Stent Thrombosis With Drug-Eluting Stents

Thrombogenicity of biodegradable metals

Biodegradable metals offer a promising means to ameliorate many of the long-term risks associated with vascular devices made of conventional biostable stent metals. While numerous biodegradable metal alloys have been developed and characterized in animal models, knowledge of their blood reactivity and thrombogenicity remains unknown. Metal hemocompatibility is particularly valuable because current generation drug-eluting stents pose a significant long-term thrombosis risk. In this study, four pure metals, widely used as degradable base materials (Fe, Zn, Mg, and Mo), and three alloys commonly used in cardiovascular devices [NiTi, CoCr, and stainless steel (SS)] were evaluated. This work examined how each of these metals activate platelets, coagulation factors, and inflammation using in vitro hemocompatibility assays and a clinically relevant ex vivo non-human primate arteriovenous shunt model. Testing found that while all metals promoted a downstream activation of platelets and coagulation in flowing whole blood, platelet and fibrin attachment to Mg was markedly reduced. Additionally, Fe and Mo trended toward higher platelet attachment and contact pathway activation. Overall, the results suggest that Mg may delay clot initiation, but not eliminate clot formation, indicating the importance of understanding thrombosis in Mg alloys that are currently being developed for clinical use as biodegradable stents.

Temporal Trends in the Outcomes of Percutaneous Coronary Intervention With Zotarolimus Eluting Stents Versus Everolimus Eluting Stents: A Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

Long-term follow-up results of various trials comparing Zotarolimus eluting stents (ZES) with Everolimus eluting stents (EES) have been published recently. Additionally, over the last decade, there have been new trials comparing the ZES with various commercially available EES. We aim to conduct an updated meta-analysis in light of new evidence from randomized controlled trials (RCTs) to provide comprehensive evidence regarding the temporal trends in the clinical outcomes.

METHODS

A comprehensive literature search was conducted across PubMed, Cochrane, and Embase. RCTs comparing ZES with EES for short (<2 years), intermediate (2-3 years), and long-term follow-ups (3-5 years) were included. Relative risk was used to pool the dichotomous outcomes using the random effects model employing the inverse variance method. All statistical analysis was conducted using Revman 5.4.

RESULTS

A total of 18 studies reporting data at different follow-ups for nine trials (n = 14319) were included. At short-term follow-up (<2 years), there were no significant differences between the two types of stents (all-cause death, cardiac death, Major adverse cardiovascular events (MACE), target vessel myocardial infarction, definite or probable stent thrombosis or safety outcomes (target vessel revascularization, target lesion revascularization, target vessel failure, target lesion failure). At intermediate follow-up (2-3 years), EES was superior to ZES for reducing target lesion revascularization (RR = 1.28, 95% CI = 1.05-1.58, p < 0.05). At long-term follow-up (3-5 years), there were no significant differences between the two groups for any of the pooled outcomes (p > 0.05).

CONCLUSION

ZES and EES have similar safety and efficacy at short, intermediate, and long-term follow-ups.

Pharmacologic targeting of coagulation factors XII and XI by monoclonal antibodies reduces thrombosis in nitinol stents under flow

BACKGROUND

Cardiovascular implantable devices, such as vascular stents, are critical for the treatment of cardiovascular diseases. However, their success is dependent on robust and often long-term antithrombotic therapies. Yet, the current standard-of-care therapies often pose significant bleeding risks to patients. Coagulation factor (F)XI and FXII have emerged as potentially safe and efficacious targets to safely reduce pathologic thrombin generation in medical devices.

OBJECTIVES

To study the efficacy of monoclonal antibody-targeting FXII and FXI of the contact pathway in preventing vascular device-related thrombosis.

METHODS

The effects of inhibition of FXII and FXI using function-blocking monoclonal antibodies were examined in a nonhuman primate model of nitinol stent-related thrombosis under arterial and venous flow conditions.

RESULTS

We found that function-blocking antibodies of FXII and FXI reduced markers of stent-induced thrombosis in vitro and ex vivo. However, FXI inhibition resulted in more effective mitigation of thrombosis markers under varied flow conditions.

CONCLUSION

This work provides further support for the translation of contact pathway of coagulation inhibitors for their adjunctive clinical use with cardiovascular devices.

An Aspirin-Free Versus Dual Antiplatelet Strategy for Coronary Stenting: STOPDAPT-3 Randomized Trial

BACKGROUND

Bleeding rates on dual antiplatelet therapy (DAPT) within 1 month after percutaneous coronary intervention (PCI) remain high in clinical practice, particularly in patients with acute coronary syndrome or high bleeding risk. Aspirin-free strategy might result in lower bleeding early after PCI without increasing cardiovascular events, but its efficacy and safety have not yet been proven in randomized trials.

METHODS

We randomly assigned 6002 patients with acute coronary syndrome or high bleeding risk just before PCI either to prasugrel (3.75 mg/day) monotherapy or to DAPT with aspirin (81-100 mg/day) and prasugrel (3.75 mg/day) after loading of 20 mg of prasugrel in both groups. The coprimary end points were major bleeding (Bleeding Academic Research Consortium 3 or 5) for superiority and cardiovascular events (a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischemic stroke) for noninferiority with a relative 50% margin.

RESULTS

The full analysis set population consisted of 5966 patients (no-aspirin group, 2984 patients; DAPT group, 2982 patients; age, 71.6±11.7 years; men, 76.6%; acute coronary syndrome, 75.0%). Within 7 days before randomization, aspirin alone, aspirin with P2Y12 inhibitor, oral anticoagulants, and intravenous heparin infusion were given in 21.3%, 6.4%, 8.9%, and 24.5%, respectively. Adherence to the protocol-specified antiplatelet therapy was 88% in both groups at 1 month. At 1 month, the no-aspirin group was not superior to the DAPT group for the coprimary bleeding end point (4.47% and 4.71%; hazard ratio, 0.95 [95% CI, 0.75-1.20]; Psuperiority=0.66). The no-aspirin group was noninferior to the DAPT group for the coprimary cardiovascular end point (4.12% and 3.69%; hazard ratio, 1.12 [95% CI, 0.87-1.45]; Pnoninferiority=0.01). There was no difference in net adverse clinical outcomes and each component of coprimary cardiovascular end point. There was an excess of any unplanned coronary revascularization (1.05% and 0.57%; hazard ratio, 1.83 [95%CI, 1.01-3.30]) and subacute definite or probable stent thrombosis (0.58% and 0.17%; hazard ratio, 3.40 [95% CI, 1.26-9.23]) in the no-aspirin group compared with the DAPT group.

