Malapposed Struts Research Articles

Longitudinal Neointimal Distribution Pattern After Everolimus-Eluting Stent Implantation: Insights From Optical Coherence Tomography Study

Background/purposeEverolimus-eluting stents (EES) are established as latest generation drug eluting stents. However, optical coherence tomography (OCT) assessment of neointimal distribution after EES implantation is lacking. We aimed to assess the longitudinal neointimal distribution pattern after EES implantation using OCT. MethodsData from 3 prospective studies (HEAL-EES, REVER and RESERVOIR), including patients with EES implantation and OCT follow-up study, were merged. Analyzed stents were divided into 3 segments of equal length (distal, medial, proximal). Longitudinal neointimal distribution patterns were compared between the 3 segments using generalized estimating equation. Neointimal thickness (NIT), neointimal area obstruction, and uncovered or malapposed struts were analyzed. ResultsIn total, 86 patients (92 lesions) were analyzed. Time of OCT follow-up was 9.0 ± 1.5 months. NIT was 101.7 ± 65.4 μm and neointimal obstruction area was 12.2 ± 7.6%. The number of assessed struts was the same in all three segments. NIT tended to be higher at the medial segment (108.8 ± 71.1 μm) compared to distal (103.0 ± 63.4 μm) and proximal (93.3 ± 61.1 μm) (p = 0.076). Neointimal area obstruction was significantly different between the 3 segments (12.4 ± 7.5% [distal], 13.1 ± 7.7% [medial], 11.1 ± 7.5% [proximal]; p = 0.037). In the proximal segment, there was a significantly higher frequency of uncovered struts compared to medial and distal segments (3.9% vs. 2.1% vs. 2.5%, p = 0.009). The distribution of malapposed struts was not significantly different. ConclusionsDistribution of neointimal hyperplasia seems to be different between stent segments, being higher in the medial segment as compared to proximal and distal. Whether this may reflect a response to local pre-interventional plaque burden centrally covered by the stent should be confirmed in a future study. Manuscript summaryAs optical coherence tomography based assessment of neointimal distribution after everolimus-eluting stent implantation is lacking, we analyzed data of 86 patients (92 lesions) from 3 prospective trials to evaluate neointimal distribution in distal, medial and proximal stent segments. Neointimal hyperplasia seemed to be different between the three segments, with a higher burden in the medial stent segment. Whether this reflects a response to local pre-interventional plaque burden centrally covered by the stent should be confirmed in a future study.

Influence of Plaque Characteristics on Early Vascular Healing in Patients With ST-Elevation Myocardial Infarction

ObjectivesTo compare the early vascular healing of ruptured plaques (RP) and non-ruptured plaques (NRP) one month after primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI), using optical coherence tomography (OCT). BackgroundVascular healing and strut coverage are important factors in reducing the risk of stent thrombosis after PCI. Influence of underlying lesion characteristics and differences in healing response between RP and NRP are unknown. MethodsTwenty-six STEMI-patients underwent PCI and implantation of a polymer-free drug-coated Biofreedom stent (BF-BES). OCT was performed pre-PCI, post-PCI and at 1-month follow-up. The patients were divided into two groups: RP = 15 and NRP = 11. OCT analyses of culprit lesion, post stent implantation at baseline and follow-up were performed to determine the difference in vascular healing based on presence of uncovered and/or malapposed stent struts and intraluminal filling defects. ResultsThe stent coverage did not differ significantly between the two groups at 1-month follow-up with percentage of uncovered struts: RP 26.5% [IQR 15.0–49.0] and NRP 28.1% [IQR 15.5–38.8] for NRP (p = 0.78). At 1-month, RP showed an increased percentage of late acquired malapposed struts (1.4% [IQR 0.8–2.4] vs. 0.0% [IQR 0.0–1.4], p = 0.03) and a larger total malapposition area (1.3 mm2 [IQR 0.4–2.5] vs. 0.0 mm2 [IQR 0.0–0.9], p = 0.01), compared to NRP. ConclusionThree out of four struts were covered within one month after stenting. The vascular healing was comparable in RP and NRP on stent coverage. However, RP had more and larger late acquired malapposition areas.

