Two-Year Outcomes After Sirolimus-Eluting Stent Implantation

Revolutionizing Cardiovascular Frontiers: A Dive Into Cutting-Edge Innovations in Coronary Stent Technology

Plain balloon angioplasty was the initial method used to enlarge the intracoronary lumen size. However, it was linked to acute coronary closure due to early vessel recoil. This led to the invention of coronary stents, which offer mechanical support to open and maintain the vascular lumen. Nevertheless, the metallic scaffold introduced other issues, such as thrombosis and restenosis caused by neointimal proliferation. To address these concerns, polymers were employed to cover the scaffold, acting as drug reservoirs and regulators for controlled drug release. The use of polymers prevents direct contact between blood and metallic scaffolds. Drugs within the stent were incorporated to inhibit proliferation and expedite endothelialization in the healing process. Despite these advancements, adverse effects still arise due to the inflammatory reaction caused by the polymer material. Consequently, resorbable polymers and scaffolds were later discovered, but they have limitations and are not universally applicable. Various scaffold designs, thicknesses, materials, polymer components, and drugs have their own advantages and complications. Each stent generation has been designed to address the shortcomings of the preceding generation, yet new challenges continue to emerge. Conflicting data regarding the long-term safety and efficacy of coronary stents, especially in the extended follow-up, further complicates the assessment.

Vascular Response Toward an Absorbable Sirolimus-eluting Polymeric Scaffold for Vascular Application in a Model of Normal Porcine Carotid Arteries

BACKGROUND

Fully absorbable polymeric scaffolds, as a potential alternative to permanent metallic stents, are entering the clinical field. The aim of this study is to assess the in vivo biocompatibility of a novel Sirolimus-eluting (SIR) absorbable scaffold based on poly(L-lactide) (PLLA) and poly(4-hydroxybutyrate) (P4HB) for interventional application.

METHODS

Absorbable PLLA/P4HB scaffolds either loaded with SIR coating or unloaded scaffolds were implanted interventionally into common carotid arteries of 14 female. Bare metal stents (BMS) served as control. Peroral dual anti-platelet therapy was administered throughout the study. Stented common carotid arteries segments were explanted after 4 weeks, and assessed histomorphometrically.

RESULTS

The absorbable scaffolds showed a decreased residual lumen area and higher stenosis after 4 weeks (PLLA/P4HB: 6.56 ± 0.41 mm² and 37.56 ± 4.67%; SIR-PLLA/P4HB: 6.90 ± 0.58 mm² and 35.60 ± 3.15%) as compared to BMS (15.29 ± 1.86 mm² and 7.65 ± 2.27%). Incorporation of SIR reduced the significantly higher inflammation of unloaded scaffolds however not to a level compared to bare metal stent (PLLA/P4HB: 1.20 ± 0.19; SIR-PLLA/P4HB: 0.96 ± 0.24; BMS: 0.54 ± 0.12). In contrast, the BMS showed a slightly elevated vascular injury score (0.74 ± 0.15), as compared to the PLLA/P4HB (0.54 ± 0.20) and the SIR-PLLA/P4HB (0.48 ± 0.15) groups.

CONCLUSION

In this preclinical model, the new absorbable polymeric (SIR-) scaffolds showed similar technical feasability and safety for vascular application as the permanent metal stents. The higher inflammatory propensity of the polymeric scaffolds was slightly reduced by SIR-coating. A smaller strut thickness of the polymeric scaffolds might have been a positive effect on tissue ingrowth between the struts and needs to be addressed in future work on the stent design.

Long-term safety of bioresorbable scaffolds: insights from a network meta-analysis including 91 trials

AIMS

The aim of this study was to investigate the long-term safety and efficacy of biodegradable scaffolds and metallic stents.

METHODS AND RESULTS

We analysed a total of 91 randomised controlled trials with a mean follow-up of 3.7 years in 105,842 patients which compared two or more coronary metallic stents or biodegradable scaffolds and reported the long-term clinical outcomes (≥2 years). Network meta-analysis showed that patients treated with the Absorb bioresorbable vascular scaffold (BVS) had a significantly higher risk of definite or probable scaffold thrombosis (ScT) compared to those treated with metallic DES. The risk of very late ScT was highest with the Absorb BVS among comparators. Pairwise conventional meta-analysis demonstrated that the elevated risk of ScT with Absorb BVS compared to cobalt-chromium everolimus-eluting stents was consistent across the time points of ≤30 days (early), 31 days - 1 year (late) and >1 year (very late) ScT. In addition, target lesion failure rates were significantly higher in the Absorb BVS cohort, driven by both increased risk of target vessel myocardial infarction and ischaemia-driven target lesion revascularisation.

CONCLUSIONS

Absorb BVS implantation was associated with increased risk of long-term and very late ScT compared to current-generation metallic DES. The risk of ScT occurred with a rising trend beyond one year.

40 Years of Percutaneous Coronary Intervention: History and Future Directions

The field of interventional cardiology has evolved significantly since the first percutaneous transluminal coronary angioplasty was performed 40 years ago. This evolution began with a balloon catheter mounted on a fixed wire and has progressed into bare-metal stents (BMS), first-generation drug-eluting stents (DES), second- and third-generation biodegradable polymer-based DES, and culminates with the advent of bioabsorbable stents, which are currently under development. Each step in technological advancement has improved outcomes, while new persisting challenges arise, caused by the stent scaffolds, the polymers employed, and the non-selective cytostatic and cytotoxic drugs eluted from the stents. Despite the promising technological advances made in stent technology, managing the balance between reductions in target lesion revascularization, stent thrombosis, and bleeding remain highly complex issues. This review summarizes the evolution of percutaneous coronary intervention with a focus on vascular dysfunction triggered by the non-selective drugs eluted from various stents. It also provides an overview of the mechanism of action of the drugs currently used in DES. We also discuss the efforts made in developing novel cell-selective drugs capable of inhibiting vascular smooth muscle cell (VSMC) proliferation, migration, and infiltration of inflammatory cells while allowing for complete reendothelialization. Lastly, in the era of precision medicine, considerations of patients’ genetic variance associated with myocardial infarction and in-stent restenosis are discussed. The combination of personalized medicine and improved stent platform with cell-selective drugs has the potential to solve the remaining challenges and improve the care of coronary artery disease patients.