CONCLUSIONS

The aspirin-free strategy using low-dose prasugrel compared with the DAPT strategy failed to attest superiority for major bleeding within 1 month after PCI but was noninferior for cardiovascular events within 1 month after PCI. However, the aspirin-free strategy was associated with a signal suggesting an excess of coronary events.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04609111.

Novel usage of everolimus-eluting coronary stent for intracranial atherosclerotic disease: a technical report and case series

Objectives

This report describes the use of an Everolimus-eluting stent (Xience Skypoint stent) for the treatment of medically-refractory ICAD.

Design

Retrospective, case-series.

Setting

In-hospital patients.

Participants

All patients in this report had a history of stroke secondary to ICAD. All patients failed aggressive medical treatments and had recurrence of symptoms despite anticoagulation or dual-antiplatelet therapy plus a statin. Diagnostic angiogram in each case showed severe vessel stenosis, therefore patients were recommended for intracranial artery stenting.

Main outcome measures

Technical feasibility of deploying Xience Skypoint stent for treatmet of ICAD.

Results

The Xience Skypoint stent was safely and effectively deployed in the vertebral artery (x1) and the internal carotid artery (x2) using trans-ulnar (x1), trans-radial (x1), and trans-femoral (x1) approaches without the use of an intermediate catheter.

Conclusion

Second-generation EES such as Xience Skypoint may be utilized for treatment of medically-refractory ICAD. This technical report serves as a proof of concept for further studies analysing long-term safety and efficacy of such stents for treatment of ICAD.

Comparison of Early and Late Surgeries after Coronary Stent Implantation in Patients with Normal Preoperative Troponin Level: A Retrospective Study

Current guidelines recommend delaying noncardiac surgery for 6 months after drug eluting stent implantation. However, this recommendation is largely based on limited evidence and various event definitions. Whether early surgery within 6 months of coronary stent implantation increases myocardial injury in patients with normal preoperative high-sensitivity cardiac troponin I (hs-cTnI) has not yet been investigated. This retrospective study assessed patients who received coronary stent implantation and underwent noncardiac surgery (vascular, abdominal, or thoracic) between 2010 and 2017 with normal preoperative hs-cTnI (n = 186). Patients were divided into early (within 6 months of PCI) and late (after 6 months of PCI) groups. The primary endpoint was the incidence of myocardial injury as diagnosed by hs-cTnI within 3 days post-operation. The secondary outcomes were myocardial infarction, stent thrombosis, emergent coronary revascularization, major bleeding (bleeding requiring transfusion or intracranial bleeding), stroke, renal failure, heart failure, or death within 30 days post-operation. Inverse probability treatment weighting (IPTW) was carried out to adjust for the intergroup baseline differences. Myocardial injury occurred in 28.6% (8/28) and 27.8% (44/158) of the early and late groups, respectively, with no difference between groups (odds ratio [OR] 1.067, 95% confidence interval [CI] 0.404, 2.482; p = 0.886). Secondary outcomes did not differ between the groups. IPTW analysis also showed no differences in myocardial injury and secondary outcomes between the groups. In conclusion, early surgery within 6 months after coronary stent implantation did not increase the incidence of myocardial injury in patients with normal preoperative hs-cTnI.

Predictors of Adverse Prognosis in Patients With Acute Coronary Syndrome Caused by Plaque Erosion With a Nonstent Strategy

Background The EROSION (Effective Anti-Thrombotic Therapy Without Stenting: Intravascular Optical Coherence Tomography-Based Management in Plaque Erosion) study demonstrated that antithrombotic therapy without stenting was safe and feasible in selected patients with acute coronary syndrome caused by plaque erosion. However, the factors related to the prognosis of these patients are not clear. This study aimed to explore the predictors of an adverse prognosis of a nonstent strategy in a larger sample size. Methods and Results A total of 252 (55 patients were from the EROSION study) patients with acute coronary syndrome with plaque erosion who met the inclusion criteria of the EROSION study and completed clinical follow-up were enrolled. Patients were divided into 2 groups according to the occurrence of major adverse cardiovascular events (MACE), which were defined as the composite of cardiac death, recurrent myocardial infarction, ischemia-driven target lesion revascularization, rehospitalization because of unstable or progressive angina, major bleeding, and stroke. Among 232 patients with acute coronary syndrome included in the final analysis, 50 patients (21.6%) developed MACE at a median follow-up of 2.9 years. Compared with patients without MACE, patients with MACE were older and had a higher degree of percentage of area stenosis (72.2%±9.4% versus 64.2%±15.7%, P<0.001) and thrombus burden (24.4%±10.4% versus 20.4%±10.9%, P=0.010) at baseline. Multivariate Cox regression analysis confirmed that age, percentage of area stenosis, and thrombus burden were predictors of MACE. The best cutoff values of predictors were age ≥60 years, percentage of area stenosis ≥63.5%, and thrombus burden ≥18.5%, respectively, and when they were all present, the rate of MACE rose to 57.7%. Conclusions The nonstent treatment strategy of patients with acute coronary syndrome caused by plaque erosion was heterogeneous, and patients aged ≥60 years, percentage of area stenosis ≥63.5%, and thrombus burden ≥18.5% may predict a worse clinical outcome.

P2Y12 inhibitor monotherapy in patients undergoing percutaneous coronary intervention

For 20 years, dual antiplatelet therapy (DAPT), consisting of the combination of aspirin and a platelet P2Y₁₂ receptor inhibitor, has been the gold standard of antithrombotic pharmacology after percutaneous coronary intervention (PCI). In the past 5 years, several investigations have challenged this paradigm by testing the efficacy and safety of P2Y₁₂ inhibitor monotherapy (that is, without aspirin) following a short course of DAPT. Collectively, these studies suggested a reduction in the risk of major bleeding and no significant increase in thrombotic or ischaemic events compared with guideline-recommended DAPT. Current recommendations are evolving to inform clinical practice on the ideal candidates for P2Y₁₂ inhibitor monotherapy after PCI. Generalizing the results of studies of P2Y₁₂ inhibitor monotherapy requires a thorough understanding of their design, populations, interventions, comparators and results. In this Review, we provide an up-to-date overview on the use of P2Y₁₂ inhibitor monotherapy after PCI, including supporting pharmacodynamic and clinical evidence, practical recommendations and future directions.

