Comparison of zotarolimus-eluting and sirolimus-eluting stents in patients with native coronary artery disease: a randomized controlled trial

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.

Evolution of drug-eluting coronary stents: a back-and-forth journey from the bench-to-bedside

Coronary stents have revolutionized the treatment of coronary artery disease. Compared with balloon angioplasty, bare-metal stents effectively prevented abrupt vessel closure but were limited by in-stent restenosis due to smooth muscle cell proliferation and neointimal hyperplasia. The first-generation drug-eluting stent (DES), with its antiproliferative drug coating, offered substantial advantages over bare-metal stents as it mitigated the risk of in-stent restenosis. Nonetheless, they had several design limitations that increased the risk of late stent thrombosis. Significant advances in stent design, including thinner struts, enhanced polymers' formulation, and more potent antiproliferative agents, have led to the introduction of new-generation DES with a superior safety profile. Cardiologists have over 20 different DES types to choose from, each with its unique features and characteristics. This review highlights the evolution of stent design and summarizes the clinical data on the different stent types. We conclude by discussing the clinical implications of stent design in high-risk subsets of patients.

Comparison of biodegradable and newer generation durable polymer drug-eluting stents with short-term dual antiplatelet therapy: a systematic review and Bayesian network meta-analysis of randomized trials comprising of 43,875 patients

Newer generation durable polymer drug-eluting stents (DP-DES) and biodegradable polymer DES (BP-DES) have similar efficacy with dual-antiplatelet therapy (DAPT) duration of > 6 months. However, this difference in outcomes have not been well studied in shorter DAPT regime. This study compares the safety and efficacy profiles of DP-DES and BP-DES based on short-term (1-3 months), intermediate-term (4-6 months) and standard DAPT (6-12 months) durations. A search was conducted on Embase and Medline for Randomized Controlled Trials (RCTs) comparing stent types, and DAPT durations. Primary endpoints include cardiac death, myocardial infarction (MI), definite stent thrombosis, stroke, target vessel revascularization (TVR) and major bleeding. Network analysis was conducted to summarize the evidence. A total of 15 RCTs involving 43,875 patients were included. DP-DES was associated with significantly lower major bleeding rates compared to BP-DES (RR 0.44, Crl 0.22-0.83) in short-term DAPT. Among DP-DES patients, short-term DAPT was associated with lower major bleeding risk compared to standard DAPT (RR 0.47, CrI 0.32-0.69). This favorable bleeding profile with short DAPT was not found in BP-DES patients. Cardiac death, MI, definite stent thrombosis, stroke and TVR rates were similar across the various DAPT durations and stent types. Our preliminary findings demonstrated comparable efficacy and safety outcomes between BP-DES and newer generation BP-DES across various DAPT durations. In patients requiring short DAPT, DP-DES had more favourable major bleeding profile compared to BP-DES, without compromising anti-thrombotic efficacy.

Improving PCI Outcomes Using Postprocedural Physiology and Intravascular Imaging

Although clinical outcomes after percutaneous coronary intervention (PCI) are improving, the long-term risk for target vessel failure remains concerning. Although the application of intravascular imaging and physiological indexes significantly improves outcomes, their routine use in practice remains limited. Nevertheless, merely using these modalities is not enough, and to truly improve patient outcomes, optimal intravascular dimensions with minimal vascular injury should be targeted. When assessing post-PCI results using either type of physiological or imaging technology, a broad spectrum of stent- and vessel-related anomalies can be expected. As not all of these issues warrant treatment, a profound knowledge of what to expect and how to recognize and when to treat these intraluminal problems is needed. Additionally, promising new modalities such as angiography-derived coronary physiology and hybrid imaging catheters are becoming available. The authors provide an overview of the currently available tools and techniques to define suboptimal PCI and when to apply these technologies to improve outcomes.

Thin- versus thick-strut polymer-free biolimus-eluting stents: the BioFreedom QCA randomised trial

BACKGROUND

The BioFreedom drug-coated stent with a stainless steel platform (BF-SS) has been demonstrated to be efficacious in patients at high bleeding risk and receiv-ing only one-month dual antiplatelet therapy.

AIMS

The aim of this study was to evaluate the efficacy of the new BioFreedom Ultra drug-coated stent with a thin-strut cobalt-chromium platform (BF-CoCr) compared to the BF-SS in an all-comers population undergoing percutaneous coronary intervention (PCI).

METHODS

This was a prospective, multicentre, non-inferiority trial. The primary endpoint was in-stent late lumen loss (LLL) as determined by quantitative coronary angiography at nine-month follow-up. Clinical evaluation was performed at one year.

RESULTS

A total of 200 patients were randomised (1:1) to either the BF-CoCr or the BF-SS stent at eight centres in Spain and Denmark. Baseline clinical and lesion characteristics were similar between the groups. Mean age was 66 years and 23% were female. The mean number of stents implanted per patient was 1.5. At nine-month follow-up, mean in-stent LLL was 0.34±0.49 mm in the BF-CoCr group versus 0.29±0.37 mm in the BF-SS group, p=0.005 for non-inferiority. At one year, target lesion failure was similar between the groups (7.3% in BF-CoCr vs 9.3% in the BF-SS group; p=0.60).