Impact of hyperuricemia on clinical outcomes after percutaneous coronary intervention for in-stent restenosis

Background

There have been limited data on the impact of hyperuricemia on long-term clinical outcomes after percutaneous coronary intervention (PCI) for in-stent restenosis (ISR).

Methods

From January 2009 to July 2015, 317 patients who underwent repeat PCI for ISR were divided into two groups: patients with normal serum uric acid (UA) levels (normal UA group) and patients with higher serum UA levels (higher UA group). The higher UA group included patients with serum UA levels > 6.8 mg/dL or patients who were taking anti-hyperuricemic medication.

Results

During a median follow-up period of 1088 days, the cumulative incidence rates of major adverse event (MAE), including a composite of all-cause death, non-fatal myocardial infarction, and any revascularization, were similar between the two groups (higher UA 36.4% vs. normal UA 29.9%, p = 0.389, log-rank p = 0.367). Follow-up angiographic data showed similar outcomes of late lumen loss (0.8 ± 0.9 mm vs. 0.8 ± 1.1 mm, p = 0.895) and binary restenosis rate (28.1% vs. 34.7%, p = 0.622). Multivariate Cox regression analysis indicated higher levels of low-density lipoprotein cholesterol (hazard ratio [HR] 1.011, 95% confidence interval [CI] 1.003–1.019, p = 0.006) and lower left ventricular ejection fraction (HR 0.972, 95% CI 0.948–0.996, p = 0.022), but not UA levels, to be the independent risk predictors of MAE.

Conclusion

Hyperuricemia is not associated with poor clinical outcomes after repeat PCI for ISR lesions.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0840-2) contains supplementary material, which is available to authorized users.

Rationale of a novel study design for the BIOFLOW V study, a prospective, randomized multicenter study to assess the safety and efficacy of the Orsiro sirolimus-eluting coronary stent system using a Bayesian approach

BACKGROUND

Traditional study design submitted to the Food and Drug Administration to test newer drug-eluting stents (DES) for marketing approval is the prospective randomized controlled trial. However, several DES have extensive clinical data from trials conducted outside the United States that have led to utilization of a novel design using the Bayesian approach. This design was proposed for testing DES with bioresorbable polymer compared with DES most commonly in use today that use durable polymers for drug elution.

STUDY DESIGN AND OBJECTIVES

This prospective, multicenter, randomized, controlled trial is designed to assess the safety and efficacy of the Orsiro bioresorbable polymer sirolimus-eluting stent (BP SES). Up to 1,334 subjects with up to 3 de novo or restenotic coronary artery lesions who qualify for percutaneous coronary intervention with stenting will be randomized 2:1 to the BP SES versus the Xience durable polymer everolimus-eluting stent (DP EES). Data from this trial will be combined with data from 2 similarly designed trials that also randomize subjects to BP SES and DP EES (BIOFLOW II, N=452 and BIOFLOW IV, N=579) by using a Bayesian approach. The primary end point is target lesion failure at 12 months post index procedure, defined as cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization, and the primary analysis is a test of noninferiority of the BP SES versus DP EES on the primary end point according to a noninferiority delta of 3.85%. Secondary end points include stent thrombosis and the individual components of target lesion failure. Subjects will be followed for 5 years after randomization.

CONCLUSIONS

The BIOFLOW V trial offers an opportunity to assess clinical outcomes in patients treated with coronary revascularization using the Orsiro BP SES relative to a commonly used DP EES. The use of a Bayesian analysis combines a large randomized cohort of patients 2 two smaller contributing randomized trials to augment the efficiency of the comparison.

Clinical, humanistic, and economic outcomes between drug-eluting stent (DES) and bare metal stent (BMS): 18-month follow-up study

BACKGROUND

Percutaneous coronary intervention (PCI) is one of the most performed interventions for ischemic heart diseases. In Hong Kong, the total number of patient discharges and deaths for ischemic heart diseases in 2009 was 33,363, including 4,360 deaths. There are over 5,000 cases of PCI yearly. This study aimed to compare clinical, economic, and humanistic outcomes among patients receiving drug-eluting stent (DES) or bare metal stent (BMS) in Hong Kong.

METHODS

Patients who received stent implantation between September 15, 2009 and October 11, 2010 in Prince of Wales Hospital, Hong Kong, were recruited and followed for 18 months. Occurrence of major adverse cardiac events (cardiac death, non-fatal MI, TLR and TVR) was employed as the clinical outcome measurements. Improvement in quality-of-life by stent interventions was measured as quality-adjusted life-year (QALY). EQ-5D questionnaire was adopted to assess the QALY gained. Cost-utility analysis and cost-effectiveness analysis for BMS and DES were employed as the economic outcome measurement.

RESULTS

Six hundred and eighty-four patients (DES = 402; BMS = 282) were included. From 0-18 months, TLR rate (2.7% vs 3.5%, p = .549) and TVR rate (3.7% vs 6.4%, p = .111) were lower in the DES group, but without statistical significance. EQ VAS (71.06 ± 14.56 vs 71.07 ± 16.57, p = .998) and utility score (0.81 ± 0.17 vs 0.78 ± 0.16, p = .162) were comparable between DES and BMS group. Overall, the cost per QALY gained was HKD + 1,178,100 and ICER was HKD + 187,000 (1USD = 7.8 HKD).

CONCLUSIONS

No significant difference in TVR, TLR rates, EQ VAS, and utility score was found between the DES and BMS group. The higher cost of index procedure for the DES group was found to be partly offset by reduced cost of follow-up, offering cost-effectiveness in ACS patients, predominantly in STEMI patients. DES was recommended for STEMI patients.

WITHDRAWN: Drug-eluting stents versus bare metal stents for angina or acute coronary syndromes

This review 'topic' has been included in work being carried out as part of a Health Technology Assessment commissioned by the National Institute for Clinical Excellence in England and Wales. Details of this research is available via www.nice.org.uk.

The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the HTA programme, NICE, NIHR, NHS or the Department of Health.

The review has been split into 2 reviews that will be published as "Drug‐eluting stents versus bare‐metal stents for stable ischaemic heart disease" and "Drug‐eluting stents versus bare‐metal stents for acute coronary syndrome".

The editorial group responsible for this previously published document have withdrawn it from publication.

