Temporal changes in coronary plaque as assessed by an artificial intelligence-based optical coherence tomography: from the first-in-human trial on DREAMS 3G scaffold

AIMS

The aim of the study is to assess the impact of the baseline plaque composition on the DREAMS 3G luminal late loss and to compare the serial plaque changes between baseline and 6 and 12 months (M) follow-up.

METHODS AND RESULTS

A total of 116 patients were enrolled in the BIOMAG-I trial. Patients were imaged with optical coherence tomography (OCT) pre- and post-DREAMS 3G implantation and at 6 and 12 M. OCTPlus software uses artificial intelligence to assess composition (i.e. lipid, calcium, and fibrous tissue) of the plaque. The differences between the OCT-derived minimum lumen area (MLA) post-percutaneous coronary intervention and 12 M were grouped into three terciles. Patients with larger MLA differences at 12 M (P = 0.0003) had significantly larger content of fibrous tissue at baseline. There was a reduction of 24.8% and 20.9% in lipid area, both P < 0.001, between the pre-DREAMS 3G OCT and the 6 and 12 M follow-up. Conversely, the fibrous tissue increased by 48.4% and 36.0% at 6 and 12 M follow-up, both P < 0.001.

CONCLUSION

The larger the fibrous tissue in the lesion at baseline, the larger the luminal loss seen at 6 and 12 M. Following the implantation of DREAMS 3G, favourable healing of the vessel coronary wall occurs as shown by a decrease in the lipid area and an increase in fibrous tissue.

Development and Future Trends of Protective Strategies for Magnesium Alloy Vascular Stents

Magnesium alloy stents have been extensively studied in the field of biodegradable metal stents due to their exceptional biocompatibility, biodegradability and excellent biomechanical properties. Nevertheless, the specific in vivo service environment causes magnesium alloy stents to degrade rapidly and fail to provide sufficient support for a certain time. Compared to previous reviews, this paper focuses on presenting an overview of the development history, the key issues, mechanistic analysis, traditional protection strategies and new directions and protection strategies for magnesium alloy stents. Alloying, optimizing stent design and preparing coatings have improved the corrosion resistance of magnesium alloy stents. Based on the corrosion mechanism of magnesium alloy stents, as well as their deformation during use and environmental characteristics, we present some novel strategies aimed at reducing the degradation rate of magnesium alloys and enhancing the comprehensive performance of magnesium alloy stents. These strategies include adapting coatings for the deformation of the stents, preparing rapid endothelialization coatings to enhance the service environment of the stents, and constructing coatings with self-healing functions. It is hoped that this review can help readers understand the development of magnesium alloy cardiovascular stents and solve the problems related to magnesium alloy stents in clinical applications at the early implantation stage.

First randomised controlled trial comparing the sirolimus-eluting bioadaptor with the zotarolimus-eluting drug-eluting stent in patients with de novo coronary artery lesions: 12-month clinical and imaging data from the multi-centre, international, BIODAPTOR-RCT

Background

The DynamX™ bioadaptor is the first coronary implant technology with a unique mechanism of unlocking the bioadaptor frame after polymer resorption over 6 months, uncaging the vessel while maintaining a dynamic support to the vessel. It aims to achieve the acute performance of drug-eluting stents (DES) with the advantages of restoration of vessel function.

Methods

This international, single blinded, randomised controlled (1:1) trial compared a sirolimus-eluting bioadaptor with a contemporary zotarolimus-eluting stent (DES) in 34 hospitals in Europe, Japan and New Zealand. Patients with de novo coronary lesions and absence of acute myocardial infarction were enrolled from January 2021 to Feburary 2022. The implantation of the bioadaptor followed the standards of DES. An imaging subset of 100 patients had angiographic and intravascular ultrasound assessments, and 20 patients additionally optical coherence tomography. Data collection will continue through 5 years, we herein report 12-month data based on an intention-to-treat population. This trial is registered at ClinicalTrials.gov (NCT04192747).

Findings

445 patients were randomised between January 2021 and February 2022. Device, lesion and procedural success rates, and acute gain were similar amongst the groups. The primary endpoint, 12-month target lesion failure, was 1.8% [95% CI: 0.5; 4.6] (n = 4) versus 2.8% [95% CI: 1.0; 6.0] (n = 6), pnon-inferiority < 0.001 for the bioadaptor and the DES, respectively (Δ-1.0% [95% CI: -3.3; 1.4]). One definite or probable device thrombosis occurred in each group. The 12-month imaging endpoints showed superior effectiveness of the bioadaptor such as in-device late lumen loss (0.09 mm [SD 0.34] versus 0.25 mm [SD 0.39], p = 0.04), and restored compliance and cyclic pulsatility (%mid in-device lumen area change of 7.5% versus 2.7%, p < 0.001).

Interpretation

This is the first randomised controlled trial comparing the novel bioadaptor technology against a contemporary DES. The bioadaptor demonstrated similar acute performance and 12-month clinical outcomes, and superior imaging endpoints including restoration of vessel function.

Funding

The study was funded by Elixir Medical.

