Safety and efficiency of percutaneous coronary intervention using a standardised optical coherence tomography workflow.

BACKGROUND: While intravascular imaging guidance during percutaneous coronary intervention (PCI) improves outcomes, routine intravascular imaging usage remains low, in part due to perceived inefficiency and safety concerns.  Aims: The LightLab (LL) Initiative was designed to evaluate whether implementing a standardised optical coherence tomography (OCT) workflow impacts PCI safety metrics and procedural efficiency. METHODS: In this multicentre, prospective, observational study, PCI procedural data were collected over 2 years from 45 physicians at 17 US centres. OCT-guided PCI incorporating the LL workflow (N=264), a structured algorithm using routine pre- and post-PCI OCT imaging, was compared with baseline angiography-only PCI (angio) (N=428). Propensity score analysis identified 207 matched procedures. Outcomes included procedure time, radiation exposure, contrast volume, device utilisation, and treatment strategy. RESULTS: Compared with angiography alone, LL workflow OCT-guided PCI increased the median procedural time by 9 minutes but reduced vessel preparation time (2 min LL workflow vs 3 min angio; p<0.001) and resulted in less unplanned additional treatment (4% LL workflow vs 10% angio; p=0.01). With LL workflow OCT guidance, fewer cineangiography views were needed compared to angiography guidance, leading to decreased radiation exposure (1,133 mGy LL workflow vs 1,269 mGy angio; p=0.02), with no difference in contrast utilisation between groups (p=0.28). Furthermore, LL workflow OCT guidance resulted in fewer predilatation balloons and stents being used, more direct stent placement, and greater stent post-dilatation than angiography-guided PCI. CONCLUSIONS: The incorporation of a standardised pre- and post-PCI OCT imaging workflow improves procedural efficiency and safety metrics, at a cost of a modestly longer procedure time.

Mechanical stress-induced hemolysis of bovine blood is donor-dependent.

INTRODUCTION: In vitro hemolysis testing is an essential method for assessing the hemolytic potential of blood pumps, but has poor reproducibility. Further investigations are needed to determine the sources and extent of variability and to find a practical way to reduce the variation. METHODS: A small volume blood circulating loop driven by a Centrimag pump was established to provide relatively higher hemolysis readouts within a short run time and to be able to sequentially perform multiple repeated hemolysis tests in a working day. RESULTS: The repeatability with this system was demonstrated as the %RSD at 4.3% for the NIH or MIH from three repeated tests using the same blood. The bovine blood from different randomly selected donors was tested and gave more than a two-fold difference in NIH results (0.077 vs. 0.032 g/100 L) under the same testing conditions and same pump. This wide variation in hemolysis using bovine blood from different donors happened repeatedly. More importantly, it was observed that the difference in hemolysis test results using the blood drawn from the same donor on multiple days was narrow although the native hematocrits varied. The %RSD of NIH values obtained on five different days were 6.8%, 8.4%, 11.5%, and 7.8% for donor-specific blood from donors 1 to 4, respectively. CONCLUSION: The study results indicate that the mechanical stress-induced hemolysis behavior is donor-dependent. It has been also demonstrated that the reproducibility of in vitro hemolysis testing can be improved when the blood drawn from same donor is used.

Comparison of Angiographic and Intravascular Ultrasound Vessel Measurements in Infra-Popliteal Endovascular Interventions: The Below-the-Knee Calibration Study.