Comparison of 2-year outcomes of repeated second-generation drug-eluting stent implantation for focal-type versus nonfocal-type in-stent restenosis

BACKGROUND

Second-generation drug-eluting stents (DES) have been used widely to treat DES in-stent restenosis (ISR), which remains a clinical challenge. Knowledge of the outcomes of repeated second-generation DES implantation for focal versus nonfocal-type ISR is still missing.

METHODS

In the current study, 254 patients with DES-ISR were divided into focal or nonfocal groups according to their ISR angiographic types. All patients with ISR lesions included in the current study received second-generation DES. Treatment modalities for both groups were similar without any systematic bias toward either group. The primary endpoint of the study was the occurrence of major adverse cardiac events (MACEs) over a 2-year follow-up period. MACEs were defined as cardiac death, myocardial infarction, and target lesion revascularization.

RESULTS

The nonfocal-type group showed significantly greater incidence of MACEs than the focal-type group (38.3 vs. 24.1%; P=0.03), in which the occurrence of target lesion revascularization was more pronounced (32.3 vs. 18.4%; P=0.02). However, this group showed a higher incidence of type B2/C lesions (69.5 vs. 41.4%; P<0.01), with longer lesion length, and received significantly more and longer reimplanted stents than the focal-type group. Cox regression analysis indicated that nonfocal-type ISR was an independent predictor of MACEs (odds ratio 2.134, 95% confidence interval 1.173-3.884; P=0.014) after adjusting for all significant variables.

CONCLUSION

In the current study, second-generation DES is more effective in the treatment of focal-type DES-ISR than nonfocal-type ISR in terms of the occurrence of MACEs. Nonfocal-type ISR is an independent predictor of MACEs after the treatment of DES-ISR with second-generation DES.

Inhibitory effects of roscovitine on proliferation and migration of vascular smooth muscle cells in vitro

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are the major cause of in-stent restenosis (ISR). Intervention proliferation and migration of VSMCs is an important strategy for antirestenotic therapy. Roscovitine, a second-generation cyclin-dependent kinase inhibitor, can inhibit cell cycle of multiple cell types. We studied the effects of roscovitine on cell cycle distribution, proliferation and migration of VSMCs in vitro by flow cytometry, BrdU incorporation and wound healing assay, respectively. Our results showed that roscovitine increased the proportion of G0/G1 phase cells after 12 h (69.57±3.65 vs. 92.50±1.68, P=0.000), 24 h (80.87±2.24 vs. 90.25±0.79, P=0.000) and 48 h (88.08±3.86 vs. 88.87±2.43, P=0.427) as compared with control group. Roscovitine inhibited proliferation and migration of VSMCs in a concentration-dependent way. With the increase of concentration, roscovitine showed increased capacity for growth and migration inhibition. Roscovitine (30 μmol/L) led to an almost complete VSMCs growth and migration arrest. Combined with its low toxicity and selective inhibition to ISR-VSMCs, roscovitine may be a potential drug in the treatment of vascular stenosis diseases and particularly useful in the prevention and treatment of ISR.

Long-term follow-up results in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents: results from a single high-volume PCI centre

OBJECTIVE

To assess both short-term and long-term prognosis in consecutive patients with coronary heart disease treated with drug-eluting stents in a high-volume percutaneous coronary intervention (PCI) centre.

DESIGN

Observational cohort study.

SETTING

A hospital in the Henan province, China, between 2009 and 2011.

PARTICIPANTS

A total of 2533 patients were enrolled. Patients with ST-elevation myocardial infarction (STEMI) treated with urgent PCI accounted for 3.9% of cases; patients with STEMI treated with delayed PCI accounted for 20.5% of cases; patients with stable angina accounted for 16.5% of cases; and patients with non-ST elevation acute coronary syndrome (NSTE-ACS) accounted for 58.6% of cases.

PRIMARY OUTCOMES

Death, major adverse cardiac and cerebrovascular events (MACCE: death/myocardial infarction/stroke), and target vessel revascularisation.

RESULTS

Follow-up after a median of 29.8 months was obtained for 2533 patients (92.6%). The mortality rate during hospitalisation was highest in the urgent PCI group (p<0.001). During follow-up, although the incidences of death and MACCE were highest in the urgent PCI group, no significant differences were observed among the different groups. The incidences of cardiac death and myocardial infarction were significantly higher in the paclitaxel-eluting stent (PES) group than in the sirolimus-eluting stent (SES) group. Independent predictors of death during follow-up were age, left ventricular ejection function <40%, diabetes mellitus, prior coronary artery bypass graft and chronic total occlusion.

CONCLUSIONS

PCI patients with STEMI had the worst hospital and long-term prognosis. The mortality rate after hospital increased markedly in patients with NSTE-ACS. SESs seem to be more effective than PESs.

Worsening late-acquired incomplete stent apposition after sirolimus-eluting stent implantation for a chronic total occlusion lesion

A 70-year-old man underwent percutaneous coronary intervention (PCI) using sirolimus-eluting stent (SES) at the just proximal site of left anterior descending coronary artery. Six months after SES implantation, he suffered from late stent thrombosis. Intravascular ultrasound (IVUS) images demonstrated positive remodeling of the vessel, indicating late-acquired incomplete stent apposition (ISA). An angioplasty with a bigger balloon was performed to obtain sufficient stent struts apposition. Twenty-six months after the second PCI, he developed ST-elevation myocardial infarction and his CAG showed re-occlusion of the SES. Optical coherence tomography showed ISA and IVUS revealed further enlargement of the coronary artery around the SES.

Regulation of smooth muscle cells in development and vascular disease: current therapeutic strategies

Vascular smooth muscle cells (SMCs) exhibit extensive phenotypic diversity and rapid growth during embryonic development, but maintain a quiescent, differentiated state in adult. The pathogenesis of vascular proliferative diseases involves the proliferation and migration of medial vascular SMCs into the vessel intima, possibly reinstating their embryonic gene expression programs. Multiple mitogenic stimuli induce vascular SMC proliferation through cell cycle progression. Therapeutic strategies targeting cell cycle progression and mitogenic stimuli have been developed and evaluated in animal models of atherosclerosis and vascular injury, and several clinical studies. Recent discoveries on the recruitment of vascular progenitor cells to the sites of vascular injury suggest new therapeutic potentials of progenitor cell-based therapies to accelerate re-endothelialization and prevent engraftment of SMC-lineage progenitor cells. Owing to the complex and multifactorial nature of SMC regulation, combinatorial antiproliferative approaches are likely to be used in the future in order to achieve maximal efficacy and reduce toxicity.