Safety and efficacy of immediate heparin reversal with protamine after complex percutaneous coronary intervention

Background

Compared to simple percutaneous coronary intervention (PCI), complex PCI is associated with higher bleeding and thrombotic risk. No previous study has evaluated the use of protamine after PCI with contemporary technologies. This study aimed to evaluate the safety and efficacy of manual compression with and without protamine after transfemoral complex PCI.

Methods

We retrospectively analyzed 160 patients (protamine group, n = 92; non-protamine group, n = 68) who underwent complex PCI via the femoral artery. The primary outcome was a composite of in-hospital death, myocardial infarction, stent thrombosis, stroke/systemic embolism, bleeding requiring blood transfusion, and vascular access complications.

Results

The primary outcome was significantly lower in the protamine group than in the non-protamine group (4.3% vs. 17.6%; p = 0.006). This was driven mainly by the lower incidences of hematoma in the protamine group (3.3% vs. 13.2%, p = 0.020). Furthermore, the protamine group had a significantly shorter hospital stay than the non-protamine group (4.8 ± 3.7 days vs. 8.4 ± 8.3 days, p = 0.001). While > 90% of the patients had acute coronary syndrome, there were no incidences of myocardial infarction or stent thrombosis in either group.

Conclusions

Among patients who underwent complex PCI via transfemoral access, immediate protamine administration was associated with a significantly lower rate of vascular access complications, especially hematoma, and shorter hospital stay than no protamine administration.

Bleeding avoidance strategies in percutaneous coronary intervention

For many years, bleeding has been perceived as an unavoidable consequence of strategies aimed at reducing thrombotic complications in patients undergoing percutaneous coronary intervention (PCI). However, the paradigm has now shifted towards bleeding being recognized as a prognostically unfavourable event to the same extent as having a new or recurrent ischaemic or thrombotic complication. As such, in parallel with progress in device and drug development for PCI, there is clinical interest in developing strategies that maximize not only the efficacy but also the safety (for example, by minimizing bleeding) of any antithrombotic treatment or procedural aspect before, during or after PCI. In this Review, we discuss contemporary data and aspects of bleeding avoidance strategies in PCI, including risk stratification, timing of revascularization, pretreatment with antiplatelet agents, selection of vascular access, choice of coronary stents and antithrombotic treatment regimens.

Overcoming challenges in refining the current generation of coronary stents

INTRODUCTION

Late stent thrombosis caused by delayed vascular healing and prolonged local inflammation were major drawbacks of 1^st generation drug-eluting stents (DES). Strut design, biocompatibility of polymer, and drug-release profiles were improved in 2^nd and 3rdgeneration DES. Accordingly, the indications for percutaneous coronary intervention with DES have been expanded to more complex patients and lesions. Despite these improvements, significant barriers such as greater flexibility in the duration of dual-antiplatelet therapy (DAPT) as well as reducing long-term stent-related events remain. To achieve ideal short- and long-term results, these existing limitations need to be overcome.

AREAS COVERED

We will discuss the current limitations of coronary DES and how they might be overcome from pathological and clinical viewpoints.

EXPERT OPINION

Optimizing DAPT duration after stent implantation and prevention of in-stent neoatherosclerosis are two major issues in current DES. Overcoming these drawbacks is a prerequisite toward achieving better short- and long-term clinical outcomes. New technologies including platform design, polymer types, and anti-proliferative agent itself might lead to further improvements. Although the initial experience with bioresorbable scaffold/stents (BRS) was disappointing, positive results of clinical studies regarding novel BRS are raising expectations. Overall, further device innovation is desired for overcoming the limitations of current DES.

The multiple roles of chemokines in the mechanisms of stent biocompatibility

While the advent of drug-eluting stents has been clinically effective in substantially reducing the rates of major stent-related adverse events compared with bare metal stents, vascular biological problems such as neointimal hyperplasia, delayed re-endothelialization, late stent thrombosis are not eliminated and, increasingly, neoatherosclerosis is the underlying mechanism for very late stent failure. Further understanding regarding the mechanisms underlying the biological responses to stent deployment is therefore required so that new and improved therapies can be developed. This review will discuss the accumulating evidence that the chemokines, small inflammatory proteins, play a role in each key biological process of stent biocompatibility. It will address the chemokine system in its specialized roles in regulating the multiple facets of vascular biocompatibility including neointimal hyperplasia, endothelial progenitor cell (EPC) mobilization and re-endothelialization after vascular injury, platelet activation and thrombosis, as well as neoatherosclerosis. The evidence in this review suggests that chemokine-targeting strategies may be effective in controlling the pathobiological processes that lead to stent failure. Preclinical studies provide evidence that inhibition of specific chemokines and/or broad-spectrum inhibition of the CC-chemokine class prevents neointimal hyperplasia, reduces thrombosis and suppresses the development of neoatherosclerosis. In contrast, however, to these apparent deleterious effects of chemokines on stent biocompatibility, the CXC chemokine, CXCL12, is essential for the mobilization and recruitment of EPCs that make important contributions to re-endothelialization post-stent deployment. This suggests that future chemokine inhibition strategies would need to be correctly targeted so that all key stent biocompatibility areas could be addressed, without compromising important adaptive biological responses.

Ultrathin biodegradable polymer sirolimus-eluting stent versus contemporary durable polymer everolimus-eluting stent for percutaneous coronary intervention: a meta-analysis of randomized trials

INTRODUCTION

Improvements in coronary drug-eluting stent technology has focused on reducing the long-term complications associated with the effects of the residual footprint on the vessel wall. Although many of the newer stents have exhibited noninferiority to the durable polymer everolimus-eluting stent (DP-EES), they have yet to exhibit clear superiority. We compared the performance of the latest ultrathin strut biodegradable polymer sirolimus-eluting stents (BP-SES) to DP-EES.

METHODS

We searched the electronic databases for randomized controlled trials comparing BP-SES to DP-EES. A random effect meta-analysis was performed using the Poisson regression model. The primary end point was target lesion failure (TLF), a composite of target vessel myocardial infarction (TVMI), cardiac death and target lesion revascularization (TLR).

RESULTS

There was no difference between the stents in stent thrombosis [incidence rate ratio (IRR) = 0.79, 95% confidence interval (CI) 0.58-1.06), TLR (IRR = 0.88, 95% CI 0.57-1.38), TVMI (IRR = 0.79, 95% CI 0.61-1.01), cardiac death (IRR = 0.99, 95% CI 0.76-1.29) and target vessel failure (IRR = 0.82, 95% CI 0.64-1.06). In addition, there was no difference in TLF (IRR = 0.82, 95% CI 0.64-1.06). There was evidence of reduced TLF in small vessels with BP-SES based on definition used (defined as ≤2.75 mm; IRR 0.64, 95% CI 0.46-0.91 versus ≤3 mm; IRR 1.11, 95% CI 0.90-1.36).