BACKGROUND: Endovascular revascularization (ER) via percutaneous transluminal angioplasty (PTA) and stenting are viable options for revascularization in below-the-knee (BTK) peripheral arterial disease. Two-dimensional angiography has been the standard of practice for estimating vessel size and selecting treatment devices during ER. However, in other vascular territories, intravascular ultrasound (IVUS) offers better visualization of the lumen dimensions. PURPOSE: To compare angiographic and intravascular ultrasound reference vessel (lumen) measurements in below-the-knee peripheral artery interventions. METHODS: Twenty consecutive patients were enrolled in the BTK Calibration study from 2 sites in the United States and Australia. Patients with at least one diseased segment in a native infra-popliteal artery (below-the-knee) and a clinical indication for endovascular therapy (EVT) were included with no limitations with regard to vessel diameter or lesion length. Digital subtraction angiography and IVUS imaging were collected pre- and post-PTA and images were sent to an independent core lab for standardized quantitative analysis of the normal-looking reference vessel dimensions when available. The results were presented as least square means with 95% confidence intervals and a p-value of <0.05 was considered significant. RESULTS: The overall (N = 19) mean reference vessel diameter for QVA was 2.98 ± 1.24 mm vs. 3.47 ± 0.72 mm for IVUS (mean difference was -0.50 mm, (95% CI: -0.80, -0.20; p = 0.14). As expected, in the proximal segments (N = 12), the mean reference vessel diameters were larger: for QVA, it was 3.17 ± 1.34 mm vs. 3.55 ± 0.76 mm in IVUS, (mean difference was -0.38 mm, (95% CI: -0.79, 0.03; p = 0.40); while in the distal segments (N = 7), mean reference vessel diameters were smaller: for QVA, it was 2.64 ± 1.06 mm vs. 3.33 ± 0.67 mm in IVUS, (mean difference was -0.69 mm, (95% CI: -1.04, 0.34; p = 0.17). We observed a greater degree of acute gain in cases where the treatment balloon size correlated with the IVUS measured reference size. CONCLUSION: Angiography underestimates infrapopliteal reference vessel lumen size even when quantitatively assessed. Adjunctive IVUS imaging use in guiding BTK procedures could help ensure adequate sizing and possibly impact immediate post-procedure indices.

Improving efficiency and operator proficiency during percutaneous coronary interventions utilizing a standardized optical coherence tomography workflow.

OBJECTIVES: This study was designed to compare efficiency and quality metrics between percutaneous coronary intervention (PCI) procedures using optical coherence tomography (OCT) guided by a variable workflow versus a standardized workflow in a real-world population. BACKGROUND: The LightLab (LL) Initiative was designed to evaluate the impact of a standardized OCT workflow during PCI to address barriers to adoption. METHODS: The LL Initiative was a multicenter, prospective, observational study. PCI efficiency data were collected from 1/21/19 to 1/8/21 from 45 physicians at 17 US centers. OCT-guided PCIs were compared between baseline phase (variable workflow; N = 383) and the LL workflow utilization phase (N = 447). The LL workflow uses OCT to assess lesion Morphology, Length and Diameter, and then optimize outcomes by correcting for Medial dissection, stent mal-Apposition, and under-eXpansion (MLD MAX). Matching based on propensity scores was used to control for differences between PCIs. RESULTS: After propensity matching, 291 paired procedures were included. Integration of the LL versus variable workflow resulted in no difference in procedure time (51 min vs. 51 min, p = 0.93). There was a reduction in radiation exposure (1124 mGy vs. 1493 mGy, p < 0.0001) and contrast volume (160 cc vs. 172 cc, p < 0.001). The LL workflow decreased the proportion of underexpanded lesions (34% vs. 54%, p < 0.0001) and improved minimum stent expansion (85% vs. 79%, p < 0.0001). Number of noncompliant balloons used was reduced with the LL workflow. (2.0 vs. 1.7, p < 0.01). CONCLUSIONS: These data suggest that standardizing imaging with the LL workflow may overcome barriers to imaging and improve PCI outcomes without prolonging procedures.

Investigating real-world impact of optical coherence tomography workflow-guided coronary interventions: Design and rationale of the LightLab Clinical Initiative.