Systemic exposure of sirolimus after coronary stent implantation in patients with de novo coronary lesions: Supralimus-Core® pharmacokinetic study

OBJECTIVES

This study was conducted to assess the systemic drug release and distribution of sirolimus-eluting coronary stents.

METHODS

Twenty patients with coronary artery disease (CAD) were treated with 1, 2, or 3 a newly designed metallic stents. Blood samples were drawn at 14 time points to determine the pharmacokinetic of sirolimus. Whole blood concentrations of sirolimus were determined by using a sensitive validated high-performance liquid chromatography mass spectrometry/mass spectrometry method.

RESULTS

Minimal measurable blood levels were detectable at 7 days. Across all dose levels, individual T(max) values ranged from 1.00 hour and 12.00 hours; individual C(max) ranged from 0.73 ng/mL and 4.13 ng/mL.

CONCLUSION

This study confirms the limited exposure of the systemic circulation of the eluted drug with the use of the Supralimus-Core® Sirolimus-Eluting Coronary Stent System (Sahajanand Medical Technologies Pvt. Ltd., Surat, India). In this study, sirolimus concentration in systemic circulation is to be safe, well-tolerated and short-lived.

Stent outcomes for infrapopliteal arterial occlusive disease

This study aimed to determine if the different stent types used in the treatment of infrapopliteal arterial occlusive disease provide any significant advantage over one another at 6 and 12-month follow-up. Consecutive patients undergoing stenting of infrapopliteal lesions were enrolled into a non-randomised prospective registry and followed-up for 1 year. Outcome measures included binary restenosis, target lesion revascularisation, major amputation, and change in Rutherford-Becker score and ankle-brachial index (ABI).Thirty-three patients were enrolled including four patients with bilateral disease. There were 20 target vessels in the drug-eluting stent (DES) group, 13 target vessels in the balloon-expandable bare metal stent (BE-BMS) group and 14 target vessels in the self expandableb are metal stent (SE-BMS) group. Most of the patients in the study were octogenarians except in the SE-BMS group where the mean age was 73 ± 9 years. At 12 months, seven patients had died (DES = 6, BE-BMS = 1) from cardiac and cancer-related diseases. In-stent and peri-stent binary restenosis were non-statistically different between all three groups. There was a nonstatistically significant trend towards higher target vessel revascularisation in the BE-BMS group. Survival curves in all stent types demonstrated restenosis to occur within the first 6 months post-procedure. There was no significant difference in the change in Rutherford-Becker score or ABI between the groups. No major limb amputations occurred during the 12-month period. In conclusion,we did not detect a significant difference in stent performance between the different stent types used to treat infrapopliteal arterial occlusive disease. The choice of stent did not seem to affect patient survival or major amputation-free survival at 1-year follow-up.

Treatment of sirolimus-eluting stent restenosis: additional stent, balloon angioplasty, and coronary artery bypass graft

OBJECTIVE

Sirolimus-eluting stent (SES) has shown a significant efficacy in reducing restenosis after percutaneous coronary interventions. However, an increase in total number of SES use along with targeting more complex lesions generated a large number of SES restenosis. This study aimed to investigate the clinical and angiographic outcomes of different revascularization strategies for SES restenosis.

METHODS AND RESULTS

A total of 176 lesions in 149 patients were included in the study. Fifteen patients underwent coronary artery bypass graft surgery (CABG group) and the remaining patients were treated with percutaneous coronary intervention (PCI). Stent reimplantation was performed in 88 patients (Stent group), whereas 46 patients received balloon therapy (Balloon group). Among 176 lesions, major cardiac adverse event (MACE) occurred in 41 lesions (23.3%) during a median follow-up of 310 days (interquartile range: 146-517 days). The Kaplan-Meier method with a log-rank test revealed no significant difference in MACE rates between the three groups (6%, 25%, 26%, p = 0.13; CABG group, Stent group, Balloon group, respectively). However, when the Balloon group and Stent group were combined together as a PCI group, PCI group had a significantly higher rate of MACE compared with the CABG group (p = 0.04). In addition, angiographic restenosis was significantly less prevalent in the CABG group when compared with the other two groups (8%, 57%, 46%, p = 0.006; CABG group, Stent group, Balloon group, respectively).

CONCLUSIONS

CABG surgery for patients with SES restenosis is associated with the better clinical outcomes as well as better angiographic outcomes when compared with that of PCI.

Two-year results of a durable polymer everolimus-eluting stent in de novo coronary artery stenosis (The SPIRIT FIRST Trial)

AIMS

The successful use of everolimus on a durable polymer was earlier reported with 6 and 12 months data from this first-in-man study. This reports the long-term follow-up of the XIENCE V everolimus-eluting stent.

METHODS AND RESULTS

This prospective, single-blinded, randomised, multicentre clinical trial evaluated the safety and efficacy of the XIENCE V everolimus-eluting coronary stent system versus an identical bare metal stent in the treatment of patients with a single de novo coronary artery stenosis of >/=50% and <100% and a vessel diameter of 3.0 mm as assessed by on-line quantitative coronary angiography that could be covered by a single 18 mm stent.Sixty patients were randomised and at two-year follow-up, clinical data was available in 96% and 97% of patients in the everolimus and control arm, respectively. Four patients were excluded due to protocol violations and two patients withdrew consent.In the everolimus arm no additional death, myocardial infarction, clinically driven TLR, or TVR events were observed between one and two-year follow-up. The 2-year hierarchical MACE rate for the everolimus arm remained 15.4% (4/26). In the control group, two patients had a clinically driven target lesion revascularisation. MACE rate increased from 21.4% (6/28) to 25.0% (7/28) in the control group.

CONCLUSIONS

This report confirms and extends the safety and efficacy results of the durable polymer XIENCE V everolimus-eluting stent up to two years as compared to identical bare metal stents.

