Efficacy of optical frequency domain imaging in detecting peripheral artery disease: the result of a multi-center, open-label, single-arm study

Optical frequency domain imaging (OFDI) is a high-resolution intracoronary imaging modality with fast automated longitudinal pullback. We aimed to evaluate the ability of performing OFDI from the superficial femoral artery (SFA) to the below-knee (BK) artery. This clinical trial was a multi-center, single-arm, open-label study. The primary endpoint was to obtain a clear image of the intra-vascular lumen from the SFA to the BK artery, specifically  > 270° visualization of the blood vessel lumen with  > 16/21 cross sections. The proportion of the clear image (≥ 85%) was regarded as confirmatory of the ability of OFDI to visualize the vessel lumen. Overall, 20 patients were enrolled. The proportion of the primary endpoint was 90% (18/20), and the pre-specified criterion was successfully attained. The proportion of the clear image assessed by the operator was 100% (20/20), and an additional statistical analysis for the proportion of the visualization,  > 270°, of the blood vessel lumen revealed a significantly higher cut-off value than that for the pre-specified criterion, 85% (p = 0.0315). There were three adverse events not related to OFDI. OFDI achieved acceptable visualization of the vessel lumen without any adverse event related to it. After regulatory approval based on the present study, OFDI will be available as a new option of endovascular imaging for peripheral artery diseases in daily practiceTrial registration: This study was registered in the Japanese Registry of Clinical Trials (jRCT 2052190025, https://jrct.niph.go.jp/latest-detail/jRCT2052190025 ).

Influence of Self-Expanding Paclitaxel-Eluting Stent Sizing on Neointimal Hyperplasia in Superficial Femoral Artery Lesions

BACKGROUND

Although self-expanding drug-eluting stents (DES) have recently shown superior outcomes for superficial femoral artery (SFA) lesions, optimal sizing of DES diameter in SFA intervention is unclear.Methods and Results:A total of 40 de novo SFA lesions were randomized 1:1 to receive self-expanding DES with either a 1-mm or 2-mm larger diameter than the reference vessel diameter. Follow-up optical coherence tomography (OCT) was scheduled 6 months after DES implantation to evaluate the vascular response to the stents. Volume index (VI) was defined as volume divided by stent length. The primary endpoint was neointimal VI at 6 months. Baseline reference vessel diameter was similar between the 1-mm larger diameter group and the 2-mm larger diameter group (5.0±0.8 mm vs. 4.7±0.9 mm, P=0.35). Stent diameter was 6.3±0.6 mm in the 1-mm larger group and 7.1±0.6 mm in the 2-mm larger group (P<0.0001), and stent to reference vessel diameter ratio (SV ratio) was 1.3±0.2 and 1.5±0.2 (P<0.0001), respectively. At 6-month, neointimal VI was greater in the 2-mm larger diameter group (5.5±1.5 mm²vs. 9.6±3.4 mm², P<0.001). The correlation analysis revealed that degree of neointimal VI was positively correlated with SV ratio (r=0.43, P<0.01).

CONCLUSIONS

Implantation of self-expanding DES with a considerably high SV ratio resulted in neointimal hyperplasia in SFA lesions.

Assessment of Mortality and Factors Affecting Outcome of Use of Paclitaxel-Coated Stents and Bare Metal Stents in Femoropopliteal PAD

The use of drug-coated devices in intravascular therapy is aimed at preventing neointimal hyperplasia caused by excessive proliferation of vascular smooth muscle and thereby restenosis. Although its use seemed initially promising, a recent publication has shown an increased risk of mortality with paclitaxel-coated devices, and there is an urgent need to reaffirm assessments of drug-eluting stents (DES). Objective: The aim of the study was to compare mortality and effectiveness of paclitaxel-coated stents and bare-metal stents (BMS) in the treatment of peripheral arterial disease (PAD) with long-term follow-up. Materials and methods: In a single center randomized study, 256 patients with PAD were treated intravascularly with stent implantation. Patients were randomized into two groups: the first (n = 126) were treated with DES, and the second (n = 130) were treated with BMS. The study included evaluation after the procedure, after about 6 months and 36 months. Co-morbidities, with risks for atherosclerosis, were analyzed in all patients. Patients were evaluated for clinical outcome, restenosis frequency, and safety (complications and total mortality). Results: Clinical benefit at the end of the investigation was statistically significantly better in the DES group compared with the BMS group: 85.7% versus 66.2% (p = 0.0003), respectively. Restenosis occurred significantly less frequently in patients with DES: 16.0% versus BMS: 35.0%, p = 0.012. There was no significant effect of comorbidities on the frequency of restenoses. There were no differences in all-cause mortality over the three years with paclitaxel and no-paclitaxel stents cohorts (8.7% versus 7.1%; long-rank p = 0.575). No association was found with mortality and treatment with DES or BMS. Conclusions: The use of paclitaxel-coated stents gave good clinical benefit and caused a significantly lower frequency of restenosis compared to bare-metal stents. The use of paclitaxel-coated stents did not increase mortality.

Ticagrelor versus clopidogrel in patients undergoing implantation of paclitaxel-eluting stent in the femoropopliteal district: A randomized pilot study using frequency-domain optical coherence tomography

OBJECTIVES

Aim of this study was to evaluate different response in platelet reactivity and vessel healing using high-resolution frequency-domain optical coherence tomography (FD-OCT) in patients with femoropopliteal artery disease treated with ZILVER PTX drug eluting stents (DES), and randomly assigned to clopidogrel or ticagrelor for 12 months.

BACKGROUND

The optimal antithrombotic regimen for long-term management of patients with peripheral artery disease (PAD) after revascularization is poorly defined and often extrapolated from trials performed on patients undergoing percutaneous coronary intervention.

METHODS

In this single center randomized trial 40 patients with femoropopliteal artery disease treated with ZILVER PTX DES stents, were randomized to Ticagrelor (T) + Aspirin for 3 months, subsequently continuing Ticagrelor alone for another 9 months or Clopidogrel (C) + Aspirin for 3 months, subsequently continuing Clopidogrel alone for 9 months. Platelet reactivity via the P2Y12 pathway was evaluated at baseline and at 3 months follow-up, angiographic and FD-OCT follow-up along the entire stented segment was performed at 12 months.

RESULTS

No significant difference between T and C group was found concerning net percentage volume obstruction (29.7% ± 17.6% vs. 31.2% ± 10.7%; p = 0.78). FD-OCT at 12 months showed a high percentage of uncovered stent struts in both groups: 24.2% ± 32.8% in the T group vs 15.3% ± 15.8% in the C group (p = 0.4). Mean values of platelet reactivity units (PRU) at 3 month follow-up were 81 ± 72 in the T group and 200 ± 61 in the C group (p < 0.001).

CONCLUSIONS

Significantly higher platelet reactivity remains in patients treated with clopidogrel as compared to ticagrelor 3 months after PTA and stent implantation. Ticagrelor does not reduce neointimal proliferation in patients treated with DES in the femoropopliteal district as compared with clopidogrel. A large amount of uncovered stent struts at 12-month follow-up was found in these patients regardless of the antiplatelet treatment assumed.