Research on the Current Application Status of Magnesium Metal Stents in Human Luminal Cavities

The human body comprises various tubular structures that have essential functions in different bodily systems. These structures are responsible for transporting food, liquids, waste, and other substances throughout the body. However, factors such as inflammation, tumors, stones, infections, or the accumulation of substances can lead to the narrowing or blockage of these tubular structures, which can impair the normal function of the corresponding organs or tissues. To address luminal obstructions, stenting is a commonly used treatment. However, to minimize complications associated with the long-term implantation of permanent stents, there is an increasing demand for biodegradable stents (BDS). Magnesium (Mg) metal is an exceptional choice for creating BDS due to its degradability, good mechanical properties, and biocompatibility. Currently, the Magmaris® coronary stents and UNITY-BTM biliary stent have obtained Conformité Européene (CE) certification. Moreover, there are several other types of stents undergoing research and development as well as clinical trials. In this review, we discuss the required degradation cycle and the specific properties (anti-inflammatory effect, antibacterial effect, etc.) of BDS in different lumen areas based on the biocompatibility and degradability of currently available magnesium-based scaffolds. We also offer potential insights into the future development of BDS.

A new resorbable magnesium scaffold for de novo coronary lesions (DREAMS 3): one-year results of the BIOMAG-I first-in-human study

BACKGROUND

The third-generation coronary sirolimus-eluting magnesium scaffold, DREAMS 3G, is a further development of the DREAMS 2G (commercial name Magmaris), aiming to provide performance outcomes similar to drug-eluting stents (DES).

AIMS

The BIOMAG-I study aims to assess the safety and performance of this new-generation scaffold.

METHODS

This is a prospective, multicentre, first-in-human study with clinical and imaging follow-up scheduled at 6 and 12 months. The clinical follow-up will continue for 5 years.

RESULTS

A total of 116 patients with 117 lesions were enrolled. At 12 months, after completion of resorption, in-scaffold late lumen loss was 0.24±0.36 mm (median 0.19, interquartile range 0.06-0.36). The minimum lumen area was 4.95±2.24 mm² by intravascular ultrasound and 4.68±2.32 mm² by optical coherence tomography. Three target lesion failures were reported (2.6%, 95% confidence interval: 0.9-7.9), all clinically driven target lesion revascularisations. Cardiac death, target vessel myocardial infarction and definite or probable scaffold thrombosis were absent.

CONCLUSIONS

Data at the end of the resorption period of DREAMS 3G showed that the third-generation bioresorbable magnesium scaffold is clinically safe and effective, making it a possible alternative to DES.

CLINICALTRIALS

gov: NCT04157153.

Magnesium-Based Temporary Implants: Potential, Current Status, Applications, and Challenges

Biomedical implants are important devices used for the repair or replacement of damaged or diseased tissues or organs. The success of implantation depends on various factors, such as mechanical properties, biocompatibility, and biodegradability of the materials used. Recently, magnesium (Mg)-based materials have emerged as a promising class of temporary implants due to their remarkable properties, such as strength, biocompatibility, biodegradability, and bioactivity. This review article aims to provide a comprehensive overview of current research works summarizing the above-mentioned properties of Mg-based materials for use as temporary implants. The key findings from in-vitro, in-vivo, and clinical trials are also discussed. Further, the potential applications of Mg-based implants and the applicable fabrication methods are also reviewed.

In-Stent Restenosis in Saphenous Vein Grafts (from the DIVA Trial)

Saphenous vein grafts (SVGs) have high rates of in-stent restenosis (ISR). We compared the baseline clinical and angiographic characteristics of patients and lesions that did develop ISR with those who did not develop ISR during a median follow-up of 2.7 years in the DIVA study (NCT01121224). We also examined the ISR types using the Mehran classification. ISR developed in 119 out of the 575 DIVA patients (21%), with similar incidence among patients with drug-eluting stents and bare-metal stents (BMS) (21% vs 21%, p = 0.957). Patients in the ISR group were younger (67 ± 7 vs 69 ± 8 years, p = 0.04) and less likely to have heart failure (27% vs 38%, p = 0.03) and SVG lesions with Thrombolysis In Myocardial Infarction 3 flow before the intervention (77% vs 83%, p <0.01), but had a higher number of target SVG lesions (1.33 ± 0.64 vs 1.16 ± 0.42, p <0.01), more stents implanted in the target SVG lesions (1.52 ± 0.80 vs 1.31 ± 0.66, p <0.01), and longer total stent length (31.37 ± 22.11 vs 25.64 ± 17.42 mm, p = 0.01). The incidence of diffuse ISR was similar in patients who received drug-eluting-stents and BMS (57% vs 54%, p = 0.94), but BMS patients were more likely to develop occlusive restenosis (17% vs 33%, p = 0.05).

Impact of target vessel choice on outcomes following percutaneous coronary intervention in patients with a prior coronary artery bypass graft

OBJECTIVES

To evaluate and compare characteristics and clinical outcomes of percutaneous coronary intervention (PCI) among target vessel types in patients with a prior coronary artery bypass graft (CABG) surgery.

BACKGROUND

Patients with a prior CABG often require repeat revascularization with PCI. Graft PCI has been associated with worse outcomes compared to native vessel PCI, yet the optimal PCI strategy in prior CABG patients remains unknown.

METHODS

We stratified prior CABG patients who underwent PCI at a tertiary-care center between 2009 and 2017 by target vessel type: native vessel, venous graft, and arterial graft. The primary outcome of major adverse cardiac events (MACE) was a composite of all-cause death, myocardial infarction, stent thrombosis, or target vessel revascularization up to 1 year post-PCI.

RESULTS

Prior CABG patients (n = 3983) represented 19.5% of all PCI interventions during the study period. PCI was most frequently performed on native vessels (n = 2928, 73.5%) followed by venous (n = 883, 22.2%) and arterial grafts (n = 172, 4.3%). Procedural success and complications were similar among the groups; however, slow- and no-reflow phenomenon was more common in venous graft PCI compared to native vessel PCI (OR 4.78; 95% CI 2.56-8.95; p < 0.001). At 1 year, there were no significant differences in MACE or in its individual components.