The impact of proximal cell rewiring compared with distal cell rewiring with single-stent deployment and subsequent kissing balloon inflation in the inadequate jailing of a Kaname stent on the side branch ostium.

The aim of the study was to identify differences between proximal and distal cell rewir-ing with subsequent kissing balloon inflation (KBI) in the presence of a link connected to a carina on the jailed side branch ostium (SBO). Kaname stents were deployed in bifurcation models (n = 12) with subsequent KBI and were confirmed by optical coherence tomography. The jailing configuration and cell rewiring were completely controlled and classified as follows: FC-Dist, free carina (no links connected to a carina) and distal cell re-wiring; CC-Prox, connected to a carina (the presence of a link connected to a central carina) and proximal cell rewiring; CC-Dist, connected to a carina and distal cell rewiring; and FarDist, far-distal cell rewiring. The number of frames with malapposed struts (MS) in the SBO was significantly smaller in the CC-Prox group than in the CC-Dist group (26.7 ± 1.5 and 39.7 ± 0.6, respectively, p < 0.05). The number of frames with MS continuously present from the distal end to the proximal side of the SBO was significantly smaller in the CC-Prox group than in the CC-Dist group (17.0 ± 2.0 and 36.7 ± ± 5.8, respectively, p < 0.05). The ratio of the maximal opened stent cell area to the SBO area was significantly larger in the CC-Prox group than in the CC-Dist group (64.2 ± 1.2% and 38.8 ± 5.6%, respectively, p < 0.05). This study showed that in cases with a link connected to a carina, fewer malapposed struts may be present in proximal cell rewiring with subsequent KBI than in distal cell rewiring.

Optical coherence tomography for evaluating Synergy everolimus-eluting stents with biodegradable polymer and Xience durable polymer everolimus-eluting stents following percutaneous coronary intervention in patients with left main coronary artery stenosis

Aim. The development of on a new generation of stents with abluminal biodegradable polymer is aimed at accelerating the neointimal growth and reducing the inflammatory response of the vascular wall. This article presents an analysis of healing characteristics, as assessed by optical coherence tomography (OCT), of ultrathin Synergy everolimus-eluting stent with biodegradable polymer and Xience everolimus-eluting stent with durable polymer three months after implantation.Methods. In this prospective, single-center study fifty patients with significant stenosis of the left main coronary artery were randomized in 2 groups for implantation of everolimus-eluting stents with durable polymer (Xience) or abluminal biodegradable polymer (Synergy). After three months all patients underwent control coronarography supported by optical coherence tomography. A Neointimal Healing Score (NIH Score) obtained at three months after stent implantation by means of optical coherence tomography was the primary endpoint. Such OCT data as percentage of uncovered or malapposed struts only and presence of both malapposed and uncovered struts were planned as the secondary endpoints. To study the freedom from adverse events, one composite endpoint including myocardial infarction, repeat left coronary artery revascularization and death within 12 months after the procedure was determined. Results. There were no significant differences in the NIH score (primary endpoint) in two groups (25.6±12.3 in Xience vs 32.5±20.3 in Synergy, respectively; p = 0.12). The struts of both types of stents showed statistically similar coverage and apposition at 3-month OCT follow-up: percentage of uncovered struts only was 6.3±3.9 and 9.9±7.8 in Xience and Synergy groups, respectively (p = 0.098) and malapposed struts only 0.25±0.5 vs 0.37±0.5; p = 0.628. The presence of both malapposed and uncovered struts was 4.9±3.8 and 5.1±4.5 in two groups and didn’t differ statistically (p = 0.92). During 12-month follow-up, two cases of stent thrombosis were recorded (one in each group), which required repeat revascularization. In addition, one case of myocardial infarction related to the right coronary artery occurred in the Synergy group.Conclusion. The Synergy everolimus-eluting stent with abluminal biodegradable polymer has a healing profile comparable to that of Xience everolimus-eluting stent with durable polymer with a low rate of uncovered and malapposed struts at 3-month follow-up. A low incidence of adverse events in both groups during 12-month follow-up indicates the safety of the stents under study.Received 18 September 2017. Revised 13 December 2017. Accepted 15 December 2017.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.Author contributionsAll authors contributed equally to the work.

