Three-year follow-up after implantation of metallic coronary-artery stents

Neoatherosclerosis: Coronary stents seal atherosclerotic lesions but result in making a new problem of atherosclerosis

Chronic inflammation of the native vessel wall with infiltration of lipid-laden foamy macrophages through impaired endothelium results in atherosclerosis. Percutaneous coronary intervention, including metallic stent implantation, is now widely utilized for the treatment of atherosclerotic lesions of the coronary artery. Bare-metal stents and the subsequently developed drug-eluting stents seal the atherosclerosis and resolve lumen stenosis or obstruction of the epicardial coronary artery and myocardial ischemia. After stent implantation, neointima proliferates within the stented segment. Chronic inflammation caused by a foreign body reaction to the implanted stent and subsequent neovascularization, which is characterized by the continuous recruitment of macrophages into the vessel, result in the transformation of the usual neointima into an atheromatous neointima. Neointima with an atherosclerotic appearance, such as that caused by thin-cap fibroatheromas, is now recognized as neoatherosclerosis, which can sometimes cause in-stent restenosis and acute thrombotic occlusion originating from the stent segment following disruption of the atheroma. Neoatherosclerosis is emerging as a new coronary stent-associated problem that has not yet been resolved. In this review article, we will discuss possible mechanisms, clinical challenges, and the future outlook of neoatherosclerosis.

Nine-Months Clinical Outcome of Biodegradable Polymer Coated Sirolimus-eluting Stent System: A Multi-Centre "Real-World" Experience

BACKGROUND

The main culprit in first-generation drug eluting stents is 'durable' polymer, whose continuous presence may impair arterial healing and ultimately have a negative impact on late outcomes. The main enigma behind the biodegradable polymer usage is its degradation after elution of drug. This reduces adverse events in unselected patients with complex coronary artery lesions treated with biodegradable polymer coated sirolimus-eluting stents.

AIM

The aim of the INDOLIMUS-G Registry was to evaluate safety and efficacy of the Indolimus (Sahajanand Medical Technologies Pvt. Ltd., Surat, India) sirolimus-eluting stents in large cohorts of unselected patients with complex coronary artery lesions.

MATERIALS AND METHODS

It is a multi-centre, non-randomized retrospective registry with a clear aim of evaluating safety and efficacy of the Indolimus sirolimus-eluting stents in consecutive patients enrolled between April 2012 and May 2014. The primary end-point of the study was major adverse cardiac events (MACE), which is a composite of cardiac death, myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR) and stent thrombosis (ST) at the end of follow-up. Clinical follow-up were scheduled at the end of 30-days, 6-months, and 9-months period.

RESULTS

The mean age of enrolled patients was 52.6 ± 11.0 years. A total of 1137 lesions were intervened successfully with 1242 stents (1.09 ± 0.30 stent per lesion). The average stent length and diameter was 27.42 ± 9.01 mm and 3.12 ± 0.36 mm respectively. There were 740 (73.40%) male patients, indicating their high prevalence. Diabetes, hypertension and totally occluded lesions were found in 372 (36.90%), 408 (40.47%) and 170 (16.86%) patients, respectively. This showed that study also included high risk complex lesions and not ideal recruited lesions. The incidence of MACE at 30-days, 6-months and 9-months were 3 (0.30%), 18 (1.80%) and 22 (2.20%) respectively. At 9-months, TLR was found in 6 (0.50%) patients. There were 2 (0.20%) cases of ST, 10 (1.0%) cases of MI and 4 (0.40%) cases of cardiac death at 9-month follow-up.

CONCLUSION

The lower incidence of MACE, TLR and ST at 9-month follow-up clearly delineates safety and efficacy of Indolimus SES in large cohorts of unselected patients with complex coronary lesions.

Stent thrombosis and restenosis: what have we learned and where are we going? The Andreas Grüntzig Lecture ESC 2014

Modern-day stenting procedures leverage advances in pharmacotherapy and device innovation. Patients treated with contemporary antiplatelet agents, peri-procedural antithrombin therapy and new-generation drug-eluting stents (DES) have excellent outcomes over the short to medium term. Indeed, coupled with the reducing costs of these devices in most countries there remain very few indications where patients should be denied treatment with standard-of-care DES therapy. The two major causes of stent failure are stent thrombosis (ST) and in-stent restenosis (ISR). The incidence of both has reduced considerably in recent years. Current clinical registries and randomized trials with broad inclusion criteria show rates of ST at or <1% after 1 year and ∼0.2-0.4% per year thereafter; rates of clinical ISR are 5% respectively. Angiographic surveillance studies in large cohorts show rates of angiographic ISR of ∼10% with new-generation DES. The advent of high-resolution intracoronary imaging has shown that in many cases of late stent failure neoatherosclerotic change within the stented segment represents a final common pathway for both thrombotic and restenotic events. In future, a better understanding of the pathogenesis of this process may translate into improved late outcomes. Moreover, the predominance of non-stent-related disease as a cause of subsequent myocardial infarction during follow-up highlights the importance of lifestyle and pharmacological interventions targeted at modification of the underlying disease process. Finally, although recent developments focus on strategies which circumvent the need for chronically indwelling stents--such as drug-coated balloons or fully bioresorbable stents-more data are needed before the wider use of these therapies can be advocated.