OBJECTIVE: The LightLab Clinical Initiative was designed to examine adoption of optical coherence tomography (OCT) imaging during routine percutaneous coronary intervention (PCI) practice, and enable identification and reduction of barriers to broader adoption of intracoronary imaging in real-world practice. BACKGROUND: Intracoronary imaging guidance during PCI has been shown to improve clinical outcomes and features as a recommendation in societal guidelines, yet widespread routine adoption remains low. Perceived barriers to utilization include familiarity with, and ability to interpret imaging, concerns over added procedure time and contrast load, alongside a lack of actionable outcome data. METHODS AND RESULTS: LightLab was a multicenter prospective observational data-gathering project, conducted between January 2019, and June 2021, with 17 participating hospitals and physicians. Data were gathered in real-time, where OCT guidance was employed during PCI using a standardized OCT-guided workflow algorithm, MLD MAX (where MLD stands for plaque Morphology, lesion Length, vessel Diameter and MAX for Medial dissection, stent Apposition, stent eXpansion) which was developed to simplify and integrate information from OCT throughout the PCI procedure. Integration of this workflow/algorithm was implemented through a series of phases, focusing on physician decision-making, efficiency, and safety improvements during the procedure. CONCLUSIONS: Through real-time, prospective procedural data acquisition in the cardiac catheterization laboratory setting, the LightLab Clinical Initiative demonstrates the impact of a standardized OCT-guided workflow on procedural metrics, including time, contrast use, radiation exposure, as well as financial efficiencies such as device utilization. These results can potentially mitigate underlying concerns over the utility of adoption of intracoronary imaging guidance during PCI.

Very late vasomotor responses and gene expression with bioresorbable scaffolds and metallic drug-eluting stents.

OBJECTIVES: To investigate the long-term vasomotor response and inflammatory changes in Absorb bioresorbable vascular scaffold (BVS) and metallic drug-eluting stent (DES) implanted artery. BACKGROUND: Clinical evidence has demonstrated that compared to DES, BVS is associated with higher rates of target lesion failure. However, it is not known whether the higher event rates observed with BVS are related to endothelial dysfunction or inflammation associated with polymer degradation. METHODS: Ten Absorb BVS and six Xience V DES were randomly implanted in the main coronaries of six nonatherosclerotic swine. At 4-years, vasomotor response was evaluated in vivo by quantitative coronary angiography response to intracoronary infusion of Ach and ex vivo by the biomechanical response to prostaglandin F2-α (PGF2-α), substance P and bradykinin and gene expression analysis. RESULTS: Absorb BVS implanted arteries showed significantly restored vasoconstrictive responses after Ach compared to in-stent Xience V. The contractility of Absorb BVS treated segments induced by PGF2-α was significantly greater compared to Xience V treated segments and endothelial-dependent vasorelaxation was greater with Absorb BVS compared to Xience V. Gene expression analyses indicated the pro-inflammatory lymphotoxin-beta receptor (LTßR) signaling pathway was significantly upregulated in arteries treated with a metallic stent compared to Absorb BVS treated arterial segments. CONCLUSIONS: At 4 years, arteries treated with Absorb BVS compared with Xience V, demonstrate significantly greater restoration of vasomotor responses. Genetic analysis suggests mechanobiologic reparation of Absorb BVS treated arteries at 4 years as opposed to Xience V treated vessels.

Outcomes of optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation: one-year results from the ILUMIEN III: OPTIMIZE PCI trial.