CONCLUSIONS

Target vessel choice did not appear to affect MACE at 1 year in a large cohort of patients with prior CABG undergoing PCI. Whether PCI of surgical grafts versus native arteries truly results in similar outcomes warrants further investigation in randomized controlled trials.

Long-Term Results After Drug-Eluting Versus Bare-Metal Stent Implantation in Saphenous Vein Grafts: Randomized Controlled Trial

Background

Efficacy data on drug‐eluting stents (DES) versus bare‐metal stents (BMS) in saphenous vein grafts are controversial. We aimed to compare DES with BMS among patients undergoing saphenous vein grafts intervention regarding long‐term outcome.

Methods and Results

In this multinational trial, patients were randomized to paclitaxel‐eluting or BMS. The primary end point was major adverse cardiac events (cardiac death, nonfatal myocardial infarction, and target‐vessel revascularization at 1 year. Secondary end points included major adverse cardiac events and its individual components at 5‐year follow‐up. One hundred seventy‐three patients were included in the trial (89 DES versus 84 BMS). One‐year major adverse cardiac event rates were lower in DES compared with BMS (2.2% versus 16.0%, hazard ratio, 0.14; 95% CI, 0.03–0.64, P=0.01), which was mainly driven by a reduction of subsequent myocardial infarctions and need for target‐vessel revascularization. Five‐year major adverse cardiac event rates remained lower in the DES compared with the BMS arm (35.5% versus 56.1%, hazard ratio, 0.40; 95% CI, 0.23–0.68, P<0.001). A landmark‐analysis from 1 to 5 years revealed a persistent benefit of DES over BMS (hazard ratio, 0.33; 95% CI, 0.13–0.74, P=0.007) in terms of target‐vessel revascularization. More patients in the BMS group underwent multiple target‐vessel revascularization procedures throughout the study period compared with the DES group (DES 1.1% [n=1] versus BMS 9.5% [n=8], P=0.013). Enrollment was stopped before the target sample size of 240 patients was reached.

Conclusions

In this randomized controlled trial with prospective long‐term follow‐up of up to 5 years, DES showed a better efficacy than BMS with sustained benefits over time. DES may be the preferred strategy in this patient population.

Registration

URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT00595647.

Drug-eluting versus bare-metal stents for saphenous vein graft lesions

A best evidence topic was written addressing the question 'in patients with saphenous vein graft lesions requiring percutaneous coronary intervention, do long-term clinical outcomes differ between drug-eluting and bare-metal stents?' Altogether 1466 papers were found, of which seven represented the best evidence. Although one major recent randomised trial was neutral, the weight of earlier evidence supports drug-eluting stents as standard of care. Bare-metal stents may represent a reasonable, efficacious, and less expensive alternative to drug-eluting stents in well selected patient groups.

Care of the Post-CABG Patient

An estimated 400,000 coronary artery bypass graft operations are performed annually in the United States. Saphenous vein grafts are the most commonly used conduits; however, graft failure is common. In contrast, left internal mammary artery grafts have more favorable long-term patency rates. Guidelines recommend aggressive secondary prevention. In the 2 decades following surgery, 16% of patients require repeat revascularization, and percutaneous coronary intervention accounts for 98% of procedures performed. Post-coronary artery bypass graft patients presenting with symptoms of acute coronary syndrome or progressive heart failure should undergo early coronary angiography given the high likelihood that such a presentation represents graft failure. Percutaneous coronary intervention in degenerated saphenous vein grafts is associated with embolization that may cause the "no-reflow phenomenon," which can be avoided with the use of embolic protection devices. Hybrid revascularization procedures are a promising emerging strategy to avoid the placement of vein grafts.

Efficacy Over Time With Drug-Eluting Stents in Saphenous Vein Graft Lesions.J Am Coll Cardiol. 2018;71:1973-1982. [PMID: 29724350 DOI: 10.1016/j.jacc.2018.03.456]

BACKGROUND

In the ISAR-CABG (Is Drug-Eluting-Stenting Associated with Improved Results in Coronary Artery Bypass Grafts?) trial, clinical outcomes at 1 year in patients undergoing treatment of saphenous vein graft lesions were superior with drug-eluting stents (DES) versus bare-metal stents.

OBJECTIVES

The authors compared outcomes between treatment groups at 5 years.

METHODS

Patients were randomized (1:1:1:3) to receive DES (either permanent-polymer paclitaxel-eluting stents, permanent-polymer sirolimus-eluting stents, or biodegradable-polymer sirolimus-eluting stents) or bare-metal stents. The primary endpoint was the combined incidence of death, myocardial infarction (MI), or target lesion revascularization (TLR). Secondary endpoints were the composite of death or MI and TLR.

RESULTS

A total of 610 patients were allocated to treatment with DES (n = 303) or bare-metal stents (n = 307). At 5 years, the primary endpoint occurred in 159 (55.5%) versus 157 (53.6%) patients in the DES and bare-metal stent groups, respectively (hazard ratio [HR]: 0.98; 95% confidence interval [CI]: 0.79 to 1.23; p = 0.89). There was interaction between treatment effect and time (p_interaction = 0.005), with a lower event rate in the DES group at 1 year (HR: 0.64; 95% CI: 0.44 to 0.94; p = 0.02) but a numerically higher rate between 1 and 5 years (HR: 1.24; 95% CI: 0.94 to 1.63; p = 0.13). Death or MI occurred in 93 (32.8%) versus 108 (36.6%) patients, respectively (HR: 0.85; 95% CI: 0.64 to 1.12; p = 0.24), without significant interaction between treatment effect and time (p_interaction = 0.57). TLR occurred in 84 (33.1%) versus 69 (25.5%) patients in the DES and bare-metal stent groups, respectively (HR: 1.20; 95% CI: 0.87 to 1.64; p = 0.27). There was interaction between treatment effect and time (p_interaction <0.001): TLR was significantly lower in the DES group at 1 year (HR: 0.49; 95% CI: 0.28 to 0.86; p = 0.01) but significantly higher thereafter (HR: 2.02; 95% CI: 1.32 to 3.08; p = 0.001).

