Geographic disparity of pathophysiological coronary artery disease characteristics: Insights from ASET trials.

BACKGROUND: The geographical disparity in the pathophysiological pattern of coronary artery disease (CAD) among patients undergoing percutaneous coronary intervention (PCI) is unknown. OBJECTIVES: To elucidate the geographical variance in the pathophysiological characteristics of CAD. METHODS: Physiological indices derived from angiography-based fractional flow reserve pullbacks from patients with chronic coronary syndrome enrolled in the ASET Japan (n = 206) and ASET Brazil (n = 201) studies, which shared the same eligibility criteria, were analysed. The pathophysiological patterns of CAD were characterised using Murray law-based quantitative flow ratio (µQFR)-derived indices acquired from pre-PCI angiograms. The diffuseness of CAD was defined by the µQFR pullback pressure gradient index. RESULTS: Significant functional stenoses pre-PCI (µQFR ≤0.80) were more frequent in ASET Japan compared to ASET Brazil (89.9% vs. 67.5%, p < 0.001), as were rates of a post-PCI µQFR <0.91 (22.1% vs. 12.9%, p = 0.013). In the multivariable analysis, pre-procedural µQFR and diffuse disease were independent factors for predicting a post-PCI µQFR <0.91, which contributed to the different rates of post-PCI µQFR ≥0.91 between the studies. Among vessels with a post-PCI µQFR <0.91, a consistent diffuse pattern of CAD pre- and post-PCI occurred in 78.3% and 76.7% of patients in ASET Japan and Brazil, respectively; only 6.3% (Japan) and 10.0% (Brazil) of vessels had a major residual gradient. Independent risk factors for diffuse disease were diabetes mellitus in ASET Japan, and age and male gender in Brazil. CONCLUSIONS: There was geographic disparity in pre-procedural angiography-based pathophysiological characteristics. The combined pre-procedural physiological assessment of vessel µQFR and diffuseness of CAD may potentially identify patients who will benefit most from PCI.

Preprocedural physiological assessment of coronary disease patterns to predict haemodynamic outcomes post-PCI.

BACKGROUND: Even with intracoronary imaging-guided stent optimisation, suboptimal haemodynamic outcomes post-percutaneous coronary intervention (PCI) can be related to residual lesions in non-stented segments. Preprocedural assessment of pathophysiological coronary artery disease (CAD) patterns could help predict the physiological response to PCI. AIMS: The aim of this study was to assess the relationship between preprocedural pathophysiological haemodynamic patterns and intracoronary imaging findings, as well as their association with physiological outcomes immediately post-PCI. METHODS: Data from 206 patients with chronic coronary syndrome enrolled in the ASET-JAPAN study were analysed. Pathophysiological CAD patterns were characterised using Murray law-based quantitative flow ratio (µQFR)-derived indices acquired from pre-PCI angiograms. The diffuseness of CAD was defined by the pullback pressure gradient (PPG) index. Intracoronary imaging in stented segments after stent optimisation was also analysed. RESULTS: In the multivariable analysis, diffuse disease - defined by the pre-PCI µQFR-PPG index - was an independent factor for predicting a post-PCI µQFR <0.91 (per 0.1 decrease of PPG index, odds ratio 1.57, 95% confidence interval: 1.07-2.34; p=0.022), whereas the stent expansion index (EI) was not associated with a suboptimal post-PCI µQFR. Among vessels with an EI ≥80% and post-PCI µQFR <0.91, 84.0% of those vessels had a diffuse pattern preprocedure. There was no significant difference in EI between vessels with diffuse disease and those with focal disease. The average plaque burden in the stented segment was significantly larger in vessels with a preprocedural diffuse CAD pattern. CONCLUSIONS: A physiological diffuse pattern preprocedure was an independent factor in predicting unfavourable immediate haemodynamic outcomes post-PCI, even after stent optimisation using intracoronary imaging. Preprocedural assessment of CAD patterns could identify patients who are likely to exhibit superior immediate haemodynamic outcomes following PCI.