AIMS: In the ILUMIEN III trial, among 450 randomised patients with non-complex lesions undergoing percutaneous coronary intervention (PCI), optical coherence tomography (OCT) guidance led to greater stent expansion than angiography guidance, similar minimal stent area compared to both intravascular ultrasound (IVUS) guidance and angiography guidance, and lower rates of uncorrected dissection and malapposition than both IVUS guidance and angiography guidance. Whether these differences impact on clinical outcomes is unknown. The aim of the present study was to report the 12-month clinical follow-up data from the ILUMIEN III study. METHODS AND RESULTS: OCT-guided PCI, using an external elastic lamina-based protocol, was compared to operator-directed IVUS-guided or angiography-guided PCI. Target lesion failure (TLF) and major adverse cardiovascular events (MACE) at 12 months were adjudicated by a blinded clinical events committee. There were no significant differences in the rates of TLF (2.0% OCT, 3.7% IVUS, 1.4% angiography), MACE (9.8% OCT, 9.1% IVUS, 7.9% angiography), or any of the individual components of these outcomes among the groups. No independent predictors of 12-month stent-related clinical events were identified from final OCT. CONCLUSIONS: In this underpowered study, OCT-guided PCI of non-complex lesions did not show a statistical difference in clinical outcomes at 12 months compared with IVUS or angiography guidance. An appropriately powered trial, including only complex patients and lesions, is underway to substantiate the potential clinical benefit of OCT-guided PCI. TRIAL REGISTRATION: NCT02471586.

Optical coherence tomography-guided coronary stent implantation compared to angiography: a multicentre randomised trial in PCI - design and rationale of ILUMIEN IV: OPTIMAL PCI.

AIMS: Randomised trials have demonstrated improvement in clinical outcomes with intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) compared with angiography-guided PCI. The ILUMIEN III trial demonstrated non-inferiority of an optical coherence tomography (OCT)- versus IVUS-guided PCI strategy in achieving similar post-PCI lumen dimensions. ILUMIEN IV is a large-scale, multicentre, randomised trial designed to demonstrate the superiority of OCT- versus angiography-guided stent implantation in patients with high-risk clinical characteristics (diabetes) and/or complex angiographic lesions in achieving larger post-PCI lumen dimensions and improving clinical outcomes. METHODS AND RESULTS: ILUMIEN IV is a prospective, single-blind clinical investigation that will randomise between 2,490 and 3,656 patients using an adaptive design to OCT-guided versus angiography-guided coronary stent implantation in a 1:1 ratio. The primary endpoints are: (1) post-PCI minimal stent area assessed by OCT in each randomised arm, and (2) target vessel failure, the composite of cardiac death, target vessel myocardial infarction, or ischaemia-driven target vessel revascularisation. Clinical follow-up will continue for up to two years. The trial is currently enrolling, and the principal results are expected in 2022. CONCLUSIONS: The large-scale ILUMIEN IV randomised controlled trial will evaluate the effectiveness of OCT-guided versus angiography-guided PCI in improving post-PCI lumen dimensions and clinical outcomes in patients with diabetes and/or with complex coronary lesions. TRIAL REGISTRATION: NCT03507777.

Impact of Coronary Atherosclerosis on Bioresorbable Vascular Scaffold Resorption and Vessel Wall Integration.

The integration of the Absorb bioresorbable vascular scaffold (BVS) into the arterial wall has never been tested in an in vivo model of atherosclerosis. This study aimed to compare the long-term (up to 4 years) vascular healing responses of BVS to an everolimus-eluting metallic stent in the familial hypercholesterolemic swine model of atherosclerosis. The multimodality imaging and histology approaches indicate that the resorption and vascular integration profile of BVS is not affected by the presence of atherosclerosis. BVS demonstrated comparable long-term vascular healing and anti-restenotic efficacy to everolimus-eluting metallic stent but resulted in lower late lumen loss at 4 years.

Randomized Comparison Between Everolimus-Eluting Bioresorbable Scaffold and Metallic Stent: Multimodality Imaging Through 3 Years.