Efficiency and safety of the sirolimus eluting stent in complex coronary artery lesions after cessation of dual antiplatelet therapy: fifteen months clinical outcome of the randomised Stenting Coronary Arteries in Non-stress/benestent Disease (SCANDSTENT) trial

BACKGROUND

The randomised Stenting Coronary Arteries in Non-stress/benestent Disease (SCANDSTENT) trial reported considerably less angiographic restenosis after implantation of sirolimus-eluting stents (SES) vs bare metal stents (BMS) in patients with complex coronary lesions. The purpose of this study was to evaluate the clinical outcome after a majority of the SCANDSTENT patients had stopped the dual antiplatelet therapy.

METHODS AND RESULTS

The SCANDSTENT trial randomly assigned 322 patients with symptomatic complex coronary artery disease (occlusions, bifurcations, ostial or angulated lesions) to receive SES or BMS. At 15 months after stent implantation, when 80% of the patients had stopped taking clopidogrel, six patients in the SES group and 10 in the BMS group had died or suffered a myocardial infarction (non significant [NS]). Compared with BMS, SES reduced the rate of target vessel revascularisation (TVR) from 33.1% to 5.6% (P<0.001) and the frequency of major adverse cardiac events from 35.7% to 8.6% (p<0.001). Definite stent thrombosis was observed in five patients in the BMS group, and two cases of probable and possible stent thrombosis were observed in the SES group (NS). One case of possible SES thrombosis occurred more than one year after stent implantation.

CONCLUSIONS

Compared with BMS, SES markedly reduced the frequency of TVR and MACE within 15 months in SCANDSTENT patients with complex coronary artery lesions without development of delayed restenosis.

Coronary stent use in New York State in the drug-eluting stent era

OBJECTIVES

The drug-eluting stent (DES) was perceived as a revolutionary medical technology because of the lower risk of restenosis compared with bare metal stent (BMS). However, the safety of DES use was called into question in 2006 due to increased incidence of catastrophic late stent thrombosis. This study aims to describe coronary stent use in the DES era in New York State.

METHODS

Using New York State statewide hospital discharge database, we conducted descriptive analysis and logistic regression to examine the independent impacts of the introduction of DES and of the DES safety concern on DES utilization, controlling for patient demographics, co-morbidities and hospital effects.

RESULTS

In the first year following the introduction of DES technology, there was a 10-fold increase in the odds of DES use versus BMS use (AOR: 10.86, 95% CI: 9.84-11.99, P < 0.001). When the safety of DES use was called into question, the odds of DES utilization decreased by 75% over a 9-month period (AOR: 0.23, 95% CI: 0.20-0.26, P < 0.001).

CONCLUSIONS

Following the introduction of DES, there was a rapid adoption of DES by interventional cardiologists, followed by a rapid abandonment of DES when significant safety issues were raised. After the safety of DES was called into question, there was a reduction in the use of DES and in the use of stents in general.

Intra-individual head-to-head comparison of Sirolimus®- and Paclitaxel®-eluting stents for coronary revascularization. A randomized, multi-center trial

BACKGROUND

Despite the known effects of drug-eluting stents (DES), other cofactors attributed to patient characteristics affect their success. Interest focused on designing a study minimizing these factors to answer continuing concerns on the heterogeneity of response to different DESs. The study's aim was to investigate the feasibility and impact of an intra-individual comparison design in patients (pts) with two coronary artery stenosis treated with a Sirolimus- (SES) and a Paclitaxel- (PES) eluting stent.

METHODS AND RESULTS

The study was conducted as a prospective, randomized, multi-center trial in 112 pts who consented to treatment with a SES and a PES. Pts were eligible if they suffered from the presence of two single primary target lesions in two different native coronary arteries. Lesions were randomized to either SES or PES treatment. The primary endpoint was in-stent luminal late loss (LLL), as determined by quantitative angiography at 8 months; clinical follow up was obtained at 1, 8, and 12 months additionally. The LLL (0.13 ± 0.28 mm SES vs. 0.26 ± 0.35 mm PES, p=0.011) showed less neointima in SES. With a predefined cut-off criterion of 0.2mm difference in LLL, 53/87 pts SES and PES were similar effective. 34/87 pts had a divergent result, 26 pts had greater benefit from SES while 8 pts had greater benefit from PES. Overall, MACE (MI, TLR, and death) occurred in 19 (17%) pts. Based on lesion analysis of 108 lesions treated with SES and 110 lesions treated with PES, 5 (4.6%) lesions with SES and 3 (2.7%) lesions with PES required repeated TLR.

CONCLUSION

An intra-individual comparison design to assess differences in efficacy of different DESs is feasible, safe and achieves similar results to inter-individual studies. This study is among the first to show that failure of one DES does not necessarily implicate failure of another DES and vice versa.

The Generations of Drug-Eluting Stents and Outcomes in Women

Drug-eluting stents have become one of the mainstays of percutaneous coronary artery revascularization. Since their introduction, there have been many developments in this technology including the optimization of the stent platform, novel polymer coatings, and antiproliferative drugs. Although cardiovascular disease is the leading cause of death in women, the prevalence of obstructive coronary artery disease is lower, and women comprise a minority of patients included in clinical trials assessing the performance of drug-eluting stents. This article reviews the advances in drug-eluting stent technology and the studies reporting outcomes in women after implantation of these stents.

Clinical Outcomes and Treatment After Drug-Eluting Stent Failure

Background—

The optimal percutaneous treatment of drug-eluting stent (DES) in-stent restenosis (ISR) and the correlates for recurrent DES ISR remain unclear.

Methods and Results—

From 2003 to 2008, 563 patients presenting with recurrent symptoms of ischemia and angiographic ISR after DES implantation were included. Of these, 327 were treated with re-DES (58.1%), 132 underwent vascular brachytherapy (23.4%), and 104 were treated with conventional balloon angioplasty (18.5%). Variables associated with target lesion revascularization at 1 year were explored by individual proportional hazard models. This population presents a high prevalence of comorbidities, including diabetes (43.7%), previous myocardial infarction (MI) (45.8%), coronary bypass graft surgery (39.2%), chronic renal failure (18.8%), and heart failure (17.3%). Baseline clinical characteristics were balanced among the 3 groups; however, patients undergoing vascular brachytherapy presented with more complex lesions and a higher prevalence of prior stent/vascular brachytherapy failure than did the rest of the population. The overall incidence of recurrent DES failure at 1-year follow-up was 12.2%, which was similar among the 3 groups ( P =0.41). The rate of the composite end point (death, Q-wave-MI and target lesion revascularization) at 1-year follow-up was 14.1% for re-DES, 17.5% for vascular brachytherapy, and 18.0% for conventional balloon angioplasty ( P =0.57). After univariable analysis tested the traditional known covariates related to ISR, none of them were associated with repeat target lesion revascularization.

