-world survey. PMS would be useful to evaluate the safety and effectiveness of medical products throughout their total life cycles.

Favorable vessel healing after nobori biolimus A9-eluting stent implantation-6- and 12-month follow-up by optical coherence tomography.

BACKGROUND: Nobori is a novel biolimus A9-eluting stent (BES) coated with a biodegradable polymer only on the abluminal side, which degrades over 6-9 months post-stent deployment. The course of vessel reaction after deployment at these time points remains unclear. METHODS AND RESULTS: We serially evaluated 28 BES implanted in de novo coronary lesions of 23 patients using optical coherence tomography (OCT) at 6 and 12 months post-stenting. Standard OCT variables, the percentage of stent with peri-strut low-intensity area (PLIA, a region around stent struts homogenously showing lesser intensity than the surrounding tissue, suggesting fibrin deposition or impaired neointima maturation) and that with in-stent thrombi were evaluated. There was a significant, but small increase in neointimal thickness (72 ± 23 to 82 ± 25 µm, P=0.006) from the 6- to the 12-month follow-up, without a significant decrease in minimum lumen area (P=0.30). The incidences of uncovered and malapposed struts were low at 6 months and reduced further at 12 months (3.96 ± 3.97% to 1.51 ± 1.63%, P=0.001, and 0.50 ± 1.84% to 0.06 ± 0.24%, P=0.20, respectively). The frequency of stent with PLIA decreased during the follow-up (57% to 32%, P=0.05) and that with in-stent thrombi also numerically decreased (7% to 0%, P=0.24). CONCLUSIONS: Neointimal hyperplasia was persistently suppressed following BES implantation up to 12 months. Simultaneously, favorable vessel healing was achieved at 6 months without a delaying adverse reaction for up to 12 months.

Serial Optical Coherence Tomography Evaluation at 6, 12, and 24 Months After Biolimus A9-Eluting Biodegradable Polymer-Coated Stent Implantation.

BACKGROUND: The Nobori (Terumo Corporation, Tokyo, Japan) is a biolimus A9-eluting stent (BES) featured with a biodegradable polymer coated on the abluminal side only. We previously reported that favourable vessel healing was achieved at 6-12 months after BES implantation. However, detailed long-term vessel reaction after BES deployment is unclear. METHODS: Twenty-two BESs were serially evaluated using optical coherence tomography (OCT) at 6, 12, and 24 months after stenting. Average neointimal thickness, uncovered struts, and neointimal unevenness score (each cross-section as maximum neointimal thickness in 1 cross section divided by the average neointimal thickness of the same cross-section) were manually measured. In addition, we evaluated the percentage of struts with peri-strut low-intensity area (a region around stent struts that homogenously showed less intensity than the surrounding tissue, which suggests fibrin deposition or impaired neointima maturation), thrombi, and atherogenic neointimas (neointimas containing a diffuse border and poor-signal region with invisible struts due to marked signal attenuation). RESULTS: Serial OCT observation revealed a small gradual increase in neointimal thickness from 6 to 24 months (73 ± 24 µm; 81 ± 26 µm; and 108 ± 35 µm, respectively, P = 0.001) with a nonsignificant decrease in the lumen area (6.36 ± 1.98 mm(2); 6.18 ± 2.04 mm(2); and 5.87 ± 2.06 mm(2); P = 0.72). Frequency of uncovered struts (3.89 ± 3.91%; 1.55 ± 1.63%; and 0.23 ± 0.67%; P = 0.001), neointimal unevenness score (1.95 ± 0.18% to 1.86 ± 0.19% to 1.78 ± 0.17; P = 0.012), percentage of thrombi (5%, 0%, and 0%; P = 0.37) and peri-strut low-intensity area (6.8%, 5.1%, and 1.6%; P = 0.017) decreased from 6 to 12 and 24 months. Atherogenic neointima was not observed in the event-free OCT cohort. CONCLUSIONS: The Nobori stent achieved acceptable long-term vessel healing, mostly without adverse vessel reactions.