CONCLUSION

In our study, the performance of the latest generation BP-SES was comparable to DP-EES but failed to show superiority. The possible benefit in patients with small vessels should be explored future trials.

Perioperative implications of newer generation drug-eluting coronary stents: A narrative review

Newer generation drug-eluting stents are the most commonly inserted stent in the setting of percutaneous coronary intervention. This narrative review focuses on the evidence underpinning the perioperative management of patients with newer generation drug-eluting stents undergoing non-cardiac surgery. Six studies reported the incidence of major adverse cardiovascular events according to the time interval from percutaneous coronary intervention to non-cardiac surgery, and the comparative risks of newer and first generation drug-eluting stents. No study demonstrated an increased risk of major adverse cardiovascular events once three months had elapsed between stent implantation and non-cardiac surgery. Only one study included patients with third and fourth generation drug-eluting stents. Seven studies analysed the relationship between antiplatelet therapy, major adverse cardiovascular events and perioperative bleeding. The risks of major adverse cardiovascular events do not appear to be increased if antiplatelet therapy is ceased for less than seven days but are increased if it is discontinued for more than seven days. Most studies reported no differences in the incidence of major bleeding associated with antiplatelet therapy. The risk of perioperative major adverse cardiovascular events in non-cardiac surgery does not appear to be increased after three months following implantation with newer generation drug-eluting stents. However, the possibility of increased risk cannot be excluded as most studies were inadequately powered. The thrombotic risk is substantially reduced in patients with fourth (polymer free) generation drug-eluting stents, and urgent non-cardiac surgery can be considered one month after percutaneous coronary intervention. Larger multicentre studies are needed to define the optimal window for non-cardiac surgery after percutaneous coronary intervention and provide definitive perioperative strategies for patients presenting for non-cardiac surgery after the implantation of newer generation drug-eluting stents.

Vascular Wall Reactions to Coronary Stents-Clinical Implications for Stent Failure

Coronary stents belong to the most commonly implanted devices worldwide. A number of different types of stent exist, with very different mechanical and biochemical characteristics that influence their interactions with vascular tissues. Inappropriate inflammatory reactions are the major cause of the two major complications that follow implantation of stents in a percentage as high as 5-20%. It is therefore important to understand these reactions and how different they are among different generations of stents.

Histopathologic response after hydrophilic polyethylene glycol-coating stent and hydrophobic octadecylthiol-coating stent implantations in porcine coronary restenosis model

Device-related problems of drug-eluting stents, including stent thrombosis related to antiproliferative drugs and polymers, can cause adverse events such as inflammation and neointimal hyperplasia. Stent surface modification, wherein the drug and polymer are not required, may overcome these problems. We developed hydrophilic polyethylene glycol (PEG)-coating and hydrophobic octadecylthiol (ODT)-coating stents without a drug and polymer and evaluated their histopathologic response in a porcine coronary restenosis model. PEG-coating stents (n = 12), bare-metal stents (BMS) (n = 12), and ODT-coating stents (n = 10) were implanted with oversizing in 34 porcine coronary arteries. Four weeks later, the histopathologic response, arterial injury, inflammation, and fibrin scores were analyzed. A p value < 0.05 was considered statistically significant. There were significant differences in the internal elastic lamina area, lumen area, neointimal area, percent area of stenosis, arterial injury score, inflammation score, and fibrin score among the groups. Compared to the BMS or ODT-coating stent group, the PEG-coating stent group had significantly increased internal elastic lamina and lumen area (all p < 0.001) and decreased neointimal area and percent area of stenosis (BMS: p = 0.03 and p < 0.001, respectively; ODT-coating: p = 0.013 and p < 0.001, respectively). Similarly, the PEG-coating group showed significantly lower inflammation and fibrin scores than the BMS or ODT-coating groups (BMS: p = 0.013 and p = 0.007, respectively; ODT-coating: p = 0.014 and p = 0.008, respectively). In conclusion, hydrophilic PEG-coating stent implantation was associated with lower inflammatory response, decreased fibrin deposition, and reduced neointimal hyperplasia than BMS or hydrophobic ODT-coating stent implantation in the porcine coronary restenosis model.

Drug-Eluting Stents and Balloons-Materials, Structure Designs, and Coating Techniques: A Review

Controlled drug delivery is a matter of interest to numerous scientists from various domains, as well as an essential issue for society as a whole. In the treatment of many diseases, it is crucial to control the dosing of a drug for a long time and thus maintain its optimal concentration in the tissue. Heart diseases are particularly important in this aspect. One such disease is an obstructive arterial disease affecting millions of people around the world. In recent years, stents and balloon catheters have reached a significant position in the treatment of this condition. Balloon catheters are also successfully used to manage tear ducts, paranasal sinuses, or salivary glands disorders. Modern technology is continually striving to improve the results of previous generations of stents and balloon catheters by refining their design, structure, and constituent materials. These advances result in the development of both successive models of drug-eluting stents (DES) and drug-eluting balloons (DEB). This paper presents milestones in the development of DES and DEB, which are a significant option in the treatment of coronary artery diseases. This report reviews the works related to achievements in construction designs and materials, as well as preparation technologies, of DES and DEB. Special attention was paid to the polymeric biodegradable materials used in the production of the above-mentioned devices. Information was also collected on the various methods of producing drug release coatings and their effectiveness in releasing the active substance.

New Innovations and Devices in the Management of Chronic Limb-Threatening Ischemia

As the number of patients afflicted by chronic limb-threatening ischemia (CLTI) continues to grow, new solutions are necessary to provide effective, durable treatment options that will lead to improved outcomes. The diagnosis of CLTI remains mostly clinical, and endovascular revascularization remains mostly balloon-based. Multiple innovative techniques and technologies are in development or in early usage that may provide new solutions. This review categorizes areas of advancement, highlights recent developments in the management of CLTI and looks forward to novel devices that are currently under investigation.