CONCLUSIONS

The BF-CoCr was non-inferior to the BF-SS in terms of in-stent LLL at nine months. Larger studies powered for clinical endpoints are warranted to compare the efficacy of this new platform with currently available DES.

Prognostic and Practical Validation of ESC/EACTS High Ischemic Risk Definition on Long-Term Thrombotic and Bleeding Events in Contemporary PCI Patients

Aims: The ESC/EACTS myocardial revascularization guidelines recently standardized the definition of patients at high ischemic risk (HIR). However, the ability of ESC/EACTS–HIR criteria to stratify ischemic and bleeding risk in a contemporary real-world East Asian cohort remains unexplored.

Methods: A total of 10,167 consecutive patients undergoing PCI from prospective Fuwai PCI Registry (January 2013 to December 2013) were reviewed. ESC/EACTS–HIR features was defined as having at least one of the eight clinical and angiographic characteristics. The primary ischemic endpoint was target vessel failure (cardiac death, target vessel myocardial infarction [MI], or target vessel revascularization [TVR]); bleeding outcome was assessed using the BARC type 2, 3, or 5 bleeding. Median follow-up was 29 months.

Results: Compared with non-HIR patients, HIR patients ( n =5,149, 50.6%) were associated with increased risk for target vessel failure (adjusted hazard ratio [HR _adjust ]: 1.48 [1.25–1.74]) and patient-oriented composite outcome (HR _adjust : 1.44 [1.28–1.63]), as well as cardiac death, MI, and TVR. By contrast, the risk of clinically relevant bleeding was not significantly different between the two groups. (HR _adjust : 0.84 [0.66–1.06]). Greater than or equal to three implanted stents and diabetic patients with diffuse multivessel coronary disease emerged as independent predictors for long-term adverse outcomes. There was no significant interaction between high bleeding risk (HBR) status and clinical outcomes associated with ESC/EACTS–HIR criteria (all P _interaction ＞0.05).

Conclusion: The ESC/EACTS–HIR features identified patients at increased risk of thrombotic events, including cardiac death, but not for clinically relevant bleeding. Importantly, HBR did not modify cardiovascular risk subsequent to patients with ESC/EACTS–HIR features, suggesting its potential clinical applicability in tailoring antithrombotic therapy.

Bivalirudin and sirolimus co-eluting coronary stent: Potential strategy for the prevention of stent thrombosis and restenosis

Localized drug delivery with sustained elution characteristics from nanocarrier coated stents represents a viable therapeutic approach to circumvent concerns related to coronary stent therapy. We fabricated a Sirolimus (SRL) and Bivalirudin (BIV) releasing nanoparticles (NPs) coated stent for concurrent mitigation of vascular restenosis and acute stent thrombosis. SRL NPs were prepared by nanoprecipitation method whereas the BIV vesicles were generated using hydrophobic ion pair approach followed by micellization phenomenon. MTT assay and confocal microscopic analysis indicated superior anti-proliferative activity and higher cellular uptake of SRL NPs into human coronary artery smooth muscle cells, respectively. DSC and ATR-FTIR techniques confirmed the formation of complex between BIV and phosphatidylglycerol via some weak physical interactions. More than 2 fold rise in log P value was obtained for DSPG-BIV at 3:1 M ratio compared with native BIV solution. The SAXS analysis indicated formation of oligolamellar vesicles of DSPG-BIV complex which was preferentially entrapped into lipophilic lamellae of vesicles. APTT, PT, and TT tests revealed that the BIV vesicles caused significant prolongation of clotting time compared to native BIV solution. The SEM analysis showed uniform and defect free stent coating. In vitro release study demonstrated that SRL and BIV were eluted in a sustained manner from coated stents.

Second generation drug-eluting stents: a focus on safety and efficacy of current devices

Introduction: Percutaneous coronary intervention (PCI) represents the most frequent procedure performed in medicine. Second generation drug eluting stents (DES) have been developed to reduce the rates of late and very late complications of first generation DES.Areas covered: To improve long-term efficacy and safety of patients undergoing PCI, second generation DES have been developed with novel stent platforms, biocompatible durable and biodegradable polymers and newer antiproliferative agents. In this review we provide an overview of second generation DES and their clinical trials, discussing safety and effectiveness of these devices, and outlining clinical indication for use.Expert commentary: Numerous clinical trials have demonstrated the safety and efficacy of second generation DES over the last decade. These devices represent the gold standard treatment in stable and acute coronary syndromes.

Impact of Coronary Artery Tortuosity on Outcomes Following Stenting: A Pooled Analysis From 6 Trials

OBJECTIVES

The authors sought to determine whether coronary artery tortuosity negatively affects clinical outcomes after stent implantation.

BACKGROUND

Coronary artery tortuosity is a common angiographic finding and has been associated with increased rates of early and late major adverse events after balloon angioplasty.

METHODS

Individual patient data from 6 prospective, randomized stent trials were pooled. Outcomes at 30 days and 5 years following percutaneous coronary intervention of a single coronary lesion were analyzed according to the presence or absence of moderate/severe vessel tortuosity, as determined by an angiographic core laboratory. The primary endpoint was target vessel failure (TVF) (composite of cardiac death, target vessel-related myocardial infarction [TV-MI], or ischemia-driven target vessel revascularization [ID-TVR]).