Influence of insulin resistance on in-stent restenosis in patients undergoing coronary drug-eluting stent implantation after long-term angiographic follow-up

OBJECTIVE

Previous studies have reported that insulin resistance is related to early in-stent restenosis (ISR) after coronary stenting. This study aimed to evaluate the influence of insulin resistance on the long-term angiographic outcome in patients undergoing coronary drug-eluting stent (DES) implantation.

MATERIALS AND METHODS

Within a single hospital-based cohort of patients (n=529) who underwent coronary DES implantation, angiographic follow-up was performed successfully for 417 study patients at 12-48 months after coronary stenting. ISR was defined as stenosis of at least 50% of the luminal diameter. Fasting plasma glucose and fasting plasma insulin were measured. Insulin resistance was expressed by the homeostasis model assessment index (HOMA-IRI).

RESULTS

Among the 417 patients who completed angiographic follow-up (mean 17.5±10.2 months), 58 patients (13.9%) had ISR whereas the remaining 359 patients (86.1%) did not have ISR. Patients with ISR had higher insulin resistance index (IRI) than nonrestenosis patients (P=0.004). Multiple logistic regression analysis (logit) showed that IRI was associated significantly with ISR (adjusted odds ratio 1.476, 95% confidence interval 1.227-1.776; P<0.001). In the nondiabetes subgroup of 309 patients, IRI was higher in patients with ISR than in nonrestenosis patients, as confirmed in a separate logit analysis (adjusted odds ratio 1.456, 95% confidence interval 1.152-1.839; P=0.002). Multiple linear regression analysis showed that IRI was associated significantly with in-stent diameter stenosis degree (P=0.043).

CONCLUSION

Insulin resistance was associated with ISR in patients undergoing coronary DES implantation at long-term angiographic follow-up.

Predictors and impact of target vessel revascularization after stent implantation for acute ST-segment elevation myocardial infarction: lessons from HORIZONS-AMI

BACKGROUND

Target vessel revascularization (TVR) may compromise the benefits of primary percutaneous coronary intervention in ST-segment elevation myocardial infarction (STEMI) We set out to identify the predictors and examine the impact of TVR after STEMI in patients receiving a coronary stent.

METHODS

In HORIZONS-AMI, 3,602 patients with STEMI were randomized to bivalirudin versus heparin and a glycoprotein IIb/IIIa inhibitor. Stents were implanted in 3,202 patients (2,982 were randomized to bare-metal stents versus paclitaxel-eluting stents, and 220 received nonrandomized stents).

RESULTS

Target vessel revascularization occurred in 219 patients (6.9%) at 1 year and in 437 patients (14.4%) at 3 years. Target vessel revascularization was ischemia-driven in 418 cases (95.7%). Target vessel revascularization was due to restenosis in 219 patients (50.1%), definite stent thrombosis in 124 (28.4%), and disease progression in 94 (21.5%). Independent predictors of TVR were more extensive coronary artery disease, smaller vessel size, longer lesion length and the number of stents implanted, post-percutaneous coronary intervention diameter stenosis, symptom onset to balloon time, treatment with bare-metal stents rather than paclitaxel-eluting stents, and scheduled angiographic follow-up. Target vessel revascularization was an independent predictor of subsequent myocardial infarction (hazard ratio [HR] 5.25, P < .0001), ST (HR 5.98, P < .0001), and major bleeding (HR 5.25, P < .0001) but not mortality (HR 0.88, P = .61).

CONCLUSIONS

In HORIZONS-AMI, TVR within 3 years after stent implantation was performed in ~1 of every 7 patients and was associated with more extensive coronary disease, more complex procedures, and bare metal stents. Target vessel revascularization was often due to stent thrombosis and disease progression as well as restenosis and was strongly associated with adverse outcomes but not mortality.

Serial changes of neointimal tissue after everolimus-eluting stent implantation in porcine coronary artery: an optical coherence tomography analysis

Purposes. The serial changes in neointimal tissues were compared between everolimus-eluting stent (EES) and bare-metal stent (BMS) in the porcine coronary artery using optical coherence tomography (OCT). Methods. Serial (1, 3, and 6 month follow-up after stent implantation) OCT examinations were performed in 15 swine with 15 BMS- and 15 EES-treated lesions in porcine coronary arteries. Results. In BMS-implanted lesions, neointimal volume decreased from 7.3 mm³ to 6.9 mm³ and 6.4 mm³ at 1, 3, and 6 months follow-up without statistical significance (P = 0.369). At the time points of 1, 3, and 6 months, neointimal tissue appearance was mainly a homogeneous pattern (80.0%, 93.3%, and 100%, resp.), while the other pattern was layered. In contrast, in EES-implanted lesions, neointimal volume significantly increased from 4.8 mm³ to 9.8 mm³ between 1 and 3 months but significantly decreased to 8.6 mm³ between 3 and 6 months (P < 0.001). Between 1 and 3 months, the layered pattern of neointimal tissue increased from 26.7% to 66.7% but decreased to 20.0% between 3 and 6 months. Conclusions. EES had a biphasic pattern of neointimal amounts that correlated with changes in neointimal morphology.

