A Comparison of Intravascular Imaging Modalities for Detection of Stent Struts in Acute Coronary Syndrome

Background

We used optical coherence tomography (OCT) and intravascular ultrasound (IVUS) to assess the struts of implanted stents in patients with acute coronary syndrome (ACS).

Methods

A totle of 10,756 stent struts were analyzed with OCT in 42 patients of ACS. Of them, both of IVUS and OCT imaging were performed in 33 patients. Appearance of stent struts was classified as well apposed, buried, malapposed, and nondetectable, and the number of stent struts were counted by OCT and IVUS was compared.

Results

Most of stent struts were well apposed (78.1%, 8,407/10,756). However, malapposed struts were 5.6% (607/10,756), and 14.1% (1,514/10,756) of stent struts were buried by thrombus. The nondetectable struts were 2.11% (228/10,756) in ACS. 94.7% (216/228) of nondetectable stent struts were associated with red thrombus, and plaque prolapse was in 5.3% (12/228). The number of stent struts counted by OCT were larger than that of IVUS. The mean number of stent struts at the proximal and distal stent edges were 24 ± 6.57 in OCT, the stent struts IVUS counted were 20 ± 4.18 (P < 0.0001). Although the frequency of malapposed struts were similar 4.6% (376/8,248) in OCT versus 4.8% (369/7,674) in IVUS (P = 0.788). Stent struts were often buried by thrombus in ACS 15.2% (1,252/8,248) in OCT versus 9.7% (747/7,674) in IVUS; P = 0.006. The nondetectable struts were fewer in IVUS than OCT 0.2% (16/7,674) in IVUS versus 2.2% (187/8,248) in OCT; P < 0.0001.

Conclusion

Stent struts are frequently buried and nondetectable due to thrombi burden in ACS patients. Adequate thrombus removal and proper selection of the imaging device is warranted in ACS. (J Interven Cardiol 2016;29:99–107)

     

Impact of Diabetes Mellitus on Intravascular Ultrasound‐Guided Provisional Stenting in Coronary Bifurcation Lesions J‐REVERSE Sub‐Study

Objective

To investigate the impact of diabetes mellitus (DM) on provisional coronary bifurcation stenting under the complete guidance of intravascular‐ultrasound (IVUS).

Background

The efficacy of such intervention has not yet been fully elucidated in the DM patients.

Methods

A total of 100 DM and 139 non‐DM patients in a prospective multi‐center registry of IVUS‐guided bifurcation stenting were compared in angiographic results at 9 months. Vessel and luminal changes during the intervention were analyzed using the IVUS. Vascular healing at the follow‐up was also investigated in 23 lesions in each group using optical coherence tomography (OCT).

Results

No difference was detected regarding baseline reference vessel diameter and minimum lumen diameter in proximal main vessel (MV), distal MV, and side branch (SB). The rate of everolimus‐eluting stent use (78.4% vs. 78.3%), final kissing inflation (60.1% vs. 49.0%), and conversion to 2‐stent strategy (2.9% vs. 2.8%) were also similar. In the DM group, late loss was greater in proximal MV (DM 0.23 ± 0.29 vs. non‐DM 0.16 ± 0.24 mm, P < 0.05) and SB (0.04 ± 0.49 vs. ?0.08 ± 0.35 mm, P < 0.05). Smaller vessel area restricted stent expansion in the proximal MV (6.18 ± 1.67 vs. 6.72 ± 2.07 mm², P < 0.05). More inhomogeneous neointimal coverage (unevenness score, 1.90 ± 0.33 vs. 1.72 ± 0.29, P < 0.05) and more frequent thrombus attachment (26% vs. 4%, P < 0.05) were documented in the proximal MV at 9‐month follow‐up OCT.

Conclusions

Despite IVUS optimization for coronary bifurcation, DM is potentially associated with smaller luminal gain, higher late‐loss, and inhomogeneous vascular healing with frequent thrombus attachment in the proximal MV.

     

Utilizing intravascular ultrasound imaging prior to treatment of severely calcified coronary lesions with orbital atherectomy: An ORBIT II sub‐analysis

Objectives

We sought to assess the clinical outcomes when intravascular ultrasound (IVUS) was used prior to orbital atherectomy treatment (OA) versus angiography alone for lesion assessment.

Background

Percutaneous coronary intervention (PCI) of severely calcified lesions is associated with high rates of major adverse cardiac events (MACE). IVUS provides additional diagnostic information to optimize PCI.