RESULTS

A total of 6,951 patients were included, 729 of whom (10.5%) underwent percutaneous coronary intervention in vessels with moderate/severe tortuosity. At 30 days, TVF was more frequent in patients with versus without moderate/severe tortuosity (3.8% vs. 2.4%; hazard ratio [HR]: 1.64; 95% confidence interval [CI]: 1.09 to 2.46; p = 0.02), a difference driven by a higher rate of TV-MI. At 5 years, TVF remained increased in patients with moderate/severe tortuosity (p = 0.003), driven by higher rates of TV-MI (p = 0.003) and ID-TVR (p = 0.01). Definite stent thrombosis was also greater in patients with versus without moderate/severe tortuosity (1.9% vs. 1.0%; HR: 1.86; 95% CI: 1.02 to 3.39; p = 0.04). After adjustment for baseline covariates, moderate/severe vessel tortuosity was independently associated with TV-MI and ID-TVR at 5 years (p = 0.04 for both).

CONCLUSIONS

Stent implantation in vessels with moderate/severe coronary artery tortuosity is associated with increased rates of TVF due to greater rates of TV-MI and ID-TVR.

Antiplatelet therapy after PCI in patients with high risk of bleeding

The progress of percutaneous coronary interventions (PCI) over the last few decades facilitated treatment of increasingly complex patient populations. The introduction of drug-eluting stents (DESs) led to need of stronger and prolonged inhibition of platelets which in turn increased the incidence of bleeding complications. The identification and management of patients at high bleeding risk (HBR) during and after percutaneous coronary interventions (PCI) is still problematic in everyday clinical practice.

Global Approach to High Bleeding Risk Patients With Polymer-Free Drug-Coated Coronary Stents: The LF II Study

BACKGROUND

High bleeding risk (HBR) patients undergoing percutaneous coronary intervention have been widely excluded from randomized device registration trials. The LF study (LEADERS FREE) reported superior outcomes of HBR patients receiving 30-day dual antiplatelet therapy after percutaneous coronary intervention with a polymer-free drug-coated stent (DCS). LFII was designed to assess the reproducibility and generalizability of the benefits of DCS observed in LF to inform the US Food and Drug Administration in a device registration decision.

METHODS

LFII was a single-arm study using HBR inclusion/exclusion criteria and 30-day dual antiplatelet therapy after percutaneous coronary intervention with DCS, identical to LF. The 365-day rates of the primary effectiveness (clinically indicated target lesion revascularization) and safety (composite cardiac death and myocardial infarction) end points were reported using a propensity-stratified analysis compared with the LF bare metal stent arm patients as controls.

RESULTS

A total of 1203 LFII patients were enrolled with an average 1.7 HBR criteria per patient, including 60.7% >75 years of age, 34.1% on anticoagulants, and 14.7% with renal failure. Propensity-adjusted 365-day clinically indicated target lesion revascularization was significantly lower with DCS (7.2% versus 9.2%; hazard ratio, 0.72 [95% CI, 0.52-0.98]; P=0.0338 for superiority), as was the primary safety (cardiac death and myocardial infarction) composite (9.3% versus 12.4%; hazard ratio, 0.72 [95% CI, 0.55-0.94]; P=0.0150 for superiority). Stent thrombosis rates were 2.0% DCS and 2.2% bare metal stent. Major bleeding at 1 year occurred in 7.2% DCS patients and 7.2% bare metal stent.

CONCLUSIONS

LFII reproduces the results of the DCS arm of LF in an independent, predominantly North American cohort of HBR patients.

Comparison of the Major Clinical Outcomes for the Use of Endeavor® and Resolute Integrity® Zotarolimus-Eluting Stents During a Three-Year Follow-up

Background

Endeavor®-zotarolimus-eluting stent (E-ZES) was the first ZES to be developed, and Resolute integrity®-ZES (I-ZES) has been developed more recently. Comparative studies on long-term usage of these two ZESs have been rare.

Objectives

The aim of this study was to compare the efficacy and safety of E-ZES and I-ZES during a long-term follow-up of patients who underwent percutaneous coronary intervention (PCI).

Methods

A total of 767 patients who underwent PCI with E-ZES or I-ZES were eligible for this study. The primary endpoint was the occurrence of major adverse cardiac events (MACEs), defined as the composite of all-cause death, non-fatal myocardial infarction (MI), and any repeat revascularization. The secondary endpoint was stent thrombosis (ST).

Results

After propensity score-matched (PSM) analysis, two PSM groups (193 pairs, n = 386, C-statistic = 0.824) were generated. During the 3-year follow-up period, the cumulative incidence of MACEs (hazard ratio [HR], 0.837; 95% confidence interval [CI], 0.464-1.508; p = 0.553) and ST (HR, 0.398; 95% CI, 0.077-2.052; p = 0.271) was similar for the E-ZES and I-ZES groups. Additionally, the cumulative incidences of all-cause death, cardiac death, non-fatal MI, and any repeat revascularization were not significantly different between the two groups.

Conclusions

Although I-ZES utilizes a more advanced stent platform, stent design, and polymer system than E-ZES, both the ZESs showed comparable efficacy and safety during the 3-year follow-up period in this single-center, all-comers registry. However, further large-scaled, randomized, well-controlled trials with long-term follow-up are needed to verify these results.