CONCLUSIONS

In patients undergoing treatment of saphenous vein graft lesions, the advantage of DES over bare-metal stents demonstrated at 1 year was lost at 5 years due to higher attrition of efficacy in the DES group. (Efficacy Study of Drug-Eluting and Bare Metal Stents in Bypass Graft Lesions [ISAR-CABG]; NCT00611910).

Major Histocompatibility Complex-Matched Arteries Have Similar Patency to Autologous Arteries in a Mauritian Cynomolgus Macaque Major Histocompatibility Complex-Defined Transplant Model

Background

Arterial bypass and interposition grafts are used routinely across multiple surgical subspecialties. Current options include both autologous and synthetic materials; however, each graft presents specific limitations. Engineering artificial small‐diameter arteries with vascular cells derived from induced pluripotent stem cells could provide a useful therapeutic solution. Banking induced pluripotent stem cells from rare individuals who are homozygous for human leukocyte antigen alleles has been proposed as a strategy to facilitate economy of scale while reducing the potential for rejection of induced pluripotent stem cell–derived transplanted tissues. Currently, there is no standardized model to study transplantation of small‐diameter arteries in major histocompatibility complex–defined backgrounds.

Methods and Results

In this study, we developed a limb‐sparing nonhuman primate model to study arterial allotransplantation in the absence of immunosuppression. Our model was used to compare degrees of major histocompatibility complex matching between arterial grafts and recipient animals with long‐term maintenance of patency and function. Unexpectedly, we (1) found that major histocompatibility complex partial haplomatched allografts perform as well as autologous control grafts; (2) detected little long‐term immune response in even completely major histocompatibility complex mismatched allografts; and (3) observed that arterial grafts become almost completely replaced over time with recipient cells.

Conclusions

Given these findings, induced pluripotent stem cell–derived tissue‐engineered blood vessels may prove to be promising and customizable grafts for future use by cardiac, vascular, and plastic surgeons.

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.

Drug-eluting Stents Versus Bare-metal Stents for Saphenous Vein Graft Interventions: A Systematic Review and Meta-analysis of Studies With Longer Follow-up

Randomized controlled trials comparing drug eluting stents (DES) with bare-metal stents (BMS) for saphenous vein graft (SVG) interventions have shown conflicting results. We conducted this meta-analysis to evaluate the cumulative evidence for long-term efficacy and safety of DES vs BMS in SVG lesions. A systematic search was conducted of Randomized controlled trials comparing DES vs BMS in patients undergoing percutaneous interventions for SVG lesions. End-points of interest were all-cause death, cardiac death, myocardial infarction, target lesion revascularization and target vessel revascularization at longest available follow-up. Random effects meta-analysis was conducted to estimate risk ratio with 95% confidence intervals for individual end-points. Seven studies with 1639 patients were included in the final analysis. Mean follow-up period was 32 months. Compared with BMS, DES was associated with similar risks of all-cause death (risk ratio 1.06; 95% confidence intervals 0.76-1.48) and cardiac death (0.95; 0.59-1.54). Similarly, there were no differences between DES and BMS in terms of myocardial infarction (0.81; 0.50-1.29), target vessel revascularization (0.73; 0.48-1.110 or target lesion revascularization (1.05; 0.76-1.43). Current analysis suggests no strong evidence for routine DES use in patients undergoing SVG intervention. Future studies should evaluate if SVG lesion characteristics could influence these results.

Internal mammary artery graft failure: Clinical features, management, and long-term outcomes

Objective

Data on long-term outcomes after internal mammary artery (IMA) coronary graft failure are scarce. Our objective was to describe the clinical characteristics, management, and prognosis after angiographically confirmed IMA graft failure following coronary revascularization.

Methods

A three-hospital retrospective registry, observational and descriptive, with prospective follow-up of all consecutive cases of IMA graft failure between 2004 and 2014 was conducted. After treatment, clinical and procedural features were compared between those with and without cardiovascular events.

Results

Fifty-seven patients were included (89% male, mean age: 62 years, at surgery) in the registry. Most patients underwent an IMA angioplasty (percutaneous coronary intervention [PCI], 74%). In nine cases, the PCI failed at the graft level, and seven underwent a native vessel revascularization. Native vessel treatment was performed in 20% of the study subjects, all with stents. Finally, medical management was decided in three cases. Events after treatment for IMA graft failure were frequent (50.8%), during a median follow-up of 7.5 years. Acute presentation (hazard ratio_MACE = 1.35; 95% confidence interval (CI): 1.12–3.00, p < 0.01), age of the patient (hazard ratio_MACE = 1.85, 95% CI: 1.17–2.11, p < 0.01), presence of diabetes mellitus (hazard ratio_MACE = 2.75, 95% CI: 1.13–6.69, p = 0.02), and the management modality used (IMA-simple angioplasty VS IMA-stenting: hazard ratio_MACE = 5.5, 95% CI: 1.40–21.15, p = 0.01) displayed prognostic relevance on multivariate analysis. All-cause mortality occurred in 21.1% and presentation as infarction (hazard ratio_DEATH = 1.05, 95% CI: 1.01–2.17, p = 0.01), age (hazard ratio_DEATH = 9.08, 95% CI: 2.52–32.69, p < 0.01), and left ventricular ejection fraction (hazard ratio_DEATH = 3.68, 95% CI: 1.65–8.18, p < 0.01) were independent predictors of the same.

