Quantitative assessment of the stent/scaffold strut embedment analysis by optical coherence tomography

The degree of stent/scaffold embedment could be a surrogate parameter of the vessel wall-stent/scaffold interaction and could have biological implications in the vascular response. We have developed a new specific software for the quantitative evaluation of embedment of struts by optical coherence tomography (OCT). In the present study, we described the algorithm of the embedment analysis and its reproducibility. The degree of embedment was evaluated as the ratio of the embedded part versus the whole strut height and subdivided into quartiles. The agreement and the inter- and intra-observer reproducibility were evaluated using the kappa and the interclass correlation coefficient (ICC). A total of 4 pullbacks of OCT images in 4 randomly selected coronary lesions with 3.0 × 18 mm devices [2 lesions with Absorb BVS and 2 lesions with XIENCE (both from Abbott Vascular, Santa Clara, CA, USA)] from Absorb Japan trial were evaluated by two investigators with QCU-CMS software version 4.69 (Leiden University Medical Center, Leiden, The Netherlands). Finally, 1481 polymeric struts in 174 cross-sections and 1415 metallic struts in 161 cross-sections were analyzed. Inter- and intra-observer reproducibility of quantitative measurements of embedment ratio and categorical asses

Relation between bioresorbable scaffold sizing using QCA-Dmax and clinical outcomes at 1 year in 1,232 patients from 3 study cohorts (ABSORB Cohort B, ABSORB EXTEND, and ABSORB II)

Objectives This study sought to investigate the clinical outcomes based on the assessment of quantitative coronary angiography-maximal lumen diameter (Dmax). Background Assessment of pre-procedural Dmax of proximal and distal sites has been used for Absorb scaffold size selection in the ABSORB studies. Methods A total of 1,248 patients received Absorb scaffolds in the ABSORB Cohort B (ABSORB Clinical Investigation, Cohort B) study (N = 101), ABSORB EXTEND (ABSORB EXTEND Clinical Investigation) study (N = 812), and ABSORB II (ABSORB II Randomized Controlled Trial) trial (N = 335). The incidence of major adverse cardiac events (MACE) (a composite of cardiac death, any myocardial infarction [MI], and ischemia-driven target lesion revascularization) was analyzed according to the Dmax subclassification of scaffold oversize group versus scaffold nonoversize group. Results Of 1,248 patients, pre-procedural Dmax was assessed in 1,232 patients (98.7%). In 649 (52.7%) patients, both proximal and distal Dmax values were smaller than the nominal size of the implanted scaffold (scaffold oversize group), whereas in 583 (47.3%) of patients, the proximal and/or distal Dmax were larger than the implanted scaffold (scaffold nonoversize group). The rates of MACE and MI at 1 year were significantly higher in the scaffold oversize group than in the scaffold nonoversize group (MACE 6.6% vs. 3.3%; log-rank p < 0.01, all MI: 4.6% vs. 2.4%; log-rank p = 0.04), mainly driven by a higher MI rate within 1 month post-procedure (3.5% vs. 1.9%; p = 0.08). The independent MACE determinants were both Dmax smaller than the scaffold nominal size (odds ratio [OR]: 2.13, 95% confidence interval [CI]: 1.22 to 3.70; p < 0.01) and the implantation of overlapping scaffolds (OR: 2.10, 95% CI: 1.17 to 3.80; p = 0.01). Conclusions Implantation of an oversized Absorb scaffold in a relatively small vessel appears to be associated with a higher 1-year MACE rate driven by more frequent early MI. (ABSORB Clinical Investigation, Cohort B [ABSORB Cohort B], NCT00856856; ABSORB EXTEND Clinical Investigation [ABSORB EXTEND], NCT01023789; ABSORB II Randomized Controlled Trial [ABSORB II], NCT01425281)

Acute Gain in Minimal Lumen Area&#160;Following Implantation of Everolimus-Eluting ABSORB Biodegradable Vascular Scaffolds or&#160;Xience Metallic Stents: Intravascular Ultrasound Assessment From the ABSORB II Trial