Prospective evaluation of an ultrathin strut biodegradable polymer-coated sirolimus-eluting stent: 12 months' results from the S-FLEX UK registry

OBJECTIVE

To prospectively evaluate safety and efficacy of the ultrathin strut biodegradable polymer-coated Supraflex sirolimus-eluting stent (S-SES) in 'real world' patient population requiring percutaneous coronary intervention (PCI).

METHODS

National, prospective, multicentre, single-arm, all-comers, observational registry of 469 patients treated with S-SES from July 2015 and November 2016 in 11 centres in UK. Primary endpoint was target lesion failure (TLF) at 12 months (cardiac death, target vessel myocardial infarction (MI) or clinically driven target lesion revascularisation (TLR)). Secondary endpoints included safety and performance outcomes at 12 months-overall stent thrombosis (ST), all-cause mortality, any MI, target vessel failure (TVF) and major adverse cardiac events (MACE-composite of cardiac death, MI, emergent or repeat revascularisation).

RESULTS

At 12 months, the primary endpoint occurred in 11 (2.4%) of 466 patients, consisting of 4 (0.9%) cardiac deaths, 3 (0.6%) target vessel MI and 7 (1.5%) TLR. Secondary endpoints findings included all-cause mortality in 6 (1.3%), TVF of 14 (3%), no definite ST, 1 (0.2%) probable ST and 3 (0.6%) possible ST. Overall MACE was observed in 18 (3.9%).

CONCLUSIONS

The S-FLEX UK registry showed that the S-SES is safe with a low incidence of TLF in routine clinical practise in patients with coronary artery disease being treated by PCI.

The Smoker's Paradox Revisited: A Patient-Level Pooled Analysis of 18 Randomized Controlled Trials

OBJECTIVES

This study examined the smoker's paradox using patient-level data from 18 prospective, randomized trials of patients undergoing percutaneous coronary intervention (PCI) with stent implantation.

BACKGROUND

Studies on the effects of smoking and outcomes among patients undergoing PCI have reported conflicting results.

METHODS

Data from the RAVEL, E-SIRIUS, SIRIUS, C-SIRIUS, TAXUS IV and V, ENDEAVOR II to IV, SPIRIT II to IV, HORIZONS-AMI, COMPARE I and II, PLATINUM, and TWENTE I and II randomized trials were pooled. Patients were stratified by smoking status at time of enrollment. The 1- and 5-year ischemic outcomes were compared.

RESULTS

Among 24,354 patients with available data on smoking status, 6,722 (27.6%) were current smokers. Smokers were younger and less likely to have diabetes mellitus; hypertension; hyperlipidemia; or prior myocardial infarction (MI), PCI, or coronary artery bypass grafting. Angiographically, smokers had longer lesions, more complex lesions, and more occlusions, but were less likely to have moderate or severe calcification or tortuosity. At 5 years, smokers had significantly higher rates of MI (7.8% vs. 5.6%; p < 0.0001) and definite or probable stent thrombosis (3.5% vs. 1.8%; p < 0.0001); however, there were no differences in the rates of death, cardiac death, target lesion revascularization, or composite endpoints (cardiac death, target vessel MI, or ischemic target lesion revascularization). After multivariable adjustment for potential confounders, smoking was a strong independent predictor of death (hazard ratio [HR]: 1.86; 95% confidence interval [CI]: 1.63 to 2.12; p < 0.0001), cardiac death (HR: 1.68; 95% CI: 1.38 to 2.05; p < 0.0001), MI (HR: 1.38; 95% CI: 1.20 to 1.58; p < 0.0001), stent thrombosis (HR: 1.60; 95% CI: 1.28 to 1.99; p < 0.0001), and target lesion failure (HR: 1.17; 95% CI: 1.05 to 1.30; p = 0.005).

CONCLUSIONS

The present large, patient-level, pooled analysis with 5-year follow-up clearly demonstrates smoking to be an important predictor of adverse outcomes after PCI.

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.

Safety and efficacy of ultrathin strut biodegradable polymer sirolimus-eluting stent versus durable polymer drug-eluting stents: a meta-analysis of randomized trials

Background

The Orsiro biodegradable polymer sirolimus-eluting stent (O-SES) is a new-generation biodegradable polymer drug-eluting stent with the thinnest strut thickness to date developed to improve the percutaneous treatment of patients with coronary artery disease. We perform a meta-analysis of randomized clinical trials (RCTs) comparing the efficacy and safety of an ultra-thin, Orsiro biodegradable polymer sirolimus-eluting stent (O-SES) compared with durable polymer drug-eluting stents (DP-DESs).

Methods

Medline, Embase, and CENTRAL databases were searched for randomized controlled trials comparing the safety and efficacy of O-SES versus DP-DES. Paired reviewers independently screened citations, assessed risk of bias of included studies, and extracted data. We used the Mantel-Haenszel method to calculate risk ratio (RR) by means of a random-effects model.