Meeting the Unmet - The Cre8 Polymer-free Drug-eluting Stents Technology: Proceedings of a satellite symposium held at EuroPCR on May 20th - 23rd 2014 in Paris

The use of first-generation drug-eluting stents (DES) has been associated with safety concerns such as very late stent thrombosis. Today, with the release of newer DES, there is a need for comparative studies of percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG) to demonstrate their value in patients with high risk of restenosis such as diabetic patients. In a satellite symposium presented at EuroPCR 2014, the Cre8™ DES was discussed. The Cre8 device has a number of unique clinical features, including polymer-free technology, abluminal reservoir technology and bio-inducer surface that ensure effective neointima suppression and rapid endothelialisation. The efficacy of the Cre8 DES has been demonstrated in the International randomised comparison between DES Limus Carbostent and Taxus drug-eluting stents in the treatment of de novo coronary lesions (NEXT) randomised clinical study, with equivalent efficacy in the diabetic and general populations, a unique finding. Ongoing clinical studies such as Investig8 and the Tel Aviv Medical Center (TLVMC) Cre8 study have confirmed the efficacy of the device in patient populations with a high proportion of diabetic patients. The Demonstr8 randomised trial has shown almost complete Cre8 strut coverage at three months with a numerical advantage versus bare metal stent (bare metal stents [BMS] - comparator device) at one month. In addition, use of the Cre8 DES may enable a shorter duration of dual antiplatelet therapy (DAPT) following PCI. The Cre8 DES therefore represents a significant advance in stent technology and may be particularly useful in challenging clinical settings.

Microscopic bio-corrosion evaluations of magnesium surfaces in static and dynamic conditions

Biodegradable materials including biodegradable metals are continuously being investigated for the development of next generation cardiovascular stents. Predictive in vitro tests are needed that could evaluate potential materials while simulating in vivo conditions. In this manuscript we report the microscopic bio-corrosion evaluations of magnesium surfaces in static and dynamic conditions. A corrosion test bench was designed and fabricated and static and dynamic corrosion tests were carried out with samples of magnesium alloy. The fluid wall shear stress equation and the Churchill's friction factor equation were used to calculate the fluid velocity required to generate the desired shear stress on samples in the test bench. Static and dynamic corrosion tests at 24 and 72 h were carried out at 0.88 Pa shear stress mimicking the in vivo shear stress. Microscopic evaluations of the corroded surfaces were carried out by optical, scanning electron microscopy and energy dispersive X-ray spectroscopy to evaluate the corrosion behaviour and surface properties of the test samples. The surface and interface analysis of magnesium samples post test indicated that dynamic conditions prevented the build-up of corrosion by-products on the sample surface and the corrosion mechanism was uniform as compared to static conditions. The use of a masking element to restrict the exposed area of the sample didn't result in increased corrosion at the boundary. Thus, we have demonstrated the feasibility of the designed test bench as a viable method for bio-corrosion surface analysis under dynamic corrosion conditions for potential biodegradable cardiovascular stent materials.

Clinical and angiographic outcomes after intracoronary bare-metal stenting

Background

Data from a large patient population regarding very long-term outcomes after BMS implantation are inadequate. This study aimed to evaluate the very long-term (8–17 years) clinical and long-term (3–5 years) angiographic outcomes after intracoronary bare-metal stenting (BMS).

Methods and Results

From the Cardiovascular Atherosclerosis and Percutaneous TrAnsluminal INterventions (CAPTAIN) registry, a total of 2391 patients with 2966 lesions treated with 3190 BMSs between November 1995 and May 2004 were evaluated. In total, 1898 patients with 2364 lesions, and 699 patients with 861 lesions underwent 6-month and 3- to 5- year angiographic follow-up, respectively. During a mean follow-up period of 149±51 months, 18.6% of the patients died (including 10.8% due to cardiac death), 6.1% developed reinfarction, 16.2% had target lesion revascularization (including 81% of the patients within the first year), 14.5% underwent new lesion stenting (including 72% of the patients after 3 years), 2.4% underwent coronary bypass surgery, and 1.6% had definite stent thrombosis. The overall cardiovascular event-free survival rate was 58.5%. The 6-month angiographic study indicated a 20% restenosis rate. The minimal luminal diameter increased from 0.65±0.44 mm to 3.02±0.46 mm immediately after stenting, decreased to 2.06±0.77 mm at the 6-month follow-up, and increased to 2.27±0.68 mm at the 3- to 5-year follow-up.

Conclusions

This study provides clinical and angiographic results from a large population of patients who underwent BMS implantations after a long-term follow-up period (149±51 months). The progression of coronary atherosclerosis developed over time, and presented with new lesion required stent implantation. The follow-up angiographic findings reconfirmed the late and sustained improvement in luminal diameter between 6 months and 3–5 years.

Enterprise stenting for intracranial aneurysm treatment induces dynamic and reversible age-dependent stenosis in cerebral arteries

BACKGROUND

Although intracranial stenting has been associated with in-stent stenosis, the vascular response of cerebral vessels to the deployment of the Enterprise vascular reconstruction device is poorly defined.

OBJECTIVE

To evaluate the change in parent vessel caliber that ensues after Enterprise stent placement.

METHODS

Seventy-seven patients with 88 aneurysms were treated using Enterprise stent-assisted coil embolization and underwent high-resolution three-dimensional rotational angiography followed by three-dimensional edge-detection filtering to remove windowing-dependence measurement artifact. Orthogonal diameters and cross-sectional areas (CSAs) were measured proximal and distal on either side of the leading stent edge (points A, B), trailing stent edge (points D, E), and at mid-stent (point C).