Methods

ORBIT II was a single‐arm study of 443 patients with de novo, severely calcified coronary lesions treated with OA before stent placement. Patients with IVUS imaging prior to OA (N = 35) were compared to patients without IVUS imaging for initial lesion assessment (N = 405). In this post‐hoc sub‐analysis procedural outcomes and the 3‐year MACE rate were evaluated.

Results

The rates of severe angiographic complications were low in patients with and without IVUS imaging prior to OA. There was a significant reduction in the number of stents used in patients with IVUS imaging prior to OA (1.0 ± 0.2 vs 1.3 ± 0.6; P = 0.006) and increased post‐OA mean minimal lumen diameter (MLD) (1.6 ± 0.6 mm vs 1.2 ± 0.5 mm; P < 0.001). The 3‐year MACE rate was similar in both groups (IVUS: 14.3% vs No IVUS: 24.2%; P = 0.26).

Conclusions

There were significantly fewer stents placed, increased post‐OA MLD, and similar 3‐year MACE outcomes in patients with IVUS assessment of the degree of lesion calcification prior to OA as compared to patients with angiographic assessment of the degree of lesion calcification. Further studies are needed to determine the optimal integration of intravascular imaging with OA.

     

Identification of Intrastent Pathology Associated With Late Stent Thrombosis Using Optical Coherence Tomography

Objective

To better characterize intrastent pathology using optical coherence tomography (OCT) in patients presenting with late and very late stent thrombosis (LST/VLST).

Background

The contribution of specific intrastent pathologies to the development of LST/VLST is not well understood.

Methods

In this single‐center, retrospective, observational study of 796 consecutive patients treated for ST‐segment elevation myocardial infarction (STEMI) with primary PCI we identified 57 patients (7.2%) in whom STEMI resulted from LST/VLST. Of the patients with LST/VLST, 21 patients (37%) had OCT performed at the discretion of the operator during PCI for LST/VLST. Independent reviewers performed qualitative offline analysis of OCT images to determine the cause of stent thrombosis defined as the specific intrastent pathology associated with thrombus deposition.

Results

The principal intrastent pathology causing LST/VLST was determined to be stent malapposition in 11 patients (55%), of which 5 (25% of all LST/VLST patents) had findings suggestive of positive vessel remodeling. Neoatherosclerosis was determined to be the cause of LST/VLST in 7 patients (35%). LST/VLST resulted from uncovered stent struts in 2 patients (10%). Among all LST/VLST patients, in‐hospital mortality (12.3%) and post‐hospital target vessel failure (TVF) or cardiac death (21.7%, median follow‐up 1.6 years) remained high. There was a trend towards decreased TVF or cardiac death (7.7% vs. 27.3% P = 0.24) in patients who underwent OCT‐guided therapy.

Conclusions

LST/VLST remains a significant cause of STEMI and is associated with considerable morbidity and mortality. OCT use at the time of PCI consistently identifies significant intrastent pathology with potentially meaningful clinical impact. (J Interven Cardiol 2015;28:439–448)

     

Impact of stent deformity induced by the kissing balloon technique for bifurcating lesions on in‐stent restenosis after coronary intervention

Objectives

To investigate the impact of stent deformity induced by final kissing balloon technique (KBT) for coronary bifurcation lesions on in‐stent restenosis (ISR).

Background

In experimental models, the detrimental effects of KBT have been clearly demonstrated, but few data exists regarding the impact of proximal stent deformity induced by KBT on clinical outcomes.

Methods

We examined 370 coronary lesions where intravascular ultrasound (IVUS)‐guided second‐generation drug‐eluting stent (DES) implantation for coronary bifurcation lesions was performed. Based on IVUS analysis, the stent symmetry index (minimum/maximum stent diameter) and stent overstretch index (the mean of stent diameter/the mean of reference diameter) were calculated in the proximal main vessel.

Results

The stent symmetry index was significantly lower (0.75 ± 0.07 vs 0.88 ± 0.06, P < 0.0001) and the stent overstretch index was significantly higher (1.04 ± 0.08 vs 1.01 ± 0.06, P = 0.0007) in lesions with KBT (n = 174) compared to those without KBT (n = 196). The number of two‐stent technique in lesions with KBT was 31 (18%). In multivariate analysis, the degree of stent deformity indices was not associated with ISR in lesions with KBT; however, two‐stent technique use was the only independent predictor of ISR at 8 months (hazard ratio: 3.96, 95% confidence interval: 1.25‐12.5, P = 0.01).