Conclusions—

Recurrence of ISR after DES treatment failure is neither infrequent nor benign, and optimal therapy remains unclear and challenging. Given the absence of traditional risk factors for ISR in this population, further research is required to elucidate both the correlates involved in DES ISR and the optimal treatment for this condition.

Safety measures for gastrointestinal endoscopy in patients receiving antithrombotic therapy

AIM

Owing to carelessness of endoscopists, invasive procedures, such as biopsy, are sometimes carried out inadvertently in patients receiving antithrombotic therapy. The aim of the present study was to retrospectively evaluate the actual status of such careless mistakes and the efficacy of new safety measures.

METHODS

A questionnaire survey was conducted in 34 endoscopists at Toranomon Hospital about experiences of careless mistakes and experiences of anxiety before and after the procedure. 'Anxiety before procedure' was defined as the experience of discontinuing a given procedure because endoscopists remembered that the patient was receiving antithrombotic therapy, and 'anxiety after procedure' was defined as the experience of feeling anxious about the status of medication after the invasive procedure. A new measure was introduced at Health Management Center in August 2009. In this measure, endoscopists directly interview each patient about the status of medication just before examination, and attach forceps valves of one of two colors depending on the status of medication. A blue forceps valve is attached for patients undergoing antithrombotic therapy, and a conventional black forceps valve is attached for patients not undergoing antithrombotic therapy. Six months after introduction, a questionnaire survey was conducted in 10 endoscopists in this center.

RESULTS

Approximately half of endoscopists (18/34) experienced such careless mistakes. 'Anxiety' had been experienced by approximately 80%. After introduction, there was no report of careless mistakes and frequency of 'anxiety' evaluated by visual analog scale score decreased significantly.

CONCLUSION

This new safety measure is expected to facilitate safer gastrointestinal endoscopy in patients receiving antithrombotic therapy.

Two-year follow-up of the Genous™ endothelial progenitor cell capturing stent versus the Taxus Liberté stent in patients with de novo coronary artery lesions with a high-risk of restenosis: a randomized, single-center, pilot study

BACKGROUND

In the prospective randomized TRIAS pilot study, the bio-engineered Genous™ endothelial progenitor cell capturing stent was compared with the Taxus Liberté™ SR paclitaxel-eluting stent. At 1 yr, a statistically nonsignificant difference in the rates of target vessel failure (cardiac death, myocardial infarction, or target vessel revascularization) was observed. We have evaluated the safety and efficacy up to 2 yr.

METHODS

A total of 193 patients with de novo coronary artery lesions carrying a high risk of restenosis were randomized to a Genous stent versus a Taxus stent. Dual antiplatelet therapy was prescribed for ≥1 month after Genous stent implantation and for ≥6 months after a Taxus stent.

RESULTS

Between 1 and 2 yr, patients treated with the Genous stent tended to have fewer episodes of target lesion revascularization (2.0% versus 5.3%), but nearly similar rates of cardiac death (1.0% versus 0%), myocardial infarction (0% versus 1.1%), and stent thrombosis (0% versus 1.1%) when compared with the Taxus stent. As a result, at 2-yr follow-up treatment with the Genous stent compared with the Taxus stent resulted in a nonsignificant difference in target vessel failure (TVR) (20.4% versus 15.8%; risk difference 4.6%, 95% CI -6.2-15.5%). No stent thrombosis was observed in the Genous group compared to five cases (in four patients) in the Taxus group, resulting in a difference as compared with the Taxus stent (risk difference -4.2%; 95%CI -8.2% to -0.2%).

CONCLUSIONS

In the TRIAS pilot study, treatment of coronary artery lesions carrying a high risk of restenosis with the Genous compared with the Taxus stent resulted in a nonsignificant difference of TVR at 2-yr follow-up, with convergence of the Kaplan-Meier curves between 1 and 2 yr. Stent thrombosis was only observed after Taxus stent implantation.

Closed chest hybrid coronary revascularization for multivessel disease - current concepts and techniques from a two-center experience

Hybrid coronary revascularization combining minimally invasive coronary surgery and percutaneous coronary intervention (PCI) allows sternal preserving treatment of multivessel coronary disease. The main principle of the technique includes placement of mammary artery graft to the left anterior descending coronary artery (LAD) and performance of PCI in non-LAD target vessels. This principle is based on increasing data showing equivalent results of PCI with coronary revascularization using saphenous vein grafts in selected patients. Providing that perioperative and long-term results are as good as the results of conventional surgical revascularization, this option seems to be quite appealing for patients and referring cardiologists. This concept has been designed to allow rapid rehabilitation and minimize periprocedural pain under concomitant preservation of the patient's body integrity. Robotically assisted endoscopic approaches for hybrid coronary revascularization set the pace for a closed-chest treatment of multivessel coronary disease. The time point of PCI, the use of different anticoagulation protocols as well as the stent selection are some of the variables, which affect outcome. We additionally report on the midterm results of 130 after-closed-chest hybrid-coronary procedures in two institutions. Hybrid procedures using robotic technology and PCI allow closed chest treatment of multivessel coronary artery disease. Single- and double-bypass grafts are feasible and simultaneous interventions can be performed. The overall safety of the procedure seems to be adequate and perioperative clinical results are satisfactory. Intermediate term survival and freedom from angina are excellent.

Long-term outcome after drug-eluting stent implantation in comparison with bare metal stents: a single centre experience

BACKGROUND

The aim of our study was to evaluate the effect of drug-eluting stents (DES) compared with bare-metal stents (BMS) on all-cause mortality and target vessel revascularization (TVR) in a "real-world" clinical setting.