Objectives The study compared, by intravascular ultrasound (IVUS), acute gain (AG) at the site of the pre-procedural minimal lumen area (MLA) achieved by either the Absorb (Abbott Vascular, Santa Clara, California) scaffold or the Xience stent and identified the factors contributing to the acute performance of these devices. Background It is warranted that the acute performance of Absorb matches that of metallic stents; however, concern exists about acute expansion and lumen gain with the use of Absorb. Methods Of a total of 501 patients (546 lesions) in the ABSORB II (ABSORB II Randomized Controlled Trial) randomized trial, 445 patients with 480 lesions were investigated by IVUS pre- and post-procedure. Comparison of MLA pre- and post-procedure was performed at the MLA site by matching pre- and post-procedural IVUS pullbacks. Results Lower AG on IVUS (lowest tertile) occurred more frequently in the Absorb arm than in the Xience arm (3.46\ua0mm 2 vs. 4.27 mm 2 , respectively; p\ua0< 0.001; risk ratio: 3.04; 95% confidence interval: 1.94 to 4.76). The plaque morphology at the MLA cross-section was not independently associated with IVUS acute gain. The main difference in AG in MLD by angiography was observed at the time of device implantation (Xience vs. Absorb, \u394+1.50 mm vs. \u394+1.23 mm, respectively), whereas the gain from post-dilation was similar between the 2 arms (\u394+0.16 mm vs. \u394+0.16 mm) when patients underwent post-dilation, although expected balloon diameter was smaller in the Absorb arm than in the Xience arm (p\ua0= 0.003) during post-dilation. Conclusions At the site of the pre-procedural MLA, the increase of the lumen post-procedure was smaller in the Absorb-arm than in the Xience arm. To achieve equivalent AG to Xience, the implantation of Absorb may require more aggressive strategies at implantation, pre- and post-dilation than the technique used in the ABSORB II trial

Preprocedural planning, procedural guidance and follow-up assessment in percutaneous coronary intervention using multimodality coronary imaging

In 2017, percutaneous coronary intervention (PCI) celebrates the 40th anniversary of the first procedure which was performed back in 1977. There has been considerable progress in this field especially coronary stent technology. Despite the therapeutic successes achieved by DES, there is still a considerable effort to develop the new stent platforms that would offer the better clinical outcomes than the current one. In parallel with the advent of stents, coronary imaging both invasive and non-invasive have also evolved to support the field. The catheter-based imaging modalities available to date examine the coronary artery using either acoustic-based or light-based signals. Each imaging technique has individual strengths in supporting the operator for procedural planning, assessing the stent performance and monitoring the stent safety and efficacy at short- and long-term follow-up. However, the major drawback of the catheter-based imaging technique is its invasive nature. Therefore, multislices coronary computed tomography angiography (CCTA) is an alternative method to evaluate coronary anatomy. The challenge in this field has been to improve the ability of CCTA to provide assessment of coronary anatomy equivalent to the conventional coronary angiography. The aims of this thesis are 1) to demonstrate application of the multimodality imaging for planning and follow-up assessment in PCI from non-invasive coronary imaging to invasive intracoronary imaging; 2) to explore advanced OCT application for evaluating new stent technologies

Difference in hemodynamic microenvironment in vessels scaffolded with Absorb BVS and Mirage BRMS: Insights from a pre-clinical endothelial shear stress study

BACKGROUND: In silico studies have provided robust evidence that stent design affects local hemodynamic forces, which appear as a major determinant of clinical outcomes following stent implantation. However, implications of different stent/scaffold configurations on local hemodynamic forces have not yet been investigated in vivo in a comparative fashion. METHOD AND RESULTS: Eight healthy mini pigs were implanted with six Absorb everolimus-eluting Bioresorbable Vascular Scaffolds (Absorb BVS) and five Mirage sirolimus-eluting Bioresorbable Microfiber Scaffolds (Mirage BRMS). Optical coherence tomography (OCT) was performed and strut protrusion was assessed post scaffold implantation. Following the reconstruction of coronary anatomy blood flow simulation was performed and endothelial shear stress (ESS) was estimated on top of the struts and at luminal surface between the struts in each scaffold. The thicker struts in Absorb (152±140µm) resulted in an increased protruded distance compared to Mirage (117±123 µm) (p=0.003). This had an effect in the local hemodynamic microenvironment. ESS at top-of-the struts were higher in Absorb (1.69±1.20 Pa) than in Mirage (1.53±0.91 Pa), (p<0.001) but lower at inter-strut zones (0.60±0.51Pa vs 0.63±0.50 Pa; p<0.01) compared to Mirage. Both scaffold types revealed comparable percentages of vessel luminal surface exposed to recirculation. CONCLUSION: Absorb demonstrated higher shear stress on top of the struts compared to Mirage. However, in the inter-struts zones shear stress was higher in Mirage than in Absorb. Further research is required to examine potential value of in vivo computational modeling in optimizing scaffold configuration and clinical outcomes

Impact of the Orbital Atherectomy System on a Peripheral Calcified Lesion Quantitative Analysis by Intravascular Echogenicity

Cardiovascular Aspects of Radiolog