Josep Gomez-Lara

Absorb Bioresorbable Vascular Scaffold Versus Everolimus-Eluting Metallic Stent in ST-Segment Elevation Myocardial Infarction: 1-Year Results of a Propensity Score Matching Comparison: The BVS-EXAMINATION Study (Bioresorbable Vascular Scaffold-A Clinical Evaluation of Everolimus Eluting Coronary Stents in the Treatment of Patients With ST-segment Elevation Myocardial Infarction)

OBJECTIVES The purpose of this study was to compare the 1-year outcome between bioresorbable vascular scaffold (BVS) and everolimus-eluting metallic stent (EES) in ST-segment elevation myocardial infarction (STEMI) patients. BACKGROUND The Absorb BVS (Abbott Vascular, Santa Clara, California) is a polymeric scaffold approved for treatment of stable coronary lesions. Limited and not randomized data are available on its use in ST-segment elevation myocardial infarction (STEMI) patients. METHODS This study included 290 consecutive STEMI patients treated by BVS, compared with either 290 STEMI patients treated with EES or 290 STEMI patients treated with bare-metal stents (BMS) from the EXAMINATION (A Clinical Evaluation of Everolimus Eluting Coronary Stents in the Treatment of Patients With ST-segment Elevation Myocardial Infarction) trial, by applying propensity score matching. The primary endpoint was a device-oriented endpoint (DOCE), including cardiac death, target vessel myocardial infarction, and target lesion revascularization, at 1-year follow-up. Device thrombosis, according to the Academic Research Consortium criteria, was also evaluated. RESULTS The cumulative incidence of DOCE did not differ between the BVS and EES or BMS groups either at 30 days (3.1% vs. 2.4%, hazard ratio [HR]: 1.31 [95% confidence interval (CI): 0.48 to 3.52], p = 0.593; vs. 2.8%, HR: 1.15 [95% CI: 0.44 to 2.30], p = 0.776, respectively) or at 1 year (4.1% vs. 4.1%, HR: 0.99 [95% CI: 0.23 to 4.32], p = 0.994; vs. 5.9%, HR: 0.50 [95% CI: 0.13 to 1.88], p = 0.306, respectively). Definite/probable BVS thrombosis rate was numerically higher either at 30 days (2.1% vs. 0.3%, p = 0.059; vs. 1.0%, p = 0.324, respectively) or at 1 year (2.4% vs. 1.4%, p = 0.948; vs. 1.7%, p = 0.825, respectively), as compared with EES or BMS. CONCLUSIONS At 1-year follow-up, STEMI patients treated with BVS showed similar rates of DOCE compared with STEMI patients treated with EES or BMS, although rate of scaffolds thrombosis, mostly clustered in the early phase, was not negligible. Larger studies with longer follow-up are needed to confirm our findings.

A comparison of the conformability of everolimus-eluting bioresorbable vascular scaffolds to metal platform coronary stents

OBJECTIVES The aim of this study was to assess the differences in terms of curvature and angulation of the treated vessel after the deployment of either a metallic stent or a polymeric scaffold device. BACKGROUND Conformability of metallic platform stents (MPS) is the major determinant of geometric changes in coronary arteries caused by the stent deployment. It is not known how bioresorbable polymeric devices perform in this setting. METHODS This retrospective study compares 102 patients who received an MPS (Multi-link Vision or Xience V, Abbott Vascular, Santa Clara, California) in the SPIRIT FIRST and II trials with 89 patients treated with the Revision 1.1 everolimus-eluting bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) from cohort B of the ABSORB (A bioabsorbable everolimus-eluting coronary stent system) trial. All patients were treated with a single 3 × 18 mm device. Curvature and angulation were measured with dedicated software by angiography. RESULTS Both the MPS and BVS groups had significant changes in relative region curvature (MPS vs. BVS: 28.7% vs. 7.5%) and angulation (MPS vs. BVS: 25.4% vs. 13.4%) after deployment. The unadjusted comparisons between the 2 groups showed for BVS a nonsignificant trend for less change in region curvature after deployment (MPS vs. BVS: 0.085 cm(-1) vs. 0.056 cm(-1), p = 0.06) and a significantly lower modification of angulation (MPS vs. BVS 6.4° vs. 4.3°, p = 0.03). By multivariate regression analysis, the independent predictors of changes in curvature and angulation were the pre-treatment region curvature, the pre-treatment region angulation, and the used device. CONCLUSIONS Bioresorbable vascular scaffolds have better conformability than conventional MPS. The clinical significance of the observed differences will require further investigation.