Conclusions

Second‐generation DES deformity induced by KBT was not associated with mid‐term ISR.

     

Nine‐Month Angiographic and Intravascular Ultrasound Outcomes After Resolute Zotarolimus‐Eluting Stent Implantation for the Treatment of In‐Stent Restenosis

Objectives

We aimed to evaluate the mid‐term outcomes of resolute zotarolimus‐eluting stent (R‐ZES) implantation for in‐stent restenosis (ISR).

Background

There has been a paucity of data regarding the effects of new‐generation drug‐eluting stent to treat ISR.

Methods

From 2009 to 2010, a total of 98 patients with 98 ISR lesions were prospectively enrolled after R‐ZES implantation for the treatment of ISR. Among 98 patients, 73 patients underwent follow‐up angiography at 9 months. Serial intravascular ultrasound (IVUS) at both postprocedure and 9 months was evaluated in 55 patients. The overlapped segment of R‐ZES was defined as the portion of R‐ZES superimposed on previous stent.

Results

Late loss and binary restenosis rate were 0.3 ± 0.5 mm and 5.5% at 9 months. On IVUS, the percentage of neointimal volume and maximum percentage of neointimal area were 3.9 ± 6.3% and 17.3 ± 15.5%, respectively. There was no significant change of vessel volume index between postprocedure and 9 months (16.9 ± 4.7 mm³/mm vs. 17.1 ± 4.6 mm³/mm, P = 0.251). Late‐acquired incomplete stent apposition was observed in 5 (5/55, 9.1%) cases. Compared with nonoverlapped segments of R‐ZES, the overlapped did not show larger neointimal volume index (0.3 ± 0.5 mm³/mm vs. 0.2 ± 0.3 mm³/mm, P = 0.187) on 9‐month IVUS. During follow‐up (median, 353 days), repeat target‐lesion revascularization was performed in four cases, but there were no death or stent thrombosis.

Conclusions

This study suggested that R‐ZES implantation for the treatment of ISR was effective up to 9 months and showed favorable vascular responses on serial IVUS assessment.

     

Safety and Efficacy of Immediate Rotational Atherectomy in Nondilatable Calcified Coronary Lesions Complicated by Coronary Artery Dissection (RAISE)

Objectives

To examine the safety and efficacy of immediate rotational atherectomy (RA) in nondilatable calcified coronary lesions complicated by coronary dissection during percutaneous coronary intervention (PCI).

Background

In the presence of coronary dissection in nondilatable calcified coronary lesions, conservative management is suggested to permit the dissection to heal prior to treatment with RA. However, many patients have frequent angina attacks and some patients develop serious complications during this period.

Methods

One hundred and nighty‐eight patients with severe coronary calcification underwent PCI, and were randomized into immediate (n = 105) or delayed RA group (n = 93) when coronary dissections occur. The primary endpoint of the present study was all‐cause death including cardiac and non‐cardiac death in 4 years follow‐up. Non‐fatal myocardial infarction, stent thrombosis, cardiac tamponade, stroke, target lesion revascularization, New York Heart Association (NYHA) class IV heart failure were analyzed as secondary end points.

Results

At a follow‐up of 4 years, event‐free survival rates were not statistically different between the immediate and delayed RA group (81.9% vs 80.6%, P = 0.820). Rates of PCI‐ and RA‐related major adverse cardiac events (MACE) and severe RA‐related complications were not statistically different between groups. Luminal loss was not significantly different between the immediate and delayed RA group as evaluated by Intravascular ultrasound (IVUS). Two cases in the delayed RA group experienced myocardial infarction during the 4‐week waiting.

Conclusion

This study indicates that immediate RA during PCI is safe and effective in patients with coronary artery dissection. (J Interven Cardiol 2015;28:456–463)

     

Effect on Clinical Restenosis of an Ultra‐Thin‐Strut Bare Metal Cobalt‐Chromium Stent Versus a Thin‐Strut Stainless Steel Stent

Objectives

To prospectively compare the impact of ultrathin‐strut cobalt‐chromium (Cro‐Co) bare metal stent (BMS) versus thin‐strut stainless steel (SS) BMS on clinically driven target lesion revascularization (TLR).

Background

Stent characteristics are an important determinant of restenosis. Thinner strut Cro‐Co BMS is associated with a reduction of neointimal formation compared to SS BMS. The advantages of Cro‐Co BMS in a real‐world population is not clear.