RESULTS

Enterprise stent deployment caused an instant increase in the parent artery CSA by 8.98% at D, which was followed 4-6 months later by significant in-stent stenosis (15.78% at A, 27.24% at B, 10.68% at C, 32.12% at D, and 28.28% at E) in the stented artery. This time-dependent phenomenon showed resolution which was complete by 12-24 months after treatment. This target vessel stenosis showed significant age dependence with greater response in the young. No flow-limiting stenosis requiring treatment was observed in this series.

CONCLUSIONS

Use of the Enterprise stent is associated with a significant dynamic and spontaneously resolvable age-dependent in-stent stenosis. Further study is warranted on the clinical impact, if any, of this occurrence.

Current treatment of in-stent restenosis

Management of patients with in-stent restenosis (ISR) remains an important clinical problem. Although drug-eluting stents (DES) have drastically reduced the incidence of ISR, treatment of DES-ISR is particularly challenging. ISR mainly results from aggressive neointimal proliferation, but recent data also suggest that neoatherosclerosis may play an important pathophysiological role. Intracoronary imaging provides unique insights to unravel the underlying substrate of ISR and may be used to guide repeated interventions. In this paper, we systematically reviewed clinical trial data with currently available therapeutic modalities, including DES and drug-coated balloons, in patients presenting with ISR within bare-metal stents or DES.

Biomaterials and design in occlusion devices for cardiac defects: a review

This review examines the biomaterials used in occlusion devices for cardiac defects, and how the choice of these materials is dictated by design. Specifically, the devices used in three major applications, the atrial septal defect, the ventricular septal defect and the patent ductus arteriosus, are examined critically. A number of different devices are available, with varied performance in deployment and sealing. There is no device in any of the three categories that satisfies fully the range of requirements, and all have associated complications. The type and rate of complications are different among different devices. The short-term (immediate) complications are addressed by immediate retrieval. For longer-term complications, most of which can be fatal, currently only surgical retrieval and replacement are possible. Most of these longer-term complications can be alleviated by the use of fully degradable devices, which will eliminate concerns regarding the use of metals inside the heart, and if fully endothelialized, also minimize migration concerns. On the other hand, the lower moduli of currently available biodegradable materials need to be augmented. Improvements in the stiffness required for deployment can be accomplished with the use of fillers, nano- or micro-sized, and an example of this are radiopaque fillers.

Contributors to newly developed coronary artery disease in patients with a previous history of percutaneous coronary intervention beyond the early phase of restenosis

OBJECTIVE

The low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio is considered to be a sensitive marker of the risk of atherosclerotic cardiovascular disease; however, in patients with a previous history of percutaneous coronary intervention (PCI), there is little information regarding the predictive value of this parameter beyond the period of early restenosis. The aim of this study was to investigate contributing factors to newly developed coronary artery disease in patients with a previous history of PCI after stabilization.

METHODS

The clinical characteristics of 238 patients with a previous history of PCI who underwent coronary angiography following recurrent cardiac ischemia beyond the period of early restenosis were examined.

RESULTS

Overall, 64% of the patients underwent late revascularization, while 31% and 50% underwent late target lesion revascularization and new lesion revascularization, respectively. A multivariate analysis identified the LDL-C/HDL-C ratio to be an independent contributor to late revascularization (hazard ratio (HR), 1.37; p<0.001). Similarly, the independent contributors to late target lesion revascularization and new lesion revascularization were the non-HDL-C level and LDL-C/HDL-C ratio, respectively. Based on the median value of the LDL-C/HDL-C ratio, the patients were classified into high and low LDL-C/HDL-C ratio groups. The log-rank test revealed a significantly higher incidence of late revascularization in the high-LDL-C/HDL-C ratio group than in the low-LDL-C/HDL-C ratio group among the patients with an LDL-C level of ≥ 100 mg/dL (p=0.011). However, the difference between the two groups was diminished among the patients with an LDL-C level of <100 mg/dL (p=0.047), and only diabetes mellitus (HR, 2.239; p=0.009) was found to be an independent contributor to late coronary revascularization in these patients.

CONCLUSION

The LDL-C/HDL-C ratio is an important contributor to the development of new coronary artery disease in patients with a previous history of PCI beyond the period of early restenosis, particularly among patients with an LDL-C level of ≥ 100 mg/dL.

Stent evaluation with optical coherence tomography

Optical coherence tomography (OCT) has been recently applied to investigate coronary artery disease in interventional cardiology. Compared to intravascular ultrasound, OCT is able to visualize various vascular structures more clearly with higher resolution. Several validation studies have shown that OCT is more accurate in evaluating neointimal tissue after coronary stent implantation than intravascular ultrasound. Novel findings on OCT evaluation include the detection of strut coverage and the characterization of neointimal tissue in an in-vivo setting. In a previous study, neointimal healing of stent strut was pathologically the most important factor associated with stent thrombosis, a fatal complication, in patients treated with drug-eluting stent (DES). Recently, OCT-defined coverage of a stent strut was proposed to be related with clinical safety in DES-treated patients. Neoatherosclerosis is an atheromatous change of neointimal tissue within the stented segment. Clinical studies using OCT revealed neoatherosclerosis contributed to late-phase luminal narrowing after stent implantation. Like de novo native coronary lesions, the clinical presentation of OCT-derived neoatherosclerosis varied from stable angina to acute coronary syndrome including late stent thrombosis. Thus, early identification of neoatherosclerosis with OCT may predict clinical deterioration in patients treated with coronary stent. Additionally, intravascular OCT evaluation provides additive information about the performance of coronary stent. In the near future, new advances in OCT technology will help reduce complications with stent therapy and accelerating in the study of interventional cardiology.