Prasugrel Monotherapy After Percutaneous Coronary Intervention With Biodegradable-Polymer Platinum-Chromium Everolimus Eluting Stent for Japanese Patients With Chronic Coronary Syndrome (ASET-JAPAN).

BACKGROUND: P2Y12 inhibitor monotherapy without aspirin immediately after percutaneous coronary intervention (PCI) has not been tested in East Asian patients, so in this study we aimed to assess the safety and feasibility of reduced dose (3.75 mg/day) prasugrel monotherapy in Japanese patients presenting with chronic coronary syndrome (CCS).Methods and Results: ASET-JAPAN is a prospective, multicenter, single-arm pilot study that completed enrolment of 206 patients from 12 Japanese centers in September 2022. Patients with native de-novo coronary lesions and a SYNTAX score <23 were treated exclusively with biodegradable-polymer platinum-chromium everolimus-eluting stent(s). Patients were loaded with standard dual antiplatelet therapy (DAPT) and following successful PCI and optimal stent deployment, they received low-dose prasugrel (3.75 mg/day) monotherapy for 3 months. The primary ischemic endpoint was a composite of cardiac death, spontaneous target-vessel myocardial infarction, or definite stent thrombosis. The primary bleeding endpoint was Bleeding Academic Research Consortium (BARC) type 3 or 5. At 3-month follow-up, there were no primary bleeding or ischemic events, or any stent thrombosis. CONCLUSIONS: This pilot study showed the safety and feasibility of prasugrel monotherapy in selected low-risk Japanese patients with CCS. This "aspirin-free" strategy may be a safe alternative to traditional DAPT following PCI.

Reduced-dose prasugrel monotherapy without aspirin after PCI with the SYNERGY stent in East Asian patients presenting with chronic coronary syndromes or non-ST-elevation acute coronary syndromes: rationale and design of the ASET Japan pilot study.

The Acetyl Salicylic Elimination Trial (ASET) Japan pilot study is a multicentre, single-arm, open-label, proof-of-concept study with a stopping rule based on the occurrence of definite stent thrombosis. This study aims to demonstrate the feasibility and safety of low-dose prasugrel monotherapy following percutaneous coronary intervention (PCI) in Japanese patients presenting with chronic coronary syndromes (CCS) or non-ST-elevation acute coronary syndromes (NSTE-ACS). Four hundred patients with a SYNTAX score <23 requiring PCI due to CCS or NSTE-ACS will be screened and considered eligible for the study. The enrolment is planned in two phases: 1) 200 patients presenting with CCS, followed by 2) 200 patients presenting with NSTE-ACS. After optimal PCI with implantation of a SYNERGY (Boston Scientific) stent, patients will be enrolled and loaded with prasugrel 20 mg, followed by a maintenance dose of prasugrel 3.75 mg once daily without aspirin continued for 3 months in Phase 1 (CCS patients), and for 12 months in Phase 2 (NSTE-ACS patients). After these follow-up periods, prasugrel will be replaced by standard antiplatelet therapy according to local practice. The primary endpoint is a composite of cardiac death, target vessel myocardial infarction, or definite stent thrombosis after the index procedure. The primary bleeding endpoint is any Bleeding Academic Research Consortium type 3 or 5 bleeding occurring within 3 months of the index PCI for CCS patients, or 12 months for NSTE-ACS patients. The ASET Japan study is designed to demonstrate the feasibility and safety of reduced-dose prasugrel monotherapy after PCI in East Asian patients with acute and chronic coronary syndromes.

Angioscopic Comparison of Early- and Mid-Term Vascular Responses Following Treatment of ST-Elevation Acute Myocardial Infarction With Biodegradable vs. Durable Polymer Everolimus-Eluting Stents　- A Prespecified Subanalysis of the MECHANISM AMI RCT.

