Optical coherence tomography assessment of the acute effects of stent implantation on the vessel wall: a systematic quantitative approach

Intravascular imaging for left main stem assessment: An update on the most recent clinical data

Left main (LM) stem has different structural and anatomical characteristics compared to all of the other segments of the coronary tree, thus its management through percutaneous coronary intervention (PCI) is a challenge and is associated with worse clinical outcome and higher need for revascularization as compared to other lesion settings. Intravascular imaging, by means of intravascular ultrasound (IVUS) or optical coherence tomography (OCT), is an important tool for LM PCI guidance, aiming at improving the immediate performance and the long term outcome of this procedure. Following current guidelines and recent scientific findings, IVUS becomes important to firstly assess, and finally evaluate the result of LM stenting, according to the experience and preferences of the operator. The role of OCT still remains to be defined, but recent data is shedding light also on this imaging technique. The aim of this review is to highlight the latest scientific advancements regarding intravascular imaging in LM coronary artery disease.

Vascular Injury After Stenting - Insights of Systemic Mechanisms of Vascular Repair

BACKGROUND

The role of circulating progenitor cells (CPC) in vascular repair following everolimus-eluting stent (EES) implantation is largely unknown. The aim of the study was to investigate the relationship between temporal variation in CPC levels following EES implantation and the degree of peri-procedural vascular damage, and stent healing, as measured by optical coherence tomography (OCT).Methods and Results:CPC populations (CD133+/KDR+/CD45low) included patients with stable coronary artery disease undergoing stent implantation, and were evaluated using a flow cytometry technique both at baseline and at 1 week. OCT evaluation was performed immediately post-implantation to quantify the stent-related injury and at a 9-month follow up to assess the mid-term vascular response. Twenty patients (mean age 66±9 years; 80% male) with EES-treated stenoses (n=24) were included in this study. Vascular injury score was associated with the 1-week increase of CD133+/KDR+/CD45low (β 0.28 [95% CI 0.15; 0.41]; P<0.001) and with maximum neointimal thickness at a 9-month follow up (β 0.008 [95% CI 0.0004; 0.002]; P=0.04). Inverse relationships between numbers of uncoated and apposed struts for the 9-month and the 1-week delta values of CD133+/KDR+/CD45low (β -12.53 [95% CI -22.17; -2.90]; P=0.011), were also found.

CONCLUSIONS

The extent of vessel wall injury influences early changes in the levels of CPC and had an effect on mid-term vascular healing after EES implantation. Early CPC mobilisation was associated with mid-term strut coverage.

Post-stenting angiographically silent coronary dissection: OCT comes to the rescue

Stent edge dissection is one of the procedural complications concerning percutaneous coronary intervention (PCI). We present a clinical case of multi-vessel PCI where the patient had to return with recurring symptoms within two weeks of a seemingly successful PCI, only to teach us a valuable lesson in the more frequent and judicious use of intracoronary imaging.

Post-Stent Optical Coherence Tomography Findings at Index Percutaneous Coronary Intervention - Characteristics Related to Subsequent Stent Thrombosis

BACKGROUND

The association between unfavorable post-stent optical coherence tomography (OCT) findings and subsequent stent thrombosis (ST) remains unclear. This study investigated the ST-related characteristics of post-stent OCT findings at index percutaneous coronary intervention (PCI).Methods and Results:Fifteen patients with ST onset after OCT-guided PCI (ST group) were retrospectively enrolled. Post-stent OCT findings in the ST group were compared with those in 70 consecutive patients (reference group) without acute coronary syndrome onset for at least 5 years after OCT-guided PCI. The incidence of acute myocardial infarction (AMI) was higher in the ST than reference group (60.0% vs. 17.1%, respectively; P=0.0005). The incidence of incomplete stent apposition (93.3% vs. 55.7%; P=0.0064), irregular protrusion (IP; 93.3% vs. 62.8%; P=0.0214), and thrombus (93.3% vs. 51.4%; P=0.0028) was significantly higher in the ST than reference group. The maximum median (interquartile range) IP arc was significantly larger in the ST than reference group (265° [217°-360°] vs. 128° [81.4°-212°], respectively; P<0.0001). In AMI patients, the incidence of a maximum IP arc >180° was significantly higher in the ST than reference group (100% vs. 58.3%, respectively; P=0.0265).

CONCLUSIONS

IP with a large arc was a significant feature on post-stent OCT in patients with ST.

Early Vascular Healing Following Bioresorbable-Polymer Sirolimus-Eluting Stent Placement Compared to That with Durable-Polymer Everolimus-Eluting Stent

A recent thinner strut drug-eluting stent might facilitate early strut coverage after its placement. We aimed to investigate early vascular healing responses after the placement of an ultrathin-strut bioresorbable-polymer sirolimus-eluting stent (BP-SES) compared to those with a durable-polymer everolimus-eluting stent (DP-EES) using optical coherence tomography (OCT) imaging.This study included 40 patients with chronic coronary syndrome (CCS) who underwent OCT-guided percutaneous coronary intervention (PCI). Twenty patients each received either BP-SES or DP-EES implantation. OCT was performed immediately after stent placement (baseline) and at 1-month follow-up.At one month, the percentage of uncovered struts reduced significantly in both the BP-SES (80.9 ± 10.3% to 2.9 ± 1.7%; P < 0.001) and DP-EES (81.9 ± 13.0% to 5.7 ± 1.8%; P < 0.001) groups, and the percentage was lower in the BP-SES group than in the DP-EES group (P < 0.001). In the BP-SES group, the percentage of malapposed struts also decreased significantly at 1 month (4.9 ± 3.7% to 2.6 ± 3.0%; P = 0.025), which was comparable to that of the DP-EES group (2.5 ± 2.2%; P = 0.860). The optimal cut-off value of the distance between the strut and vessel surface immediately after the placement to predict resolved malapposed struts was ≤ 160 μm for BP-SES and ≤ 190 μm for DP-EES.Compared to DP-EES, ultrathin-strut BP-SES demonstrated favorable vascular responses at one month, with a lower rate of uncovered struts and a comparable rate of malapposed struts.

Efficacy of optical frequency domain imaging in detecting peripheral artery disease: the result of a multi-center, open-label, single-arm study

Optical frequency domain imaging (OFDI) is a high-resolution intracoronary imaging modality with fast automated longitudinal pullback. We aimed to evaluate the ability of performing OFDI from the superficial femoral artery (SFA) to the below-knee (BK) artery. This clinical trial was a multi-center, single-arm, open-label study. The primary endpoint was to obtain a clear image of the intra-vascular lumen from the SFA to the BK artery, specifically  > 270° visualization of the blood vessel lumen with  > 16/21 cross sections. The proportion of the clear image (≥ 85%) was regarded as confirmatory of the ability of OFDI to visualize the vessel lumen. Overall, 20 patients were enrolled. The proportion of the primary endpoint was 90% (18/20), and the pre-specified criterion was successfully attained. The proportion of the clear image assessed by the operator was 100% (20/20), and an additional statistical analysis for the proportion of the visualization,  > 270°, of the blood vessel lumen revealed a significantly higher cut-off value than that for the pre-specified criterion, 85% (p = 0.0315). There were three adverse events not related to OFDI. OFDI achieved acceptable visualization of the vessel lumen without any adverse event related to it. After regulatory approval based on the present study, OFDI will be available as a new option of endovascular imaging for peripheral artery diseases in daily practiceTrial registration: This study was registered in the Japanese Registry of Clinical Trials (jRCT 2052190025, https://jrct.niph.go.jp/latest-detail/jRCT2052190025 ).