Results

Six RCTs with a total of 6949 patients were selected. All included trials were rated as low risk of bias. The O-SES significantly reduced the risk of myocardial infarction (RR 0.78, 95% confidence interval [CI] 0.62–0.98; I² = 0%; 10 fewer per 1000 [from 1 fewer to 18 fewer]; high quality) compared with the DP-DES. There was no significant difference between O-SES and DP-DES in the prevention of stent thrombosis (RR: 0.75; 95% CI: 0.52–1.08), cardiac death (RR: 0.93; 95% CI: 0.63–1.36), target lesion revascularization (RR 1.10, 95% CI 0.86–1.42) and target vessel revascularization (RR 0.97, 95% CI 0.78–1.21).

Conclusion

Among patients undergoing percutaneous coronary intervention, O-SES resulted in significantly lower rates of myocardial infarction than DP-DES and had a trend toward reduction in stent thrombosis.

Safety and Efficacy of the Endeavor Resolute® Stent in Patients with Multivessel Disease: The HEART (Honam EndeAvor ResoluTe) Prospective, Multicenter Trial

The Endeavor Resolute® (ER) is a zotarolimus-eluting stent (ZES) with a biocompatible BioLinx polymer. This study prospectively compared the clinical outcomes of 2 versions of ZES, ER and Endeavor Sprint® (ES), in patients with multivessel disease. A total of 488 patients who underwent multivessel percutaneous coronary intervention (PCI) were divided into 2 groups the ER group (n=288) and the ES group (n=200). The primary endpoint was a composite of major adverse cardiac events (MACE) consisting of death, myocardial infarction, and target vessel revascularization after 12 months. In all patients, the prevalence of diabetes was higher in the ER group (42.7% vs. 31.0%, p=0.009). The rate of post-PCI Thrombolysis in Myocardial Infarction flow grade 3 was higher in the ER group (100.0% vs. 98.0%, p=0.028). There were no between-group differences in the in-hospital, 1-month and 12-month clinical outcomes. In the propensity score matched cohort (n=200 in each group), no differences were observed in the baseline and procedural characteristics. There were no statistical differences in the rates of in-hospital, 1-month and 12-month events (12-month MACE in the ER and ES groups: 6.0% vs. 3.5%, p=0.240, respectively). The safety and efficacy of both versions of ZES were comparable in patients with multivessel disease during a 12-month clinical follow-up.

Ultrathin, bioresorbable polymer sirolimus-eluting stents versus thin, durable polymer everolimus-eluting stents in patients undergoing coronary revascularisation (BIOFLOW V): a randomised trial

BACKGROUND

The development of coronary drug-eluting stents has included use of new metal alloys, changes in stent architecture, and use of bioresorbable polymers. Whether these advancements improve clinical safety and efficacy has not been shown in previous randomised trials. We aimed to examine the clinical outcomes of a bioresorbable polymer sirolimus-eluting stent compared with a durable polymer everolimus-eluting stent in a broad patient population undergoing percutaneous coronary intervention.

METHODS

BIOFLOW V was an international, randomised trial done in patients undergoing elective and urgent percutaneous coronary intervention in 90 hospitals in 13 countries (Australia, Belgium, Canada, Denmark, Germany, Hungary, Israel, the Netherlands, New Zealand, South Korea, Spain, Switzerland, and the USA). Eligible patients were those aged 18 years or older with ischaemic heart disease undergoing planned stent implantation in de-novo, native coronary lesions. Patients were randomly assigned (2:1) to either an ultrathin strut (60 μm) bioresorbable polymer sirolimus-eluting stent or to a durable polymer everolimus-eluting stent. Randomisation was via a central web-based data capture system (mixed blocks of 3 and 6), and stratified by study site. The primary endpoint was 12-month target lesion failure. The primary non-inferiority comparison combined these data from two additional randomised trials of bioresorbable polymer sirolimus-eluting stent and durable polymer everolimus-eluting stent with Bayesian methods. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT02389946.

FINDINGS

Between May 8, 2015, and March 31, 2016, 4772 patients were recruited into the study. 1334 patients met inclusion criteria and were randomly assigned to treatment with bioresorbable polymer sirolimus-eluting stents (n=884) or durable polymer everolimus-eluting stents (n=450). 52 (6%) of 883 patients in the bioresorbable polymer sirolimus-eluting stent group and 41 (10%) of 427 patients in the durable polymer everolimus-eluting stent group met the 12-month primary endpoint of target lesion failure (95% CI -6·84 to -0·29, p=0·0399), with differences in target vessel myocardial infarction (39 [5%] of 831 patients vs 35 [8%] of 424 patients, p=0·0155). The posterior probability that the bioresorbable polymer sirolimus-eluting stent is non-inferior to the durable polymer everolimus-eluting stent was 100% (Bayesian analysis, difference in target lesion failure frequency -2·6% [95% credible interval -5·5 to 0·1], non-inferiority margin 3·85%, n=2208).

INTERPRETATION

The outperformance of the ultrathin, bioresorbable polymer sirolimus-eluting stent over the durable polymer everolimus-eluting stent in a complex patient population undergoing percutaneous coronary intervention suggests a new direction in improving next generation drug-eluting stent technology.

FUNDING

BIOTRONIK.