NIRS and IVUS for characterization of atherosclerosis in patients undergoing coronary angiography

OBJECTIVES The aim of this study was to compare the findings of near-infrared spectroscopy (NIRS), intravascular ultrasound (IVUS) virtual histology (VH), and grayscale IVUS obtained in matched coronary vessel segments of patients undergoing coronary angiography. BACKGROUND Intravascular ultrasound VH has been developed to add tissue characterization to the grayscale IVUS assessment of coronary plaques. Near-infrared spectroscopy is a new imaging technique able to identify lipid core-containing coronary plaques (LCP). METHODS We performed NIRS and IVUS-VH pullbacks in a consecutive series of 31 patients with a common region of interest (ROI) between 2 side branches. For each ROI, we analyzed the chemogram blocks by NIRS, plaque area and plaque burden by grayscale IVUS, and tissue types by IVUS-VH. The chemogram block is a summary metric of a 2-mm vertical slice of the chemogram. The value ranges from 0 to 1 according to the presence of lipids and represents the probability of LCP with a color scale from red (low probability) through orange and tan to yellow (high probability). RESULTS Plaque area (mm(2)) increases as percentage VH derived-necrotic core (NC) content (4.6 ± 2.7 vs. 7.4 ± 3.5 vs. 8.6 ± 3.4 vs. 7.9 ± 3.3, grouped in percentage NC quartiles, p<0.001) and chemogram block probability color bin thresholds increase (4.9 ± 3.8 red, 7.3 ± 3.6 orange, 8.1 ± 3.4 tan, and 8.7 ± 3.4 yellow, p<0.001). The correlation between the block chemogram detection of lipid core and percentage NC content by VH was weak (r=0.149). Correction for the presence of calcium does not improve this correlation. CONCLUSIONS Larger plaque area by grayscale IVUS was more often associated with either elevated percentage VH-NC or LCP by NIRS; however, the correlation between the detection of LCP by NIRS and necrotic core by VH is weak.

Serial Analysis of the Malapposed and Uncovered Struts of the New Generation of Everolimus-Eluting Bioresorbable Scaffold With Optical Coherence Tomography

OBJECTIVES The aim of this study is to assess the serial changes in strut apposition and coverage of the bioresorbable vascular scaffolds (BVS) and to relate this with the presence of intraluminal masses at 6 months with optical coherence tomography (OCT). BACKGROUND Incomplete strut/scaffold apposition (ISA) and uncovered struts are related to a higher risk of scaffold thrombosis. Bioresorbable vascular scaffolds can potentially avoid the risk of scaffold thrombosis because of its complete resorption. However, during the resorption period, the risk of scaffold thrombosis is unknown. METHODS OCT was performed in 25 patients at baseline and 6 months. Struts were classified according to apposition, coverage, and presence of intraluminal masses. Persistent ISA was defined as malapposed struts present at baseline and follow-up, and late acquired ISA as ISA developing at follow-up, and scaffold pattern irregularities when the strut distribution suggested scaffold fracture. RESULTS At baseline, 3,686 struts were analyzed: 128 (4%) were ISA, and 53 (1%) were located over side-branches (SB). At 6 months, 3,905 struts were analyzed: 32 (1%) ISA, and 35 (1%) at the SB. Persistent ISA was observed more frequently than late acquired-ISA (81% vs. 16%, respectively; 3% were unmatchable). Late acquired ISA was associated with scaffold pattern irregularities, which were related to overstretching of the scaffold. Uncovered struts (63 struts, 2%) were more frequently observed in ISA and SB struts, compared with apposed struts (29% vs. 1%; p < 0.01). Intraluminal masses (14 cross-sections, 3%; in 6 patients, 24%) were more frequently located at the site of ISA and/or uncovered struts (39% vs. 2% and 13% vs. 2%, respectively; p < 0.01). CONCLUSIONS The lack of strut apposition at baseline is related to the presence of uncovered struts and intraluminal masses at 6 month. An appropriate balloon/artery ratio respecting the actual vessel size and avoiding the overstretching of the scaffold can potentially decrease the risk of scaffold thrombosis. (ABSORB Clinical Investigation, Cohort B [ABSORB B).