Vascular Response Occurring at 3 Months After Everolimus-Eluting Cobalt-Chromium Stent Implantation in Patients With ST-Segment Elevation Myocardial Infarction vs. Stable Coronary Artery Disease

BACKGROUND

Second-generation drug-eluting stents (DES) reduce the incidence of stent thrombosis, even in patients with ST-segment elevated myocardial infarction (STEMI). However, the early local vascular healing after DES implantation in STEMI lesions, which mainly concerns stent thrombosis, is still unclear.Methods and Results:We attempted to determine early local vascular healing 3 months after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation in STEMI lesions relative to stable coronary artery disease (CAD) lesions. This prospective, multicenter study analyzed 96 total lesions (STEMI=49, stable CAD=51) by frequency domain-optical coherence tomography (FD-OCT) performed post-procedure and at the 3-month follow-up. Although CoCr-EES implanted in STEMI were almost entirely covered at 3 months, they had a relatively high incidence of uncovered struts compared with stable CAD (5.5% vs. 1.6%, P<0.001). Intrastent thrombus in the 2 groups was primarily resolved at the 3-month follow-up (STEMI: 91.7%→26.5%, stable CAD: 74.5%→11.8%). Regarding irregular protrusion, complete resolution was observed in stable CAD (21.6%→0%), while a few stents remained in STEMI (79.2%→8.2%). Although there were almost no changes for the serial change of average lumen area in STEMI, there were slight but significant decreases in stable CAD [STEMI 0.08 (-0.44, 0.55) mm², stable CAD -0.35 (-0.55, 0.11) mm²; P=0.009].

CONCLUSIONS

Although strut coverage after CoCr-EES implantation for STEMI lesions was slightly delayed, the healing process appeared to be acceptable in both STEMI and stable CAD.

Clinical impact of angiographically insignificant suboptimal poststent findings detected by optical coherence tomography after drug-eluting stent implantation

Background

Although optical coherence tomography (OCT)-detected suboptimal findings (SF-OCT) such as malapposition, edge dissection, tissue protrusion, thrombus and small minimal stent area (MSA) are frequently observed after the implantation of drug-eluting stents (DES), their clinical implications are controversial.

Hypothesis

Clinical outcomes may differ between patients with SF-OCTs and without SF-OCTs after DES implantation.

Methods

A total of 576 patients undergoing OCT analysis after DES implantation were divided into SF-OCT group (n = 379, 379 lesions) and No SF-OCT group (n = 197, 197 lesions). The study population had no significant abnormal finding in final angiography. Quantification was performed for each SF-OCT. The incidences of major adverse cardiovascular events (MACE: all-cause death, non-fatal myocardial infarction, target vessel revascularization, and stent thrombosis) were compared between the two groups. A median follow-up duration was 21.5 months.

Results

Among 379 patients with SF-OCT, 32.4% had multiple SF-OCTs. Malapposition (32.1%, IQR of maximal depth 315–580 μm) was the most frequent, followed by small MSA (31.6%), edge dissection (12.5%, IQR of maximal flap of opening 0.27–0.52 mm), thrombus (7.6%, IQR of diameter 1.31–1.97mm) and tissue protrusion (6.8%, IQR of diameter 1.05–1.67 mm). The SF-OCT group showed smaller stent diameter and longer stent length, and lower in-stent lumen expansion rate. The incidence of MACE did not differ between the two groups (3.0% for No SF-OCT vs. 5.0% for SF-OCT; HR 1.601; 95% CI 0.639 to 4.011; P = 0.310).

Conclusions

The presence of angiographically insignificant SF-OCTs were not associated with clinical outcomes in this study.

Open-Label Multicenter Registry on the Outcomes of In-Stent Restenosis Treated by Balloon Angioplasty with Optical Frequency Domain Imaging in the Superficial Femoral Artery (ISLAND-SFA Study)

Objectives: Balloon angioplasty for in-stent restenosis (ISR) in the superficial femoral artery (SFA) has a high recurrent restenosis rate; however, its mechanism has not been fully and precisely evaluated using high-resolution intravascular imaging. Thus, we aimed to evaluate the relationship between vascular features obtained by optical frequency domain imaging (OFDI) and recurrent restenosis at 6 months. Methods: This was a prospective multicenter single-arm study. OFDI was performed before and after balloon angioplasty, and vascular features were assessed. A multi-layered ISR pattern detected by OFDI was defined as several signal-poor appearances with a high-signal band adjacent to the luminal surface. The primary outcome was defined as recurrent restenosis 6 months after balloon angioplasty. Results: Given that this study was terminated early, only 18 patients completed the 6-month follow-up; of these, 8 developed restenosis. Recurrent restenosis at 6 months tended to be related to a multi-layered ISR pattern (odds ratio (OR), 6.67; 95% confidence interval (CI), 0.81-54.96; p=0.078) and the minimum lumen area (MLA) after balloon angioplasty (OR, 0.71; 95%CI, 0.48-1.04; p=0.077). Conclusion: A multi-layered ISR pattern and MLA after balloon angioplasty detected by OFDI might be risk factors for recurrent ISR in the SFA.

Stent strut thickness and acute vessel injury during percutaneous coronary interventions: an optical coherence tomography randomized clinical trial

AIMS

Compare the degree of acute vascular injury caused by a polymer-free, thin-strut drug-eluting stent (DES) to that caused by a bioresorbable polymer, thick-strut DES using optical coherence tomography (OCT).

METHODS AND RESULTS

Fifty patients requiring nonurgent PCI were randomized to receive either a thin or a thick-strut DES. OCT was performed before and after stent implantation. OCT-based injury score (IS) after implantation was numerically higher within thick-strut stents 0.32 vs. 0.23, but the difference was NS (P = 0.61). Edge dissections were present in 36% of the patients without differences between groups. Tissue prolapse (TP) area was larger with thin-strut stents (2.26 vs. 1.83 mm2, P = 0.04). Stent expansion and symmetry index were similar between the two platforms (85% vs. 94%, P = 0.08; and 0.82 vs. 0.80, P = 0.25). No differences were observed in total malapposition area (1.85 mm2 in thin-strut stents vs. 1.47 mm2, P = 0.48). Regarding the influence of plaque-type, IS tended to be higher (non-significant) with thick strut DES in fibrocalcific plaques. Stent malapposition area was smaller in fibrous plaques, especially with thin strut stents (P = 0.03).

CONCLUSION

There was no difference in the extent of OCT-based vessel injury associated with thin and thick-strut DES platforms. TP was larger with the thin strut DES, potentially reflecting a deeper stent embedment in the vessel wall.