TWILIGHT: A Randomized Trial of Ticagrelor Monotherapy Versus Ticagrelor Plus Aspirin Beginning at 3 Months in High-risk Patients Undergoing Percutaneous Coronary Intervention

A P2Y12 inhibitor-based monotherapy after a short period of dual antiplatelet therapy is emerging as a plausible strategy to decrease bleeding events in high-risk patients receiving dual antiplatelet therapy after percutaneous coronary intervention. Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention (TWILIGHT), a randomized double-blind trial, tested this approach by dropping aspirin at 3 months and continuing with ticagrelor monotherapy for an additional 12 months. The study enrolled 9,006 patients, of whom 7,119 who tolerated 3 months of dual antiplatelet therapy were randomized after 3 months into two arms: ticagrelor plus placebo and ticagrelor plus aspirin. The primary endpoint of interest, Bleeding Academic Research Consortium type 2, 3, or 5 bleeding, occurred less frequently in the experimental arm (HR 0.56; 95% CI [0.45–0.68]; p<0.001), whereas the secondary endpoint of ischemic events was similar between the two arms (HR 0.99; 95% CI [0.78–1.25]). Transition from dual antiplatelet therapy consisting of ticagrelor plus aspirin to ticagrelor-based monotherapy in high-risk patients at 3 months after percutaneous coronary intervention resulted in a lower risk of bleeding events without an increase in risk of death, MI, or stroke.

Outcomes of the novolimus-eluting bioresorbable vascular scaffold in real world clinical practice

BACKGROUND

Most of the current data regarding the use of bioresorbable scaffolds (BRS) come from everolimus-eluting stent platforms. Adverse events with the everolimus-eluting BRSs which are the most comprehensively characterized BRS, hampered the clinical use of other BRS. There is paucity of published data regarding long term use of novolimus-eluting BRS.

METHODS

This study sought to evaluate the performance of novolimus-eluting BRS device at midterm follow-up in real world clinical practice. One hundred and forty-four patients (mean age 57.5±9.7 years, 78.5% male) treated with 206 scaffolds between October 2015 and December 2017 were enrolled. A device-oriented composite endpoint (DOCE) comprising cardiac death, target vessel myocardial infarction (TV-MI), clinically driven target lesion revascularization (TLR) and rate of scaffold thrombosis were investigated.

RESULTS

During a mean follow-up of 33±9 months, DOCE occurred in 9 patients (6.3%) of which cardiac death occurred in 2 patients (1.4%), and clinically driven TLR in 7 patients (4.9%), TV-MI in one patient. Target vessel revascularization (TVR) was observed in nine patients. None of the patients experienced scaffold thrombosis.

CONCLUSIONS

The use of novolimus-eluting BRS in this real-world population achieved good clinical outcomes.

Cardiac Risk of Noncardiac Surgery After Percutaneous Coronary Intervention With Second-Generation Drug-Eluting Stents

BACKGROUND

Noncardiac surgery (NCS) following percutaneous coronary intervention (PCI) with stenting is sometimes associated with major adverse cardiac events (MACEs). Second-generation drug-eluting stents (DES) were developed to decrease the incidence of MACE seen with bare metal and first-generation DES.

METHODS

The medical records of all adult patients who underwent second-generation DES placement between July 29, 2008 and July 28, 2011 followed by NCS between September 22, 2008 and July 1, 2013 were reviewed. All episodes of MACE following surgery were recorded.

RESULTS

A total of 282 patients (74.8% male) were identified who underwent NCS after PCI with second-generation DES. MACE occurred in 15 patients (5.3%), including 11 deaths. The incidence of MACE changed significantly with time from PCI to NCS: 17.1%, 10.0%, 0.0%, and 3.1% for patients undergoing NCS at 0-90, 91-180, 181-365, and ≥366 days, respectively. Compared with those having NCS ≥366 days after PCI, the odds ratio for MACE (95% confidence interval) was 6.4 (1.9 to 21.3) at 0-90 days and 3.4 (0.8 to 15.3) at 91-180 days. Seven days prior to NCS, 146 (52%) patients were on dual antiplatelet therapy (DAPT), 106 (38%) were on aspirin, and 30 (11%) did not receive antiplatelet therapy. Excessive surgical bleeding occurred in 19 cases (6.7%). While observed bleeding rates were lowest in those not receiving antiplatelet therapy, there were no statistically significant differences based on the presence or absence of antiplatelet therapy (3% [1/30] for no antiplatelet therapy compared to 6% [6/106] for aspirin monotherapy and 8% [12/146] for DAPT; Fisher exact test: P = .655).

CONCLUSIONS

The incidence of MACE in patients with second-generation DES undergoing NCS was 5.3% and was highest in the first 180 days following DES implantation. The rate of excessive surgical bleeding was 6.7% with the highest observed rate in those on DAPT. However, differences by the presence or absence of antiplatelet therapy were not significant, and future large observational studies will be necessary to further define bleeding risk with continued DAPT.

Early and Mid-Term Vascular Responses to Optical Coherence Tomography-Guided Everolimus-Eluting Stent Implantation in Stable Coronary Artery Disease

BACKGROUND

Analysis of pooled clinical data has shown the safety of 3 months of dual antiplatelet therapy with everolimus-eluting cobalt-chromium stents (Co-Cr EESs). This study evaluated early and mid-term vascular responses to Co-Cr EESs in patients with stable coronary artery disease.

METHODS

The Multicenter Comparison of Early and Late Vascular Responses to Everolimus-Eluting Cobalt-Chromium Stent and Platelet Aggregation Studies in Patients With Stable Angina Managed as Elective Case (MECHANISM-Elective) study (NCT02014818) is a multicenter optical coherence tomography (OCT) registry. Enrolled patients were evaluated by OCT immediately after everolimus-eluting stent implantation were prospectively allocated to 1 month (n = 50) or 3 months (n = 50) OCT follow-up and then received a 12-month OCT evaluation. The incidences of intrastent thrombus (IS-Th) and irregular protrusion (IRP) were also assessed.

RESULTS

The percentage of uncovered struts was 6.4% ± 10.3% at 1 month (P < 0.001 vs. postprocedure) and 0.5% ± 0.9% at 12 months (P < 0.001 vs. 1 month). The corresponding values in the 3-month cohort were 2.0% ± 2.5% (P < 0.001 vs. postprocedure) and 0.5% ± 1.5% (P < 0.001 vs. 3 months). The incidence of IS-Th was 32.7% at 1 month, 5.4% at 3 months, and 2.0% at 12 months. IRP was observed in 21.8% of patients post-EES but had totally resolved at 1, 3, and 12 months.

CONCLUSION

Early and mid-term vascular reactions after Co-Cr EES implantation in stable patients with coronary artery disease in the MECHANISM-Elective included dynamic resolution of IS-Th and IRP and rapid decrease in uncovered struts. Thus, EES may allow shortening of dual antiplatelet therapy duration less than 3 months in this patient subset.