Vascular response and healing profile of everolimus-eluting bioresorbable vascular scaffolds for percutaneous treatment of chronic total coronary occlusions: A one-year optical coherence tomography analysis from the GHOST-CTO registry

BackgroundBioresorbable vascular scaffolds (BVS) have been heralded with potential benefits that are especially desired in long lesions, including chronic total occlusions (CTOs). Procedural feasibility and mid-term outcomes of BVS in CTOs have been reported. However, there is still a paucity of data regarding the vascular and healing response to BVS in CTOs evaluated by optical coherence tomography (OCT). MethodsThis study included prospectively 21 patients who had a CTO lesion treated with a BVS. Angiography and OCT scan were recorded at either post-implantation and 1-year follow-up. Quantitative coronary angiography and OCT analyses were performed by an independent core laboratory. ResultsThe angiographic analysis showed a significant increase in the percentage of in-segment diameter stenosis at 1year (11.89±9.5% vs. 21.84±11.7%; p=0.002). The OCT analysis showed a trend (p=0.07) towards increased mean scaffold area and significant reductions in mean lumen diameter (3.1±0.36mm vs. 2.85±0.47mm; p=0.0046), mean lumen area (7.8±1.73mm2 vs. 6.76±2mm2; p=0.0082) and minimal lumen area (5.26±1.86mm2 vs. 3.56±1.52mm2; p<0.0001). Malapposition area and volume decreased from 0.26±0.17mm2 to 0.08±0.1mm2 (p=0.0003) and from 14.17±12.92mm3 to 3.99±4.46mm3 (p=0.0014), respectively. The rate of uncovered or malapposed struts, measured at the frame level, was 5.29±6.48% at 1year. ConclusionsIn a small series of CTO patients treated with BVS implantation, OCT outcomes at 1year displayed an overall favorable vascular response and healing profile.

Haemodynamic effects of incomplete stent apposition in curved coronary arteries.

Incomplete stent apposition (ISA, also known as malapposition) is a complication that affects day-to-day coronary stenting procedures. ISA is more prominent in complex arterial geometries, such as curvature, asa result of the limited conformability of coronary stents. These malapposed struts disturb the otherwise near-wall laminar blood flow and form a micro-recirculation environment. The micro-recirculation environment is often associated with low wall shear stress (WSS) and upsets the delicate balance of vascular biology, providing possible nidus for thrombosis and restenosis. In this study, a three-dimensional (3D) stent model was virtually deployed into an idealised curved coronary artery. Computational fluid dynamics (CFD) simulations were carried out to systematically analyse the haemodynamic effects of increasing maximum ISA distances, ranging from 180 (moderate), 400 (intermediate) to 910μm (severe) in an artery with decreasing radius of curvature (ROC). Micro-recirculations around both proximal and distal malapposed struts become more pronounced as compared to fully-apposed struts. The accompanying areas of low temporally-averaged WSS (AL-TAWSS) can increase twofold compared to the fully-apposed condition. Furthermore, substantial regions (∼5.2% and 9.0%) of AL-TAWSS are detached from the distal end of the malapposed struts in both moderate and intermediate cases respectively. Malapposed stents also induce more variation of TAWSS at the inner bend of the artery. At the stent surface, maximum WSS increases threefold from the fully-apposed case to intermediate ISA. High WSS on the strut surface is known to activate platelets which when exposed to the micro-recirculation environment may lead to their deposition and thrombosis.

Optical coherence tomography follow-up 18 months after titanium-nitride-oxide-coated versus everolimus-eluting stent implantation in patients with acute coronary syndrome