Conclusions

In this long-term registry, most patients presented with an acute condition (myocardial infarction, progressive angina) within 12 months after surgery. Acute presentation, age, diabetes mellitus, reduced left ventricular ejection fraction, IMA graft failure segment affected, and the management strategy were related with long-term prognosis.

Drug-Eluting Versus Bare Metal Stents in Saphenous Vein Graft Intervention: An Updated Comprehensive Meta-Analysis of Randomized Trials

BACKGROUND

Drug eluting stents (DES) are preferred over bare metal stents (BMS) for native coronary artery revascularization unless contraindicated. However, the preferred stent choice for saphenous venous graft (SVG) percutaneous coronary interventions (PCI) is unclear due to conflicting results.

METHODS

PubMed, Clinical trials registry and the Cochrane Center Register of Controlled Trials were searched through June 2018. Seven studies (n = 1639) comparing DES versus BMS in SVG-PCI were included. Endpoints were major adverse cardiac events (MACE), cardiovascular mortality, all-cause mortality, myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), in-stent thrombosis, binary in-stent restenosis, and late lumen loss (LLL).

RESULTS

Overall, during a mean follow up of 32.1 months, there was no significant difference in the risk of MACE, cardiovascular mortality, all-cause mortality, MI, stent thrombosis, TVR and TLR between DES and BMS. However, short-term follow up (mean 11 months) showed lower rate of MACE (OR 0.66 [0.51, 0.85]; p = 0.002), TVR (OR 0.47 [0.23, 0.97]; p = 0.04) and binary in-stent restenosis (OR 0.14 [0.06, 0.37]; p < 0.0001) in DES as compared with BMS. This benefit was lost on long-term follow up with a mean follow up 35.5 months.

CONCLUSION

In this meta-analysis of SVG-PCI, DES use was associated with similar MACE, cardiovascular mortality, all-cause mortality, MI, in-stent thrombosis, TVR and TLR compared with BMS during long-term follow up. There was high incidence of MACE noted in both DES and BMS suggesting a need for exploring novel strategies to treat SVG disease to improve clinical outcomes.

A comprehensive meta-analysis of randomized controlled trials comparing drug-eluting stents with bare-metal stents in saphenous vein graft interventions

BACKGROUND

Several large randomized controlled trials (RCTs) have proven the superiority of drug-eluting stents (DESs) over bare-metal stents (BMSs) for native coronary stenosis. However, RCTs comparing DESs with BMSs for SVG lesions have predominantly been small in size and have yielded conflicting results. Therefore, we conducted an updated comprehensive meta-analysis of RCTs comparing DESs versus BMSs for SVG interventions using the largest sample size to date.

METHODS

Scientific databases and websites were searched to find RCTs. Data from six RCTs involving 1,582 patients were included. Pooled risk ratios (RRs) were calculated using random-effects models. The primary outcome of this meta-analysis was target vessel revascularization (TVR). The secondary outcomes were major adverse cardiac events (MACEs), myocardial infarction (MI), stent thrombosis, all-cause mortality, and cardiac mortality.

RESULTS

Data from six RCTs involving 1,582 patients were included. Saphenous vein graft interventions with DESs reduced TVR (RR, 0.52; 95% CI, 0.30-0.88; P = 0.017) and MACE rate (RR, 0.60; 95% CI, 0.42-0.87; P = 0.007) compared to BMSs. No difference between the stents were found in rates of MI (RR, 0.69; 95% CI, 0.43-1.10; P = 0.123), stent thrombosis (RR, 0.61; 95% CI, 0.27-1.41; P = 0.255), all-cause mortality (RR, 1.13; 95% CI, 0.74-1.71; P = 0.554), or cardiac mortality.

CONCLUSION

For SVG intervention, the MACE rate was lower for DESs compared to BMSs, driven primarily by decreased non-MI-related TVR. Rates of MI, all-cause mortality, cardiac mortality, and stent thrombosis were not different between the stents.

Drug-eluting stents versus bare-metal stents in saphenous vein grafts: a double-blind, randomised trial

BACKGROUND

Few studies have examined the efficacy of drug-eluting stents (DES) for reducing aortocoronary saphenous vein bypass graft (SVG) failure compared with bare-metal stents (BMS) in patients undergoing stenting of de-novo SVG lesions. We assessed the risks and benefits of the use of DES versus BMS in de-novo SVG lesions.

METHODS

Patients were recruited to our double-blind, randomised controlled trial from 25 US Department of Veterans Affairs centres. Eligible participants were aged at least 18 years and had at least one significant de-novo SVG lesion (50-99% stenosis of a 2·25-4·5 mm diameter SVG) requiring percutaneous coronary intervention with intent to use embolic protection devices. Enrolled patients were randomly assigned, in a 1:1 ratio, by phone randomisation system to receive a DES or BMS. Randomisation was stratified by presence or absence of diabetes and number of target SVG lesions requiring percutaneous coronary intervention (one or two or more) within each participating site by use of an adaptive scheme intended to balance the two stent type groups on marginal totals for the stratification factors. Patients, referring physicians, study coordinators, and outcome assessors were masked to group allocation. The primary endpoint was the 12-month incidence of target vessel failure, defined as the composite of cardiac death, target vessel myocardial infarction, or target vessel revascularisation. The DIVA trial is registered with ClinicalTrials.gov, number NCT01121224.