BACKGROUND: The vessel healing process after implantation of biodegradable polymer (BP) and durable polymer (DP) everolimus-eluting stent (EES) in ST-elevation myocardial infarction (STEMI) lesions remains unclear.Methods and Results: We conducted a multicenter prospective randomized controlled trial to compare early (2 weeks) and mid-term (12 months) vascular responses after implantation of BP-EES vs. DP-EES in STEMI patients. In this prespecified subanalysis, serial coronary angioscopy (CAS) analysis was performed in 15 stents in the BP-EES arm (n=10 patients) and 14 stents in the DP-EES arm (n=10 patients). At the 2-week follow-up, there was no significant difference in the estimated marginal means of the neointimal coverage grade (primary endpoint) between the 2 arms (mean [±SE] 0.00±0.00 in both arms; P>0.999). There were no significant differences between the BP-EES and DP-EES groups in the yellow color grade (1.046±0.106 vs. 0.844±0.114, respectively; P=0.201) or the presence of thrombus (77.8% vs. 88.8%, respectively; P=0.205). At 12 months, competent strut coverage, defined as yellow color grade ≤1, no thrombus, and a neointimal coverage grade ≥1 was achieved more frequently in the BP-EES than DP-EES arm (85.2% vs. 53.1%; adjusted odds ratio 2.11 [95% confidence interval 1.26-3.53]; P=0.023). CONCLUSIONS: Neointimal coverage 2 weeks after implantation of BP-EES and DP-EES in STEMI lesions was comparable on CAS evaluation. However, at 1 year, BP-EES was independently associated with competent strut coverage.

Communicating Coronary and Ventricular Pseudoaneurysms Complicating Coronary Artery Perforation.

We present the case of a 75-year-old man who experienced rebleeding after surgical treatment of grade III coronary perforation, resulting in intertwined complications including communicating coronary and ventricular pseudoaneurysms. The percutaneous intervention of sealing the rebleeding site with a covered stent implantation managed this rare pseudoaneurysm successfully. (Level of Difficulty: Advanced.).

Online three-dimensional OFDI-guided versus angiography-guided PCI in bifurcation lesions: design and rationale of the randomised OPTIMUM trial.

AIMS: The feasibility of offline optical coherence tomography (OCT) guidance in bifurcation (with either two-dimensional or three-dimensional images) and its potential benefits have been demonstrated in retrospective studies; however, these have not yet been investigated prospectively. The aim of this trial is to determine the superiority of online three-dimensional optical frequency domain imaging (3D-OFDI)-guided stenting to angiography-guided percutaneous coronary intervention (PCI) in terms of incomplete stent apposition (ISA) at the bifurcation segment. METHODS AND RESULTS: The OPTIMUM trial is a randomised, superiority, multicentre clinical trial. The primary endpoint of this trial is the post-procedural percentage of malapposed struts assessed by OFDI in the main branch bifurcation region after final kissing balloon dilatation (FKBD). A total of 106 patients will be randomly allocated to either 3D-OFDI guidance or angiography guidance PCI. Bifurcation lesions will be treated with a provisional single-stent strategy using the Ultimaster sirolimus-eluting stent. Patients randomised to the 3D-OFDI guidance arm will undergo OFDI assessment in the main branch (MV) after rewiring into the jailed side branch following stent implantation, while in the angiography guidance arm re-crossing of a wire into the side branch will be performed using conventional fluoroscopic/angiographic guidance. In patients in the 3D-OFDI guidance arm, if the position of the wire is not located in the optimal cell, further attempts to redirect the wire to the optimal cell will be performed, with subsequent OFDI acquisitions to confirm the re-crossing position. The proximal optimisation technique and FKBD are mandatory in this trial. The study will provide a 90% power to show superiority of 3D-OFDI guidance PCI compared with angiography-guided PCI. CONCLUSIONS: The OPTIMUM trial will be the first prospective, randomised trial to evaluate the efficacy and safety of online 3D-OFDI-guided PCI in bifurcation lesions. ClinicalTrials.gov Identifier: NCT02972489.