Background Inadequate neointimal coverage of stent struts is associated with late stent thrombosis. Purpose To demonstrate the extent of neointimal coverage and strut malapposition in titanium-nitride-oxide-coated bioactive stents (BAS) versus everolimus-eluting stents (EES) by optical coherence tomography (OCT) performed at 18-month follow-up. Material and Methods In the BASE-ACS trial, 827 patients presenting with acute coronary syndrome were randomized to receive either BAS or EES. Forty patients (20 BAS, 20 EES) underwent OCT at 18-month follow-up for evaluation of stent strut coverage, malapposition, and neointimal hyperplasia (NIH). Primary endpoint was binary stent strut coverage (ratio of covered struts to all analyzed struts multiplied by 100). Co-primary endpoint was the percentage of malapposed struts. Results We analyzed 3465 struts in 330 cross-sections of BAS and 3327 struts in 316 cross-sections of EES. Binary stent strut coverage, based on strut-level analysis, was higher with BAS versus EES (99.5% versus 94.2%, respectively; P < 0.001), the strut-level percentage of malapposed struts was lower with BAS (0.6% versus 2.5%, respectively; P < 0.001). Yet, the mean NIH thickness was greater with BAS (237 ± 125 versus 108 ± 62 µm, respectively; P < 0.001). Conclusion In the current post-hoc analysis with OCT performed at 18 months, binary strut coverage, based on strut-level analysis, was higher with BAS versus EES; strut-level malapposed struts were fewer with BAS; yet, BAS induced thicker NIH.

Incidence and Morphological Predictors of Intrastent Coronary Thrombus After Drug-Eluting Stent Implantation (from a Multicenter Registry)

The mechanisms responsible for late and very late stent thrombosis remain incompletely understood. This study aimed to evaluate the incidence and morphologic predictors of intrastent thrombus in patients after drug-eluting stent (DES) implantation using optical coherence tomography (OCT). A total of 208 patients with 262 DES who underwent follow-up OCT examination >6 months after DES implantation were included. The detailed vascular morphology including characteristics of neointima was analyzed. Thrombus was identified in 24 patients (11.5%) 11 months after DES implantation. Minimal lumen cross-sectional area was significantly smaller in the thrombus group than in the nonthrombus group (2.9 ± 1.7 vs 4.6 ± 2.0 mm(2); p <0.001). No difference was found in the frequency of uncovered or malapposed struts between the 2 groups. Thin-cap fibroatheroma (20.6% vs 0.1%; p <0.001) and heterogeneous neointima (22.2% vs 9.0%; p = 0.001) were more frequently detected in the thrombus group compared to the nonthrombus group. Second-generation DES showed lower incidence of thrombus, uncovered struts, and extrastent lumen compared with first-generation DES. In conclusion, the present OCT study revealed that smaller lumen cross-sectional area and neointimal morphology are important factors associated with intrastent thrombus. Second-generation DES demonstrated improved arterial healing and a lower incidence of intrastent thrombus compared with first-generation DES.

Optical coherence tomography analysis of the stent strut and prediction of resolved strut malapposition at 3 months after 2nd-generation drug-eluting stent implantation.

Our objective was to clarify whether thrombogenic problems with stent struts are resolved at 3months after 2nd-generation drug-eluting stent implantation. Twenty-one patients with stable angina pectoris having 28 (22 zotarolimus-eluting, 6 everolimus-eluting) stents with optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) were evaluated. Stent strut coverage and malapposition were evaluated by OCT immediately after PCI and at 3-month follow-up. Acute strut malapposition was observed in 26 out of 28 analyzed stents (92.9%). At 3-month follow-up, 7 (26.9%) of those 26 stents with strut malapposition were completely resolved, and the mean percentages of uncovered struts and malapposed struts were 8.3 and 2.0% when analyzed by each individual stent. When analyzing a total of 30,060 struts, 807 struts (2.7%) demonstrated acute strut malapposition. Among these, 219 struts (27.1%) demonstrated persistent strut malapposition. On the basis of receiver-operating characteristic curve analysis, a strut-to-vessel (S-V) distance≤160µm on post-stenting OCT images was the corresponding cutoff point for resolved malapposed struts (sensitivity 78.1%, specificity 62.8%, area under the curve 0.758). The S-V distance of persistent malapposed struts on post-stenting OCT images was longer than that of resolved malapposed struts (235±112 vs. 176±93µm, p<0.01). At 3months after PCI, the prevalence rates of uncovered and malapposed struts were relatively low in 2nd-generation drug-eluting stent. Our results suggest that OCT-guide PCI with an S-V distance≤160µm may be recommended especially in patients with planed short-term DAPT.

Causes of very late stent thrombosis investigated using optical coherence tomography.