Intravascular ultrasound versus angiogram guided drug eluting stent implantation. A systematic review and updated meta-analysis with trial sequential analysis

Background

Further advances have been achieved in the field of intravenous ultrasound (IVUS) guided drug eluting stent (DES) implantation and hence there was a need to rejuvenate the evidence. Hence, we performed a cumulative meta-analysis with trial sequential analysis (TSA) of randomized controlled trials (RCTs) comparing IVUS versus angiogram guided DES implantation.

Methodology

We searched PubMed/Medline and Cochrane database for relevant articles using predefined inclusion and exclusion criteria. Outcomes of interest were cardiovascular mortality, myocardial infarction (MI), target lesion revascularisation (TLR), stent thrombosis (ST). We used Mantel-Haenszel method with random error model to calculate odds ratio (OR) with 95% confidence interval (CI). We also performed TSA to accommodate for possible type I error.

Results

A total of 11 RCTs with 5352 patients were included in the final analysis. Follow up duration of included studies varied from 12 to 24 months. IVUS use was associated with significantly reduced incidence of cardiovascular mortality [OR: 0.45, CI: 0.25–0.80, p value = 0.007, I² = 0%, χ²p-value = 0.98], TLR [OR: 0.56, CI: 0.41–0.77, p value = 0.0004, I² = 0%, χ²p-value = 0.95] and ST [OR: 0.47, CI: 0.24–0.94, p value = 0.03, I² = 0%, χ²p-value = 0.75]. IVUS use had no effect on incidence of MI on follow up. The cumulative z curve crosses the TSA boundary indicating sufficient evidence without type I error for reduced incidence of cardiovascular mortality and TLR with the use IVUS.

Conclusion

IVUS-guided DES implantation should be the standard of care as it significantly reduced cardiovascular mortality and TLR.

Vitamin K antagonist vs direct oral anticoagulants with antiplatelet therapy in dual or triple therapy after percutaneous coronary intervention or acute coronary syndrome in atrial fibrillation: Meta-analysis of randomized controlled trials

BACKGROUND

The combination of vitamin K antagonists (VKA) for atrial fibrillation (AF) and antiplatelet agents following percutaneous coronary intervention (PCI) is associated with an increased bleeding risk.

HYPOTHESIS

Direct oral anticoagulants (DOAC) are associated with a greater safety profile but the optimal antithrombotic treatment strategy, especially when considering ischemic events, is unclear.

METHODS

We performed a meta-analysis of randomized controlled trials comparing outcomes in AF patients following PCI and/or acute coronary syndrome (ACS) when treated with DOAC vs VKA, both in combination with one (dual) or two (triple) antiplatelet regimens. A systematic review was performed by searches of electronic databases MEDLINE (source PubMed) and the Cochrane Controlled Clinical Trials Register Database as well as Cardiology annual meetings. Three studies were finally included.

RESULTS

Compared to VKA triple therapy, the use of DOAC was associated with a decreased risk of any bleeding (relative risk [RR] 0.68 [0.62; 0.74]), major bleeding (RR 0.61 [0.51; 0.75]) and intracranial bleeding (RR 0.33 [0.17; 0.66]) and similar rates of the composite efficacy endpoint (RR 1.0 [0.87; 1.14]) and its components. Similar and consistent results were observed with both dual and triple therapy including a DOAC compared to VKA.

CONCLUSION

Our meta-analysis supports the use of dual therapy combining a DOAC and clopidogrel as the default regimen in most AF patients after PCI and/or ACS.

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.

Two-year safety evaluation of a biodegradable polymer sirolimus-eluting stent with increased drug elution and polymer absorption kinetics in complex patient and lesion cohort

OBJECTIVES

The aim of the present report was to compare 2-year safety outcomes of two biodegradable polymer (BP) sirolimus-eluting stents (SESs) with different drug eluting and polymer absorption kinetics in a subgroup of complex patients and lesions.

BACKGROUND

The previously published PANDA III study showed the BuMA BP SES, with faster drug elution and polymer absorption, was non-inferior to the Excel SES in target lesion failure (TLF).

METHODS

In PANDA III trial, patients who fulfilled one or more of the following criteria were included: Small vessel disease (reference vessel diameter ≤ 2.5 mm); long lesion (lesion length ≥ 20 mm); chronic total occlusion lesion; and diabetic patients.

RESULTS

Among 2,348 patients randomly assigned to treatment with BuMA (n = 1,174) or Excel SES (n = 1,174) in the PANDA III study, 858 in the BuMA group and 855 in the Excel group satisfied the inclusion criteria. At 2-year follow-up, the incidence of definite/probable stent thrombosis (ST) was significantly lower with BuMA SES as compared with Excel SES (0.7% vs. 1.9%, p = 0.03). This difference was mainly caused by decreased subacute stent thrombosis rate (0% vs. 0.6%, p = 0.03). In patients who did not fulfill the complex patient and lesion criteria, there were no between-group difference in ST (0.7% vs. 0%, p = 0.50). Myocardial infarction and TLF rates were similar (5.7% vs. 6.0%, p = 0.79 and 8.8% vs. 7.5%, p = 0.34, respectively), whereas patient-oriented composite endpoint was higher with BuMA SES mainly due to high risk of revascularization (15.6% vs. 11.4%, p = 0.01; 8.4% vs. 4.6%, p < 0.01).

CONCLUSIONS

Two-year subgroup analysis of the all-comer PANDA III trial revealed the increased safety benefit of the BuMA SES is more prominently seen in complex patient and lesion population.

CLINICAL TRIAL

ClinicalTrial.gov, Identifier-NCT02017275.

Revascularization Strategies for Non-ST-Elevation Myocardial Infarction

PURPOSE OF REVIEW

Non-ST-elevation myocardial infarction (NSTEMI) is an urgent medical condition that requires prompt application of simultaneous pharmacologic and non-pharmacologic therapies. The variation in patient clinical characteristics coupled with the multitude of treatment modalities makes optimal and timely management challenging. This review summarizes risk stratification of patients, the role and timing of revascularization, and highlights important considerations in the revascularization approach with attention to individual patient characteristics.

RECENT FINDINGS

The early invasive management of NSTEMI has fostered a reduction in future ischemic events. Risk calculators are helpful in determining which patients should receive early invasive management. As many patients have multivessel disease, identifying the true culprit lesion can be challenging. Special attention should be given to those at the highest risk, such as diabetics, patients with renal failure, and those with left main disease. In patients with acute coronary syndrome, the decision and mode of revascularization should carefully integrate the patient's clinical characteristics as well as the complexity of the coronary anatomy.