Open-label multicenter registry on the outcomes of peripheral arterial disease treated by balloon angioplasty with optical frequency domain imaging in superficial femoral artery and popliteal artery (OCEAN-SFA study)

Although balloon angioplasty for femoropopliteal artery lesions has been associated with restenosis rates of up to 60% at 12 months, the mechanism of restenosis has not been fully evaluated. The aim of this study was to evaluate the relationship between the vascular features observed on optical frequency domain imaging (OFDI) before and after balloon angioplasty of femoropopliteal artery lesions, and restenosis at 6 months. This study was a prospective multicenter single arm study. OFDI was performed before and after balloon angioplasty and plaque characteristics and vascular features, along with de novo lesions, were assessed. The primary outcome was the presence or absence of restenosis 6 months after balloon angioplasty. Residual platelet reactivity was assessed according to VerifyNow platelet reactivity units (PRUs). The number of patients completing 6 months of follow-up was 47, of which 14 had developed restenosis. Maximum thickness of the dissection flap (odds ratio (OR) 2.71; 95% confidence interval [0.9-8.0]; p = 0.071) and lesion length were identified as risk factors for restenosis (OR 1.015; 95% confidence interval [0.001-0.029]; p = 0.039). The mean PRU at the time of treatment in patients with restenosis was significantly higher than in those without restenosis (286.3 ± 82.6 vs. 208.5 ± 03.6, p = 0.026). Long lesions and major dissection on OFDI after balloon angioplasty for femoropopliteal artery lesions increase restenosis at 6 months. In addition, high residual platelet reactivity at the time of EVT may also be a risk factor for restenosis.Clinical Trial Registration Number UMIN000021120.

Insulin-like growth factor-1 levels predict myocardial injury and infarction after elective percutaneous coronary intervention: an optical coherence tomography study

INTRODUCTION

Periprocedural myocardial necrosis, which can range from a low level elevation of cardiac biomarkers to a large myocardial infarction (MI), is a common complication after percutaneous coronary intervention (PCI).

AIM

We hypothesized that insulin-like growth factor-1 (IGF-1) levels may play a protective role in myocardial injury after coronary stent placement and aimed to investigate the relationship between IGF-1 levels and plaque characteristics assessed by optical coherence tomography (OCT).

MATERIAL AND METHODS

Between May 2015 and December 2015 we prospectively enrolled 74 patients with stable angina pectoris in whom single de novo coronary artery stenosis was present. PCI was performed according to standard methods. OCT was applied to all patients. TnT was analyzed at admission, before PCI and at 6, 12, 24 and 48 h after PCI. Serum IGF-1 was measured prior to PCI.

RESULTS

A total of 25 (33.7%) patients had periprocedural myocardial injury or type 4a myocardial infarction, and 49 (66.2%) patients had no events. IGF-1 level and reference intimal thickness, medial thickness, and plaque fibrous cap thickness in OCT had strong correlations (r = 0.88, 0.80 and 0.88 respectively, p < 0.001). IGF-1 was an independent predictor of periprocedural myocardial injury or type 4a MI in univariate (OR = 0.929, 95% CI: 0.895-0.964, p < 0.001) and multivariate regression analysis (OR = 0.757, 95% CI: 0.575-0.998, p = 0.04). Based on ROC analysis, the best cut-off value of IGF-1 for predicting periprocedural myocardial injury or type 4a myocardial infarction was 144.5 ng/ml, with a maximum sensitivity of 88% and specificity of 77.6% (AUC = 0.80, 95% CI: 0.69-0.88, p < 0.0001).

CONCLUSIONS

The results from this study indicate that low IGF-1 levels are associated with plaque instability assessed by OCT. Low IGF-1 levels may identify patients who are at increased risk for periprocedural myocardial injury/infarction.

The Role of Imaging for MINOCA (Myocardial Infarction with No Obstructive Coronary Artery Disease): a Review of Literature and Current Perspectives

Purpose of Review

The objective of this review is to summarize scientific statements on the diagnosis and management of myocardial infarction with no obstructive coronary artery disease (MINOCA); define the diagnostic role of optical coherence tomography (OCT), intravascular ultrasound (IVUS), and cardiac magnetic resonance imaging (CMR); and provide representative case examples.

Recent Findings

The majority of patients with MINOCA are evaluated by conventional coronary angiography. However, intracoronary imaging using OCT or IVUS permits more accurate understanding of the underlying pathology. These and other imaging modalities provide significant diagnostic and prognostic value.

Summary

Although nonobstructive disease is the hallmark of the disease, MINOCA is associated with significant morbidity and mortality. Every effort to define the underlying pathology is necessary and requires more standardized use of imaging in clinical practice.

Clinical considerations and recommendations for OCT-guided carotid artery stenting

Introduction: Optical Coherence Tomography (OCT) is an intravascular imaging providing high-resolution images of morphological features of arterial wall. Nowadays, OCT is an accepted intravascular modality to study coronary arteries, stent implantation, and vessel injury. In the last decade, an increasing interest have been focused on the application of OCT in carotid arteries.Areas covered: Literature evidence in the application of OCT in carotid arteries still remains debated. So far, OCT has been used as a research tool, aiming to evaluate atherosclerotic plaques' features and stents' behavior after implantation. This paper is intended to summarize clinical evidences and practices in the use of OCT in carotid arteries district and during CAS procedures. Literature review was completed via Pubmed search using Keywords.Expert opinion: CAS is a safe and effective procedure when performed by trained physicians with a tailored approach. In this scenario, ambiguous pictures at ultrasound, angiography, and IVUS might be clarified using OCT.By providing unprecedented microstructural information on atherosclerotic plaques, OCT may identify the features of vulnerable carotid plaque and, by identifying possible defects after stent implantation as malapposition and plaque prolapse, it may help the tailoring approach to CAS.

Cut-off value of strut-vessel distance for the resolution of acute incomplete stent apposition in the early phase using serial optical coherence tomography after cobalt-chromium everolimus-eluting stent implantation

OBJECTIVE

The purpose of this study was to identify a cut-off value to predict the resolution of incomplete-stent-apposition (ISA) after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation at early follow-up.

BACKGROUND

To date, appropriate stent apposition at the acute period using intracoronary imaging has been recommended because persistent ISA is considered to be a risk factor for stent thrombosis. We examined the indices for resolving acute ISA. In particular, we determined the cut-off value for strut vessel distance (SV-distance) as visualized by optical coherence tomography (OCT) at 8 months after CoCr-EES implantation. However, the cut-off value of SV-distance for the earlier resolution of ISA is unclear.

METHODS

A total of 95 cases and 103 stents were registered in the MECHANISM Elective substudy. The SV-distance was measured at the deepest site of the target malapposition and every 1 mm from the proximal edge to the distal edge of the mal-apposed area using OCT. Cut-off values for ISA resolution at 1 and 3 months were estimated by SV-distance using receiver operating characteristic analysis.

RESULTS

The total number of analyzed struts was 14,418 at the 1-month follow-up and 11,986 at the 3-month follow-up. The optimal SV-distance cut-off values just after stent implantation to predict ISA resolution were 185 µm at the 1-month follow-up and 195 μm at the 3-month follow-up.