Very late stent thrombosis (VLST) remains an unresolved problem, and recent reports have indicated that VLST onset can occur in patients treated with both drug-eluting stents (DES) and bare metal stents (BMS). We evaluated the causes of VLST using optical coherence tomography (OCT). OCT was performed in 22 patients (12 DES-treated patients, 10 BMS-treated patients). Because two instances of VLST occurred simultaneously in one case in the DES group, the DES group comprised 13 lesions, while the BMS group comprised 10 lesions. All struts were counted in each frame, and the proportion of uncovered or malapposed struts was calculated based on the overall number of struts in the stent. The interval from stent implantation to VLST onset was significantly longer in the BMS group. The proportion of uncovered struts and the ratio of malapposed struts were significantly higher in the DES group than in the BMS group. The OCT analysis demonstrated intimal hyperplasia or intimal disruption in all patients in the BMS group. However, in the DES group, severe hyperplasia and/or neoatherosclerosis was observed in only eight lesions (61.5%), while uncovered and malapposed struts were involved in the other lesions. In most BMS-treated lesions, it appeared that VLST was caused by the occurrence of neoatherosclerosis after stent implantation. The causes of VLST in DES-treated lesions are more various and complicated than those observed for BMS-treated lesions.

Abstract 9625: Late Malapposition and Endothelial Coverage of Drug-Eluting-Stents - A Prospective Optical Coherence Tomography Study

Background: Uncovered stent struts of drug-eluting stents (DES) are associated with late stent thrombosis. Early and late malapposition of stent struts may be the major mechanisms for uncovered struts. Data regarding coverage of malapposed struts are missing. Aims: This study examines malapposition of DES and the coverage of late malapposed struts in patients who underwent elective percutaneous coronary intervention (PCI). Methods: Fifty patients treated with 60 DES (25 Everolimus-eluting stents [EES], 18 Zotarolimus-eluting stents [ZES], 17 Biolimus-eluting stents [BES]) underwent optical coherence tomography (OCT) directly after implantation and after 12 months. Results: Postintervention acute stent malapposition (ASM) occurred in 30 stents (50%). Of these, 21 stents (70%) resolved completely, whereas 6 stents resolved partly and 3 persisted completely after one year. At this time-point, a total of 15 stents (25%) with late stent malappositions (LSM) were detected due to late acquired stent malapposition (LASM) in additional 10 stents (Table 1). Twelve of these 15 stents showed complete or almost complete (&gt;80%) coverage of the malapposed struts, whereas 3 stents had no coverage of any malapposed strut (Table 2). Conclusion: A quarter of electively implanted DES is associated with LSM. Uncoverage of malapposed struts applies only to a minority of stents with LSM. The reason for coverage/uncoverage and the clinical impact has to be determined.

Optical coherence tomography evaluation of late strut coverage patterns between first‐generation drug‐eluting stents and everolimus‐eluting stent

To compare strut coverage patterns between everolimus-eluting stent (EES) and first-generation drug-eluting stents (DES) at more than 12 months after successful implantation, using optical coherence tomography (OCT). No sufficient OCT data has been reported comparing late strut coverage patterns between EES and first-generation DES. The favorable late results after EES implantation could be related to lower rates of uncovered and malapposed struts. A total of 66 DES (21 EES, 23 SES, and 22 PES) that were implanted at least 1 year in advance in 40 patients and met good late angiographic results were evaluated by OCT. The percentage of uncovered and malapposed struts, calculated as the ratio of uncovered or malapposed struts to total struts in all cross-sectional images per stent, was compared among the three groups. A total of 35,061 struts were analyzed: 11,967 from EES, 11,855 from SES, and 11m239 from PES. The average tissue coverage thickness of the struts per stent was greater in EES than in SES and PES (109 ± 40 µm vs. 72 ± 27 µm and 83 ± 26 µm, respectively; P = 0.001). The percentage of uncovered struts (1.9 ± 4.1% in EES vs. 11.6 ± 12.7% in SES, P = 0.01 and vs. 7.1 ± 5.2% in PES, P < 0.001) and malapposed struts (0.1 ± 0.3% in EES vs. 1.8 ± 3.5% in SES, P = 0.01 and vs. 3.5 ± 5.1% in PES, P = 0.02) was much lower in EES than in first-generation DES, with no significant differences between SES and PES. Late strut coverage patterns are not similar between EES and first-generation DES. EES showed a lower percentage of uncovered and malapposed struts.