OBJECTIVES: The aim of this study was to investigate the vascular responses and fates of the scaffold after bioresorbable vascular scaffold (BVS) implantation using multimodality imaging. BACKGROUND: Serial comprehensive image assessments after BVS implantation in the context of a randomized trial have not yet been reported. METHODS: In the ABSORB Japan trial, 400 patients were randomized to a BVS (n = 266) or a cobalt-chromium everolimus-eluting stent (n = 134). Through 3 years, patients underwent serial angiography and intravascular ultrasound or optical coherence tomography (OCT). RESULTS: Luminal dimension at 3 years was consistently smaller with the BVS than with the cobalt-chromium everolimus-eluting stent (mean angiographic minimal luminal diameter 2.04 ± 0.63 mm vs. 2.40 ± 0.56 mm, mean difference -0.37 mm [95% confidence interval: -0.50 to -0.24 mm]; p < 0.001), mainly because of smaller device area (6.13 ± 2.03 mm2 vs. 7.15 ± 2.16 mm2, mean difference -1.04 mm2 [95% confidence interval: -1.66 to -0.42 mm2]; p < 0.001), and larger neointimal area (2.10 ± 0.61 mm2 vs. 1.86 ± 0.64 mm2, mean difference 0.24 mm2 [95% confidence interval: 0.06 to 0.43 mm2]; p = 0.01) by OCT. BVS-treated vessels did not show previously reported favorable vessel responses, such as positive vessel remodeling, late luminal enlargement, and restoration of vasomotion, although the OCT-based healing score was on average zero (interquartile range: 0.00 to 0.00). At 3 years, intraluminal scaffold dismantling (ISD) was observed in 14% of BVS. On serial OCT, ISD was observed in 6 lesions at 2 years, where the struts had been fully apposed at post-procedure, while ISD was observed in 12 lesions at 3 years, where 8 lesions were free from ISD on 2-year OCT. In 5 cases of very late scaffold thrombosis, strut discontinuities were detected in all 4 cases with available OCT immediately before reintervention. CONCLUSIONS: In this multimodality serial imaging study, luminal dimension at 3 years was smaller with the BVS than with the cobalt-chromium everolimus-eluting stent. ISD, suspected to be one of the mechanisms of very late BVS thrombosis, was observed in a substantial proportion of cases at 3 years, which developed between post-procedure and 2 years and even beyond 2 years. (AVJ-301 Clinical Trial: A Clinical Evaluation of AVJ-301 [Absorb™ BVS] in Japanese Population [ABSORB JAPAN]; NCT01844284).

Design Effect of Metallic (Durable) and Polymeric (Resorbable) Stents on Blood Flow and Platelet Activation.

Bioresorbable vascular scaffolds (BVS) provide transient vessel support for occluded coronary arteries while resorbing over time, potentially allowing vessel restoration approximating the native, healthy state. Clinical trials indicate that the Absorb BVS (Abbott Vascular, Santa Clara, CA) performance was similar to that of the Xience metallic drug-eluting stent (DES), with low long-term complications rates. However, when under-deployed in very small vessels (diameter < 2.25 mm), the thrombosis rate of BVS was higher, possibly due to the effect of strut thickness on the hemodynamics (157 µm BVS vs. 81 µm DES). This study aims to determine the influence of BVS design in vessels of varying diameter on the potential platelet activation. Sixteen computational fluid dynamics models of vessels of varying diameter (1.8-3.0 mm), strut thickness (81-157 µm), and BVS/DES designs were compared. Platelet stress accumulation (SA), a metric for the activation potential, was calculated along platelet flow trajectories and their probability distribution was compared. The models were consistent with clinical observations, indicating that devices deployed in very small vessels exhibited increased probability for platelet activity as compared to the same devices deployed in nominal sized vessels. Deployment, although with residual stenosis, increased probability for higher SA than in similar diameter straight vessels. Reducing BVS struts thickness while maintaining their pattern improved performance closer to that of DES. Our findings highlight the importance of appropriate vessel sizing and deployment technique for BVS, and may help designing future BVS with thinner struts, ultimately improving performance in very small vessels.

Evaluation of chemical stability of polymers of XIENCE everolimus-eluting coronary stents in vivo by pyrolysis-gas chromatography/mass spectrometry.