Methods

Patients undergoing percutaneous coronary intervention (PCI) with BMS for any reason were enrolled. Patient with multi‐vessel PCI, multi‐lesions PCI, PCI of unprotected left main and coronary grafts were not excluded. They were divided in two groups according to stent type: Cro‐Co or SS group. The primary endpoint was clinically driven TLR at follow‐up.

Results

A total of 383 patients were enrolled: 222 in SS and 161 in Cro‐Co group. During the follow‐up, Cro‐Co patients had a significantly lower occurrence of TLR compared to SS patients (1.9% vs 8.6%, P = 0.006). There were no significant differences for the composite endpoint of death, myocardial infarct, and stroke (4.9% in Cro‐Co group vs 9.5% in SS group, P = 0.119). At multivariate analysis, the variables that were predictors of TLR were: use of SS stent (OR 4.43, P = 0.019) and diabetes (OR 2.84, P = 0.025).

Conclusions

Ultra‐thin strut Cro‐Co BMS is associated with a significant reduction of clinically driven TLR in all comers population with any type of coronary disease complexity. (J Interven Cardiol 2016;29:300–310)

     

Prevalence,Correlation and Clinical Outcome of Intra‐Procedural Stent Thrombosis in Patients Undergoing Primary Percutaneous Coronary Intervention for Acute Coronary Syndrome

Objectives

To assess the occurrence, correlation, and clinical outcome of intraprocedural stent thrombosis (IPST) in patients undergoing primary percutaneous coronary intervention (PCI) in the setting of acute coronary syndromes (ACSs).

Background

Stent thrombosis (ST), a rare complication of PCI, is more common in the setting of ACS. It is not known whether IPST carries the same prognosis as postprocedural ST.

Methods

This retrospective study comprised a review of 1,901 consecutive ACS patients who received primary PCI in our center from January 2006 to January 2011. IPST was defined as new, reappearing or increased thrombus within the deployed stent before the index PCI procedure was completed. All angiograms were independently reviewed frame by frame for the incidence of IPST. Patients with and without IPST were compared with respect to clinical characteristics, angiographic parameters, and major adverse cardiac events (MACEs) at 30 days and 1‐year follow‐up.

Results

Overall, there were 23 cases of IPST detected, thus, the prevalence of IPST was 1.2%. There were no significant differences in baseline clinical characteristics between the 2 groups. Patients with compared to those without IPST had significantly more bifurcation lesions involved, and more thrombus burden at baseline. IPST group compared to no IPST group had more MACEs on 30 days (26.1% vs. 8.7%, P = 0.01) and 1‐year follow‐up (30.4% vs. 14.4%, P = 0.02).

Conclusions

IPST was a rare complication of PCI in the setting of ACS. It correlated with lesion morphology, presence of thrombus at baseline and was more likely to cause MACEs in 30 days and 1‐year follow‐up. (J Interven Cardiol 2013;26:215–220)

     

Long Coronary Lesions Treated With Thin Strut Bioresorbable Polymer Drug Eluting Stent: Experience From Multicentre Randomized CENTURY II Study

Objectives

to assess performance of new, bioresorbable polymer sirolimus‐eluting stent (BP‐SES), in patients with long coronary lesions (LL) and to compare it to permanent polymer everolimus‐eluting stent (PP‐EES).

Background

LL have been associated with worse clinical outcomes in percutaneous coronary interventions (PCI). The impact of lesion length on the outcomes of drug eluting stent (DES) implantations is not as clear.

Methods

In the frame of a randomized, multicentre CENTURY II study, out of 1119 patients enrolled, 182 patients had LL (defined as ≥25 mm), and were assigned randomly to treatment with BP‐SES (101) or PP‐EES (81). Primary endpoint was target lesion failure (TLF, composite of cardiac death, target vessel related myocardial infarction [MI], and target lesion revascularization [TLR]) at 9 months. All data were 100% monitored and adverse events were adjudicated by an independent clinical event committee.

Results

The baseline patient and lesion characteristics were similar in the 2 study arms. At 9‐months, the rates of cardiac death (2.0% vs 1.2%; P = 0.70), MI (3.0% vs 4.9%; P = 0.49) and clinically driven TLR (2.0% vs 3.7%; P = 0.48) and TLF (6.9% vs 8.6%; P = 0.67) were similar for BP‐SES and PP‐EES, respectively. There was no stent thrombosis (ST) in BP‐SES group up to 9 months, while 1 case (1.2%) of ST was recorded in PP‐EES group (P = 0.44).