Different neointimal response to overlapping segments between everolimus eluting stents and sirolimus eluting stents -optical coherence tomographic study

Purpose: Although overlapping coronary stents in long lesions by percutaneous coronary intervention are common, some recent clinical studies have revealed an adverse neointimal response to overlapping segments of drug eluting stents due to increased drug and polymer toxicity. Thus, the purpose of this study was to evaluate the difference of neointimal response to overlapping segments of Everolimus- Eluting Stents (EES) and Sirolimus-Eluting Stents (SES) by Optical Coherence Tomography (OCT). Methods: Thirty-seven consecutive lesions treated with overlapping stents (20 EES and 17 SES) were analyzed by OCT. We compared the OCT parameters including the rate of uncovered or malapposed struts, percentage Neointimal Hyperplasia (%NIH) and strut-level neointimal thickness between overlapping segments of EES and those of SES. Heterogeneity index (sum of (max NIH thickness – minimum one) at each cross-section/number of cross-sections) was also calculated. Results: A total of 2984 struts in 277 cross-sections of 37 stented segments were analyzed. At overlapping segments, the rate of uncovered or malapposed struts, %NIH, strut-level neointimal thickness and heterogeneity index in EES were significantly lower than those in SES (Table). ![Figure][1] Conclusions: According to our study assessed by OCT, EES showed more favorable neointimal response to the overlapping segments than SES. These findings should be considered when deploying overlapping stents in long lesions. [1]: pending:yes

Prolonged high‐pressure is required for optimal stent deployment as assessed by optical coherence tomography

Optimizing stent deployment is important for both acute- and long-term outcomes. High-pressure balloon inflation is the standard for coronary stent implantation. However, there is no standardized inflation protocol. We hypothesized that prolonged high-pressure balloon inflation until stabilization of inflation pressure is superior to a rapid inflation/deflation sequence for both stent expansion and strut apposition. A high-pressure rapid inflation/deflation sequence was deployed followed by angiography to assure no residual stenosis. Optical coherence tomography (OCT) was then performed followed by prolonged inflation until balloon pressure was stabilized for 30 sec using the same balloon at the same pressure as the rapid sequence. A second OCT run was then done. Thirteen thousand nine hundred thirteen stent struts were evaluated by OCT in 12 patients undergoing successful stenting. Stent expansion improved with prolonged (206 ± 115 sec) vs. rapid (28 ± 17 sec) inflation for both minimal stent diameter (3.0 ± 0.5 vs. 2.75 ± 0.44 mm, P < 0.0001) and area (7.83 ± 2.45 vs. 6.63 ± 1.85 mm(2) , P = 0.0003). The number of malapposed struts decreased (45 ± 41 vs. 88 ± 75, P = 0.005) as did the maximal malapposed strut distance (0.31 ± 0.2 vs. 0.43 ± 0.2 mm, P = 0.0001). Factors related to strut malapposition after rapid inflation included localized asymmetry in 67%, stent underexpansion in 75%, and stent undersizing in 67%. These data demonstrate that prolonged inflation is superior to a rapid inflation/deflation technique for both stent expansion and strut apposition. We recommend for routine stent deployment a prolonged inflation protocol as described above to optimize stent deployment.

Natural consequence of post-intervention stent malapposition, thrombus, tissue prolapse, and dissection assessed by optical coherence tomography at mid-term follow-up