The polymers poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(n-butyl methacrylate) (PBMA) are employed in manufacturing the XIENCE family of coronary stents. PBMA serves as a primer and adheres to both the stent and the drug coating. PVDF-HFP is employed in the drug matrix layer to hold the drug everolimus on the stent and control its release. Chemical stability of the polymers of XIENCE stents in the in-vivo environment was evaluated by pyrolysis-gas chromatography with mass spectrometry (Py-GC/MS) detection. For this evaluation, XIENCE stents explanted from porcine coronary arteries and from human coronary artery specimens at autopsy after 2-4 and 5-7 years of implantation, respectively, were compared to freshly manufactured XIENCE stents (controls). The comparison of pyrograms of explanted stent samples and controls showed identical fragmentation fingerprints of polymers, indicating that PVDF-HFP and PBMA maintained their chemical integrity after multiple years of XIENCE coronary stent implantation. The findings of the present study demonstrate the chemical stability of PVDF-HFP and PBMA polymers of the XIENCE family of coronary stents in the in-vivo environment, and constitute a further proof of the suitability of PVDF-HFP as a drug carrier for the drug eluting stent applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1721-1729, 2018.

Lessons Learned Regarding Handling and Deployment of the Absorb Bioresorbable Vascular Scaffold in Infrapopliteal Arteries.

PURPOSE: To describe relevant technical details with which to facilitate safe and effective use of the Absorb coronary bioresorbable vascular scaffold (BVS) in lower extremity arteries. TECHNIQUE: The Absorb BVS is a balloon-expandable, poly-l-lactide structure covered in a poly-d,l-lactide bioresorbable polymer that contains the antiproliferative drug everolimus. As a polymeric structure, it has a number of unique physical, handling, and imaging properties that may differ from metallic stents and pose a challenge to the interventionist. Attention must be paid to lesion selection, preparation, scaffold sizing, deployment, and postdilation to achieve optimal outcomes. A detailed description of these issues and deployment techniques is offered based on experience using this BVS in below-the-knee arteries. CONCLUSION: The Absorb BVS may have application in the infrapopliteal circulation; however, its unique properties warrant careful consideration before use in the lower limb.

Paving the way to a bioresorbable technology: Development of the absorb BRS program.

Bioresorbable scaffolds (BRS) combine attributes of the preceding generations of percutaneous coronary intervention (PCI) devices with new technologies to result in a novel therapy promoted as being the fourth generation of PCI. By providing mechanical support and drug elution to suppress restenosis, BRS initially function similarly to drug eluting stents. Thereafter, through their degradation, BRS undergo a decline in radial strength, allowing a gradual transition of mechanical function from the scaffold back to the artery in order to provide long term effectiveness similar to balloon angioplasty. The principles of operation of BRS, whether of polymeric or metallic composition, follow three phases of functionality reflective of differing physiological requirements over time: revascularization, restoration, and resorption. In this review, these three fundamental performance phases and the metrics for the nonclinical evaluation of BRS, including both bench and preclinical testing, are discussed. © 2016 Wiley Periodicals, Inc.

Two-year clinical, angiographic, and serial optical coherence tomographic follow-up after implantation of an everolimus-eluting bioresorbable scaffold and an everolimus-eluting metallic stent: insights from the randomised ABSORB Japan trial.

AIMS: We sought to investigate two-year clinical and serial optical coherence tomography (OCT) outcomes after implantation of a fully bioresorbable vascular scaffold (BVS) or a cobalt-chromium everolimus-eluting stent (CoCr-EES). METHODS AND RESULTS: In the ABSORB Japan trial, 400 patients were randomised in a 2:1 ratio to BVS (N=266) or CoCr-EES (N=134). A pre-specified OCT subgroup (N=125, OCT-1 group) underwent angio-graphy and OCT post procedure and at two years. Overall, the two-year TLF rates were 7.3% and 3.8% in the BVS and CoCr-EES arms (p=0.18), respectively. Very late scaffold thrombosis (VLST) beyond one year was observed in 1.6% (four cases: all in non-OCT-1 subgroups) of the BVS arm, while there was no VLST in the CoCr-EES arm. In three cases, OCT at the time of or shortly after VLST demonstrated strut discontinuities, malapposition and/or uncovered struts. However, the vessel healing by two-year OCT was nearly complete in both BVS and CoCr-EES arms with almost fully covered struts, and minimal malapposition. The flow area by two-year OCT was smaller in the BVS arm than in the CoCr-EES arm, mainly due to tissue growth inside the device. However, there were no differences between the BVS and CoCr-EES with regard to the quality of homogenous tissues growing inside the devices. CONCLUSIONS: The rate of TLF was numerically higher in the BVS arm than in the CoCr-EES arm, although this difference was not statistically significant. VLST was observed only in the BVS arm at a rate of 1.6% between one and two years. Further studies are mandatory to investigate the risk of BVS relative to metallic stents for VLST, and the underlying mechanisms of BVS VLST.