Everolimus-eluting bioresorbable vascular scaffolds: learning from the past to improve the future

Bioresorbable vascular scaffolds (BVS) were developed to overcome the long-term limitations of metallic drug-eluting stents (DES). Shortcomings of DES include their permanent metallic cage which prevents normal coronary vasomotion, vascular remodeling, precludes future bypass grafting, and creates a nidus for very late stent thrombosis. With its transient scaffold which provides early mechanical support and subsequently resorbs thereby restoring physiologic properties and architecture of the vasculature, BVS offers a promising development within the field of interventional cardiology. Even though various BVS have been or are currently under development, the ABSORB BVS from Abbott Vascular was the first FDA approved device. In this review, we shed light on shortcomings of the current generation DES and theoretical advantages of BVS. In addition, we will discuss in detail clinical data from observational studies, meta-analyses, registries, and randomized controlled trials as it pertains to the efficacy and safety outcomes with everolimus-eluting BVS as compared to the current generation everolimus-eluting metallic stents (EES). We will summarize reasons behind the disappointing results from clinical trials and the failure of first generation BVS leading to its withdrawal from the market. Lastly, we will briefly review ongoing developments with the newer-generation BVS and future pre-clinical and clinical studies that are underway to evaluate the efficacy and safety of second-generation BVS.

To revascularize or not before transcatheter aortic valve implantation?

Concomitant coronary artery disease (CAD) and aortic stenosis occur in approximately 60-75% of patients referred for surgical or transcatheter aortic valve replacement (TAVR). Current guidelines support simultaneous surgical aortic valve replacement and bypass surgery with a class IIa recommendation, based on observational, non-randomized data. With the inception of TAVR, this strategy has been challenged, as observational studies have not shown significant outcome differences in patients with and without CAD treated with TAVR. Performing percutaneous coronary intervention (PCI) in patients with aortic stenosis is safe, but the indication and timing remain controversial. Complete revascularization before TAVR with low residual Syntax score (<8) may be considered in selected cases with extensive, proximal, and severe CAD to improve outcomes. PCI before TAVR may require less contrast and reduce the risk of acute kidney injury, but uninterrupted dual antiplatelet therapy may increase the risk of bleeding during TAVR. Combined PCI and TAVR can be considered for unstable patients with simple lesions or ostial lesions, with risk of coronary occlusion after deployment of the transcatheter heart valve. PCI after TAVR may be considered in patients who remain symptomatic with significant residual ischemia despite optimal medical therapy. In the near future, it is expected that randomized clinical trials will further clarify the indications and role of revascularization in patients undergoing TAVR. In this article we provide an extensive review on the management of CAD in TAVR candidates, including additional considerations on technical aspects, device selection, and adjunctive pharmacological therapies.

EROSION Study (Effective Anti-Thrombotic Therapy Without Stenting: Intravascular Optical Coherence Tomography-Based Management in Plaque Erosion): A 1-Year Follow-Up Report

BACKGROUND

The initial EROSION study (Effective Anti-Thrombotic Therapy Without Stenting: Intravascular Optical Coherence Tomography-Based Management in Plaque Erosion) demonstrated that patients with acute coronary syndrome caused by plaque erosion might be stabilized with aspirin and ticagrelor without stenting for ≤1 month. However, a long-term evaluation of outcomes is lacking. The aim of this study was to assess whether the initial benefit of noninterventional therapy for patients with acute coronary syndrome caused by plaque erosion is maintained for ≤1 year.

METHODS AND RESULTS

Among 53 patients who completed clinical follow-up, 49 underwent repeat optical coherence tomography imaging at 1 year. Median residual thrombus volume decreased significantly from 1 month to 1 year (0.3 mm³ (0.0-2.0 mm³] versus 0.1 mm³ [0.0-2.0 mm³]; P=0.001). Almost half of the patients (46.9%) had no residual thrombus at 1 year. Minimal effective flow area remained unchanged (2.1 mm² [1.5-3.8 mm²] versus 2.1 mm² [1.6-4.0 mm²]; P=0.152). Among 53 patients, 49 (92.5%) remained free from major adverse cardiovascular event for ≤1 year: 3 (5.7%) patients required revascularization because of exertional angina and 1 (1.9%) patient had gastrointestinal bleeding.

CONCLUSIONS

One-year follow-up optical coherence tomography demonstrated a further decrease in thrombus volume between 1-month and 1-year follow-up. A majority (92.5%) of patients with acute coronary syndrome caused by plaque erosion managed with aspirin and ticagrelor without stenting remained free of major adverse cardiovascular event for ≤1 year.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02041650.

Effect of Gender on Unplanned Readmissions After Percutaneous Coronary Intervention (from the Nationwide Readmissions Database)

Women who undergo percutaneous coronary intervention (PCI) are at higher risk of adverse outcomes compared with men, but it is unknown whether gender affects early unplanned rehospitalization. We analyzed 832,753 patients who underwent PCI from 2013 to 2014 in the Nationwide Readmissions Database. We compared gender differences in incidences, predictors, causes, and cost of unplanned 30-day readmissions and examined the effect of co-morbidity. A total of 832,753 men and women who survived the index PCI and were not admitted for a planned readmission were included in the analysis. Overall, 9.4% of patients had an unplanned readmission within 30 days. Thirty-day readmission rates were higher in women compared with men (11.5% vs 8.4%, p <0.001) even after multivariate adjustment (odds ratio 1.19, 95% confidence interval 1.16 to 1.22, p <0.001), although women had significantly lower costs associated with the readmission ($11,927 vs $12,758, p <0.001). The cause of readmission for women and men were similar and the majority of the readmissions were due to noncardiac causes (58% vs 55%), the most common of which were nonspecific chest pain, gastrointestinal disease, and infections. In contrast, for cardiac readmissions, women are more likely to be readmitted for heart failure (29.64% vs 22.34%), whereas men are more likely to be readmitted for coronary artery disease, including angina (33.47% vs 28.54%). In conclusion, gender disparities exist in rates of unplanned rehospitalization after PCI, where more than 1 in 10 women who undergo PCI are readmitted within 30 days. Gender differences were not observed for causes of noncardiac readmissions, whereas important differences were observed for cardiovascular causes.