FINDINGS

Between Jan 1, 2012, and Dec 31, 2015, 599 patients were randomly assigned to the stent groups, and the data for 597 patients were used. The patients' mean age was 68·6 (SD 7·6) years, and 595 (>99%) patients were men. The two stent groups were similar for most baseline characteristics. At 12 months, the incidence of target vessel failure was 17% (51 of 292) in the DES group versus 19% (58 of 305) in the BMS group (adjusted hazard ratio 0·92, 95% CI 0·63-1·34, p=0·70). Between-group differences in the components of the primary endpoint, serious adverse events, or stent thrombosis were not significant. Enrolment was stopped before the revised target sample size of 762 patients was reached.

INTERPRETATION

In patients undergoing stenting of de-novo SVG lesions, no significant differences in outcomes between those receiving DES and BMS during 12 months of follow-up were found. The study results have important economic implications in countries with high DES prices such as the USA, because they suggest that the lower-cost BMS can be used in SVG lesions without compromising either safety or efficacy.

FUNDING

US Department of Veterans Affairs Cooperative Studies Program.

Comparison between the STENTYS self-apposing bare metal and paclitaxel-eluting coronary stents for the treatment of saphenous vein grafts (ADEPT trial)

AIMS

To describe the safety and performance of STENTYS self-expandable bare metal stents (BMS) versus paclitaxel-eluting stents (PES) in saphenous vein grafts (SVGs).

METHODS AND RESULTS

A randomised controlled trial was performed in four hospitals in three European countries between December 2011 and December 2013. Patients with de novo lesions (>50% stenosis) in an SVG with a diameter between 2.5-6 mm were included. Primary endpoint was late lumen loss at 6 months. Secondary endpoints included procedural success and the occurrence of major adverse cardiac events (MACE) at 12 months. A total of 57 patients were randomised to STENTYS self-apposing BMS (n = 27) or PES (n = 30). Procedural success was obtained in 89.5%. No significant differences in late lumen loss were found between BMS and PES at 6 months (0.53 mm vs 0.47; p = 0.86). MACE rates at 12 months were comparable in both groups (BMS 22.2% vs. PES 26.7%; p = 0.70).

CONCLUSIONS

Treatment of SVGs with STENTYS self-expandable stents is safe and effective. No significant differences were found in late lumen loss and MACE between BMS and PES.

Current State of the Art in Approaches to Saphenous Vein Graft Interventions

Saphenous vein grafts (SVGs), used during coronary artery bypass graft surgery for severe coronary artery disease, are prone to degeneration and occlusion, leading to poor long-term patency compared with arterial grafts. Interventions used to treat SVG disease are susceptible to high rates of periprocedural MI and no-reflow. To minimise complications seen with these interventions, proper stents, embolic protection devices (EPDs) and pharmacological selection are crucial. Regarding stent selection, evidence has demonstrated superiority of drug-eluting stents over bare-metal stents in SVG intervention. The ACCF/AHA/SCA American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Society for Cardiovascular Angiography and Interventions guidelines recommend the use of EPDs during SVG intervention to decrease the risk of periprocedural MI, distal embolisation and no-reflow. The optimal pharmacological treatment for slow or no-reflow remains unclear, but various vasodilators show promise.

Rationale and design of the Drug-Eluting Stents vs Bare-Metal Stents in Saphenous Vein Graft Angioplasty (DIVA) Trial

VA Cooperative Studies Program #571 (DIVA) was designed to evaluate the efficacy of drug-eluting stents (DES) for reducing aortocoronary saphenous vein bypass graft (SVG) failure when compared with bare-metal stents (BMS) in participants undergoing stenting of de novo SVG lesions. Participants undergoing clinically indicated stenting of de novo SVG lesions were randomized in a 1:1 ratio to DES or BMS. Randomization was stratified by presence/absence of diabetes mellitus and the number of target SVG lesions (1 vs ≥2) within each participating site. At sites that did not routinely administer 12-months of dual antiplatelet therapy after SVG stenting participants without acute coronary syndromes received 1 month of open-label clopidogrel, followed by 11 months of clopidogrel for those assigned to DES and 11 months of placebo for those assigned to BMS. The primary endpoint was the 12-month incidence of target-vessel failure (defined as the composite of cardiac death, target-vessel myocardial infarction, or target-vessel revascularization). Secondary endpoints included the incidence of other clinical endpoints and the incremental cost-effectiveness of DES relative to BMS. Due to lower-than-anticipated target-vessel failure rates, target enrollment was increased from 519 to 762. The study had randomized 599 participants when recruitment ended in December 2015. The DIVA trial will provide clarity on the appropriate stent type for de novo SVG lesions.

Management and Prevention of Saphenous Vein Graft Failure: A Review

Coronary artery bypass grafting (CABG) remains a vital treatment for patients with multivessel coronary artery disease (CAD), especially diabetics. The long-term benefit of the internal thoracic artery graft is well established and remains the gold standard for revascularization of severe CAD. It is not always possible to achieve complete revascularization through arterial grafts, necessitating the use of saphenous vein grafts (SVG). Unfortunately, SVGs do not have the same longevity, and their failure is associated with significant adverse cardiac outcomes and mortality. This paper reviews the pathogenesis of SVG failure, highlighting the difference between early, intermediate, and late failure. It also addresses the different surgical techniques that affect the incidence of SVG failure, as well as the medical and percutaneous prevention and treatment options in contemporary practice.