CONCLUSION

For resolution of ISA, SV-distance cut-off values of 185 µm at 1 month postimplantation and 195 μm at 3 months postimplantation can be used as the index of endpoint of the percutaneous coronary intervention.

Assessment of residual thrombus burden in patients with ST-segment elevation myocardial infarction undergoing bivalirudin versus unfractionated heparin infusion: The MATRIX (minimizing adverse hemorrhagic events by transradial access site and angioX) OCT study

BACKGROUND

Residual stent strut thrombosis after primary percutaneous coronary intervention (PCI), negatively affects myocardial perfusion, may increase stent thrombosis risk, and it is associated with neointima hyperplasia at follow-up.

OBJECTIVES

To study the effectiveness of any bivalirudin infusion versus unfractionated heparin (UFH) infusion in reducing residual stent strut thrombosis in patients with ST-elevation myocardial infarction (STEMI).

METHODS

Multi-vessel STEMI patients undergoing primary PCI and requiring staged intervention were selected among those randomly allocated to two different bivalirudin infusion regimens in the MATRIX (Minimizing Adverse Haemorrhagic Events by TRansradial Access Site and angioX) Treatment-Duration study. Those receiving heparin only were enrolled into a registry arm. Optical coherence tomography (OCT) of the infarct-related artery was performed at the end of primary PCI and 3-5 days thereafter during a staged intervention. The primary endpoint was the change in minimum flow area (ΔMinFA) defined as (stent area + incomplete stent apposition [ISA] area) - (intraluminal defect + tissue prolapsed area) between the index and staged PCI.

RESULTS

123 patients in bivalirudin arm and 28 patients in the UFH arm were included. Mean stent area, percentage of malapposed struts, and mean percent thrombotic area were comparable after index or staged PCI. The ΔMinFA in the bivalirudin group was 0.25 versus 0.05 mm² in the UFH group, which resulted in a between-group significant difference of 0.36 [95% CI: (0.05, 0.71); p = .02]. This was mostly related to a decrease in tissue protrusion in the bivalirudin group (p = .03). There was a trend towards more patients in the bivalirudin group who achieved a 5% difference in the percentage of OCT frames with the area >5% (p = .057).

CONCLUSIONS

The administration of bivalirudin after primary PCI significantly reduces residual stent strut thrombosis when compared to UFH. This observation should be considered hypothesis-generating since the heparin-treated patients were not randomly allocated.

Residual atherothrombotic burden after primary percutaneous coronary intervention and myocardial reperfusion-An optical frequency domain imaging study

OBJECTIVES

We aimed to assess the relationship between residual in-stent atherothrombotic burden (ATB) after primary percutaneous coronary intervention (PCI) measured by optical frequency domain imaging (OFDI) using different measurement methods and myocardial blush grade (MBG).

BACKGROUND

The impact of residual ATB after primary PCI on myocardial reperfusion remains unclear.

METHODS

We prospectively included 60 ST-elevation myocardial infarction patients pretreated with aspirin and ticagrelor. OFDI volumetric quantification using planimetry (with intervals every frame or every millimeter) and semiquantitative score were used to determine ATB. Patients were divided into two groups according to final MBG 3 or <3.

RESULTS

The mean ATB was 10.08 ± 5.21%. ATB was lower in patients with final MBG 3 compared to those with impaired MBG, regardless of the measurement method (8.15 ± 5.58 vs. 11.77 ± 4.28%; p = .007 for quantification per frame; 7.8 ± 5.19 vs. 11.07 ± 4.07%; p = .009 for quantification per mm and 11.21 ± 11.75 vs. 22.91 ± 17.35; p = .003 for the semiquantitative thrombus score, respectively).

CONCLUSION

Residual post-stenting ATB remains substantial after primary PCI in STEMI patients, even when pretreated with ticagrelor and aspirin. ATB appears as a significant correlate of suboptimal myocardial reperfusion, a known surrogate of clinical outcome.

Impact of dual antiplatelet therapy with adjusted-dose prasugrel on mid-term vascular response in patients undergoing elective percutaneous coronary intervention with everolimus-eluting stents

The impact of dual antiplatelet therapy (DAPT) with adjusted-dose (3.75 mg/day) prasugrel for Japanese patients has not been fully investigated in terms of local arterial healing following the elective percutaneous coronary intervention (PCI). The ROUTE-01 elective study was a prospective, 12-center and single-arm registry that enrolled 123 patients who underwent elective PCI with everolimus-eluting stents (EESs) under DAPT with a combination of adjusted-dose prasugrel and aspirin. Serial optical coherence tomography (OCT) was performed at the index PCI and 9-month follow-up to assess the relationship between in-stent thorombus (IST) and residual platelet reactivity measuring platelet reactivity unit (PRU). The patients were classified as extensive, intermediate, and poor metabolizers by cytochrome P450 2C19 (CYP2C19) loss-of-function polymorphisms. The prevalence of IST was 9.0% by 9-month OCT, with no difference amongst the three groups (p = 0.886). The incidences of malapposed and uncovered struts were not different among the groups. PRU was not statistically different among the groups. In multivariate logistic regression analysis, the independent predictor for IST on 9-month OCT was irregular protrusion (odds ratio = 8.952, p = 0.037) on post-PCI OCT, not CYP2C19 loss-of-function polymorphisms. An adequate anti-thrombotic effect with an acceptable incidence of IST was observed irrespective of CYP2C19 loss-of-function polymorphisms. Our data suggests that adjusted-dose prasugrel and aspirin is a feasible treatment option in Japanese patients treated with EESs in elective PCI.

Optimization of Percutaneous Coronary Intervention Using Optical Coherence Tomography

Compared to the luminogram obtained by angiography, intravascular modalities produce cross-sectional images of coronary arteries with a far greater spatial resolution. It is capable of accurately determining the vessel size and plaque morphology. It also eliminates some disadvantages such as contrast streaming, foreshortening, vessel overlap, and angle dependency inherent to angiography. Currently, the development of its system and the visualization of coronary arteries has shown significant advancement. Of those, optical coherence tomography (OCT) makes it possible to obtain high-resolution images of intraluminal and transmural coronary structures leading to navigation of the treatment strategy before and after stent implantations. The aim of this review is to summarize the published data on the clinical utility of OCT, focusing on the use of OCT in interventional cardiology practice to optimize percutaneous coronary intervention.

