Absorb Implantation Research Articles

Two-Year Outcomes for Patients with Non-ST-Elevation Acute Coronary Syndrome Treated with Magmaris and Absorb Bioresorbable Scaffolds in Large-Vessel Lesions.

The acute coronary syndrome (ACS) continues to be a fundamental indication for revascularization by percutaneous coronary intervention (PCI). Drug-eluting stent (DES) implantation remains a part of contemporary practice but permanent caging of the vascular structure with the metallic stent structure may increase the rate of device-related adverse clinical events. As an alternative to classic metallic DESs, the bioresorbable scaffolds (BRSs) have emerged as a temporary vascular support technology. We evaluated the mid-term outcomes of two generations of bioresorbable scaffolds-Absorb (Abbott-Vascular, Chicago, IL, USA) and Magmaris (Biotronik, Germany)-in patients with non-ST-elevation ACS. The study cohort consisted of 193 subjects after Magmaris implantation and 160 patients following Absorb implantation in large-vessel lesions. At 2 years, a significantly lower rate of a primary outcome (cardiac death, myocardial infarction, stent thrombosis) was observed with Magmaris (5.2% vs. 15%; p = 0.002). In addition, we observed a significantly lower rate of MI in the target vessel (2.6% vs. 9.4%; p = 0.009) and a lower rate of scaffold thrombosis (0% vs. 3.7%; p = 0.008). The TLF rate between the two groups was not significantly different. Magmaris demonstrated a good safety profile and more favorable clinical outcomes when compared to Absorb in patients with non-ST-elevation ACS.

ImpaCt of an Optimal Implantation Strategy on Absorb Long-Term Outcomes: The CIAO Registry

AimTo compare the long-term outcomes of patients implanted with Absorb bioresorbable scaffold (BRS) with optimal versus suboptimal technique. Methods and resultsAll patients who received an Absorb between March 2012 and January 2016 were selected from 19 Italian centers databases to assess the impact of an optimal implantation technique (CIAO criteria) on long-term device-oriented composite end-point (DOCE) - including cardiac death (CD), target-vessel myocardial infarction (TV-MI) and ischemia-driven target lesion revascularization (ID-TLR) - on its single components and on scaffold thrombosis (ScT). CIAO criteria consist of predilation (balloon/vessel ratio 1:1), correct sizing (BRS/proximal reference vessel diameter -RVD- ratio 0.8–1.2) and high-pressure postdilation with non-compliant (NC) balloon (≥20 atm for balloon/BRS ratio 1:1 or ≥16 atm for a 0.25–0.5 mm oversized balloon).Among the 1.434 patients analyzed, 464 (32.4%) fulfilled all CIAO criteria for every BRS implanted (CIAO 3 group), while 970 (67.6%) did not in at least one of the received BRS (CIAO 0-1-2 group). At 31.0 (interquartile range -IQR- 24.8–38.5) months follow-up, CIAO criteria did not impact on DOCE (8.2% vs. 8.0%, p = 0.92), ID-TLR (6.9% vs. 7.1%, p = 0.72) or ScT (1.9% vs. 1.8%, p = 0.80) in the overall population. At multivariate analysis overall BRS length (p = 0.001), severely calcified lesions (p = 0.03) and absence of CIAO criteria (CIAO 0, p = 0.005) were independent predictors of DOCE in long-term follow-up. ConclusionOur data suggest that strict application of an optimal Absorb implantation technique doesn't improve long-term DOCE or ScT but may mitigate the worse outcome of patients with calcific lesions.

Long-term clinical outcomes of direct absorb bioresorbable vascular scaffold implantation in acute coronary syndrome.

Preferred technique for bioresorbable vascular scaffold (BVS) implantation included high pressure predilation. Data about direct BVS implantation in acute coronary syndrome (ACS) patients are scarce. Analysis of 90 consecutive patients with acute myocardial infarction (MI) treated with primary PCI with Absorb deployment between 2013-2016 in a single center. In 45 patients, scaffolds were implanted in the direct technique, other 45 patients underwent Absorb deployment after balloon predilation. Follow-up was available in 100% of patients with mean duration of 32±11 months. No cardiac death or scaffold thrombosis were observed in both groups. In the direct group, no target lesion revascularization (TLR) was reported. In the predilation arm, TLR occurred in 4 (9%) patients (P=0.12). Target vessel revascularization (TVR) was observed in 1 (2%) case in the direct group and in 6 (13%) patients from the predilation group (P=0.11). Target vessel MI was reported in one patient from each group. In an intention to treat analysis, we observed significantly higher rates of TVR (15% vs. 2%; P<0.043) and TLR (10% vs. 0%; P=0.038) in the predilation arm. Kaplan-Meier survival analysis did not show significant differences in TLR, TVR and device oriented composite endpoint (a combination of cardiac death, target vessel MI and ischemia driven TLR) between patients treated with both methods. Direct Absorb implantation in patients with ACS may be feasible and safe.