Human autopsy study of drug-eluting stents restenosis: histomorphological predictors and neointimal characteristics

AIMS

Restenosis in drug-eluting stents (DESs) occurs infrequently, however, it remains a pervasive clinical problem. We interrogated our autopsy registry to determine the underlying mechanisms of DES restenosis, and further we investigated the neointimal characteristics of DESs and compared with bare metal stents (BMSs).

METHODS AND RESULTS

Coronary lesions from patients with DES implants (n = 82) were categorized into four groups based on cross-sectional area narrowing: patent (<50%), intermediate (50-74%), restenotic (≥ 75% with residual lumen), and total occlusion (organized thrombus within the stent). Restenosis and occlusion were significantly dependent on the total stented length: restenosis (26.7 mm) and occlusion (25.7 mm) compared with patent DESs (17.3 mm). Further, restenotic and occluded lesions were located more distally in the coronary arteries and had greater vessel injury and uneven strut distribution suggesting local drug gradient. Multivariate analysis revealed that normalized maximum inter-strut distance was associated with DES restenosis (OR: 17.4, P = 0.04) while medial tear length was a predictor of DES occlusion (OR: 5.1, P = 0.03). No differences were observed between different DESs (sirolimus-, paclitaxel-, and everolimus-eluting stents) for restenosis and occlusion. Further, neointimal compositions of restenotic DESs demonstrated greater proteoglycan deposition and less smooth muscle cellularity over time, when compared with BMS with greater cell density and collagen deposition.

CONCLUSIONS

Our study indicates the impacts of inadequate drug concentration due to wider inter-strut distance and vessel injury as primary mechanisms of DES restenosis and occlusion, respectively. Moreover, the differences in neointimal compositions between DESs and BMSs might serve as a potential target for the suppression of late neointima growth via inhibition of proteoglycans in DESs.

Incidence and predictors of the late catch-up phenomenon after drug-eluting stent implantation

BACKGROUND

Although clinical restenosis within 1 year after percutaneous coronary intervention has been remarkably reduced with the advent of drug-eluting stents (DES), the late catch-up (LCU) phenomenon remains an issue despite medical advances. The aim of this study was to investigate the incidence and predictive factors of the LCU phenomenon in an unselected population treated with first-generation DES.

METHODS

A total of 923 patients treated with DES between June 2004 and August 2008 were analyzed. The LCU phenomenon was defined as secondary revascularization 1 year after index stenting. Retreatment for very late stent thrombosis was considered as part of the LCU phenomenon.

RESULTS

Incidence of the LCU phenomenon was seen in 33 patients (3.6%). Very late stent thrombosis was observed in 5 patients (0.6%) and very late in-stent restenosis was observed in 28 patients (3.0%). At the 12-month landmark analysis, the cumulative rate of cardiac death was significantly higher in patients with the LCU phenomenon than in those without any target lesion revascularization (9.0% vs. 0.9%, p<0.001). In the multivariate analysis, hemodialysis [odds ratio (OR) 6.07, p=0.003], number of stents (OR 1.58, p=0.02), and coronary bifurcation lesions (OR 2.06, p=0.048) were identified as independent predictors of the LCU phenomenon.

CONCLUSION

The LCU phenomenon is associated with serious consequences and adverse events and remains an important issue in modern practice, despite medical advances. DES should be deployed with a minimum number of stents, and special consideration must be given to patients on hemodialysis and those with coronary bifurcation lesions.

Neointimal tissue component assessed by tissue characterization with 40 MHz intravascular ultrasound imaging: comparison of drug-eluting stents and bare-metal stents

OBJECTIVES

The present study used iMap IVUS system to compare neointimal tissue components between DES and bare-metal stents (BMSs).

BACKGROUND

Drug-eluting stents (DESs) can cause impaired arterial healing, which constitutes the most important pathological substrate underlying late DES thrombosis. Intravascular ultrasound (IVUS)-based tissue characterization allows for the in vivo identification of neointimal tissue components.

METHODS AND RESULTS

Follow-up IVUS data after coronary stenting (9.8 ± 9.4 months from index procedures) was obtained from consecutive 61 lesions (34 in DES, 27 in BMS). The iMap tissue components (fibrotic, lipidic, necrotic, and calcified) were measured in every recorded frame and expressed as percentages of mean neointimal cross-sectional area for the stented segment. Patients' characteristics were comparable between DES and BMS. When compared with BMSs, smaller (2.9 ± 0.4 mm vs. 3.2 ± 0.4 mm, P = 0.004) and longer (34 ± 18 mm vs. 26 ± 14 mm, P = 0.03) DESs were implanted. When compared with BMS group, minimum lumen area at follow-up was significantly greater in DES group (3.9 ± 1.8 mm(2) vs. 3.1 ± 1.5 mm(2) , P < 0.04), mainly attributable to suppression of neointimal hyperplasia (1.7 ± 0.8 mm(2) vs. 3.1 ± 1.5 mm(2) , P < 0.0001). The iMap analyses showed that neointima after DES placement was composed of smaller fibrotic component (67 ± 8% vs. 78 ± 7%, P < 0.0001), larger necrotic (14 ± 4% vs. 9 ± 3%, P < 0.0001) and calcified (15 ± 6% vs. 7 ± 4%, P < 0.0001) components compared with BMS. Logistic regression analysis showed that only intra-DES neointima was a significant predictor of necrotic neointima at follow-up.