Comparison of the vessel healing process after everolimus-eluting stent and bare metal stent implantations in patients with ST-elevation myocardial infarction

Cobalt-chromium everolimus-eluting stent (CoCr EES) is associated with a lower rate of stent thrombosis even in patients with ST-elevation myocardial infarction (STEMI). However, the time-serial changes of endothelial coverage of the stent struts in the extremely early period have never been reported, especially in patients with STEMI. The aim of this study was to compare the vessel healing process between CoCr EES and cobalt-chromium bare metal stent (CoCr BMS) implantations using optical coherence tomography (OCT) in patients with STEMI. Sixty-three patients who had primary emergent percutaneous coronary intervention (PCI) with CoCr EES (42 patients) or CoCr BMS (21 patients) were enrolled in this study for 3 years. OCT was performed just after, 2 and 12 weeks after EES or BMS implantations. Time-serial changes in the neointimal coverage (NIC), the neointimal thickness, and malapposition of stent struts were evaluated. NIC of stent struts did not differ between CoCr EES (23.2%, 99.4%) and CoCr BMS (24.0%, 97.8%) at 2 weeks and 12 weeks after PCI, respectively. Thicknesses of the neointima on the stent strut was significantly thinner in CoCr EES (34.0 ± 13.8, 107.0 ± 32.4 µm) than in CoCr BMS (40.0 ± 14.6, 115.7 ± 33.8 µm) at 2 weeks and 12 weeks after PCI (p = 0.011, p = 0.008), respectively. The malapposition did not differ just after PCI, and was completely resolved at 12 weeks after PCI in both groups. Thrombus was significantly less in CoCr EES than in CoCr BMS at 2 weeks (19.0% vs 42.9%, p < 0.01), and decreased over time in both groups, but at 12 weeks, disappeared only in CoCr EES (CoCr EES: 0% vs. CoCr BMS: 4.8%, p = 0.56). This study demonstrated that NIC and apposition of the stent struts almost completed at 12 weeks after EES and BMS implantations, while the neointimal thickness on the stent struts were thinner in EES than in BMS. Moreover, thrombus was significantly less in EES than in BMS implantations 2 weeks after PCI, which may explain the lower rate of acute and subacute stent thrombosis of EES compared with BMS.

Optical coherence tomography-verified longer balloon inflation time may provide better stent apposition and optimal index parameters

BACKGROUND

Incomplete stent expansion and inadequate apposition predispose to stent thrombosis following percutaneous coronary intervention. Recent studies have shown that increasing the duration of balloon inflation during stent employment was beneficial. Thus, the balloon inflation time required for optimal stent expansion and apposition in patients receiving second-generation drug-eluting stents (DES) were determined using optical coherence tomography (OCT).

PATIENTS AND METHODS

Between April 2014 and March 2015, 38 patients (28 men, 10 women; mean age 60.5 ± 11.4 years) with stable angina pectoris due to single significant de novo coronary artery stenosis were prospectively enrolled. All patients were administered aspirin and clopidogrel and received weight-adjusted intravenous unfractionated heparin. Images of basal lesions were obtained using the C7XR LightLab Dragonfly OCT catheter.

RESULTS

Expansion and apposition parameters improved with increasing duration of balloon inflation (30 s or 60 s) with nominal pressure (12 atm). Mean lesion length was 19.8 ± 7.6 mm. Mean stent diameter and length were 2.8 ± 0.36 mm and 24.9 ± 7.6 mm, respectively.

CONCLUSION

With deployment of a stent at nominal pressure with conventional duration, inadequate stent expansion and malapposition frequently occurred as detected by OCT; however, a balloon inflation duration of 60 s markedly improved stent expansion and apposition parameters without significant complications.

Clinical significance of optical coherence tomography-guided angioplasty on treatment selection

The present study aimed to observe whether optical coherence tomography (OCT)-guided angioplasty is able to provide useful clinical information beyond that obtained by angiography as well as provide recommendations for physicians that may improve treatment selection. This prospective study included 83 patients with coronary artery disease (>18 years) undergoing coronary angiography (CAG) for ST-elevation myocardial infarction (n=13), non-ST-elevation myocardial infarction (n=19), stable angina (n=22), unstable angina (n=10), silent ischemia (n=11), or elective percutaneous coronary intervention (n=8). Following the initial CAG (CAG-pre), the patients underwent OCT before angioplasty (OCT-pre, 24 patients), after angioplasty (OCT-post, 22 patients), or both (37 patients). The thrombus burden, calcification and plaque dissection or rupture were compared between the OCT-pre and CAG-pre recordings. Following angioplasty, stent malapposition, suboptimal stent deployment, suboptimal stent lesion coverage, and edge dissection were compared between OCT-post and CAG-post alone. Among the 83 patients, 45.7% had single-vessel and 54.3% had multiple-vessel disease. OCT pre- and post-angioplasty revealed significantly more information on the procedure than CAG alone. This clinical information changed the clinical strategies in 41/83 (49.4%) patients, including 58 modifications of therapeutic strategy (69.9%, 58/83): Thrombus aspiration in 2 cases (2.4%), administration of glycoprotein IIb/IIIa inhibitors in 8 cases (9.6%), additional balloon inflation in 23 cases (27.7%), additional stent implantation in 17 cases (20.5%), avoiding stent implantation in 4 cases (4.8%), collateral intervention in 2 cases (2.4%), and guidewire reposition in 2 cases (2.4%). In conclusion, OCT-pre and OCT-post provided additional clinical information beyond that obtained by angiography alone, which resulted in modification of the treatment strategies in half of the included patients.

Lower on-treatment platelet reactivity during everolimus-eluting stent implantation contributes to the resolution of post-procedural intra-stent thrombus: serial OCT observation in the PRASFIT-Elective study

Intra-stent thrombus (IS-Th) formed immediately after percutaneous coronary intervention (PCI) is associated with subsequent adverse coronary events. However, the impact of on-treatment platelet reactivity on IS-Th is unknown. PRASFIT-Elective is a multicenter study of PCI patients receiving prasugrel (20/3.75 mg, loading/maintenance dose) or clopidogrel (300/75 mg), with aspirin (100 mg). Among the 742 study patients, 111 were pre-specified for the OCT sub-study. Of these, 82 underwent OCT immediately after PCI to assess IS-Th and at an 8-month follow-up to evaluate the fate of the IS-Th. Lesions were considered resolved when IS-Th were detected after PCI but not on the follow-up or persistent when IS-Th were observed on both scans. The P2Y12 Reactive Unit (PRU) value was determined at the initial PCI and 4 and 48 weeks post-PCI. In 76 patients (86 lesions), we detected 230 IS-Th initially, and 196 IS-Th (85.2%) were resolved at the 8-month OCT. At PCI, but not 4 or 48 weeks after, the resolved IS-Th group had a lower PRU than the persistent IS-Th group (199 ± 101 vs. 266 ± 102, p = 0.008). Multivariate logistic regression analyses revealed that lower PRU at PCI and less calcified lesions were independent predictive factors for the resolution of IS-Th. Local lesion-related factors and lower on-treatment platelet reactivity at the time of PCI may contribute to the resolution of IS-Th after EES implantation, potentially improving clinical outcome.