A comparative assessment by optical coherence tomography of the performance of the first and second generation of the everolimus-eluting bioresorbable vascular scaffolds

AIMS The first generation of the everolimus-eluting bioresorbable vascular scaffold (BVS 1.0) showed an angiographic late loss higher than the metallic everolimus-eluting stent Xience V due to scaffold shrinkage. The new generation (BVS 1.1) presents a different design and manufacturing process than the BVS 1.0. This study sought to evaluate the differences in late shrinkage, neointimal response, and bioresorption process between these two scaffold generations using optical coherence tomography (OCT). METHODS AND RESULTS A total of 12 lesions treated with the BVS 1.0 and 12 selected lesions treated with the revised BVS 1.1 were imaged at baseline and 6-month follow-up with OCT. Late shrinkage and neointimal area (NIA) were derived from OCT area measurements. Neointimal thickness was measured in each strut. Strut appearance has been classified as previously described. Baseline clinical, angiographic, and OCT characteristics were mainly similar in the two groups. At 6 months, absolute and relative shrinkages were significantly larger for the BVS 1.0 than for the BVS 1.1 (0.98 vs. 0.07 mm² and 13.0 vs. 1.0%, respectively; P = 0.01). Neointimal area was significantly higher in the BVS 1.0 than in the BVS 1.1 (in-scaffold area obstruction of 23.6 vs. 12.3%; P < 0.01). Neointimal thickness was also larger in the BVS 1.0 than in the BVS 1.1 (166.0 vs. 76.4 µm; P < 0.01). Consequently, OCT, intravascular ultrasound, and angiographic luminal losses were higher with the BVS 1.0 than with the BVS 1.1. At 6 months, strut appearance was preserved in only 2.9% of the BVS 1.0 struts, but remained unchanged with the BVS 1.1 indicating different state of strut microstucture and/or their reflectivity. CONCLUSION The BVS 1.1 has less late shrinkage and less neointimal growth at 6-month follow-up compared with the BVS 1.0. A difference in polymer degradation leading to changes in microstructure and reflectivity is the most plausible explanation for this finding.

Head-to-head comparison of the neointimal response between metallic and bioresorbable everolimus-eluting scaffolds using optical coherence tomography