METHODS AND RESULTS

One thousand four hundred and ninety consecutive patients, who underwent PCI, were included in a prospective registry from January 2003 until December 2006. Patients were divided retrospectively into two groups: those who received a DES and those who received a BMS. The primary combined endpoint all-cause mortality or TVR and the individual endpoints death and TVR were evaluated during a mean follow-up period of 24.56 ± 12.5 months (range 6-52 months). In total 1,033 patients (69.3%) received BMS, while 457 patients (30.7%) received DES. With respect to clinical characteristics, significant differences between groups were found for age, hyperlipidemia, diabetes mellitus, heart failure, previous cerebral insult and presence of acute coronary syndrome (ACS) during intervention. Propensity score analysis was performed in attempt to eliminate this selection bias. With respect to the combined endpoint all-cause death or TVR, 12.9% of patients with DES and 21.3% with BMS (p = 0.015) had an event during the follow-up. 12.3% of patients with BMS but only 5.7% with DES died during the follow-up (p = 0.025). Thirty-three patients (7.2%) of the DES group and 99 patients (9.6%) of the BMS group (p = 0.1) needed TVR.

CONCLUSION

Our results obtained in a "real-world" clinical setting exhibit a clinical long-term benefit for DES compared with BMS and underline the safety and efficacy of DES over BMS.

Sera from patients with diabetes do not alter the effect of mammalian target of rapamycin inhibition on smooth muscle cell proliferation

Clinical studies of drug-eluting stents delivering the mammalian target of rapamycin (mTOR) inhibitor, rapamycin (Sirolimus), have demonstrated a reduced efficacy for these devices in patients with diabetes, which suggests that the mTOR pathway may cease to be dominant in mediating the vascular response to injury under diabetic conditions. We hypothesized that changes in serum composition accompanying diabetes may reduce the role of mTOR in mediating the vascular response to injury. We measured the ability of a median dose of rapamycin (10 nM) to inhibit the proliferation of human coronary artery smooth muscle cells (huCASMCs) stimulated with serum obtained from donors with diabetes (n = 14) and without diabetes (n = 16). In an additional analysis, we compared the effects of rapamycin on huCASMCs stimulated with the serum of donors with metabolic syndrome (n = 15) versus those without (n = 7). There was no difference in the effect of rapamycin on huCASMC proliferation after stimulation with serum from either donors with diabetes or donors with metabolic syndrome compared with the respective controls. We conclude that the changes in the serum composition common to diabetes and metabolic syndrome are insufficient to diminish the role of mTOR in the progression of cardiovascular disease.

Five-year long-term clinical follow-up of the XIENCE V everolimus eluting coronary stent system in the treatment of patients with de novo coronary artery lesions: the SPIRIT FIRST trial

BACKGROUND

Drug-eluting stents have shown to be superior over bare metal stents in clinical and angiographic outcomes after percutaneous treatment of coronary artery stenosis. However, long-term follow-up data are scarce and only available for sirolimus- and paclitaxel-eluting stents.

AIM

To assess the feasibility and performance of the XIENCE V everolimus-eluting stent (EES) versus an identical bare metal stent after a 5-year follow-up period.

METHODS

SPIRIT FIRST was a First in Man, multicentre, prospective, single-blind, clinical trial, randomizing 60 patients with a single de novo coronary artery lesion in a ratio of 1:1 to either an everolimus eluting or a bare metal control stent.

RESULTS

At 5-year clinical follow-up, data were available in 89% and 86% of patients in the everolimus and control arm, respectively. In the everolimus arm, no additional death, myocardial infarction, clinically driven target lesion revascularization (TLR), or clinically driven target vessel revascularization (TVR) events were observed between 1- and 5-year follow-up. The 5-year hierarchical major adverse cardiac events (MACE) and target vessel failure (TVF) rates for the everolimus arm were 16.7% (4/24) for both endpoints. In the control group, no additional cardiac death, myocardial infarction, or clinically driven TLR events were observed between 2- and 5-year follow-up. No additional clinically driven TVR events were observed between 3- and 5-year follow-up. The 5-year hierarchical MACE and TVF rates for the control arm were 28.0% (7/25) and 36.0% (9/25), respectively. No stent thromboses were observed in either the everolimus arm or the control arm up to 5 years.

CONCLUSION

The favorable 5-year long term clinical outcome of the EES is consistent with the results from other studies of the EES with shorter follow-up.

Drug-eluting stents versus bare metal stents for angina or acute coronary syndromes

BACKGROUND

Coronary artery stents are tiny tubular devices used to 'scaffold' vessels open during percutaneous transluminal coronary angioplasty (PTCA). Restenosis (re-narrowing) of vessels treated with stents is a problem; in order to reduce restenosis, stents that elute drugs over time are now available. However these drug-eluting stents are more expensive and there is a need to assess their clinical benefits prior to recommending their use.

OBJECTIVES

To examine evidence from randomised controlled trials (RCTs) to assess the impact of drug eluting stents (DES) compared to bare metal stents (BMS) in the reduction of cardiac events.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 4), MEDLINE (1990 - April 2009) and EMBASE (1980 - January 2009) were searched. We carried out handsearching (electronic and manual) up to January 2008.

SELECTION CRITERIA

We included RCTs comparing DES with BMS used in conjunction with PTCA techniques in the review. Participants were adults with stable angina or acute coronary syndrome (ACS). We considered published and unpublished sources and included them if they reported outcome data of interest.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data, assessed trial quality assessment and checked decisions within the group. Data extraction included composite event rates (major adverse cardiac event, target vessel failure); death; acute myocardial infarction (AMI); target lesion revascularisation (TLR); target vessel revascularisation (TVR) and thrombosis. Data synthesis included meta-analysis of composite event rate, death, AMI and revascularisation rates, presented as odds ratios with 95% confidence intervals (CI) using a fixed-effect model. We assessed heterogeneity between trials.

MAIN RESULTS

We included more than 14,500 patients in 47 RCTs. There were no statistically significant differences in death, AMI or thrombosis between DES and BMS. For composite events, TLR and TVR reductions were evident with use of sirolimus, paclitaxel, everolimus, dexamethasone, zotarolimus and (to a limited extent) tacrolimus-eluting stents. These effects are demonstrated in the longer term follow up. Subgroup analyses (e.g. diabetics) largely mirrored these findings.