A Randomized Trial Evaluating Online 3-Dimensional Optical Frequency Domain Imaging-Guided Percutaneous Coronary Intervention in Bifurcation Lesions.

BACKGROUND: Clinical implications of online 3-dimensional optical frequency domain imaging (3D-OFDI)-guided stenting for bifurcation lesions have not been investigated in the randomized controlled trials. The purpose of this study was to determine whether online 3D-OFDI-guided stenting is superior to angiography-guided percutaneous coronary intervention (PCI) in terms of incomplete stent apposition at the bifurcation segment. METHODS: The OPTIMUM trial (Online 3-Dimensional Optical Frequency Domain Imaging to Optimize Bifurcation Stenting Using UltiMaster Stent) was a randomized, multicenter clinical trial. Eligible patients had an angiographically significant stenosis in the bifurcation lesion treated with a provisional single stent strategy using the Ultimaster sirolimus eluting stent. Patients were randomly allocated to either online 3D-OFDI-guided or angiography-guided PCI. Patients randomized to 3D-OFDI guidance underwent online 3D-OFDI assessment after rewiring into the jailed side branch after stenting and proximal optimization technique, while in the angiography guidance arm, rewiring was performed using conventional fluoroscopic/angiographic guidance. The primary end point of this trial was the postprocedural average percentage of malapposed struts per lesion assessed by OFDI in the confluence zone of the main and side branches. RESULTS: Between June 8, 2017 and September 26, 2018, 110 patients with 111 bifurcation lesions were randomized at 4 Japanese centers. Of these, 56 patients with 57 lesions were treated with 3D-OFDI-guided PCI, whereas 54 patients with 54 lesions were treated with angiography-guided PCI. In the 3D-OFDI guidance arm, the feasibility of online 3D-OFDI was 98.2%. The average percentage of incomplete stent apposition per lesion at bifurcation was lower in the 3D-OFDI guidance arm than that in the angiography guidance arm (19.5±15.8% versus 27.5±14.2%, P=0.008). The superiority of the 3D-OFDI guidance arm was also confirmed in the strut level analysis (odds ratio: 0.54 [95% CI, 0.36-0.81]; P=0.003). CONCLUSIONS: Online 3D-OFDI-guided bifurcation PCI was superior to angiography-guided bifurcation PCI in terms of acute incomplete stent apposition at bifurcation. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02972489.

Five-year clinical efficacy and safety of contemporary thin-strut biodegradable polymer versus durable polymer drug-eluting stents: a systematic review and meta-analysis of 9 randomized controlled trials.

Very long-term data of the biodegradable polymer drug-eluting stents (BP-DES) in comparison with the contemporary durable polymer DES (DP-DES) are still to be investigated. We aimed to investigate the very long-term clinical performance of contemporary BP-DES against the DP-DES. We performed a systematic review to evaluate very long-term clinical outcomes of BP-DES versus DP-DES. Inclusion criteria were randomized design comparing BP-DES against DP-DES and follow-up duration ≥ 36 months. MEDLINE, EMBASE, and CENTRAL without restricting language or publication status were searched up to December 2018. The primary efficacy and safety endpoints were target lesion failure (TLF; a composite of cardiac death, target vessel myocardial infarction and ischemia-driven target lesion revascularization) and definite/probable stent thrombosis (ST), respectively. Primary analysis was done for the contemporary thin-strut BP- and DP-DES (strut thickness < 100 µm). A total of 9 trials comprising 10,699 patients (BP-DES, n = 6241 versus DP-DES, n = 4458) were analyzed. The mean follow-up duration was 63 months. No significant difference was found in TLF [Odds ratio (95% CI) 1.04 (0.89-1.21)] and definite/probable ST (odds ratio (95% CI) 0.78 (0.59-1.01)] between the BP- and DP-DESs. The present meta-analysis suggested that the contemporary thin-strut BP- and DP-DES have similar efficacy and safety profile at 5-year follow-up.Clinical trial registration PROSPERO; CRD42018101983 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=101983.