CONCLUSIONS

DES implantation would be associated with iMap-derived necrotic and less-fibrotic neointimal formation. In vivo iMap evaluation of neointimal tissue may provide useful information in detecting impaired healing after stenting.

Serial gray scale intravascular ultrasound findings in late drug-eluting stent restenosis

The primary aim of the present study was to assess the gray scale intravascular ultrasound (IVUS) findings that might be associated with late drug-eluting stent restenosis. The study included 47 patients (54 lesions) who had undergone either baseline IVUS-guided stent implantation or IVUS-guided repeat stenting to treat in-stent restenosis and then had IVUS follow-up data for ≥1.5 years afterward without any intervening procedures. The left anterior descending artery was the culprit in 59% of cases, and 50% of the lesions were at bifurcation sites. Quantitative and qualitative IVUS analyses showed a decreased minimum lumen area at follow-up from 6.0 ± 1.8 to 3.8 ± 1.4 mm(2) (p <0.0001) that was mainly due to neointimal hyperplasia with chronic stent recoil (defined as a >15% decrease in minimum stent area) in only 2 lesions and stent fracture in only 5 lesions. Calcified neointima appeared in 12 lesions, mostly in the form of macrocalcification, and was associated with increased calcium both behind the stent and in the reference segment. In conclusion, late drug-eluting stent restenosis showed neointimal calcification in 20% of cases, and chronic stent recoil was rare.

Seven-year clinical outcomes of sirolimus-eluting stent versus bare-metal stent: a matched analysis from a real world, single center registry

The aim of this study is to compare clinical outcomes for seven years, between sirolimus-eluting stent (SES) and bare metal stent (BMS). During the BMS and drug-eluting stent (DES) transition period (from April 2002 to April 2004), 434 consecutive patients with 482 lesions underwent percutaneous coronary intervention, using BMS or SES. Using propensity score matching, 186 patients with BMS and 166 patients with SES were selected. Seven year clinical outcomes of major adverse cardiac events (MACE), such as cardiac death, myocardial infarction (MI) and ischemia-driven target vessel revascularization (TVR), and angiographic definite stent thrombosis (ST) were compared. At one-year follow up, patients with SES showed significantly lower MACE (9.1% in BMS vs 3.0% in SES, P = 0.024). However, cumulative MACE for 7 yr was not significantly different between two groups (24.7% in BMS vs 17.4% in SES, P = 0.155). There was no significant difference in MI, TVR, death and ST. The TVR were gradually increased from 1 to 7 yr in SES, on the contrary to that of BMS. In conclusion, although SES showed better clinical outcomes in the early period after implantation, it did not show significant benefits in the long-term follow up, compared with that of BMS.

Lesion length impacts long term outcomes of drug-eluting stents and bare metal stents differently

BACKGROUND

Long lesions have been associated with adverse outcomes in percutaneous coronary interventions with bare metal stents (BMS). However, the exact impact of lesion length on the short- and long-term outcomes of drug-eluting stent (DES) implantations is not as clear.

METHODS AND RESULTS

This study compared the impact of lesion length on angiographic and clinical outcomes of BMS and DES in a single-center prospective registry. Lesion length was divided into tertiles. The primary endpoints were angiographically defined binary in-stent restenosis (ISR) rate and major adverse cardiac event (MACE). Of the 4,312 de novo lesions in 3,447 consecutive patients in the CAPTAIN registry, 2,791 lesions (of 2,246 patients) received BMS, and the remaining 1,521 lesions (of 1,201 patients) received DES. The mean follow-up duration was 4.5 years. The longer the lesion, the higher the ISR rate (14%, 18%, and 29%, p<0.001) and the lower the MACE-free survivals (p = 0.007) in the BMS group. However, lesion length showed no such correlation with ISR rates (4.7%, 3.3%, and 7.8%, p = 0.67) or MACE-free survivals (p = 0.19) in the DES group.

CONCLUSIONS

In our single-center prospective registry, lesion length defined in tertiles has no impact on the short-term (ISR) or long-term (MACE) outcomes of patients implanted with DES. In contrast, longer lesion correlates with higher ISR and MACE rates in BMS group.

Very long-term outcomes after percutaneous coronary intervention with bare metal stents for unprotected left main coronary artery disease

AIMS

The aim of this study was to evaluate very long-term clinical outcomes and potential predictors after percutaneous coronary intervention (PCI) with bare metal stents (BMS) for unprotected left main coronary artery disease (ULMCAD).

METHODS AND RESULTS

From March 1991 to August 2001, 151 patients who underwent PCI with BMS for ULMCAD were investigated retrospectively. The patient-oriented major adverse cardiac events (MACE) were defined as the occurrence of all-cause death, any MI, and any coronary revascularisation. The median follow-up duration was 10.5 years. The mean age was 69.9±11.5 years, and 106 patients (70.2%) were male. At 10 years, the incidences of cardiac death (CD), target lesion revascularisation (TLR) and patient-oriented MACE were 11.1%, 25.2% and 81.9%, respectively. In multivariate analysis, the pre-reference diameter of the left main trunk (LMT) was significantly associated with TLR (adjusted hazard ratio [HR] [95% confidence interval (CI)], 0.28 [0.14-0.54], p<0.001) and the SYNTAX score remained an independent predictor of patient-oriented MACE (adjusted HR [95% CI], 1.03 [1.007-1.05], p=0.009).