AUTHORS' CONCLUSIONS

Drug-eluting stents releasing sirolimus, paclitaxel, dexamethasone and zotarolimus reduce composite cardiac events. However, this reduction is due largely to reductions in repeat revascularisation rates as there is no evidence of a significant effect on rates of death, MI or thrombosis. The increased cost of drug-eluting stents and lack of evidence of their cost-effectiveness means that various health funding agencies are having to limit or regulate their use in relation to price premium.

Recent progress in percutaneous coronary intervention: evolution of the drug-eluting stents, focus on the XIENCE V drug-eluting stent

Although originally the practice of using balloon catheters proved successful in the short term, the long-term prognosis was less promising because of restenosis, which occurred in >or=30% of patients. This prompted the development of new techniques and mechanical adjuncts, or stents, to maintain lumen patency after balloon angioplasty. Bare metal stents (BMS), the first type of stent used in percutaneous coronary intervention, were designed to address the issues met by balloon angioplasty. BMS reduced the angiographic and clinical restenosis rates in de novo lesions compared to percutaneous transluminal coronary angioplasty alone and decreased the need for emergency coronary artery bypass graft surgery. BMS substantially reduced the incidence of abrupt artery closure, but restenosis still occurred after 6 months in about 20% of cases, necessitating repeat procedures. Drug-eluting stents (DES) improved on the principle of BMS by also delivering drugs locally to inhibit neointimal hyperplasia. DES greatly reduced the incidence of restenosis and resulted in a better safety profile as compared to radiation or systemic drug administration. These advantages and a lower cost compared to surgical interventions make DES an attractive option to treat coronary artery disease. Currently, five DES are available in the USA: the CYPHER sirolimus-eluting stent from Cordis (approved by FDA on 24 April 2003), the TAXUS Express(2) and Liberté paclitaxel-eluting stents from Boston Scientific (approved by FDA on 4 March 2004 and 10 October 2008, respectively) (hereafter TAXUS Express is referred to as TAXUS), the ENDEAVOR zotarolimus-eluting stent from Medtronic (approved by FDA on 1 February 2008), and the XIENCE V everolimus-eluting stent from Abbott Vascular (approved by FDA on 2 July 2008). Following the approval of CYPHER and TAXUS, the clinical data suggested a potential small increase in the rate of stent thrombosis (ST) in DES compared with BMS after implantation. To determine the differences in ST and other rare events between different stents, some modifications have been made to DES clinical trial design, and postmarket surveillance programs have been included to further evaluate the safety and efficacy of each DES. In this review, we will discuss the key clinical outcomes of DES clinical trials, design and key features of the current coronary stents, and major clinical development programs. Postmarket trials, designed to establish long-term safety around ST and other rare clinical events, are also discussed. The future of DES design technologies will also be outlined.

Drug-eluting stents: issues of late stent thrombosis

In in-stent restenosis, drug-eluting stents are superior compared with bare metal stents. However, there are concerns about safety because of the reports of increased risk of late and very late stent thrombosis. Stent thrombosis remains a major pitfall in contemporary percutaneous coronary intervention, leading to high rates of death and nonfatal myocardial infarction. A new standardized definition of stent thrombosis was established to provide consistency in the reporting of this complication and to enable accurate and reliable data to be described for both types of stents, bare metal and drug-eluting. This new consensual definition reflects a large amount of new data reported in the literature. New generations of drug-eluting stents with novel polymers, antiproliferative drugs, and improved platforms are now approved and available for use. In this article, the authors provide a critical appraisal of the safety of different drug-eluting stents based on the published clinical data focusing on late and very late stent thrombosis.

Rationale and design of the Patient Related OuTcomes with Endeavor versus Cypher stenting Trial (PROTECT): randomized controlled trial comparing the incidence of stent thrombosis and clinical events after sirolimus or zotarolimus drug-eluting stent implantation

Drug-eluting stents (DES) reduce restenosis rates compared to bare-metal stents. Most trials using DES enrolled selected patient and lesion subtypes, and primary endpoint focused on angiographic metrics or relatively short-term outcomes. When DES are used in broader types of lesions and patients, important differences may emerge in long-term outcomes between stent types, particularly the incidence of late stent thrombosis. PROTECT is a randomized, open-label trial comparing the long-term safety of the zotarolimus-eluting stent and the sirolimus-eluting stent. The trial has enrolled 8,800 patients representative of those seen in routine clinical practice, undergoing elective, unplanned, or emergency procedures in native coronary arteries in 196 centers in 36 countries. Indications for the procedure and selection of target vessel and lesion characteristics were at the operator's discretion. Procedures could be staged, but no more than 4 target lesions could be treated per patient. Duration of dual antiplatelet therapy was prespecified to achieve similar lengths of treatment in both study arms. The shortest predefined duration was 3 months, as per the manufacturer's instructions. The primary outcome measure is the composite rate of definite and probable stent thrombosis at 3 years, centrally adjudicated using Academic Research Consortium definitions. The main secondary end points are 3-year all-cause mortality, cardiac death, large nonfatal myocardial infarction, and all myocardial infarctions. This large, international, randomized, controlled trial will provide important information on comparative rates of stent thrombosis between 2 different DES systems and safety as assessed by patient-relevant long-term clinical outcomes.

Coronary pressure measurement based decision making for percutaneous coronary intervention

The fractional flow reserve (FFR) is a simple, reliable, and reproducible physiologic index of lesion severity. In patients with intermediate stenosis, FFR≥0.75 can be used to safely defer percutaneous coronary intervention (PCI), and patients with FFR≥0.75 have a very low cardiac event rate. Coronary pressure measurement can determine which lesion should be treated with PCI in patients with tandem lesions, and PCI on the basis of FFR has been demonstrated to result in an acceptably low repeat PCI rate. FFR can identify patients with equivocal left main coronary artery disease who benefit from coronary bypass surgery. Coronary pressure measurement distinguishes patients with an abrupt pressure drop pattern from those with a gradual pressure drop pattern, and the former group of patients benefit from PCI. Coronary pressure measurement is clinically useful in evaluating sufficient recruitable coronary collateral blood flow for prevention of ischemia, which affects future cardiac events. FFR is useful for the prediction of restenosis after PCI. As an end-point of PCI, FFR ≥0.95 and ≥0.90 would be appropriate for coronary stenting and coronary angioplasty, respectively. In summary, if you encounter a coronary stenosis in doubt you should measure pressure rather than dilate it.