Differential thrombotic prolapse burden in either bioresorbable vascular scaffolds or metallic stents implanted during acute myocardial infarction: The snowshoe effect: Insights from the maximal footprint analysis.

BACKGROUND: The hypothesized increased thrombus entrapment during bioresorbable vascular scaffold implantation in acute myocardial infarction, the so-called "snowshoe effect" has never been demonstrated. METHODS: Patients enrolled in the BVS STEMI FIRST study matched with STEMI patients implanted with everolimus-eluting metal stents (EES) and undergoing optical coherence tomography (OCT) at the index procedure were compared. Quantitative coronary angiography analysis and optical coherence tomography data for evaluation of thrombotic prolapse were reported. Percentage maximal footprint (%MFP) analysis as an indicator of the snowshoe effect was performed. RESULTS: A total of 302 patients were analyzed (151 with BVS and 151 with EES). Of those patients 30 implanted with BVS and 17 implanted with EES were imaged at the index procedure with OCT. Baseline clinical characteristics, TIMI-flow and thrombus burden were similar between groups. Aspiration thrombectomy was similarly performed in the two groups (BVS 83.3% vs 94.1% EES, p=0.405). At the end of the procedure, final TIMI 3 flow was achieved in 93.3% and 82.4% of BVS and EES patients respectively (p=0.296). The %MFP was significantly higher in the BVS treated patients (36.59±5.65% vs 17.61±4.30, p<0.001). The results of the OCT analysis showed a mean prolapse area (0.61±0.26mm(2) vs 0.90±0.31mm(2), p=0.001) and a percentage prolapse area (7.11±2.98mm(2) vs 9.98±2.90mm(2), p=0.002) significantly higher in the EES group. CONCLUSIONS: Scaffold structural characteristics such as strut width may play a role in terms of thrombus dislodgment patterns and acute prolapsing material.

Bioresorbable Everolimus-Eluting Vascular Scaffold for Patients With Peripheral Artery Disease (ESPRIT I): 2-Year Clinical and Imaging Results.

OBJECTIVES: This is the first-in-human study of a drug-eluting bioresorbable vascular scaffold (BVS) for treatment of peripheral artery disease (PAD) involving the external iliac artery (EIA) and superficial femoral artery (SFA). BACKGROUND: Drug-eluting BVS has shown promise in coronary arteries. METHODS: The ESPRIT BVS system is a device-drug combination consisting of an everolimus-eluting poly-l-lactide scaffold. Safety and performance were evaluated in 35 subjects with symptomatic claudication. RESULTS: Lesions were located in the SFA (88.6%) and EIA (11.4%). Mean lesion length was 35.7 ± 16.0 mm. The study device was successfully deployed in 100% of cases, without recoil. Procedure-related minor complications were observed in 3 patients (groin hematoma, dissection). Within 2 years there was 1 unrelated death, but no patients in this cohort had an amputation. At 1 and 2 years, the binary restenosis rates were 12.1% and 16.1%, respectively, and target lesion revascularization was performed in 3 of 34 patients (8.8%) and 4 of 32 patients (11.8%), respectively. The ankle brachial index 0.75 ± 0.14 improved from pre-procedure to 0.96 ± 0.16 at 2 years' follow-up. At 2 years, 71.0% of the patients were Rutherford-Becker 0, and 93.5% achieved a maximum walking distance of 1,500 feet. CONCLUSIONS: The safety of the ESPRIT BVS was demonstrated with no procedure or device-related deaths or amputations within 2 years. The low occurrence of revascularizations was consistent with duplex-ultrasonography showing sustained patency at 2-years. (A Clinical Evaluation of the Abbott Vascular ESPRIT BVS [Bioresorbable Vascular Scaffold] System [ESPRIT I]; NCT01468974).