OBJECTIVES This study sought to compare the neointimal response of metallic everolimus drug-eluting stents (DES) and polymeric everolimus bioresorbable vascular scaffolds (BVS) by optical coherence tomography at 1 year. BACKGROUND DES decrease the risk of restenosis by reducing the neointimal response. However, DES may impair strut coverage, and this has been associated with late stent/scaffold thrombosis. BVS may overcome the risk of stent/scaffold thrombosis when completely resorbed. It is unknown if, during the bioresorption process, the neointimal response of the everolimus BVS (Absorb, Abbott Vascular, Santa Clara, California) differs from that of the metallic everolimus DES (Xience, Abbott Vascular). METHODS A total of 19 lesions were treated with a single everolimus DES, and 31 lesions were treated with everolimus BVS and imaged with optical coherence tomography at 1 year. Neointimal response was assessed as percentage of uncovered struts, neointimal thickness, in-stent/scaffold area obstruction, and pattern of neointima. RESULTS At 1 year, no significant differences in the angiographic lumen loss were seen for the everolimus DES and everolimus BVS (0.18 ± 0.20 mm vs. 0.29 ± 0.36 mm; p = 0.42). optical coherence tomography analysis of 951 cross sections and 8,385 struts demonstrated similar rates of uncovered struts (5.3% everolimus DES vs. 4.5% everolimus BVS; p = 0.11), mean neointimal thickness (120.6 ± 46.0 μm vs. 136.1 ± 71.4 μm; p = 0.82) and in-stent/scaffold area obstruction (12.5 ± 7.1% vs. 13.6 ± 9.7%; p = 0.91), respectively. There was a trend of higher heterogenic tissue pattern of neointima (21.1% vs. 6.5%; p = 0.12) and less intraluminal masses (0% vs. 12.9%; p = 0.10) with everolimus DES than with everolimus BVS. CONCLUSIONS The everolimus BVS (Absorb) demonstrated a similar neointimal response as the everolimus DES (Xience). However, the presence of intraluminal masses at 12 months in a small proportion of patients warranted watchful follow-up of these cases.

Three-dimensional optical frequency domain imaging in conventional percutaneous coronary intervention: the potential for clinical application

Two-dimensional (2D) frequency domain optical coherence tomography (FD-OCT) has enhanced our understanding of coronary atherosclerotic disease and is increasingly being used in conventional percutaneous coronary intervention (PCI) to elucidate mechanisms of disease and improve our understanding of complex coronary anatomy. Since the first report of three-dimensional (3D) OCT applied in human coronary vessels,1 the technology has rapidly progressed.2–10 Currently, the main limitation of this technology is the need for off-line creation of 3D reconstructions—prototypes of current generation ‘real time’ (i.e. available peri-procedurally at the ‘push-of-a-button’) remain experimental, work in progress, and are limited by relatively poor image quality/resolution.4 As of now, the potential clinical application of 3D FD-OCT remains undefined. Recently, the application of this emerging technology to the coronary bifurcation has allowed visualization and assessment of jailed side branches (SideBs) at a level of detail not previously reported.2–7 The assessment of a jailed SideB, after implantation of a bioresorbable scaffold in the main branch (MainB) of a bifurcation, lead to the proposal of a new classification system based on the assessment of the number of compartments the SideB ostium was divided into, with examples of how this may potentially effect the neointimal response and subsequent coverage of the struts.2 More recently, the application of this technology to the coronary bifurcation in patients implanted with conventional metallic stents, utilizing the Terumo optical frequency domain imaging (OFDI) system, was described for the first time.3 Hypotheses related to types of coronary bifurcation (‘parallel’ and ‘perpendicular’ bifurcations) based on the bifurcation angle, and how this leads to certain specific characteristics of the carina, which potentially made the SideB more vulnerable to the effects of carina shift and potential SideB closure, were described. Furthermore, the potential practical application of 3D FD-OCT in guiding the …

Comparison of in vivo eccentricity and symmetry indices between metallic stents and bioresorbable vascular scaffolds: Insights from the ABSORB and SPIRIT trials