Choice of Stent for Percutaneous Coronary Intervention of Saphenous Vein Grafts

Background—

There are limited data on comparison of contemporary drug-eluting stent (DES) platforms, previous generation DES, and bare-metal stents (BMS) for percutaneous coronary intervention in saphenous vein grafts (SVG). We aimed to assess clinical outcomes following percutaneous coronary intervention to SVG in patients receiving bare-metal stents (BMS), first-generation DES, and newer generation DES in a large unselected national data set from the BCIS (British Cardiovascular Intervention Society).

Methods and Results—

Patients undergoing percutaneous coronary intervention to SVG in the United Kingdom from January 2006 to December 2013 were divided into 3 groups according to stent use: BMS, first-generation DES, and newer generation DES group. Study outcomes included in-hospital major adverse cardiovascular events, 30-day mortality, and 1-year mortality. Patients (n=15 003) underwent percutaneous coronary intervention to SVG in England and Wales during the study period. Of these, 38% received BMS, 15% received first-generation DES, and 47% received second-generation DES. The rates of in-hospital major adverse cardiovascular events were significantly lower in patients treated with second-generation DES (odds ratio, 0.51; 95% confidence interval, 0.38–0.68; P <0.001), but not with first-generation DES, compared with BMS-treated patients. Similarly, 30-day mortality (odds ratio, 0.43; 95% confidence interval, 0.32–0.59; P <0.001) and 1-year mortality (odds ratio, 0.60; 95% confidence interval, 0.51–0.71; P <0.001) were lower in patients treated with second-generation DES, but not with first-generation DES, compared with the patients treated with BMS.

Conclusions—

Patients receiving second-generation DES for the treatment SVG disease have lower rates of in-hospital major adverse cardiovascular events, 30-day mortality, and 1-year mortality, compared with those receiving BMS.

Sealing Intermediate Nonobstructive Coronary Saphenous Vein Graft Lesions With Drug-Eluting Stents as a New Approach to Reducing Cardiac Events

Background—

The objective of this study was to assess the efficacy of sealing intermediate nonobstructive coronary saphenous vein graft (SVG) lesions with drug-eluting stents (DES; paclitaxel- or everolimus-eluting stents) for reducing major adverse cardiac events (MACE).

Methods and Results—

This was a randomized controlled multicenter clinical trial that enrolled patients with a previous coronary artery bypass graft who had developed at least 1 intermediate nonobstructive SVG lesion (30%–60% diameter stenosis by visual estimation). Patients were randomized (1:1) to DES implantation (SVG-DES) or medical treatment (SVG-MT) of the target SVG lesion. The primary efficacy outcome was the first occurrence of MACE defined as the composite of cardiac death, myocardial infarction, or coronary revascularization related to the target SVG during the duration of follow-up (minimum of 2 years). Secondary efficacy outcomes included MACE related to the target SVG lesion and overall MACE. A total of 125 patients (mean age 70±9 years, 87% men) were included, with a mean time from coronary artery bypass graft of 12±5 years. Sixty and 65 patients were allocated to the SVG-DES and SVG-MT groups, respectively. There were no events related to the target SVG at 30 days. After a median follow-up of 3.4 (interquartile range: 2.8–3.9) years, the MACE rate related to the target SVG was not significantly different in the 2 groups (SVG-DES: 15.0%, SVG-MT: 20.0%; hazard ratio, 0.65; 95% confidence interval, 0.23–1.53; P =0.33). There were no significant differences between groups in MACE related to the target SVG lesion (SVG-DES: 10.0%, SVG-MT: 16.9%; hazard ratio, 0.53; 95% confidence interval, 0.20–1.43; P =0.21) or global MACE (SVG-DES: 36.7%, SVG-MT: 44.6%; hazard ratio, 0.73; 95% confidence interval, 0.42–1.27; P =0.26).

Conclusions—

Sealing intermediate nonobstructive SVG lesions with DES was safe but was not associated with a significant reduction of cardiac events at 3-year follow-up.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01223443.

Effects of radial versus femoral artery access in patients with acute myocardial infarction: A large centre prospective registry

Aim

This study sought to assess whether radial artery access improves clinical outcomes in patients presenting with acute myocardial infarction compared with femoral artery access.

Methods

This is a single-centre, prospective observational registry of all STEMI and NSTEMI patients who underwent coronary angiography and/or primary PCI in the period January 2010 to December 2013. Primary endpoint was 30-day all-cause mortality. Choice of access was left to the discretion of the cardiologist. Differences in the risk of death at 30 days between patients undergoing transradial intervention versus transfemoral intervention was assessed on an intention-to-treat comparison.

Results

Retrospective analysis of prospectively collected data was performed in 3580 patients with an acute coronary syndrome who underwent coronary angiography, of which 1310 had radial artery access. PCI was performed in 77 % of the patients. Before propensity score matching, patients who underwent transradial intervention and those intended to undergo transfemoral approach differed significantly in intra-aortic balloon pump use (1.7 % vs. 6.7 %, p < 0.001), and Killip class (Killip 1: 10.8 % vs. 17.3 %, p < 0.001). 30-day mortality rates were 1.7 % in the transradial group and 4.6 % in the transfemoral group (p < 0.001). After matching on the propensity score, the hazard ratio for 30-day mortality in the transradial group was 0.56 (95 % CI: 0.29–1.07, p = 0.08).

Conclusion

This registry-based study showed that radial access is associated with improved outcome in patients with an acute coronary syndrome. However, this difference was no longer significant after multivariate and propensity score adjustment for differences in baseline characteristics.