Neointimal characteristics comparison between biodegradable-polymer and durable-polymer drug-eluting stents: 3-month follow-up optical coherence tomography light property analysis from the RESTORE registry.

We aimed to quantitatively assess a possible difference of the neointimal quality between biodegradable polymer- (BP-) and durable polymer drug-eluting stents (DP-DESs). We conducted a single-center all-comer prospective cohort study: the RESTORE registry (UMIN000033009). All patients who received successful OCT examination at planned 3-month follow-up after DES implantation were analyzed. Study population was divided into 2 groups, BP-DES versus DP-DES groups. We evaluated standard OCT variables, coverage percent, and the quantitative light property values including light intensity, attenuation, and backscatter. We performed OCT analyses of 121 lesions in 98 patients (BP-DES 55 lesions in 51 patients vs. DP-DES 66 lesions in DP-DES 53 patients). Lesion and procedural characteristics were overall well-balanced between both groups. At 3-month follow-up, neointimal thickness (BP-DES 49.3 [38.2, 57.7] µm versus DP-DES 54.7 [45.1, 70.7] µm, p = 0.059) and coverage percent (BP-DES 94.5 [89.8, 97.0]% vs. DP-DES 95.8 [91.1, 98.1]%, p = 0.083) did not significantly differ. Light intensity of superficial neointima in the BP-DES was lower than that in the DP-DES, whereas that of deep neointima did not differ between both groups. Both superficial and deep neointima of the BP-DES presented significantly lower light attenuation and backscatter than those of the DP-DES did. Almost complete coverage at 3 months in both contemporary BP- and DP-DES would support the ultra-short DAPT strategy in the upcoming decade. Nevertheless, there was a significant difference in the neointimal characteristics on OCT light property 3 months after BP- versus DP-DES implantation.Trial Registration UMIN000033009.

Early vessel healing after implantation of biodegradable-polymer and durable-polymer drug-eluting stent: 3-month angioscopic evaluation of the RESTORE registry.

The purpose of this study was to evaluate the vessel healing status 3 months after stent implantation of bioresorbable-polymer drug-eluting stents (BP-DESs) in comparison with durable-polymer DESs (DP-DESs) by angioscopy. Study design was a single-center all-comer prospective cohort study: the RESTORE registry (UMIN000033009). All patients who received successful angioscopic examination at planned 3-month follow-up after the DES implantation in the native coronary artery were enrolled. We evaluated main, maximum, minimum strut coverage grades and coverage heterogeneity score defined as a difference between maximum and minimum coverage grades. All lesions were divided into three segments: proximal, mid, and distal segments. A total of 108 patients (66.6 ± 10 years) with 124 lesions were analyzed (BP-DES 57 patients 61 lesions 226 segments vs. DP-DES 57 patients 63 lesions 203 segments; six patients had both BP-DES and DP-DES). Patient and lesion demographics, procedural characteristics were well balanced. Main coverage grade (mean ± standard error; 1.08 ± 0.02 vs. 1.05 ± 0.03, p = 0.354) and minimum coverage grade (1.00 ± 0.00 vs. 1.00 ± 0.00, p > 0.999) were not significantly different between BP-DES and DP-DES groups. Maximum coverage grade was significantly higher in the BP-DES than in the DP-DES (1.45 ± 0.04 vs. 1.35 ± 0.04, p = 0.049). Coverage heterogeneity score did not differ between BP-DES and DP-DES groups (1.05 ± 0.07 vs. 0.90 ± 0.07, p = 0.162). At 3-month follow-up, the current BP-DES had higher maximum stent coverage than the contemporary DP-DES, while main and minimum coverage grades and heterogeneity of the neointimal coverage were comparable. Further prospective randomized trials should be conducted to evaluate the clinical significance of the present imaging results.

Impact of the one-year angioscopic findings on long-term clinical events in 504 patients treated with first-generation or second-generation drug-eluting stents: the DESNOTE-X study.