Conclusions

Patients with LL showed similar clinical outcomes when treated with Ultimaster BP‐SES and Xience PP‐EES. (J Interven Cardiol 2016;29:47–56)

     

Is Postdilatation with a Noncompliant Balloon Necessary after Coronary Stent Deployment during Primary Angioplasty?

Background

Postdilatation (PD) with noncompliant balloon during elective percutaneous coronary intervention (PCI) is performed usually in clinical practice in order to optimize stent expansion. However, current knowledge about its use in patients undergoing primary PCI is controversial. This study aims to evaluate the angiographical and clinical results of PD in patients who underwent primary PCI with drug eluting stents (DESs).

Methods

A total of 405 consecutive patients (mean age 56.9 ± 12.3 years; 302 male) with ST elevation myocardial infarction were evaluated retrospectively. Patients received DES with or without predilatation according to physician's discretion. Eligible patients were divided into 2 groups based on PD procedure. The clinical end‐points were death, target vessel revascularization (TVR) and stent thrombosis at 6 months after PCI. The angiographic end‐points were postprocedural correct Thrombolysis in Myocardial Infarction (TIMI) frame count (cTFC), final TIMI flow, and myocardial blush grade (MBG).

Results

PD was performed in 214 patients (52.8%). Angiographical parameters such as TIMI flow, cTFC, and MBG did not differ after PD (P > 0.05). During 6‐month follow‐up, TVR and stent thrombosis rates were lower in the PD group (6 vs. 16, P = 0.03; and 3 vs. 10, P = 0.04, respectively). PD and diabetes were detected as independent predictors of MACE (β = 0.52, P = 0.01, and β = ?0.47, P = 0.02; respectively).

Conclusion

Our study revealed that PD does not yield adverse effects on final angiographic parameters when performed during primary PCI. Besides PD seems to decrease probability of stent thrombosis and TVR.

     

The effects of types of guidewires and pressure applied during stent implantation in the main vessel on the incidence of damage to coronary guidewires during angioplasty of coronary bifurcation lesions—Wide Beast study

Objectives

We evaluated the impact of stent inflation pressure and type of guidewire on “jailed” coronary guidewire damage occurring during bifurcation angioplasty.

Background

Despite new techniques and treatment options during percutaneous coronary intervention (PCI) we still observe peri‐ and postoperative complications for to various known and unknown reasons.

Methods

Patients undergoing PCI within the coronary bifurcation were randomly assigned to one of four groups: Pilot 50 or BMW guidewire and pressure ≤12 or >12 atm. After PCI each “jailed” guidewire was evaluated under an optical microscope. The Wide Beast Scale (WBS) was developed for the internal purposes of the study and was used for qualitative assessment. Also, the inflation pressure, the patients’ characteristics and the technical parameters of the procedure were recorded.

Results

The clinical characteristics were similar in all the groups. There was no statistical significance of the degree of damage, rated on the WBS, for either guidewire group with respect to inflation pressure (P = 0.49). The prevalence of guidewire damage was higher in the BMW versus the Pilot 50 group (98.4% vs 67.4% respectively, P = 0.00001) as was the severity of the damage (grades 3 and 4) in BMW versus Pilot 50 (55.6% vs 13.0% respectively, P = 0.00001).

Conclusions

The inflation pressure during stent implantation had no impact on “jailed” guidewire damage. The difference in the prevalence of serious damage and total damage number was statistically significant for the BMW guidewire compared to the Pilot50. The BMW guidewire was an independent predictor of the degree of damage to the guidewire.

     

Recurrent Myocardial Infarction After Primary Percutaneous Coronary Intervention in Multivessel Coronary Disease Is Primarily Related to Stent Failure

Objectives

Our aim was to investigate the risk of events related to non‐culprit lesions after primary percutaneous coronary intervention (PCI) in patients with multivessel coronary disease (MVD).

Background

In patients undergoing primary PCI for ST‐elevation myocardial infarction (STEMI) who are diagnosed with MVD, the optimal treatment strategy is currently under debate. Although observational data exposed an increased risk of multivessel PCI in the acute phase of STEMI, 2 recently published randomized controlled trials showed a reduction of death or recurrent myocardial infarction (MI) after preventive PCI of non‐culprit lesions when compared with culprit‐lesion PCI only.

Methods

We performed a post‐hoc analysis of 279 patients with MVD included in the Paclitaxel‐Eluting Stent versus Conventional Stent in Myocardial Infarction with ST‐Segment Elevation (PASSION) trial. We analyzed the incidence and cause of recurrent MI. Recurrent MI due to stent failure was assumed in the event of definite or probable stent thrombosis.