Efficacy and safety of bioresorbable vascular scaffold Absorb: 6-month outcomes of GABI-R: Russia registry

Aim. The paper demonstrates the interim analysis of efficacy and safety after everolimus-eluting bioresorbable vascular scaffold (BVS) Absorb implantation in “real-world patients” with coronary artery disease.Methods. A cohort of 500 consecutive patients who underwent percutaneous coronary intervention for stable chest pain or acute coronary syndrome with implantation of at least one BVS (Absorb, Abbott Vascular) and followed up by telephone interview and review of medical charts were included in a singlecenter, prospective, all-comers, first in Russia registry. The primary endpoint, target vessel failure, defined as the combination of cardiac death, target vessel myocardial infarction, or clinically driven target vessel revascularization and secondary endpoints, MACCE (composite of cardiovascular death, myocardial infarction, coronary artery bypass surgery, target vessel revascularization, stroke) and stent thrombosis, were assessed during 6-month follow-up.Results. A total of 500 patients with coronary artery disease (CAD) (stable CAD 54.4%, acute coronary syndrome 45.6%) and different amount of affected vessels (1 vessel CAD 40.8%, n = 204; 2-vessel CAD 32.8%, n = 164; 3-vessel CAD 26.4%, n = 132) received 664 scaffolds and 55 stents in 603 stenoses. Procedure success, defined as a residual stenosis less than 30% and TIMI 3 flow in target vessel at the end of procedure, was observed in 98.51% (n = 594). At the moment of 6-month follow-up 4.2% (n = 24) of patients were lost to contact. After 6 months, incidence of target vessel failure and MACCE was 4.2% (n = 21) and 5% (n = 25). The cumulative rate of definite/probable scaffold thrombosis was 1.6% (n = 8).Conclusion. The interim analysis of Gabi-R: Russia registry, the largest trial of BVS Absorb implantation in routine clinical practice, showed high procedural success and low incidence of adverse events during follow-up. However, a tendency to high incidence of scaffold thrombosis compared to drug-eluting stents can be observed. Considering the long-term results of randomized trials retrospective registries, safety in terms of BVS routine use is of big concern. Longterm 24-month data regarding safety endpoints are required to test the afore-mentioned suggestion. Received 5 January 2019. Revised 28 March 2019. Accepted 29 March 2019.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.

One-Year Results Following a Pre-Specified ABSORB Implantation Strategy in ST-Elevation Myocardial Infarction (BVS STEMI STRATEGY-IT Study).

data from clinical experiences with Absorb bioresorbable scaffold (BRS) in STEMI raised concerns among clinicians about the device safety because a noteworthy scaffold thrombosis (ScT) rate was reported at early and long-term follow-up. Nevertheless, pre-specified technical suggestions of how to perform an optimal BRS procedure in STEMI were lacking. In this study we sought to assess the 1-year results following a pre-specified BRS implantation strategy in ST-elevation myocardial infarction (STEMI) patients undergoing primary PCI (pPCI). This is a prospective, multicenter study on 505 STEMI patients undergoing pPCI with Absorb following a dedicated implantation protocol. The primary end-point (a device oriented composite end-point (DOCE) of cardiac death, target-vessel myocardial infarction (TV-MI) and ischemia-driven target lesion revascularization (ID-TLR) within 30 days) was already reported. We here present DOCE, its singular components and ScT rates (secondary end-points) at 1-year. According to the study protocol direct Absorb implantation was feasible in 47 (9.3%) patients while post-dilatation was performed in 468 (92.7%) cases. The hierarchical DOCE rate at 1-year was 1.2% (0.4% cardiac death, 0.4% TV-MI and 0.8% ID-TLR) versus 0.6% at 30-day. Two episodes (0.4%) of ScT (one probable subacute and one late definite) were reported. At 1-year, 99.2% patients were on dual antiplatelet therapy (95% with ticagrelor or prasugrel). A pre-specified Absorb implantation strategy in STEMI patients was associated with persistent low DOCE and ScT rates at 1-year. Longer term follow-up is needed to assess the role of this strategy on preventing very-late events (NCT02601781).