Objective: To compare the geometrical parameters of a bioresorbable vascular scaffold (BVS) with a standard metallic stent. Background: The introduction of polymeric bioresorbable materials in the design of novel coronary scaffolds may affect some geometrical parameters, such as eccentricity and symmetry indices, previously introduced as IVUS criteria for optimal metallic stent deployment. Methods: From ABSORB Cohort A, ABSORB Cohort B, SPIRIT I, and SPIRIT II, all patients implanted with BVS 1.0, BVS 1.1, or XIENCE V, respectively and intravascular ultrasound analyses post‐implantation were selected. The eccentricity index was calculated frame by frame and expressed as an average per device (minimum diameter/maximum diameter). The symmetry index of the device was reported as ([maximum diameter − minimum diameter]/maximum diameter).Six months major adverse cardiac events (MACE) were analyzed. Results: A total of 242 patients were selected (BVS 1.0: n = 28, BVS 1.1: n = 94, XIENCE V: n = 120). The BVS exhibited a significantly lower eccentricity index (BVS 1.0: 0.83 ± 0.09; BVS 1.1: 0.85 ± 0.08; XIENCE V: 0.90 ± 0.06; P < 0.01) and a significantly higher symmetry index (BVS 1.0: 0.30 ± 0.07; BVS 1.1: 0.31 ± 0.06, XIENCE V 0.26 ± 0.07; P < 0.01) as compared to the XIENCE V. An inverse correlation was found between the symmetry and eccentricity indices for both (BVS r = −0.69, P < 0.01; XIENCE V r = −0.61, P < 0.01). No differences in MACE were detected between the groups according to their geometrical parameters. Conclusions: The introduction of a new polymeric material in the design of BVS resulted in a lower eccentricity index and a higher symmetry index as compared to metallic stents, without detectable impact in MACE, at 6 months.

New Insights Into the Coronary Artery Bifurcation: Hypothesis-Generating Concepts Utilizing 3-Dimensional Optical Frequency Domain Imaging

Coronary artery bifurcations are a common challenging lesion subset accounting for approximately 10% to 20% of all percutaneous coronary interventions. The provisional T-stenting approach is generally recommended as the first-line management of most lesions. Carina shift is suggested to be the predominant mechanism of side-branch pinching during provisional T-stenting and has been indirectly inferred from bench work and other intravascular imaging modalities. Offline 3-dimensional (3D) reconstructions of patients studied in the first-in-man trial of the high-frequency (160 frames/s) Terumo optical frequency domain imaging system were undertaken using volume-rendering software. Through a series of 3D reconstructions, several novel hypothesis-generating concepts are presented.

Angiographic maximal luminal diameter and appropriate deployment of the everolimus-eluting bioresorbable vascular scaffold as assessed by optical coherence tomography: An ABSORB cohort B trial sub-study

AIMS Bioresorbable vascular scaffolds (BVS) present different mechanical properties as compared to metallic platform stents. Therefore, the standard procedural technique to achieve appropriate deployment may differ. METHODS AND RESULTS Fifty-two lesions treated with a 3 x 18 mm BVS were imaged with optical coherence tomography (OCT) post-implantation and screened for parameters suggesting non-optimal deployment. These included minimal scaffold area (minSA)<5 mm², residual area stenosis (RAS)>20%, edge dissections, incomplete scaffold/strut apposition (ISA)>5% and scaffold pattern irregularities. The angiographic proximal and distal maximal lumen diameters (DMAX) were measured by quantitative coronary angiography. Based on the DMAX values, the population was divided into three groups: DMAX <2.5 mm (n=13), DMAX between 2.5-3.3 mm (n=30) and DMAX >3.3 mm (n=9). All three groups presented with similar pre-implantation angiographic characteristics except for the vessel size and were treated with similar balloon/artery ratios. The group with a DMAX <2.5 mm presented with a higher percentage of lesions with minSA <5 mm² (30.8% vs. 10.0% vs. 0%; p=0.08) and edge dissections (61.5% vs. 33.3% vs. 11.1%; p=0.05). Lesions with >5% of ISA were significantly higher in the group with DMAX >3.3 mm (7.7% vs. 36.7% vs. 66.7%; p=0.02). RAS >20% was similar between all groups (46.2 vs. 53.3 vs. 77.8%; p=0.47) and scaffold pattern irregularities were only documented in three cases. CONCLUSIONS BVS implantation guided with quantitative angiography may improve the OCT findings of optimal deployment. The clinical significance of these angiographic and OCT findings warranted long term follow-up of larger cohort of patients.