Circulating microRNAs as potential biomarkers for coronary plaque rupture

Coronary plaque rupture is the most common cause of acute coronary syndrome. However, the timely biomarker-based diagnosis of plaque rupture remains a major unmet clinical challenge. Balloon dilatation and stent implantation during percutaneous coronary intervention (PCI) could cause plaque injury and rupture. Here we aimed to assess the possibility of circulating microRNAs (miRNAs) as biomarkers of acute coronary plaque rupture by virtue of the natural model of PCI-induced plaque rupture. Stable coronary artery disease patients underwent PCI with single stent implantation were recruited and a three-phase approach was conducted in the present study: (i) profiling of plasma miRNAs in a group of patients before (0 h) and after balloon dilatation for 1 h (1 h vs. 0 h), (ii) replication of significant miRNAs in the second group of patients (1 h vs. 0 h), (iii) validation of a multi-miRNAs panel in the third group of patients (0.5 h, 1 h vs. 0 h). Out of 24 miRNAs selected for replication, 6 miRNAs remained significantly associated with plaque rupture. In the validation phase, combinations of miR-483-5p and miR-451a showed the highest area under the receiver-operating-characteristic curve (AUC) (0.982; CI: 0.907-0.999) in patients with plaque rupture for 0.5 h; combinations of miR-483-5p and miR-155-5p showed the highest AUC (0.898; CI: 0.790-0.962) after plaque rupture for 1 h. In conclusion, using a profiling-replication-validation model, we identified 3 miRNAs including miR-155-5p, miR-483-5p and miR-451a, which may be biomarkers for the early identification of plaque rupture.

Healing score of the Xinsorb scaffold in the treatment of de novo lesions: 6-month imaging outcomes

The objectives of this study are to assess the healing score (HS) and neointimal thickness of the Xinsorb scaffold, and explore the relationships between the implanted patterns, neointimal thickness, and HS. The Xinsorb bioresorbable sirolimus-eluting scaffold is the first domestically designed and fabricated bioresorbable scaffold in China. The 6-month follow-up found it to be safe and effective in the treatment of single de novo coronary lesions. The Xinsorb scaffolds were implanted in 30 patients with symptomatic ischemic coronary disease. A 6-month follow-up was performed in a subset of 19 patients; the HS and neointimal thickness were evaluated by optical coherence tomography. Struts were classified as ApposedCovered, ApposedUncovered, MalapposedCovered, MalapposedUncovered, jailing and presence of intraluminal masses. The implanted pressure, implanted duration, and post-expansion pressure were recorded during the operation. We evaluated the relationship between the HS or neointimal thickness and the implanted pressure, holding time, and post-expansion pressure. The device and procedure success rates were both 100%. No major adverse cardiac or scaffold-thrombus related events occurred. At 6 months, 12,295 struts were analyzed to determine the HS (6.23) and neointimal thickness (0.1021 ± 0.05718 mm) in the Xinsorb scaffolds. There was a strong negative relationship between the HS and the implantation duration (Pearson r = - 0.518, p = 0.023). A significant negative relationship also existed between the HS and post-dilatation (Pearson r = - 0.631, p = 0.004). The Xinsorb scaffold HS appears negative correlated with the implanted duration and post-dilatation. We will further evaluate the HS of randomized controlled trial of the Xissorb scaffold.

SYNTAX Score and Pre- and Poststent Optical Coherence Tomography Findings in the Left Anterior Descending Coronary Artery in Patients With Stable Angina Pectoris

SYNTAX score (SS) has been reported to be an independent predictor of future cardiac events including target lesion revascularization. The aim of this study was to assess the relation between SS and plaque characteristics and poststent vascular response using optical coherence tomography in coronary artery tree and left anterior descending artery (LAD) in patients with stable angina. A total of 179 lesions among 165 patients, including 100 lesions in LAD, were analyzed. Patients were stratified into tertiles. In pre-percutaneous coronary intervention analysis of whole coronary tree and LAD, lesions of the third tertile had the highest prevalence of lipid-rich plaque. Compared with the first tertile, the third tertile had greater lipid index, thinner fibrous cap, and higher prevalence of thin-cap fibroatheroma. In poststent optical coherence tomography, the incidence of stent edge dissection and irregular protrusion was higher in the third tertile compared with the first tertile in coronary tree analysis. In LAD analysis, the prevalence of irregular protrusion was the highest in the third tertile. In conclusion, high SS may reflect higher plaque vulnerability. Stent edge dissection and irregular protrusion were more frequent in patients with higher SS, indicating poor vascular response to stenting. Our results may explain higher cardiac event rate and target lesion revascularization in patients with higher SS.

Coronary Stent Failure: Fracture, Compression, Recoil, and Prolapse

Current-generation coronary drug-eluting stents are associated with low rates of restenosis and target lesion revascularization. However, several mechanisms of stent failure remain clinically important. Stent fracture may occur in areas of excessive torsion or angulation. Longitudinal stent deformation is related to axial stent compression owing to extrinsic forces or secondary devices that disrupt stent architecture. Stent recoil occurs when a stent does not deploy at its optimal cross-sectional area. Tissue prolapse between stent struts may also predispose patients to adverse outcomes. Prevention, recognition, and treatment of these stent failures are necessary to optimize patient outcomes after percutaneous coronary interventions.

Optical coherence tomography assessment of incidence, morphological characteristics, and spontaneous healing course of edge dissections following percutaneous coronary intervention with stent implantation in patients with non-ST segment elevation myocardial infarction

BACKGROUND

Stenting-induced edge dissections (ED) can be assessed in detail by optical coherence tomography (OCT). This study sought to investigate the incidence, morphological characteristics, and spontaneous healing course of OCT-identified EDs following drug-eluting stent (DES) implantation in a non-ST segment elevation myocardial infarction (NSTEMI) patient-population.

METHODS

Acute vessel wall injury at the 5-mm stent adjacent distal and proximal reference segments was assessed by post-procedure OCT and intravascular ultrasound (IVUS) in n=97 NSTEMI-patients (n=97 lesions). Six months OCT follow-up was available in 82 patients (including 35 untreated post-procedure EDs).

RESULTS

The overall incidence of post-procedure OCT-detected ED was 38 per 97 patients (39.2%), and 47 per 182 stent edges (25.8%). None of the EDs were angiographically visualizable, while 10 (21.3%) were visible on concomitant IVUS-analysis. Morphologically, there was a significant difference in plaque type present at ED-edges vs. non-ED-edges when assessed with OCT; (1) lipid-rich and calcified plaques: 80.9% vs. 57.0%, (2) fibrous plaques: 17.0% vs. 26.7%, and (3) normal coronary vessels: 2.1% vs. 16.3%, p<0.01. Plaqueburden, assessed by IVUS, was substantially larger at ED-containing borders: 54.5±10.0% vs. 43.7±11.6%, p=0.01. Three dissections (8.6%) were incompletely healed at 6-month OCT follow-up. None of the EDs caused cardiac events during the 6-month follow-up, however, 1 ED-patient had target lesion revascularization with PCI and DES-implantation in extension of the scheduled OCT-control.

CONCLUSIONS

OCT-detected EDs were frequent after stent implantation due to NSTEMI, and the majority of these EDs healed without leading to an adverse prognosis at 6months.

Concise Review of Optical Coherence Tomography in Clinical Practice

Optical coherence tomography (OCT) is a novel image modality with higher resolution in the catheterization laboratory. It can differentiate tissue characteristics and provide detailed information, including dissection, tissue prolapse, thrombi, and stent apposition. In this study, we comprehensively reviewed the current pros and cons of OCT clinical applications and presented our clinical experiences associated with the advantages and limitations of this new imaging modality.