Direct Absorb bioresorbable scaffold implantation in acute coronary syndrome.

Direct stent implantation is a preferred technique for primary percutaneous coronary intervention (PCI). For the deployment of a bioresorbable vascular scaffold (BVS), the current guidelines recommend aggressive predilatation. Data about direct BVS implantation in patients with acute coronary syndrome (ACS) are scarce. We sought to assess procedural characteristics and immediate outcomes of direct Absorb BVS implantation in ACS patients. A total of 91 patients with acute myocardial infarction (MI) requiring urgent coronary revascularisation were enrolled. Among them, 50 patients underwent an attempt of direct Absorb implantation. The control group consisted of 41 patients treated with PCI with BVS deployment after elective predilatation. In the direct group BVS deployment was successful in 91% of lesions, and in the remaining 9% of lesions direct implantation failed. In the control group scaffolds were successfully deployed after predilatation in 98% of lesions. In one case Absorb implantation failed even after balloon angioplasty. Type C lesions with severe tortuosity and angulation > 90° were associated with failure in direct Absorb deployment. Quantitative coronary analysis showed similar final percentages of diameter stenosis in the study and control groups. Flow analyses did not show significant differences between both methods. During hospitalisation no recurrent MI, scaffold thrombosis, or target lesion revascularisation was reported in either group. Direct Absorb implantation in ACS patients may be feasible in a suitable lesion anatomy.

A Prospective Evaluation of a Pre-Specified Absorb BVS Implantation Strategy in ST-Segment Elevation Myocardial Infarction: The BVS STEMI STRATEGY-IT Study

ObjectivesThe aim of this study was to assess the feasibility and clinical results following a pre-specified bioresorbable scaffold (Absorb BVS) implantation strategy in patients with ST-segment elevation myocardial infarction (STEMI). BackgroundConcerns were raised about the safety of Absorb because a non-negligible rate of thrombosis was reported within 30 days and at midterm follow-up after primary percutaneous coronary intervention. MethodsThis was a prospective, multicenter study of patients with STEMI (<75 years of age with symptom onset <12 h) undergoing primary percutaneous coronary intervention with Absorb following a dedicated implantation protocol. The primary endpoint was a device-oriented composite endpoint of cardiac death, target vessel myocardial infarction, and ischemia-driven target lesion revascularization within 30 days. ResultsDuring the study period, 505 patients with STEMI (16.9% of the overall STEMI population) were treated with the Absorb BVS. The mean age was 56.6 ± 9.4 years, and 487 patients (96.4%) were in Killip class I or II at admission. According to the study protocol, direct Absorb implantation was feasible in 47 patients (9.3%), whereas post-dilatation was performed in 468 cases (92.7%). Procedural success was attained in 94.8% of the cases. Dual antiplatelet therapy with ticagrelor or prasugrel was administered at discharge in 481 patients (95.1%). At 30-day follow-up, the hierarchical device-oriented composite endpoint rate was 0.6% (0.4% cardiac death, 0.2% target vessel myocardial infarction and ischemia-driven target lesion revascularization). One episode (0.2%) of probable scaffold thrombosis was reported. ConclusionsA pre-specified Absorb implantation strategy in real-world patients with STEMI undergoing primary percutaneous coronary intervention was feasible and associated with a low 30-day device-oriented composite endpoint rate. Mid- and long-term follow-up is strongly needed to eventually confirm these early results. (Use of BVS in ST-Segment Elevation Myocardial Infarction [STEMI]: The BVS STEMI STRATEGY-IT Prospective Registry [STRATEGY-IT]; NCT02601781)

Vasomotor Response to Nitroglycerine Over 5 Years Follow-Up After Everolimus-Eluting Bioresorbable Scaffold Implantation