CONCLUSIONS

The pre-reference diameter of LMT was significantly associated with TLR, and the SYNTAX score significantly predicted the risk of patient-oriented MACE at 10 years. BMS implantation for larger size of ULMCAD with a lower SYNTAX score was feasible for up to 10 years.

Impact of cilostazol on angiographic restenosis after balloon angioplasty for infrapopliteal artery disease in patients with critical limb ischemia

OBJECTIVE

To investigate whether cilostazol reduces restenosis and revascularization after infrapopliteal angioplasty.

DESIGN

This study was a retrospective analysis of a multicenter prospective registry.

MATERIALS AND METHODS

Between February and April 2011, 63 patients (68 limbs, 101 lesions) with critical limb ischemia (CLI) were enrolled. Of these, 32 were cilostazol treated and 31 were the non-cilostazol-treated group. Outcome measures were binary restenosis by angiogram, reocclusion, target lesion revascularization (TLR), limb salvage rate and complete wound healing at 3 months.

RESULT

Procedural success was obtained in all patients. The backgrounds and lesion characteristics of patients with isolated tibial artery disease and CLI did not differ significantly between the two groups. In a lesion-based analysis, binary restenosis and reocclusion were significantly lower in the cilostazol group than in the non-cilostazol group (56.8% vs. 86.0%; p = 0.015, 20.5% vs. 43.6%; p = 0.015, respectively). The TLR was also significantly lower in the cilostazol group (27.5% vs. 52.8%, p = 0.014). After adjustment for covariables, cilostazol was found to be associated with reduced angiographic restenosis, reocclusion and TLR rates in CLI patients at 3 months after infrapopliteal angioplasty. However, it remained unclear whether cilostazol was also associated with improved clinical outcomes.

CONCLUSION

Cilostazol may be associated with reduced restenosis, reocclusion and clinically driven TLR at 3 months after infrapopliteal angioplasty.

Very long-term (15 to 23 years) outcomes of successful balloon angioplasty compared with bare metal coronary stenting

BACKGROUND

Target lesion revascularization (TLR) continues to occur beyond 4 years after bare metal stent (BMS) implantation. However, long-term outcomes after balloon angioplasty (BA) compared with BMS are currently unknown.

METHODS AND RESULTS

From 1989 to 1990, 659 patients (748 lesions) underwent successful BA with final balloon ≥3.0 mm excluding patients with acute myocardial infarction and were compared with 405 patients (424 lesions) with BMS implantation from June 1990 to 1993. Cumulative incidences of death and target lesion thrombosis (>1 year) were similar between the BA group and the BMS group (44.4% versus 45.4%, P=0.60; and 1.5% versus 0.7%, P=0.99; respectively). Cumulative incidence of TLR during overall follow-up was significantly higher after BA than after BMS implantation (44.6% versus 36.0%, P<0.001), whereas cumulative incidence of late TLR (>4 years) tended to be lower in the BA group than in the BMS group (16.3% versus 21.4%, P=0.16). Cumulative incidence of late TLR after BA was significantly lower in patients with small percent diameter stenosis (%DS) at early follow-up angiography compared with large %DS (14.5% versus 28.0%, P=0.02). In lesions with serial angiography, late lumen loss from early (6 to 14 months) to long-term (4 to 10 years) follow-up angiography was significantly smaller in the BA group (n=42) than in the BMS group (n=55) (-0.08±0.45 mm versus 0.11±0.46 mm, P=0.047).

CONCLUSIONS

Compared with BMS implantation, BA was associated with a trend for less late TLR beyond 4 years and with significantly smaller late lumen loss from early to long-term follow-up angiography.

Novel stents for the prevention of restenosis

Since the introduction of Interventional Cardiology in 1976, there has been rapid expansion both in its clinical application and the tools of the trade. This growth was accelerated with the introduction of the intra-coronary stent in 1987. The demonstration that stents may reduce the incidence of restenosis after percutaneous coronary revascularization has further stimulated the search for the perfect endovascular prosthesis. By creating a hybrid stent, incorporating natural coatings and local drug delivery in the design, it is hoped that the complications associated with stent thrombosis and restenosis can be eradicated. (Trends Cardiovasc Med 1997;7:245-249). © 1997, Elsevier Science Inc.

Percutaneous coronary intervention with bare metal stent vs. drug-eluting stent in hemodialysis patients

BACKGROUND

Percutaneous coronary intervention (PCI) with drug-eluting stent (DES) is widely performed in patients with coronary artery disease, but the high restenosis rate remains a major clinical problem after implantation of DES in patients on hemodialysis (HD). Until now, there are limited reports regarding the long-term clinical outcome after implantation of DES in this patient population.

METHODS AND RESULTS

We compared bare metal stent (BMS) and DES for long-term clinical outcomes, such as target lesion revascularization (TLR), in HD patients undergoing PCI. BMS and DES were implanted in 204 and 301 patients, respectively. Baseline and lesion characteristics were comparable between the 2 groups. By Kaplan-Meier analysis, event rates of major adverse cardiac events for 6 years were significantly lower in the DES group than in the BMS group (42.5% vs. 58.0%, P=0.036). Although there were no significant differences in TLR rates between patients treated with DES and those with BMS at 1 year after PCI (17.8% vs. 21.3%, P=0.32), patients treated with DES had significantly lower rates of TLR compared with those treated with BMS beyond the 1-year follow-up after PCI (16.4% vs. 30.9%, P=0.019).