AimsWe performed this study to clarify natural consequences of abnormal structures (stent malapposition, thrombus, tissue prolapse, and stent edge dissection) after percutaneous coronary intervention (PCI).Methods and resultsThirty-five patients treated with 40 drug-eluting stents underwent serial optical coherence tomography (OCT) imaging immediately after PCI and at the 8-month follow-up. Among a total of 73 929 struts in every frame, 431 struts (26 stents) showed malapposition immediately after PCI. Among these, 49 remained malapposed at the follow-up examination. The mean distance between the strut and vessel wall (S–V distance) of persistent malapposed struts on post-stenting OCT images was significantly longer than that of resolved malapposed struts (342 ± 99 vs. 210 ± 49 μm; P <0.01). Based on receiver-operating characteristic curve analysis, an S–V distance ≤260 µm on post-stenting OCT images was the corresponding cut-off point for resolved malapposed struts (sensitivity: 89.3%, specificity: 83.7%, area under the curve = 0.884). Additionally, 108 newly appearing malapposed struts were observed on follow-up OCT, probably due to thrombus dissolution or plaque regression. Thrombus was observed in 15 stents post-PCI. Serial OCT analysis revealed persistent thrombus in 1 stent, resolved thrombus in 14 stents, and late-acquired thrombus in 8 stents. Tissue prolapse observed in 38 stents had disappeared at the follow-up. All eight stent edge dissections were repaired at the follow-up.ConclusionMost cases of stent malapposition with a short S–V distance, thrombus, tissue prolapse, or minor stent edge dissection improved during the follow-up. These OCT-detected minor abnormalities may not require additional treatment.

Stent strut coverage of titanium-nitride-oxide coated stent compared to paclitaxel-eluting stent in acute myocardial infarction: TITAX-OCT study

Drug-eluting stents (DES) have reduced the rate of restenosis but recent studies have raised concern over the risk of late stent thrombosis (LST). Incomplete stent endothelialization and delayed vascular healing have been associated with LST. The titanium-nitride-oxide coated bio-active stent (BAS) has shown promising results in patients with acute coronary syndromes, but there is little long-term optical coherence tomography (OCT) data comparing BAS with DES. The TITAX-AMI trial is a prospective, randomized, multicenter trial comparing BAS to paclitaxel-eluting stent (PES) in 425 patients with acute myocardial infarction. A total of 18 patients (9 per group) with no major cardiac events during follow-up, were enrolled in this substudy >36 months (mean 47 months) after stent implantation. Quantitative coronary angiography was performed and stent strut endothelialization and vascular healing were assessed with OCT. The binary stent strut coverage was significantly higher in the BAS group compared with the PES group (99.6 vs. 89.2%, p < 0.001) and there were less malapposed struts in the BAS group (0.2 vs. 13.8%, respectively, p < 0.001). The neointimal hyperplasia (NIH) thickness (266 ± 166 vs. 126 μm ± 126 μm, p < 0.001) and percentage of NIH area (26.2 vs. 7.6%, p < 0.001) were greater in the BAS group than in the PES group. Late incomplete endothelialization was not uncommon after PES implantation. Stents in the BAS group were completely endothelialized. This difference may contribute to the more common LST after PES implantation in the TITAX-AMI trial.

Comparison of Optical Coherence Tomographic Assessment between First- and Second-Generation Drug-Eluting Stents

PurposeThere is a lack of sufficient data in comparison of optical coherence tomographic (OCT) findings between first- and second-generation drug-eluting stents (DES). Compared to first-generation (i.e., sirolimus- or paclitaxel-eluting stents), second-generation DESs (i.e., everolimus- or biolinx-based zotarolimus-eluting stents) might have more favorable neointimal coverage.Materials and MethodsFollow-up OCT findings of 103 patients (119 lesions) treated with second-generation DESs were compared with those of 139 patients (149 lesions) treated with first-generation DESs. The percentage of uncovered or malapposed struts, calculated as the ratio of uncovered or malapposed struts to total struts in all OCT cross-sections, respectively, was compared between the two groups.ResultsBoth DES groups showed similar suppression of neointimal hyperplasia (NIH) on OCT (mean NIH cross-sectional area; second- vs. first-generation=1.1±0.5 versus 1.2±1.0 mm2, respectively, p=0.547). However, the percentage of uncovered struts of second-generation DESs was significantly smaller than that of first-generation DESs (3.8±4.8% vs.7.5±11.1%, respectively, p<0.001). The percentage of malapposed struts was also significantly smaller in second-generation DESs than in first-generation DESs (0.4±1.6% vs.1.4±3.7%, respectively, p=0.005). In addition, intra-stent thrombi were less frequently detected in second-generations DESs than in first-generation DESs (8% vs. 20%, respectively, p=0.004).ConclusionThis follow-up OCT study showed that second-generation DESs characteristically had greater neointimal coverage than first-generation DESs.