ObjectivesThis study investigated the vasomotor response to nitroglycerine (NTG) up to 5 years after ABSORB implantation. BackgroundThere are no data regarding long-term vasomotor response after everolimus-eluting bioresorbable vascular scaffold ABSORB implantation. MethodsWe performed quantitative coronary angiography of the scaffolded and proximal and distal adjacent segments of patients from ABSORB Cohort B study before and after 200 μg of intracoronary NTG at 2, 3, and 5 years of follow-up. The mean changes of maximal and mean lumen diameters in the scaffolded and adjacent segments were calculated. ResultsThe mean in-scaffold lumen diameter change in response to NTG showed a trend to increase over time with absolute values of 0.03 ± 0.09 mm, 0.05 ± 0.12 mm, and 0.07 ± 0.08 mm at 2, 3, and 5 years, respectively (p = 0.40). The maximal in-scaffold lumen diameter change significantly increased with values of 0.03 ± 0.14 mm, 0.06 ± 0.16 mm, and 0.11 ± 0.1 mm at 2, 3, and 5 years, respectively (p = 0.03). The normalized mean lumen diameter change after NTG in the scaffold relative to the adjacent segments was 51.9 ± 54.8% at 5 years of follow-up (p = 0.60). ConclusionsAlthough there was a numerical increase of the vasomotor response to NTG after ABSORB implantation measured by quantitative coronary angiography with mean lumen diameter, the change was not statistically significant. However, the maximal lumen diameter changes increased over time from 2 to 5 years and attained statistical significance. The vasomotor response to NTG after ABSORB implantation moderately trended to increase, which is consistent with the progressive degradation and bioresorption of the scaffold, but the degree of vasomotor response remained lower in comparison with adjacent segments.

Head to head comparison of optical coherence tomography, intravascular ultrasound echogenicity and virtual histology for the detection of changes in polymeric struts over time: insights from the ABSORB trial

To analyse and to compare the changes in the various optical coherence tomography (OCT), echogenicity and intravascular ultrasound virtual histology (VH) of the everolimus-eluting bioresorbable scaffold (ABSORB) degradation parameters during the first 12 months after ABSORB implantation. In the ABSORB study, changes in the appearance of the ABSORB scaffold were monitored over time using various intracoronary imaging modalities. The scaffold struts exhibited a progressive change in their black core area by OCT, in their ultrasound derived grey level intensity quantified by echogenicity, and in their backscattering ultrasound signal, identified as "pseudo dense-calcium" (DC) by VH. From the ABSORB Cohort B trial 35 patients had paired OCT, echogenicity and VH assessment at baseline and at six- (n=18) or 12-months follow-up (n=17). Changes in OCT strut core area, hyperechogenicity and VH-derived DC were analysed and compared at the various time points. At six months, the change (median[IQR]) in OCT strut core area was -7.2% (-14.0-+0.9) (p=0.053), in hyperechogenicity -12.7% (-33.7-+1.4) (p=0.048) and VH-DC 22.1% (-10.8-+48.8) (p=0.102). At 12 months, all the imaging modalities showed a decrease in the various parameters considered (OCT: -12.2% [-17.5--1.9], p=0.093; hyperechogenicity -24.64% [-36.6--16.5], p=0.001; VH-DC: -24.66% [-32.0--7.0], p=0.071). However, the correlation between the relative changes in these parameters was statistically poor (Spearman's rho <0.4). OCT, echogenicity and VH were able to detect changes in the ABSORB scaffold struts, although the correlation between those changes was poor. This is likely due to the fact that each imaging modality interrogates different material properties on different length scales. Further studies are needed to explore these hypotheses.

Vascular Compliance Changes of the Coronary Vessel Wall After Bioresorbable Vascular Scaffold Implantation in the Treated and Adjacent Segments

Implantation of a metallic prosthesis creates local stiffness with a subsequent mismatch in the compliance of the vessel wall, disturbances in flow and heterogeneous distribution of wall shear stress. Polymeric bioresorbable ABSORB scaffolds have less stiffness than metallic platform stents. We sought to analyze the mismatch in vascular compliance after ABSORB implantation and its long-term resolution with bioresorption. A total of 83 patients from the ABSORB trials underwent palpography investigations (30 and 53 patients from ABSORB Cohorts A and B, respectively) to measure the compliance of the scaffolded and adjacent segments at various time points (from pre-implantation up to 24 months). The mean of the maximum strain values was calculated per segment by utilizing the Rotterdam Classification (ROC) score and expressed as ROC/mm. Scaffold implantation lead to a significant decrease in vascular compliance (median [IQR]) at the scaffolded segment (from 0.37 [0.24-0.45] to 0.14 [0.09-0.23], P<0.001) with mismatch in compliance in a paired analysis between the scaffolded and adjacent segments (proximal: 0.23 [0.12-0.34], scaffold: 0.12 [0.07-0.19], distal: 0.15 [0.05-0.26], P=0.042). This reported compliance mismatch disappears at short- and mid-term follow-up. The ABSORB scaffold decreases vascular compliance at the site of scaffold implantation. A compliance mismatch is evident immediately post-implantation and in contrast to metallic stents disappears in the mid-term, likely leading to a normalization of the rheological behavior of the scaffolded segment.