AIMS: We aimed to test the hypothesis that the presence of in-stent yellow plaque (YP) assessed by angioscopy would be a risk of very late stent failure (VLSF) of the cobalt-chromium everolimus-eluting stent (CoCr-EES) in comparison with first-generation drug-eluting stents (DES). METHODS AND RESULTS: DESNOTE-X was a prospective cohort study, an extended study of the DESNOTE study (UMIN000013515). All patients who received successful angioscopic examination at planned one-year follow-up of DES were clinically followed. The primary endpoint was VLSF defined as a composite of cardiac death, target vessel myocardial infarction, and target lesion revascularisation. A total of 504 patients with 549 lesions were enrolled over a period of 12.5 years. At one-year follow-up, the incidence of YP was significantly higher in the first-generation DES than in the CoCr-EES (199/292 [68%] vs 80/257 [31%], p<0.001). Maximum yellow colour grade on coronary angioscopy at one-year follow-up was an independent predictor of future VLSF in the first-generation DES (HR 2.604 [95% CI: 1.265-5.361], p=0.009), whereas it was not in the CoCr-EES (p for interaction 0.022). CONCLUSIONS: The incidence of in-stent atherosclerosis identified as YP on angioscopy was lower and its impact on late clinical events appeared smaller in the CoCr-EES than in the first-generation DES.

Histogram-based standardization of intravascular optical coherence tomography images acquired from different imaging systems.

PURPOSE: Intravascular optical coherence tomography (OCT) is widely used for analysis of the coronary artery disease. Its high spatial resolution allows for visualization of arterial tissue components in detail. There are different OCT systems on the market, each of which produces data characterized by its own intensity range and distribution. These differences should be taken into account for the development of image processing algorithms. In order to overcome this difference in the intensity range and distribution, we developed a framework for matching intensities based on the exact histogram matching technique. METHODS: In our method, the key step for using the exact histogram matching is to determine the target histogram. For this, we proposed two schemes: a global scheme that uses a single histogram as the target histogram for all the pullbacks, and a local scheme that selects for each single image a target histogram from a predefined database. These two schemes are compared on a unique dataset containing pairs of pullbacks that were acquired shortly after each other with systems from two vendors, St. Jude and Terumo. Pullbacks were aligned according to anatomical landmarks, and a database of matched histogram pairs was created. A leave-one-out cross validation was used to compare performance of the two schemes. The matching accuracy was evaluated by comparing: (a) histograms using Euclidean (dx2 ) and Kolmogorov-Smirnov (dKS ) distances, and (b) median intensity level within anatomical regions of interest. RESULTS: Leave-one-out validation indicated that both matching schemes yield comparably high accuracies across the entire validation dataset. The local scheme outperforms the global scheme with marginally lower dissimilarities at both histogram level and intensity level. High visual similarity was observed when comparing the matched images to their aligned counterparts. CONCLUSION: Both local and global schemes are robust and produce accurate intensity matching. While local scheme performs marginally better than the global scheme, it requires a predefined histogram dataset and is more time consuming. Thus, for offline standardization of the images, the local scheme should be preferred for being more accurate. For online standardization or when another system is involved, the global scheme can be used as a simple and nearly-as-accurate alternative.

Imaging assessment of bioresorbable vascular scaffolds.

Vascular reparative therapy has become a reality with bioresorbable scaffolds (BRSs). To assess acute and long-term performance of the device, multimodality imaging would be essential. Radiopacity of metal hinders the imaging assessment, whereas radiolucent polymeric scaffolds allow for a precise imaging assessment with either invasive or non-invasive modality at baseline and at follow-up, which is one of the advantages of polymeric BRSs. Recent large trials evaluating clinical results of the first-generation BRS technology raised concerns about the safety and efficacy of these devices, namely, scaffold thrombosis. Intensive research with multimodality imaging in the field is being conducted to have in-depth understanding of the issues, which will facilitate the improvement of implantation techniques and the development of the next-generation BRSs. The current review focuses on the clinical application of the imaging modalities to assess the short- and long-term performance of the Absorb BVS.