Drug-eluting versus bare metal stent in treatment of patients with saphenous vein graft disease: A meta-analysis of randomized controlled trials

Drug-eluting stent (DES) and bare metal stent (BMS) are effective treatments for preventing vascular disease, but whether using DES is associated with positive clinical outcomes compared with BMS in patients with saphenous vein graft disease (SVGD) has not been established. Three electronic databases including PubMed, EmBase, and the Cochrane Central Register of Controlled Trials were searched to identify potentially includible studies. We did a random-effects meta-analysis of randomized controlled trials (RCTs) to obtain summary effect estimates for the clinical outcomes with the use of relative risk calculated from the raw data of individual trial. Among 812 patients from 4 RCTs, DES was associated with lower risk of short-term major cardiovascular events (MACEs) when compared with BMS, whereas no significant effect on the risk of long-term MACEs. Furthermore, there was no significant difference between DES and BMS for short-term myocardial infarction (MI) and long-term MI. Similarly, DES was not associated with risk of short- and long-term mortality risk as compared with BMS. In addition, DES has no significant effect on the risk of cardiac death and stent thrombosis. Finally, DES therapy significantly reduced the risk of TLR, TVF, and TVR. SVGD patients received DES can minimize the risk of short-term MACEs, TLR, TVF, and TVR when compared with BMS. However, it does not effect on the incidence of long-term MACEs, MI, mortality, cardiac death, and stent thrombosis.

Saphenous Vein Graft Interventions

Saphenous vein graft interventions compose a small but important subset of percutaneous coronary revascularization. Because of their unique biology, percutaneous angioplasty and stenting require tailored patient and lesion selection and modification of intervention technique to optimize outcomes. The use of embolic protection and appropriate adjunctive pharmacology can help minimize periprocedural complications, such as the no-reflow phenomenon. Recommendations for best practice in saphenous vein graft interventions continue to evolve with emerging research and therapy.

The impact of diabetes mellitus on long-term clinical outcomes after percutaneous coronary saphenous vein graft interventions in the drug-eluting stent era

OBJECTIVES

We aimed to compare early and late clinical outcomes in diabetic and nondiabetic patients who underwent saphenous vein graft (SVG) percutaneous coronary interventions (PCI) with the use of drug-eluting stents (DES).

BACKGROUND

Patients with diabetes mellitus are shown to have less favorable outcomes after SVG intervention with the use of bare metal stents. In the DES era, the impact of diabetes mellitus on restenosis and clinical outcomes post-SVG intervention is not clearly defined.

METHODS

From our institutional PCI registry database, we retrospectively analyzed 477 consecutive patients with prior coronary artery bypass graft surgery undergoing SVG PCI with the implantation of DES stratified by the presence or absence of diabetes mellitus. The primary end-point was 1-year major adverse cardiac event (MACE) rate, defined as death, Q wave myocardial infarction, and target lesion revascularization.

RESULTS

Baseline clinical characteristics, including mean graft age (120 ± 77 vs. 131 ± 86 months, P = 0.14), were similar between groups, save for a higher prevalence of systemic hypertension and chronic renal insufficiency, and higher body mass index in the diabetic group. Among the 604 SVG lesions treated with DES, the angiographic and procedural characteristics were well matched between groups except for the higher rate of distal protection device use (32% vs. 29%, P = 0.007) in the diabetic group. The rates of 1-year MACE (21% vs. 15%, P = 0.12) and all-cause mortality (7.6% vs. 6.7%, P = 0.86) were similar between groups. After adjustment for the relevant clinical co-variables, diabetic status was not associated with the composite end-point.

CONCLUSION

In conclusion, DES, when used for the treatment of vein graft lesions, equate the short- and long-term outcomes between diabetic and nondiabetic patients, suggesting that DES should be considered the default stent in diabetic populations undergoing PCI for the treatment of SVG lesions.

Percutaneous coronary intervention strategies and prognosis for graft lesions following coronary artery bypass grafting

The purpose of this study was to compare the prognosis of graft-percutaneous coronary intervention (PCI) and native vessel (NV)-PCI, drug-eluting stents (DESs) and bare-metal stents (BMSs) for the treatment of graft lesions following coronary artery bypass grafting (CABG), and to determine the risk factors for major adverse cardiac events (MACEs). A total of 289 patients who underwent PCI following CABG between August 2005 and March 2010 were retrospectively analyzed. The effects on survival were compared among patients who underwent NV- and graft-PCI, and DES and BMS implantation. Additionally, the risk factors for MACEs following PCI for graft lesions were analyzed. The findings showed that MACE-free and revascularization-free survival rates were significantly higher in the NV-PCI group compared with those in the graft-PCI group. There were 63 cases (29.0%) of MACEs in the DES group and 25 cases (52.1%) in the BMS group. In patients undergoing NV-PCI, the DES group had significantly fewer MACEs and less target vessel revascularization (TVR) than the BMS group. In patients undergoing graft-PCI, the DES group showed a tendency for fewer MACEs and a lower incidence of cardiac mortality, myocardial infarction and TVR compared with the BMS group. Diabetes, an age of >70 years and graft-PCI were independent risk factors for MACEs in patients post-PCI. It is concluded that NV-PCI has superior long-term outcomes compared with graft-PCI, and should therefore be considered as the first-line treatment for graft disease following CABG. Despite this, graft-PCI remains a viable option. DESs are the first choice for graft-PCI due to their safety and efficacy and their association with reduced mortality and MACE rate. Diabetes, older age and graft-PCI are independent risk factors for MACEs in patients post-CABG who are undergoing revascularization.