Vasomotor Function Comparative Assessment at 1 and 2 Years Following Implantation of the Absorb Everolimus-Eluting Bioresorbable Vascular Scaffold and the Xience V Everolimus-Eluting Metallic Stent in Porcine Coronary Arteries: Insights From In Vivo Angiography, Ex Vivo Assessment, and Gene Analysis at the Stented/Scaffolded Segments and the Proximal and Distal Edges.

OBJECTIVES: The purpose of this study was to assess and compare in vivo the restoration of vasomotor function following Absorb bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) and metallic Xience V (XV) (Abbott Vascular, Santa Clara, California) stent implantations in porcine coronary arteries at 1 and 2 years. BACKGROUND: Drug-eluting metallic coronary stents induce sustained vasomotor dysfunction, and preliminary observations from arteries with bioresorbable scaffolds have indicated partially restored vasoreactivity. METHODS: A total of 15 Absorb BVS (3.0 × 18.0 mm) and 14 XV (3.0 × 18.0 mm or 3.0 × 12.0 mm) stents were randomly implanted in the main coronaries of 12 nonatherosclerotic swine. The effect of implant on vasomotor performance (constrictive and expansive) was measured in the stented/scaffolded segments and the 5-mm proximal and distal adjacent segments in vivo by angiography assessing mean luminal diameter changes following infusion of vasoactive agents at 1 year (n = 6) and 2 years (n = 6) as well as ex vivo at 2 years using a tissue chamber apparatus. Endothelial cell function and smooth muscle cell phenotype gene marker levels were evaluated with quantitative real-time polymerase chain reaction. RESULTS: The scaffolded Absorb BVS segments showed fully restored constrictive response compared with XV implanted vessels at 1 year: -24.30 ± 14.31% versus -1.79 ± 6.57% (p < 0.004) and at 2 years: -28.13 ± 14.60% versus -3.90 ± 6.44% (p < 0.004). The early restoration of vasomotor function within the scaffolded segments reached a peak at 1 year and did not significantly change up to 2 years. The vasoactive responses of Absorb BVS-implanted vessels within the scaffolded segments were similar to those observed within the proximal and distal edge segments at both time points. Conversely, the stented XV segments demonstrated significantly impaired constrictive response compared with the distal XV edges at 1 year: -1.79 ± 6.57% versus -21.89 ± 7.17% (p < 0.0002) and at 2 years: -3.90 ± 6.44% versus -21.93 ± 15.60% (p < 0.03). Ex vivo assessment of contraction induced by PGF2α and relaxation induced by substance P of isolated BVS segments compared with XV-treated segments generated greater contraction force of 3.94 ± 0.97 g versus 1.83 ± 1.03 g (p < 0.05), and endothelial-dependent relaxation reached 35.91 ± 24.74% versus 1.20 ± 3.79% (p < 0.01). Quantitative real-time polymerase chain reaction gene analysis at 2 years demonstrated increased Connexin 43 messenger ribonucleic acid levels of Absorb BVS-treated vessels compared with XV-treated vessels: 1.92 ± 0.23 versus 0.77 ± 12 (p < 0.05). CONCLUSIONS: Absorb BVS-implanted coronary arteries demonstrate early functional restoration of the scaffolded and adjacent segments at 1 year, which is preserved up to 2 years.