Results

After 5 years, 14 patients (5.7%) with MVD had a recurrent MI versus 17 (5.4%) patients with 1‐vessel disease (HR 1.06, 95%CI 0.52–2.15, P = 0.87). The majority of events was attributable to stent failure, while of the remaining 6 events, only 1 was proven to originate from a lesion that was judged significant at enrolment.

Conclusions

In this post‐hoc analysis of the PASSION trial, recurrent MI in patients with MVD was mainly related to stent failure rather than a new event originating from a significant stenosis in a non‐culprit coronary artery. (J Interven Cardiol 2015;28:523–530)

     

Outcomes in Elderly Patients With Severely Calcified Coronary Lesions Undergoing Orbital Atherectomy

Objectives

We evaluated the clinical outcomes of elderly patients who underwent orbital atherectomy for the treatment of severe coronary artery calcification (CAC) prior to stenting.

Background

Percutaneous coronary intervention (PCI) of severe CAC is associated with worse clinical outcomes including death, myocardial infarction (MI), and target vessel revascularization (TVR). The elderly represents a high‐risk group of patients, often have more comorbid conditions, and have worse outcomes after PCI compared to younger patients. Clinical trials and a large multicenter registry have demonstrated the safety and efficacy of orbital atherectomy for the treatment of severe CAC. Clinical outcomes of elderly patients who undergo orbital atherectomy are unknown.

Methods

Of the 458 patients, 229 were ≥75 years old (elderly) and 229 were <75 years old (younger). The primary endpoint was rate of 30‐day major adverse cardiac and cerebrovascular events (MACCE), comprised of cardiac death, MI, TVR, and stroke.

Results

The primary endpoint was similar in the elderly and younger groups (2.2% vs. 2.2%, P = 1), as were the individual endpoints of death (2.2% vs. 0.4%, P = 0.1), MI (0.9% vs. 1.3%, P = 0.65), TVR (0% vs. 0%, P = 1), and stroke (0% vs. 0.4%, P = 0.32). The rates of angiographic complications and stent thrombosis were similarly low in both groups.

Conclusions

The elderly represented a sizeable number of patients who underwent orbital atherectomy. It is a safe and effective treatment strategy for elderly patients with severe CAC as the clinical outcomes were similar to their younger counterparts. A randomized trial should further clarify the role of orbital atherectomy in these patients.

     

Three‐months optical coherence tomography analysis of a biodegradable polymer,sirolimus‐eluting stent

Objective

We aimed to assess early neointimal healing by optical coherence tomography (OCT) 3 months after implantation of the ultrathin Orsiro® sirolimus‐eluting stent with biodegradable polymer.

Background

New generations of drug‐eluting stents with biodegradable polymer have been developed to avoid the continued vascular irritation of durable polymers.

Methods

In this prospective, open‐label study, 34 patients received an Orsiro® sirolimus‐eluting stent with biodegradable polymer. In a subgroup of patients (n = 15), the intervention was performed under OCT guidance. All patients underwent OCT‐examination at three months. The primary endpoint was 3‐month neointimal healing (NIH) score, calculated by weighing the presence of filling defects, malapposed and uncovered struts. Secondary endpoint was maturity of tissue coverage at 3 months.

Results

At 3 months, NIH score was 13.7 (5.4‐22), covered struts per lesion were 90% (84‐97%), malapposed struts were 2.7% (0.8‐5.4%) and rate of mature tissue coverage was 47% (42‐53%). No target lesion failure occurred up to 12 months. Patients with OCT‐guided stent implantation demonstrated a trend toward earlier stent healing as demonstrated by superior NIH scores (angio guided: 17.6% [8.8‐26.4]; OCT‐guided: 9.8% [4.0‐15.5]; mean difference ?8, [95%CI: ?18.7‐2.9], P = 0.123). This group had significantly more covered struts per lesion (angio‐guided: 86% [82‐90]; 95% [92‐99]; mean difference 9% [95%CI: 3‐15], P = 0.001).

Conclusion

The Orsiro® sirolimus‐eluting stent with biodegradable polymer shows early vascular healing with a high rate of strut coverage at 3‐month follow‐up. OCT guided stent implantation had a positive impact on early vascular healing.

     

Racial Differences in Long‐Term Outcomes after Percutaneous Coronary Intervention with Paclitaxel‐Eluting Coronary Stents

Objectives

To assess the influence of race on long‐term outcomes following percutaneous coronary intervention (PCI) with paclitaxel‐eluting stents (PES).