Coronary stents and vascular response to implantation: literature review

Drug-eluting stents (DESs) have minimized the limitations of bare-metal stents (BMSs) after percutaneous coronary interventions. Nevertheless, serious concerns remain about possible late complications of stenting, such as stent thrombosis (ST) and in-stent restenosis (ISR), although the introduction of second-generation DESs seems to have softened the phenomenon, compared to the first-generation ones. ST is a potentially catastrophic event, which has been markedly reduced by optimization of stent implantation, novel stent designs, and dual antiplatelet therapy. The exact mechanism to explain its occurrence is under investigation, and, realistically, multiple factors are responsible. ISR of BMSs has been previously considered as a stable condition with an early peak (at 6 months) of intimal hyperplasia, followed by a regression period beyond 1 year. On the contrary, both clinical and histologic studies of DESs have demonstrated evidence of continuous neointimal growth during long-term follow-up, named "late catch-up" phenomenon. The acknowledgment that ISR is a relatively benign clinical condition has been recently challenged by evidences which reported that patients with ISR can experience acute coronary syndromes. Intracoronary imaging is an invasive technology that allows identifying features of atherosclerotic plaque of stent implanted and of vascular healing after stenting; it is often used to complete diagnostic coronary angiography and to drive interventional procedures. Intracoronary optical coherence tomography is currently considered a state-of-the-art imaging technique; it provides, compared to intravascular ultrasound, better resolution (at least >10 times), allowing the detailed characterization of the superficial structure of the vessel wall. Imaging studies "in vivo," in agreement with histological findings, suggest that chronic inflammation and/or endothelial dysfunction may induce late de novo "neoatherosclerosis" inside both BMSs and DESs. So, neoatherosclerosis has become the prime suspect in the pathogenesis of late stent failure.

Thrombin generation test for evaluation of antiplatelet treatment in patients with coronary artery disease after percutaneous coronary intervention

To study the possibility of using thrombin generation tests in platelet-rich and platelet-poor plasma for evaluation of dual antiplatelet therapy efficacy in patients with coronary artery disease (CAD), following percutaneous coronary intervention. Venous blood was analyzed from CAD patients aged 53-75 years who had undergone percutaneous coronary intervention with stenting within one year and had been receiving standard doses of clopidogrel and aspirin (75 and 75-100 mg per day, respectively). The control group comprised age- and sex-matched subjects without clinical signs of CAD who were not receiving these drugs. Thrombin generation tests were performed in platelet-rich and platelet-poor plasma. Intravascular platelet activation, induced platelet aggregation, and routine coagulation were evaluated. Antiplatelet treatment did not influence results of routine coagulation tests or intravascular platelet activation. The dual antiplatelet therapy affects collagen-induced platelet aggregation (44 ± 2.5 vs. 7.9 ± 2.6%, р = 10^-7) and leads to decreases in endogenous thrombin potential (1900 ± 85 vs. 1740 ± 95 nM∙min, p = 0.0045), maximum thrombin concentration (134 ± 9.5 vs. 106 ± 6.5 nM, p = 4∙10^-6), and increases in time to peak thrombin (27 ± 1.5 vs. 31 ± 2 min, p = 0.0012). Decreases in thrombin generation rate showed the highest statistical significance (13 ± 2 vs. 7.9 ± 0.8 nM/min, p = 10^-8). Antiplatelet treatment did not alter thrombogram parameters for platelet-poor plasma.

Predictors and Long-Term Clinical Impact of Acute Stent Malapposition: An Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) Intravascular Ultrasound Substudy

BACKGROUND

The impact of acute stent malapposition (ASM) on long-term clinical outcomes in patients undergoing percutaneous coronary intervention is still controversial. We sought to evaluate predictors and long-term clinical outcomes of ASM.

METHODS AND RESULTS

ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective multicenter study of 8663 patients undergoing percutaneous coronary intervention using drug-eluting stents. In a prespecified intravascular ultrasound-guided substudy, 2072 patients with 2446 culprit lesions had post-percutaneous coronary intervention intravascular ultrasound and were classified according to the presence or absence of ASM. After intravascular ultrasound-guided percutaneous coronary intervention, the overall prevalence of ASM after successful drug-eluting stents implantation was 14.4% per patient and 12.6% per lesion. Compared to lesions without ASM, lesions with ASM had larger in-stent lumen areas, larger stent areas, and larger in-stent vessel areas. A larger mean plaque area along with more attenuated plaque was observed in lesions with ASM versus lesions without ASM. Lesions with ASM had greater proximal and distal reference lumen areas and more distal, but not proximal, reference calcium compared to lesions without ASM. At 2-year follow-up, there was no significant difference in the incidence of cardiac death; myocardial infarction; early, late, or very late stent thrombosis; or clinically driven target lesion revascularization in patients with ASM versus those without ASM. Furthermore, ASM was not an independent predictor of 2-year major adverse cardiac events or target lesion revascularization even when forced into the multivariate model.

CONCLUSIONS

In patients treated with intravascular ultrasound-guided drug-eluting stents implantation, ASM was not associated with adverse clinical events during long-term follow-up including, but not limited to, stent thrombosis.

CLINICAL TRIAL REGISTRATION

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

DESyne novolimus-eluting coronary stent is superior to Endeavor zotarolimus-eluting coronary stent at five-year follow-up: final results of the multicentre EXCELLA II randomised controlled trial

AIMS

Newer-generation drug-eluting stents (DES) have been shown to be superior to first-generation DES. Current-generation DES have zotarolimus, everolimus or biolimus as antiproliferative drugs. Novolimus, a metabolite of sirolimus, has been specifically developed to provide efficacy similar to currently available agents at a lower dose and thus requires a lower polymer load. We report the final five-year outcomes of the EXCELLA II trial comparing a zotarolimus-eluting stent (ZES) with a novolimus-eluting stent (NES).