Serial volumetric assessment of coronary fibroatheroma by optical frequency domain imaging: insights from the TROFI trial.

Aims: Coronary lesions precursors of acute events remain elusive, since they undergo continuous changes and their temporal changes are not very well-characterized. In natural history studies, optical frequency domain imaging (OFDI) has been used only to assess fibroatheromas as a 2D structure and sometimes in a single frame fashion. We aim at describing the serial volumetric modifications of the fibrous cap (FC) of the fibroatheromas as determined by OFDI over a 6-month follow-up period. Methods and results: In 49 patients, OFDI investigation was performed following treatment of culprit lesion and at 6-month follow-up in patients with ST-segment elevation myocardial infarction (STEMI). A fully automatic volumetric quantification of FC was done in all lipid-containing frames of non-culprit lesions in the infarct related artery. These lesions were matched at baseline and 6-month follow-up. A total of 58 non-culprit lipid rich lesions (34 TCFAs and 24 thick-cap fibroatheroma [ThCFA]) were found in 34 patients at baseline. Overall, there was a FC volume decrease of 1.57 (Inter-quartile Range [IQR] -4.13 to 0.54) mm3 at 6-months. 27% of the lesions changed their phenotype over time (TCFA or ThCFA). TCFAs that became ThCFAs at follow-up had smaller mean and maximal FC as compared with lesions that remained TCFAs (P = 0.01 for both). Conclusions: Non-culprit fibroatheromas located in the infarct related artery of patients with STEMI had a volumetric reduction of the FC after 6-month follow-up. Quantitative FC assessment was able to differentiate high-risk lesions that became ThCFAs. There was a considerable change of plaque phenotype (TCFAs or ThCFAs) over time.

Serial 5-Year Evaluation of Side Branches Jailed by Bioresorbable Vascular Scaffolds Using 3-Dimensional Optical Coherence Tomography: Insights From the ABSORB Cohort B Trial (A Clinical Evaluation of the Bioabsorbable Everolimus Eluting Coronary Stent System in the Treatment of Patients With De Novo Native Coronary Artery Lesions).

BACKGROUND: The long-term fate of Absorb bioresorbable vascular scaffold (Abbott Vascular, Santa Clara, CA) struts jailing side branch ostia has not been clarified. We therefore evaluate serially (post-procedure and at 6 months, 1, 2, 3, and 5 years) the appearance and fate of jailed Absorb bioresorbable vascular scaffold struts. METHODS AND RESULTS: We performed 3-dimensional optical coherence tomographic analysis of the ABSORB Cohort B trial (A Clinical Evaluation of the Bioabsorbable Everolimus Eluting Coronary Stent System in the Treatment of Patients With De Novo Native Coronary Artery Lesions) up to 5 years using a novel, validated cut-plane analysis method. We included 29 patients with a total of 85 side branch ostia. From the 12 ostia which could be assessed in true serial fashion, 7 showed a pattern of initial decrease in the ostial area free from struts, followed by an increase in strut-free ostial area toward the end of the 5 years of follow-up. In a repeated-measures analysis with time as fixed variable and ostial area free from struts as dependent variable, we showed a numeric decrease in the estimated ostial area free from struts from 0.75 mm2 (baseline) to 0.68 mm2 (first follow-up visit at 6 months or 1 year) and 0.63 mm2 (second follow-up visit at 2 or 3 years). However, from the second visit to the 5-year follow-up visit, there was a statistically significant increase from 0.63 to 0.89 mm2 (P=0.001). Struts overlying an ostium divided the ostium into compartments, and the number of these compartments decreased over time. CONCLUSIONS: This study showed that in most cases, the side branch ostial area free from struts initially decreased. However, with full scaffold bioresorption, the ostial area free from scaffold increased between 2 to 3 years and 5 years in the vast majority of patients. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00856856.