Prevalence, Features, and Prognostic Importance of Edge Dissection After Drug-Eluting Stent Implantation: An ADAPT-DES Intravascular Ultrasound Substudy

Background—

Intravascular ultrasound detects stent edge dissections after percutaneous coronary intervention that are not seen angiographically. This study investigated the association between stent edge dissections and clinical outcomes.

Methods and Results—

ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a large-scale, prospective, multicenter study of patients undergoing drug-eluting stent implantation. In this prospective substudy, 2062 patients (2433 lesions) were evaluated with intravascular ultrasound to characterize the morphological features and clinical outcomes of stent edge dissection after percutaneous coronary intervention. The prevalence of post–percutaneous coronary intervention stent edge dissection was 6.6% per lesion (161 of 2433). Calcified plaque at the proximal stent edge (relative risk [RR]=1.72; P =0.04) and proximal stent edge expansion (RR=1.18; P =0.004) were predictors for proximal dissection; attenuated plaque at the distal stent edge (RR=3.52; P =0.004), distal reference plaque burden (RR=1.56; P <0.0001), and distal edge stent expansion (RR=1.11; P =0.02) were predictors for distal dissection. At 1-year follow-up, target lesion revascularization was more common in lesions with versus without dissection (5.2% versus 2.7%; P =0.04). Multivariable analysis indicated that residual dissection was associated with target lesion revascularization at 1-year follow-up (RR=2.67; P =0.02). Among lesions with dissection, smaller effective lumen area increased the risk of target lesion revascularization at 1-year follow-up (cutoff value of 5.1 mm 2 ; P =0.05).

Conclusions—

Greater stent expansion and the presence of large, calcified, and/or attenuated plaques were independent predictors of stent edge dissection. Residual stent edge dissection, especially with a smaller effective lumen area, was associated with target lesion revascularization during 1-year follow-up after drug-eluting stent implantation.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00638794.

Choice of Intracoronary Imaging: When to use Intravascular Ultrasound or Optical Coherence Tomography

Intracoronary imaging has the capability of accurately measuring vessel and stenosis dimensions, assessing vessel integrity, characterising lesion morphology and guiding optimal percutaneous coronary intervention (PCI). Coronary angiography used to detect and assess coronary stenosis severity has limitations. The 2D nature of fluoroscopic imaging provides lumen profile only and the assessment of coronary stenosis by visual estimation is subjective and prone to error. Performing PCI based on coronary angiography alone is inadequate for determining key metrics of the vessel such as dimension, extent of disease, and plaque distribution and composition. The advent of intracoronary imaging has offset the limitations of angiography and has shifted the paradigm to allow a detailed, objective appreciation of disease extent and morphology, vessel diameter, stent size and deployment and healing after PCI. It has become an essential tool in complex PCI, including rotational atherectomy, in follow-up of novel drug-eluting stent platforms and understanding the pathophysiology of stent failure after PCI (e.g. following stent thrombosis or in-stent restenosis). In this review we look at the two currently available and commonly used intracoronary imaging tools - intravascular ultrasound and optical coherence tomography - and the merits of each.

Edge Vascular Response After Resorption of the Everolimus-Eluting Bioresorbable Vascular Scaffold - A 5-Year Serial Optical Coherence Tomography Study

BACKGROUND

The edge vascular response (EVR) has been linked to important prognostic implications in patients treated with permanent metallic stents. We aimed to investigate the relationship of EVR with the geometric changes in the everolimus-eluting bioresorbable scaffold using serial optical coherence tomography (OCT) analysis.

METHODS AND RESULTS

In the first-in-man ABSORB trial, 28 patients (29 lesions) underwent serial OCT at 4 different time points (Cohort B1: post-procedure, 6, 24, and 60 months [n=13]; Cohort B2: post-procedure, 12, 36, and 60 months [n=15]) following implantation of the scaffold. In Cohort B1, there was no significant luminal change at the distal or proximal edge segment throughout the entire follow-up. In contrast, there was a significant reduction of the lumen flow area (LFA) of the scaffold between post-procedure and 6 months (-1.03±0.49 mm(2)[P<0.001]), whereas between 6 and 60 months the LFA remained stable (+0.31±1.00 mm(2)[P=0.293]). In Cohort B2, there was a significant luminal reduction of the proximal edge between post-procedure and 12 months (-0.57±0.74 mm(2)[P=0.017]), whereas the lumen area remained stable (-0.26±1.22 mm(2)[P=0.462]) between 12 and 60 months. The scaffold LFA showed a change similar to that observed in Cohort B1.

CONCLUSIONS

Our study demonstrated a reduction in the scaffold luminal area in the absence of major EVR, suggesting that the physiological continuity of the lumen contour is restored long term. (Circ J 2016; 80: 1131-1141).

Usefulness of Frequency Domain Optical Coherence Tomography Compared with Intravascular Ultrasound as a Guidance for Percutaneous Coronary Intervention

OBJECTIVES

To compare outcomes and rates of optimal stent placement between optical coherence tomography (OCT) and intravascular ultrasound (IVUS) guided percutaneous coronary intervention (PCI).

BACKGROUND

Unlike IVUS-guided PCI, rates of clinical outcomes and optimal stent placement have not been well characterized for OCT-guided PCI.

METHODS

The study enrolled 290 patients who underwent implantation of a second generation drug eluting stent under OCT (122 patients) or IVUS (168 patients) guidance. The two groups were compared after adjusting for baseline differences using 1:1 propensity score matching (PSM) (114 patients in each group). Optimal stent placement was defined as achieving an adequate lumen (optimal minimum stent area [MSA > 4.85 mm(2) for OCT, >5 mm(2) for IVUS] or a final MSA ≥ 90% of the distal reference lumen area, without edge dissection, incomplete stent apposition, or tissue prolapse), or otherwise performing additional interventions to address suboptimal post-stenting OCT or IVUS findings. The primary endpoint was one-year cumulative incidence of major adverse cardiac events (MACE; cardiac death, myocardial infarction and target lesion revascularization). Definite or probable stent thrombosis (ST) rates were evaluated.

RESULTS

In adjusted comparisons between OCT and IVUS groups, there was no significant difference in rates of MACE (3.5% vs. 3.5%, P = 1.000) and ST (0% vs. 0.9%, P = 1.000) at 1 year, optimal stent placement (89.5% vs. 92.1%, P = 0.492), and further intervention (7.9% vs.13.2%, P = 0.234), despite OCT significantly more frequently detecting tissue prolapse (97.4% vs. 47.4%, P < 0.001), and numerically more edge dissection (10.5% vs. 4.4%, P = 0.078) or incomplete stent apposition (48.2% vs. 36.8%, P = 0.082).

CONCLUSIONS

OCT guidance showed comparable results to IVUS in mid-term clinical outcomes, suggesting that OCT can be an alternative tool for stent placement optimization.