Circumferential evaluation of the neointima by optical coherence tomography after ABSORB bioresorbable vascular scaffold implantation: Can the scaffold cap the plaque?

ObjectiveTo quantify the circumferential healing process at 6 and 12 months following scaffold implantation. BackgroundThe healing process following stent implantation consists of tissue growing on the top of and in the space between each strut. With the ABSORB bioresorbable vascular scaffold (BVS), the outer circumference of the scaffold is detectable by optical coherence tomography (OCT), allowing a more accurate and complete evaluation of the intra-scaffold neointima. MethodsA total of 58 patients (59 lesions), who received an ABSORB BVS 1.1 implantation and a subsequent OCT investigation at 6 (n=28 patients/lesions) or 12 (n=30 patients with 31 lesions) months follow-up were included in the analysis. The thickness of the neointima was calculated circumferentially in the area between the abluminal side of the scaffold and the lumen by means of an automated detection algorithm. The symmetry of the neointima thickness in each cross section was evaluated as the ratio between minimum and maximum thickness. ResultsThe neointima area was not different between 6 and 12 months follow-up (1.57±0.42mm2 vs. 1.64±0.77mm2; p=0.691). No difference was also found in the mean thickness of the neointima (median [IQR]) between the two follow-up time points (210μm [180–260]) vs. 220μm [150–260]; p=0.904). However, the symmetry of the neointima thickness was higher at 12 than at 6 months follow-up (0.23 [0.13–0.28] vs. 0.16 [0.08–0.21], p=0.019). ConclusionsA circumferential evaluation of the healing process following ABSORB implantation is feasible, showing the formation of a neointima layer, that resembles a thick fibrous cap, known for its contribution to plaque stability.

Proximal and distal maximal luminal diameters as a guide to appropriate deployment of the ABSORB everolimus‐eluting bioresorbable vascular scaffold

Due to the limited distensibility of the everolimus-eluting bioresorbable vascular scaffold (ABSORB) compared to metallic platform stents, quantitative coronary arteriography (QCA) is a mandatory requirement for ABSORB deployment in the on-going ABSORB EXTEND Single-Arm Study. Visual assessment of vessel size in the ABSORB Cohort B study often lead to under and over-sizing of the 3 mm ABSORB in coronary vessels (recommended range of the vessel diameter ≥ 2.5 mm and ≤ 3.3 mm), with an increased risk of spontaneous incomplete scaffold apposition post ABSORB deployment. We report whether mandatory QCA assessment of vessel size pre-implantation, utilizing the maximal luminal diameter (Dmax) and established interpolated reference vessel diameter (RVD) measurements, has improved device/vessel sizing. Pre-implantation post-hoc QCA analyses of all 101 patients from ABSORB Cohort B (102 lesions) and first consecutive 101 patients (108 lesions) from ABSORB EXTEND were undertaken by an independent core-laboratory; all patients had a 3 mm ABSORB implanted. Comparative analyses were performed. Within ABSORB Cohort B, a greater number of over-sized vessels (> 3.3 mm) were identified utilizing the Dmax compared to the interpolated RVD (17 vessels, 16.7% vs. 3 vessels, 2.9%; P = 0.002). Comparative analyses demonstrated a greater number of appropriate vessel-size selection (75 vessels, 69.4% vs. 48 vessels, 47.1%; P = 0.001), a trend towards a reduction in implantation in small (< 2.5 mm) vessels (29 vessels, 26.9% vs. 40 vessels, 39.2%; P = 0.057) and a significant decrease in the implantation in large (> 3.3 mm) vessels (4 vessels, 3.7% vs. 17 vessels, 16.7%; P = 0.002) in ABSORB EXTEND. Bland-Altman plots suggested a good agreement between operator and core-laboratory calculated Dmax measurements. The introduction of mandatory Dmax measurements of vessel size prior to ABSORB implantation significantly reduced the under-sizing of the 3.0 mm scaffold in large vessels validating the use of this technique in vessel sizing prior to ABSORB implantation.