Optical coherence tomography findings of very late stent thrombosis after drug-eluting stent implantation

Previous optical coherence tomography (OCT) studies in patients with drug-eluting stents (DESs)-related very late stent thrombosis (VLST) were scarce. Therefore, we investigated OCT findings of VLST after implantation of DESs. Using OCT, we analyzed the status of stent struts and neointimal characteristics in 18 patients who developed VLST after DES implantation. These results were compared to those in 57 patients with neointimal hyperplasia causing >40% diameter stenosis. Lipid-laden neointima was defined as a region with marked signal attenuation and a diffuse border. Four (22.2%) of 18 patients with VLST had ruptured and lipid-laden neointima inside DESs without uncovered or malapposed stent struts. In the remaining 14 patients who developed VLST without neointimal rupture, uncovered and malapposed struts were observed in nine and seven patients, respectively, and lipid-laden neointima in four patients. Lipid-laden neointima was more frequently observed in four patients with neointimal rupture than in 14 patients without neointimal rupture (100% vs. 28.6%, respectively, P = 0.023). Of 57 patients with neointimal hyperplasia, eight (14.0%) had lipid-laden neointima. Time to OCT study after DES implantation was significantly longer in the eight patients with lipid-laden neointima than in 49 patients without lipid-laden neointima (45.5 ± 17.7 months vs. 11.7 ± 7.2 months, respectively, P < 0.001). Lipid-laden neointima was detected in some patients with neointimal hyperplasia > 1 year after DES implantation. In addition to uncovered or malapposed struts, rupture of lipid-laden neointima inside DESs was identified in some patients with DES-related VLST.

Angiographic, IVUS and OCT evaluation of the long-term impact of coronary disease severity at the site of overlapping drug-eluting and bare metal stents: a substudy of the ODESSA trial

BackgroundA potentially adverse vascular response to overlapping drug eluting stents (DES) has been suggested in current research.ObjectiveTo evaluate the impact of baseline disease severity at the site of stent overlap.Methods...

Strut Coverage and Vessel Wall Response to a New-Generation Paclitaxel-Eluting Stent With an Ultrathin Biodegradable Abluminal Polymer

Background— Polymer-coated drug-eluting stents are effective in preventing restenosis but have been associated with delayed healing and incomplete strut coverage. It is unknown whether paclitaxel-eluting stents (PES) with minimal biodegradable abluminal coating enhances strut coverage while preventing neointimal hyperplasia. Using optical coherence tomography (OCT) as a primary imaging modality, we assessed the proportion of uncovered struts at 6-month follow-up in PES coated with durable versus ultrathin (&lt;1 μm) biodegradable abluminal polymers. Methods and Results— In this pilot trial, 60 patients with de novo lesions (≤25 mm) in native coronary vessels were randomly assigned to receive either TAXUS Liberté PES or JACTAX PES, a Liberté stent with polymer deposited abluminally as microdots (JACTAX HD: 9.2 μg each of polymer and paclitaxel per 16-mm stent; JACTAX LD: 5 μg each). OCT follow-up occurred at 6 months with clinical follow-up through 1 year. The primary end point was percent uncovered struts by OCT. An independent core laboratory blinded to stent assignment analyzed images. The 6-month rate of uncovered struts per patient was 5.3±14.7% for TAXUS Liberté, 7.0±12.2% for JACTAX HD, and 4.6±7.3% for JACTAX LD ( P =0.81); percent malapposed struts was 1.4±4.4%, 0.8±1.9%, and 1.1±2.8%, respectively ( P =0.86). Strut-level intimal thickness was 0.20±0.10, 0.22±0.15, and 0.24±0.15 mm ( P =0.64); percent volume obstruction by OCT was 22.2±12.8, 22.5±16.2, and 25.8±15.2 ( P =0.69). There were no deaths, Q-wave myocardial infarctions, or stent thromboses through 1 year. Conclusions— JACTAX PES with an ultrathin microdot biodegradable abluminal polymer did not result in improved strut coverage at 6 months compared with TAXUS Liberté. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00776204.