Background

Data on the influence of race on long‐term outcomes following PCI with drug‐eluting stents are limited because of severe underrepresentation of minority populations in randomized trials.

Methods

We compared 5‐year outcomes of 2,301 Whites, 127 Blacks, and 169 Asians treated with PES in the TAXUS IV, V, and ATLAS trials. Outcomes were adjusted using a propensity score logistic regression model with 1:4 matching.

Results

Blacks were more likely than Whites to be female, have a history of hypertension, diabetes mellitus, congestive heart failure, and stroke, but were less likely to have prior coronary artery disease. Compared with Whites, Asians were younger, more likely to be male, have stable angina, and left anterior descending disease, and less likely to have silent ischemia, previous coronary artery bypass surgery, prior coronary artery disease, diabetes mellitus, peripheral vascular disease, and to receive glycoprotein IIb/IIIa inhibitors. Despite higher antiplatelet compliance, the adjusted 5‐year rates of myocardial infarction (15.4% vs. 5.4%, P < 0.001) and stent thrombosis (5.6% vs. 1.1%, P = 0.002) were higher in Blacks than Whites. Despite lower antiplatelet compliance, Asians had no differences in myocardial infarction and stent thrombosis compared with Whites. Mortality and revascularization rates were similar between the three groups.

Conclusions

The long‐term risk of major thrombotic events after PCI with PES was higher in Blacks, but not Asians, compared with Whites. The mechanisms underlying these racial differences warrant further investigation. (J Interven Cardiol 2013;26:49–57)

     

Incidence and Characteristics of Late Catch‐Up Phenomenon Between Sirolimus‐Eluting Stent and Everolimus‐Eluting Stent: A Propensity Matched Study

Objectives

We evaluated and compared the incidence and characteristics of late catch‐up phenomenon (LCU) between everolimus‐eluting stent (EES) and sirolimus‐eluting stent (SES) implantations.

Background

Late catch‐up phenomenon after everolimus‐eluting stent (EES) implantation has not yet been evaluated sufficiently.

Methods

Between April 2007 and May 2011, 1,234 patients with coronary artery disease were treated with SES and 502 patients with EES. Following propensity score matching, we evaluated 495 SES‐treated patients and 495 ESS‐treated patients. The incidences of LCU (i.e., late target lesion revascularization [TLR] [1–3 years]) were compared.

Results

The cumulative incidence of TLR at 3 years was 11.9% in the SES group and 6.1% in the EES group (P = 0.001). The incidence of late TLR was 7.5% in the SES group and 3.4% in the EES group (P = 0.004). Even though not statistically significant, intravascular ultrasound showed a higher tendency of stent fracture (SF) in late restenosis lesions in the SES group than in the EES group (37.0% vs 7.7%; P = 0.052). Moreover, the SF rate tended to increase in late restenosis compared with early restenosis (within 1 year) in the SES group compared with the EES group (SES: 37.0% vs 22.2%; P = 0.293, EES: 7.7% vs 10.0%; P = 0.846), although the increase was not significantly different.

Conclusions

EES was superior to SES in terms of LCU. SF may be associated with LCU after SES implantation. (J Interven Cardiol 2015;28:551–562)

     

Application of an enhanced device to transluminal retrieval of malappositioned coronary stents: An experimental study

Objectives

This study investigated the application of a novel enhanced device to retrieval of deployed stents in a porcine coronary model.

Background

Recurrence of in‐stent restenosis and stent thrombosis still remains to be resolved. Under these conditions, it is sometimes necessary to retrieve malfunctional stents responsible for thrombosis. However, few data exist regarding the feasibility and safety of retrieval device use in previously deployed coronary stents.

Methods

We have developed an enhanced device consisting of an asymmetric forceps, conducting shaft (1.6 mm diameter, 150 cm length), and control handle. Bare‐metal stents (3 mm diameter) were implanted in four pigs to create a malapposition model. Coronary artery injury was evaluated by intravascular ultrasound (IVUS) and histological imaging on the first and 14th days.

Results

The device was delivered to the coronary artery using the existing catheter (7 Fr). After opening the forceps, the blade was forced into the space between the vessel wall and the stent, and the stent struts were then grasped with the forceps. This was then pulled back into the catheter, still grasping the stent struts with the forceps. All stents were successfully retrieved by this method (n = 4). On the first day, no apparent vessel wall injury was detectable by IVUS, although histological findings revealed damage to endothelial monolayer on retrieval of deployed stent. On the 14th day, mild intimal thickening was observed by IVUS and histology.