Bioresorbable Scaffolds in Coronary Intervention: Unmet Needs and Evolution

Bioresorbable scaffolds (BRS) represent a novel paradigm in the 40-year history of interventional cardiology. Restoration of cyclic pulsatility and physiologic vasomotion, adaptive vascular remodeling, plaque regression, and removal of the trigger for late adverse events are expected BRS benefits over current metallic drug-eluting stents. However, first-generation BRS devices have significant manufacturing limitations and rely on optimal implantation technique to avoid experiencing an excess of clinical events. There are currently at least 22 BRS devices in different stages of development, including many trials of device iterations with thinner (<150 µm) struts than first-generation BRS. This article reviews the outcomes of commercially available and potentially upcoming BRS, focusing on the most recent stages of clinical development and future directions for each scaffold type.

Three-Year Outcomes With the Absorb Bioresorbable Scaffold: Individual-Patient-Data Meta-Analysis From the ABSORB Randomized Trials

BACKGROUND

The Absorb bioresorbable vascular scaffold (BVS) completely resorbs within 3 years after coronary artery implantation. The safety and effectiveness of BVS through this critical 3-year period have not been characterized.

METHODS

We performed an individual-patient-data pooled meta-analysis of the 4 randomized ABSORB trials in which 3389 patients with coronary artery disease were randomly assigned to everolimus-eluting Absorb BVS (n=2164) or cobalt-chromium everolimus-eluting stents (n=1225). The primary efficacy outcome measure was target lesion failure (cardiac mortality, target vessel myocardial infarction, or ischemia-driven target lesion revascularization), and the primary safety outcome measure was device thrombosis.

RESULTS

BVS compared with cobalt-chromium everolimus-eluting stents resulted in higher 3-year rates of target lesion failure (11.7% versus 8.1%; risk ratio [RR], 1.38; 95% confidence interval [CI], 1.10-1.73; P=0.006), driven by greater target vessel myocardial infarction (7.8% versus 4.2%; RR, 1.72; 95% CI, 1.26-2.35; P=0.0006) and ischemia-driven target lesion revascularization (6.6% versus 4.4%; RR, 1.44; 95% CI, 1.05-1.98; P=0.02), with comparable cardiac mortality (1.1% versus 1.1%; RR, 0.93; 95% CI, 0.47-1.88; P=0.85). Device thrombosis rates through 3 years were also higher with BVS (2.4% versus 0.6%; RR, 3.71; 95% CI, 1.70-8.11; P=0.001). Between 1 and 3 years, target lesion failure rates (6.1% versus 3.9%; P=0.02) and device thrombosis rates (1.1% versus 0.0%; P<0.0001) were higher with BVS than cobalt-chromium everolimus-eluting stents.

CONCLUSIONS

In the present individual-patient-data pooled meta-analysis of the ABSORB trials, BVS was associated with increased rates of target lesion failure and device thrombosis between 1 and 3 years and cumulatively through 3 years of follow-up compared with everolimus-eluting stents.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifiers: NCT01751906, NCT01844284, NCT01923740, and NCT01425281.

Impact of Aspirin and Clopidogrel Hyporesponsiveness in Patients Treated With Drug-Eluting Stents: 2-Year Results of a Prospective, Multicenter Registry Study

OBJECTIVES

In this analysis of 2-year outcomes in the ADAPT-DES (Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents) study, the authors sought to examine the independent associations between platelet reactivity to both aspirin and clopidogrel and subsequent outcomes.

BACKGROUND

The relationship between platelet reactivity and long-term adverse events following implantation of drug-eluting stents (DES) has been incompletely characterized.

METHODS

The ADAPT-DES study was a multicenter registry of patients undergoing routine platelet function testing following percutaneous coronary intervention with DES. The primary study endpoint was definite or probable stent thrombosis (ST); other endpoints were all-cause mortality, myocardial infarction, and clinically relevant bleeding.

RESULTS

A total of 8,582 patients were enrolled between 2008 and 2010; 46.3% of patients were on dual antiplatelet therapy at 2 years without discontinuation. At 2 years, definite or probable ST occurred in 92 patients (1.07%). In patients treated with dual antiplatelet therapy continuously for 2 years, high platelet reactivity on clopidogrel was independently associated with definite or probable ST (adjusted hazard ratio [HR]: 2.16; 95% confidence interval [CI]: 1.27 to 3.67; p = 0.003), myocardial infarction (adjusted HR: 1.35; 95% CI: 1.05 to 1.74; p = 0.02), freedom from clinically relevant bleeding (adjusted HR: 0.74; 95% CI: 0.62 to 0.90; p = 0.002), and all-cause mortality (adjusted HR: 1.36; 95% CI: 1.01 to 1.85; p = 0.04). Between years 1 and 2, high platelet reactivity was not associated with the very late ST and in patients on aspirin monotherapy, aspirin hyporesponsiveness was not associated with adverse outcomes.

CONCLUSIONS

The present study confirms the strong relationship of high platelet reactivity on clopidogrel to 2-year ischemic and bleeding outcomes after DES. The majority of stent-related events occurred within the first year.

Meta-Analysis of Randomized Control Trials Comparing Drug-Eluting Stents Versus Coronary Artery Bypass Grafting for Significant Left Main Coronary Narrowing

Previous meta-analyses showed that drug-eluting stent (DES) implantation may serve as an alternative to coronary artery bypass grafting (CABG) for unprotected left main coronary artery (ULMCA) stenosis, largely driven by data from registries. Hence, we performed a meta-analysis of randomized controlled trials (RCTs) to overcome this limitation. PubMed, the Cochrane Library, and Scopus were systematically searched through October 2016 to identify eligible RCTs. The primary outcomes were major adverse cardiac and cerebrovascular events (MACCE) at 1-year and long-term (≥3 years) follow-ups. This meta-analysis included 5 RCTs, totaling 4,595 patients with ULMCA disease. Compared with CABG, DES showed similar 1-year rates of MACCE (risk ratio [RR] 1.14, 95% confidence interval [CI] 0.91-1.42), all-cause death, and myocardial infarction, with a higher incidence of revascularization (RR 1.68, 95% CI 1.24-2.27) and lower incidence of stoke (RR 0.43, 95% CI 0.23-0.78). At long-term follow-up, DES placement was inferior to CABG in terms of MACCE (RR 1.27, 95% CI 1.13-1.43) and revascularization (RR 1.70, 95% CI 1.43-2.01). There was no difference in long-term risk of other outcomes between these 2 strategies. In conclusion, DES stenting and CABG for ULMCA disease yield comparable rates of MACCE at 1-year follow-up; however, CABG is associated with a decreased risk of long-term MACCE compared with DES, exclusively driven by the considerable reduction in revascularization events.