METHODS AND RESULTS

EXCELLA II is a prospective, multicentre, single-blind, non-inferiority clinical trial. Patients (n=210) with a maximum of two de novo lesions in two different epicardial vessels were randomised (2:1) to treatment with either NES (n=139) or ZES (n=71). At five-year follow-up, patients in the NES group had a significantly lower incidence of the patient-oriented (HR 0.53, 95% CI: 0.32-0.87, p=0.013) and device-oriented (HR 0.38, 95% CI: 0.17-0.83, p=0.011) composite endpoints. There was no difference in cardiac death and definite/probable stent thrombosis between the two groups; however, there was a trend towards reduction in myocardial infarction and repeat revascularisation in the NES group at five-year follow-up.

CONCLUSIONS

At five-year follow-up, the incidence of device- and patient-oriented events was significantly lower in the NES group. Further studies, adequately powered for clinical outcomes, are warranted.

Long-term performance of the second-generation cobalt-chromium sirolimus-eluting stents in real-world clinical practice: 3-year clinical outcomes from the prospective multicenter FOCUS registry

BACKGROUND

The short- and mid-term outcomes of the second-generation cobalt-chromium sirolimus-eluting stent (CoCr-SES) in real-world patients had been reported previously, but the long-term performance remained unclear. The objective of this analysis was to evaluate the long-term safety and efficacy of the second-generation CoCr-SES from the FOCUS registry.

METHODS

The FOCUS registry (ClinicalTrials.gov Identifier: NCT00868829) enrolled all-comers eligible to receive Firebird-2 CoCr-SES. Follow-up was continued to 3 years to evaluate long-term safety and effectiveness of the second-generation CoCr-SES in real-world practice. Results of the extended-use group and standard-use group are compared to explore performance of CoCr-SES in more severe patients with more complex lesions.

RESULTS

The rate of 3-year MACE was 7.37%, consisting of 84 cases (1.78%) of cardiac death, 166 cases (3.52%) of MI and 98 cases (2.08%) of TVR. ARC definite/probable stent thrombosis happened in 34 (0.72%) patients, only 3 new cases (<0.1%) of very late stent thrombosis was reported in the third year. Meanwhile, the difference of MACE (7.77% vs. 6.06%; P=0.058), TLF (4.71% vs. 3.49%; P=0.085) and ARC definite/probable stent thrombosis (0.83% vs. 0.37%; P=0.116) between extended-use group and standard-use group showed no significance.

CONCLUSIONS

The second-generation CoCr-SES was associated with continued low rates of 3-year MACE, TLF and stent thrombosis in a broad spectrum of patients.

Percutaneous Coronary Intervention: Safety of Methotrexate and Its Possible Benefits on Restenosis After Bare-Metal Stent Deployment

Background

Percutaneous coronary intervention (PCI) revolutionized treatment of coronary artery disease. Drug-eluting stents are effective and safe but their cost is high, especially for some countries. The primary objective was to evaluate the safety of methotrexate (MTX) in patients who underwent PCI and the secondary goal was to evaluate the possibility that MTX has an impact on restenosis.

Methods

This was a transversal, prospective and descriptive study that recruited 16 patients in whom PCI was planned. MTX was administered to patients at a dose of 5 mg/week for 2 weeks before PCI and 8 weeks after PCI. Bare-metal stent (BMS) deployment was performed according to standard practice. Patients were monitored clinically every 15 days during the first 2 months after the procedure and monthly until 9 months after PCI.

Results

There were no immediate or late complications associated with PCI. Adverse events and side effects due to MTX occurred in three patients (prevalence 18.7%). These side effects are classified as minor complications. MTX was not discontinued due to these side effects. There were no reported cases of clinical restenosis.

Conclusions

MTX was safe in the study population and raised the possibility that a low-cost drug may have positive effects on restenosis after BMS implantation. However, studies with larger sample sizes and other imagine modalities (intravascular ultrasound and/or optical coherence tomography) are required to confirm this hypothesis.

Primary Stenting of Totally Occluded Native Coronary Arteries III (PRISON III): a randomised comparison of sirolimus-eluting stent implantation with zotarolimus-eluting stent implantation for the treatment of total coronary occlusions

AIMS

We investigated whether sirolimus-eluting stents (SES) are superior to next-generation zotarolimus-eluting stents (ZES) in treating patients with total coronary occlusions (TCO).

METHODS AND RESULTS

In a prospective, randomised trial we compared the SES with the zotarolimus-eluting stent (ZES; Endeavor or Resolute) after successful recanalisation of TCO. During the first phase of the trial, 51 patients were assigned to receive the SES and 46 patients to receive the Endeavor ZES. In the second phase we randomised 103 patients to the SES group and 104 patients to the Resolute ZES group. The primary endpoint was in-segment late lumen loss at eight-month follow-up. At eight months, patients in the SES group had less in-segment and in-stent late loss as compared to the Endeavor group: -0.13±0.3 mm vs. 0.27±0.6 mm (p=0.0002) and -0.13±0.5 mm vs. 0.54±0.5 mm (p<0.0001), respectively. In contrast, the SES and the Resolute ZES showed comparable amounts of in-segment (-0.03±0.7 mm vs. -0.10±0.7 mm, p=0.6) and in-stent (0.03±0.8 mm vs. 0.05±0.8 mm, p=0.9) late loss.