Conclusions

These results demonstrate that the present device can be applied to transluminal retrieval of acquired malappositioned coronary stents.

     

Assessment of Angiographic Coronary Calcification and Plaque Composition in Virtual Histology Intravascular Ultrasound

Objectives

We assessed the relation between coronary plaque composition and angiographic calcification by using virtual histology intravascular ultrasound (VH‐IVUS).

Background

The plaque vulnerability according to angiographic calcification is unclear.

Methods

Subjects were 140 consecutive patients (145 lesions) undergoing VH‐IVUS before percutaneous coronary intervention. Subjects were divided into 4 groups: no calcification group (n = 27), spotty group (n = 65) that had calcium deposits under 90° in grayscale IVUS, intermediate group (n = 37) had calcium deposits with 90° or more and under 180°, and extensive group (n = 16) had calcium deposits with 180° or more.

Results

The number of VH thin‐cap fibroatheromas in spotty group was significantly larger than no calcification group, intermediate group, and extensive group (0.66 ± 0.71 vs 0.22 ± 0.42 [P < 0.01], 0.32 ± 0.48 [P < 0.05], 0.13 ± 0.34 [P < 0.01], respectively). Spotty group without angiographic calcification had significantly larger %necrotic core than with angiographic calcification (24.5 ± 6.7% vs 19.9 ± 7.2%, P < 0.05). Intermediate group without angiographic calcification had significantly larger necrotic core area than with angiographic calcification (2.5 ± 0.9 mm² vs 1.7 ± 0.9 mm², P < 0.05). Extensive group with angiographic calcification had significantly larger %dense calcium than without angiographic calcification (18.3 ± 4.0% vs 13.4 ± 4.4%, P < 0.05).

Conclusions

Lesions with spotty calcification was highly vulnerable in VH‐IVUS. Spotty or intermediate plaque calcification without angiographic calcification was more vulnerable than those with angiographic calcification. Extensive plaque calcification with angiographic calcification had more dense calcium than those without angiographic calcification.

     

Virtual Histology Intravascular Ultrasound Analysis of Attenuated Plaque and Ulcerated Plaque Detected by Gray Scale Intravascular Ultrasound and the Relation Between the Plaque Composition and Slow Flow/No Reflow Phenomenon During Percutaneous Coronary Intervention

Objective

This study aimed to assess the plaque characteristics of attenuated and ulcerated plaques in virtual‐histology intravascular ultrasound (VH‐IVUS) and the incidence of slow flow/no reflow during percutaneous coronary intervention (PCI).

Background

The attenuated and ulcerated plaques are thought as embolic prone plaque; however, the plaque characteristics are unclear.

Methods

Subjects were 119 patient's 121 lesions undergoing VH‐IVUS before coronary stenting. These lesions were divided into the 15 lesions showing attenuated plaque, 24 lesions showing ulcerated plaque, and 82 lesions revealing neither attenuated nor ulcerated plaque (the control group).

Results

Fibro‐fatty tissue in the attenuation group was significantly larger than the control group (27.5 ± 9.5% vs 13.9 ± 8.2%, P < 0.01, 3.5 ± 1.9 mm² vs 1.6 ± 1.2 mm², P < 0.01). Necrotic core in ulceration group was significantly larger than the control group (20.7 ± 9.0% vs 15.9 ± 9.0%, P < 0.05, 2.5 ± 1.3 mm² vs 1.7 ± 1.0 mm², P < 0.01). Dense calcium in ulceration group was significantly larger than the control group (12.3 ± 6.4% vs 8.3 ± 7.1%, P < 0.05, 1.4 ± 0.7 mm² vs 0.9 ± 0.8 mm², P < 0.01). In the ulceration group, the necrotic core area of acute coronary syndrome was significantly larger than the stable angina pectoris (3.0 ± 1.4 mm² vs 1.8 ± 1.0 mm², P < 0.05). The incidence of slow flow/no reflow was significantly higher in the attenuation and ulceration group than the control group (20.0% [3/15], 20.8% [4/24] vs 4.9% [4/82], P < 0.05, 0.05).

Conclusion

The attenuated plaque had significantly larger fibro‐fatty tissue. The ulcerated plaque had significantly larger necrotic core and dense calcium. The lesions with the attenuated and the ulcerated plaque had more frequent slow flow/no reflow during PCI. (J Interven Cardiol 2013;26:295–301)