CONCLUSIONS

In patients on HD, implantation of DES might be more effective for preventing TLR in the medium to long follow-up period than BMS, although restenosis after PCI with DES is common in the short term.

Long-term follow-up after treatment of intracranial aneurysms with the Pipeline embolization device: results from a single center

BACKGROUND AND PURPOSE

Stent-like, self-expandable devices, the so-called flow diverters, are increasingly used for the treatment of wide-neck cerebral aneurysms. The immediate and short-term results are promising, but no long-term results are available. The purpose of our research was to report the long-term angiographic and cross-sectional imaging results after placement of a PED in 12 patients with wide-neck intracranial aneurysms.

MATERIALS AND METHODS

Twelve wide-neck or otherwise untreatable cerebral aneurysms in 12 patients were treated with the PED. Angiography was performed at 6 and 24 months after treatment. Additional MR and CT angiograms were acquired.

RESULTS

In all patients, angiographic or cross-sectional imaging follow-up of at least 27 months demonstrated complete occlusion of the aneurysms treated with the PED. There were no cases of aneurysm recurrence. Angiography at around 6 months showed complete occlusion in all cases, except 1 that showed complete occlusion at the 29-month follow-up. In 1 patient, a clinically asymptomatic 75% in-stent stenosis was seen on the angiography at 6 months but was resolved completely by balloon dilation. Device placement was successful in all patients. Distal embolization had occurred in 1 patient, but the clot was resolved completely without clinical sequelae. Almost immediate angiographic occlusion was achieved in 2 aneurysms and flow reduction in 10 aneurysms.

CONCLUSIONS

Treatment of wide-neck intracranial aneurysms by PED placement led to successful and durable occlusion in all cases, without severe complications. Endovascular treatment for in-stent stenosis should be considered cautiously, because the underlying stenosis may be transient and disappear within 12 months after treatment.

Angiographic evidence of progressive lumen narrowing over 2 years following drug-eluting stent implantation

BACKGROUND

Questions persist regarding the ability of drug-eluting stents (DES) to inhibit intimal growth in the long-term.

METHODS

We prospectively enrolled 766 lesions treated with DES that underwent angiographic examination at 6 months and 2 years after stenting. Lesions with 6-month restenosis (>50% of visual stenosis) were excluded. The primary end point was quantitative change in minimal lumen diameter (MLD) according to serial angiography of the segment (in-segment), the stented region (in-stent) and both edges. Late loss, defined as MLD change, was categorized as early (between post-procedure and 6 months), delayed (between 6 months and 2 years), or overall (between post-procedure and 2-years).

RESULTS

MLD progressively decreased in both the in-stent and edge regions at both 6 months and 2 years (p<0.001 in all paired analyses). In-segment MLD decreased from a median 2.27 mm (interquartile range; 1.98, 2.62) at post-procedure to 2.18 mm (1.86, 2.47; p < 0.001 with post-procedure) at 6 months, and to 2.02 mm (1.66, 2.37; p<0.001 with 6 months) at 2 years. Late loss was 0.0 6 mm (-0.05, 0.26) in the early phase, 0.09 mm (-0.01, 0.28) in the delayed phase, and 0.20mm (0.03, 0.50) overall. Two-year angiographic restenosis occurred in 54 (7.0%) lesions, and 65 (8.5%) underwent target lesion revascularization over a median follow-up of 52.5 months.

CONCLUSION

Serial angiographic analysis showed that DES lumen diameter progressively narrowed over 2 years post-procedure. However, the incidence of target lesion revascularization was relatively low due to the small amount of late loss in the delayed phase.

Patency of paclitaxel-eluting versus bare metal stents long term after implantation in acute ST-segment elevation myocardial infarction

Drug-eluting stents effectively inhibit neointimal hyperplasia within the first year, thereby reducing the need for repeat revascularization. However, a delayed pattern of restenosis might be more prominent in drug-eluting stents compared to bare metal stents (BMSs). The extent of restenosis of paclitaxel-eluting stents (PESs) long term after implantation in acute ST-segment elevation myocardial infarction is currently unknown. The present study was designed to evaluate very late luminal loss (VLLL) of PESs used in ST-segment elevation myocardial infarction compared to BMSs. A total of 116 patients (61 with PESs and 55 with BMSs) initially included in the Paclitaxel Eluting Stent Versus Conventional Stent in ST-segment Elevation Myocardial Infarction (PASSION) trial and who were free from previous lesion failure underwent angiographic follow-up. Off-line quantitative coronary analysis of the angiogram immediately after stent implantation and at follow-up was performed. The primary end point was VLLL within the stent. The presence of binary restenosis was defined as diameter stenosis >50% as a secondary end point. The mean interval between stent implantation and follow-up was 4.1 ± 0.5 years in both stent groups. In-stent VLLL was 0.12 mm (interquartile range -0.03 to 0.42) in the PES group versus 0.30 mm (interquartile range 0.08 to 0.69) in the BMS group (p = 0.011). In-segment binary restenosis was found in 4 patients (6.6%) with a PES and 6 patients (10.9%) with a BMS (p = 0.40). In conclusion, angiographic follow-up 4 years after implantation in ST-segment elevation myocardial infarction showed that in patients prospectively randomized to PESs or BMSs, VLLL was low in both stent groups. PESs were associated with lower VLLL than BMSs, and the observed rate of binary restenosis was not significantly different between the 2 stent groups.