CONCLUSIONS

In the treatment of TCOs, the SES was associated with superior angiographic outcomes compared to the Endeavor ZES. On the other hand, the SES and the Resolute ZES showed comparable angiographic outcomes.

Prognostic Significance of Polymer Coatings in Zotarolimus-Eluting Stents

Polymer coatings on drug-eluting stents (DES) serve as a vehicle for delivery of antirestenotic drugs. Whether they influence outcomes for contemporary DES is unknown. The evolution of polymer coatings for zotarolimus-eluting stents (ZES) provides a natural experiment that facilitates such analysis. The Resolute ZES (R-ZES) uses the same antirestenotic drug as the Endeavor ZES (E-ZES) but has a more biocompatible polymer with enhanced drug release kinetics. However, there are limited data on the real-world comparative efficacy of R-ZES and the preceding E-ZES. Thus, we analyzed 17,643 patients who received either E-ZES or R-ZES from 2008 to 2014 from the British Columbia Cardiac Registry. A total of 9,869 patients (56%) received E-ZES and 7,774 patients (44%) received R-ZES. Compared with E-ZES, R-ZES was associated with lower 2-year mortality (4.1% vs 6.4%, p <0.001) and 2-year target vessel revascularization (TVR; 6.8% vs 10.7%, p <0.001). R-ZES use was an independent predictor of lower mortality rate and TVR. This was confirmed in propensity-matched analyses for 2-year mortality (hazard ratio [HR] 0.59, 95% CI 0.49 to 0.71, p <0.001) and 2-year TVR (HR 0.86, 95% CI 0.75 to 0.98, p = 0.032). Instrumental variable analyses demonstrated R-ZES to be associated with lower 2-year mortality (Δ = -2.2%, 95% CI -4.3% to -0.2%, p = 0.032) and 2-year TVR (Δ = -3.3% to 95% CI -6.1% to -0.7%, p = 0.015). Acknowledging the limitations of observational analyses, this study has shown that R-ZES was associated with lower long-term TVR and mortality. These data are reassuring for the newer R-ZES and demonstrate how polymer coatings may influence the clinical performance of DES with wider implications for future DES development and design.

Drug-eluting stents: the past, present, and future

Since the advent of percutaneous coronary intervention, enormous advances have been made in the treatment of coronary artery disease. Angioplasty and bare metal stents were plagued by high rates of restenosis leading to repeat revascularization procedures. Examination of the underlying pathophysiology of restenosis led to the development of drug-eluting stents to reduce neointimal hyperplasia. However, as restenosis rates declined, length of dual antiplatelet therapy use and risk of long-term stent thrombosis associated with drug-eluting stents increased. Subsequent generations have improved each facet of stent design. Novel alloys maintain durability and reduce strut thickness to increase deliverability, biocompatible polymers decrease the inflammatory response and improve drug elution kinetics, and new generations of drugs predictably inhibit restenosis. Developments on the horizon include stents with bioabsorbable polymers and platforms. The purpose of this review is to assess the evolution of stent design and the evidence behind each generation and to peer into the future of stent technology.

Long-Term Safety of Drug-Eluting and Bare-Metal Stents: Evidence From a Comprehensive Network Meta-Analysis

BACKGROUND

Previous meta-analyses have investigated the relative safety and efficacy profiles of different types of drug-eluting stents (DES) and bare-metal stents (BMS); however, most prior trials in these meta-analyses reported follow-up to only 1 year, and as such, the relative long-term safety and efficacy of these devices are unknown. Many recent studies have now reported extended follow-up data.

OBJECTIVES

This study sought to investigate the long-term safety and efficacy of durable polymer-based DES, bioabsorbable polymer-based biolimus-eluting stents (BES), and BMS by means of network meta-analysis.

METHODS

Randomized controlled trials comparing DES to each other or to BMS were searched through MEDLINE, EMBASE, and Cochrane databases and proceedings of international meetings. Information on study design, inclusion and exclusion criteria, sample characteristics, and clinical outcomes was extracted.

RESULTS

Fifty-one trials that included a total of 52,158 randomized patients with follow-up duration ≥3 years were analyzed. At a median follow-up of 3.8 years, cobalt-chromium everolimus-eluting stents (EES) were associated with lower rates of mortality, definite stent thrombosis (ST), and myocardial infarction than BMS, paclitaxel-eluting stents (PES), and sirolimus-eluting stents (SES) and less ST than BES. Phosphorylcholine-based zotarolimus-eluting stents had lower rates of definite ST than SES and lower rates of myocardial infarction than BMS and PES. The late rates of target-vessel revascularization were reduced with all DES compared with BMS, with cobalt-chromium EES, platinum chromium-EES, SES, and BES also having lower target-vessel revascularization rates than PES.

CONCLUSIONS

After a median follow-up of 3.8 years, all DES demonstrated superior efficacy compared with BMS. Among DES, second-generation devices have substantially improved long-term safety and efficacy outcomes compared with first-generation devices.