New Invasive Assessment Measures of Coronary Artery Disease Severity

Ischemic heart disease is the leading cause of mortality worldwide. The assessment and treatment of patients with ischemic heart disease have advanced greatly over the past decade. Particular attention has been given recently to the recognition of lesions that cause ischemia or that are prone to plaque rupture. New invasive measures of coronary artery disease have been developed, including fractional flow reserve, intravascular ultrasound, optical coherence tomography, and most recently, near-infrared spectroscopy. These technologies have helped to guide the assessment of hemodynamically significant lesions and have shown particular promise in guiding percutaneous coronary interventions. However, mortality and the rate of revascularization have shown mixed results to date. This review seeks to investigate the use and potential benefit of these technologies, with particular attention to clinical end points.

Incidence and Clinical Significance of Poststent Optical Coherence Tomography Findings

Background—

Optical coherence tomography (OCT) was recently introduced to optimize percutaneous coronary intervention. However, the exact incidence and significance of poststent OCT findings are unknown.

Methods and Results—

A total of 900 lesions treated with 1001 stents in 786 patients who had postprocedure OCT imaging were analyzed to evaluate the incidence of poststent OCT findings and to identify the OCT predictors for device-oriented clinical end points, including cardiac death, target vessel–related myocardial infarction, target lesion revascularization, and stent thrombosis. Patients were followed up to 1 year. Stent edge dissection was detected in 28.7% of lesions, and incomplete stent apposition was detected in 39.1% of lesions. The incidences of smooth protrusion, disrupted fibrous tissue protrusion, and irregular protrusion were 92.9%, 61.0%, and 53.8%, respectively. Small minimal stent area, defined as a lesion with minimal stent area <5.0 mm 2 in a drug-eluting stent or <5.6 mm 2 in a bare metal stent, was observed in 40.4% of lesions. One-year device-oriented clinical end points occurred in 33 patients (4.5%). Following adjustment, irregular protrusion and small minimal stent area were independent OCT predictors of 1-year device-oriented clinical end points ( P =0.003 and P =0.012, respectively).

Conclusions—

Abnormal poststent OCT findings were frequent. Irregular protrusion and small minimal stent area were independent predictors of 1-year device-oriented clinical end points, which were primarily driven by target lesion revascularization.

Incidence and imaging outcomes of acute scaffold disruption and late structural discontinuity after implantation of the absorb Everolimus-Eluting fully bioresorbable vascular scaffold: optical coherence tomography assessment in 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). JACC Cardiovasc Interv. 2014;7:1400-1411. [PMID: 25523532 DOI: 10.1016/j.jcin.2014.06.016]

OBJECTIVES

This study sought to describe the frequency and clinical impact of acute scaffold disruption and late strut discontinuity of the second-generation Absorb bioresorbable polymeric vascular scaffolds (Absorb BVS, Abbott Vascular, Santa Clara, California) in the ABSORB (A Clinical Evaluation of the Bioabsorbable Everolimus Eluting Coronary Stent System in the Treatment of Patients With De Novo Native Coronary Artery Lesions) cohort B study by optical coherence tomography (OCT) post-procedure and at 6, 12, 24, and 36 months.

BACKGROUND

Fully bioresorbable scaffolds are a novel approach to treatment for coronary narrowing that provides transient vessel support with drug delivery capability without the long-term limitations of metallic drug-eluting stents. However, a potential drawback of the bioresorbable scaffold is the potential for disruption of the strut network when overexpanded. Conversely, the structural discontinuity of the polymeric struts at a late stage is a biologically programmed fate of the scaffold during the course of bioresorption.

METHODS

The ABSORB cohort B trial is a multicenter single-arm trial assessing the safety and performance of the Absorb BVS in the treatment of 101 patients with de novo native coronary artery lesions. The current analysis included 51 patients with 143 OCT pullbacks who underwent OCT at baseline and follow-up. The presence of acute disruption or late discontinuities was diagnosed by the presence on OCT of stacked, overhung struts or isolated intraluminal struts disconnected from the expected circularity of the device.

RESULTS

Of 51 patients with OCT imaging post-procedure, acute scaffold disruption was observed in 2 patients (3.9%), which could be related to overexpansion of the scaffold at the time of implantation. One patient had a target lesion revascularization that was presumably related to the disruption. Of 49 patients without acute disruption, late discontinuities were observed in 21 patients. There were no major adverse cardiac events associated with this finding except for 1 patient who had a non-ischemia-driven target lesion revascularization.

CONCLUSIONS

Acute scaffold disruption is a rare iatrogenic phenomenon that has been anecdotally associated with anginal symptoms, whereas late strut discontinuity is observed in approximately 40% of patients and could be viewed as a serendipitous OCT finding of a normal bioresorption process without clinical implications. (ABSORB Clinical Investigation, Cohort B [ABSORB B]; NCT00856856).

Assessment and Quantitation of Stent Results by Intracoronary Optical Coherence Tomography

Optical coherence tomography evaluation of poststent results includes stent expansion as the absolute minimum stent area ratio by comparing the minimum stent area with the proximal and distal reference lumen areas or mean stent area defined as the total stent volume divided by the analyzed stent length; stent strut malapposition defined when the distance from the center of the blooming artifact and the surface of plaque is greater than the sum of stent thickness and polymer thickness; tissue protrusion through the stent struts; semiquantitative residual thrombus evaluation; and stent edge dissection.

Impacts of lesion angle on incidence and distribution of acute vessel wall injuries and strut malapposition after drug-eluting stent implantation assessed by optical coherence tomography

AIMS

To investigate the impact of lesion angle on the incidence and distribution of acute vessel wall injuries and incomplete stent apposition (ISA) following second-generation drug-eluting stent (DES) implantation using optical coherence tomography (OCT). Several ex vivo studies demonstrated that angled arterial walls are exposed to imbalanced mechanical stress from deployed stents.

METHODS AND RESULTS

We included 243 lesions treated with a single DES (148 everolimus-eluting stent and 95 zotarolimus-eluting stent). Angled lesions were defined as lesions with angle ≥45° on an angiogram (n = 58). The vessel wall injuries and ISA were evaluated by OCT. The results were compared with non-angled lesions (<45°, n = 185). The incidence of instent dissection, thrombus, and ISA was significantly higher in the angled group than in the non-angled group (84.5 vs. 63.2%, P < 0.01; 55.2 vs. 35.1%, P < 0.01; 75.9 vs. 44.9%, P < 0.001, respectively). In the angled group, the normalized tissue protrusion volume around the centre of angle (6.59 ± 6.81, mm(3) × 10(2)) was higher than in the distal sub-segment (2.21 ± 2.87, mm3 × 10(2), P < 0.001), in the proximal sub-segment (4.14 ± 5.34, mm3 × 10(2), P = 0.02), and in the non-angled group (3.30 ± 2.81, mm3 × 10(2), P < 0.001). The incidence of major adverse cardiac events within 12 months was similar between the groups.

CONCLUSIONS

Angled coronary lesions had a higher incidence rate of OCT-detected vessel wall injuries and ISA compared with non-angled lesions following second-generation DES implantation. Further studies are needed to understand the long-term clinical significance of these findings.